WO1998037425A1 - Element detecteur d'acceleration et son procede de production - Google Patents
Element detecteur d'acceleration et son procede de production Download PDFInfo
- Publication number
- WO1998037425A1 WO1998037425A1 PCT/JP1997/003811 JP9703811W WO9837425A1 WO 1998037425 A1 WO1998037425 A1 WO 1998037425A1 JP 9703811 W JP9703811 W JP 9703811W WO 9837425 A1 WO9837425 A1 WO 9837425A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- weight
- sheet
- gap
- layer
- frame
- Prior art date
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P15/00—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration
- G01P15/02—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses
- G01P15/08—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P15/00—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration
- G01P15/02—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses
- G01P15/08—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values
- G01P15/12—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values by alteration of electrical resistance
- G01P15/123—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values by alteration of electrical resistance by piezo-resistive elements, e.g. semiconductor strain gauges
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
- G01B7/16—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring the deformation in a solid, e.g. by resistance strain gauge
- G01B7/24—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring the deformation in a solid, e.g. by resistance strain gauge using change in magnetic properties
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P15/00—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration
- G01P15/02—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses
- G01P15/08—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values
- G01P15/0802—Details
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P15/00—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration
- G01P15/02—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses
- G01P15/08—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values
- G01P15/125—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values by capacitive pick-up
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P15/00—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration
- G01P15/02—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses
- G01P15/08—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values
- G01P15/13—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values by measuring the force required to restore a proofmass subjected to inertial forces to a null position
- G01P15/132—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values by measuring the force required to restore a proofmass subjected to inertial forces to a null position with electromagnetic counterbalancing means
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P15/00—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration
- G01P15/18—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration in two or more dimensions
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P15/00—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration
- G01P15/02—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses
- G01P15/08—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values
- G01P2015/0805—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values being provided with a particular type of spring-mass-system for defining the displacement of a seismic mass due to an external acceleration
- G01P2015/0822—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values being provided with a particular type of spring-mass-system for defining the displacement of a seismic mass due to an external acceleration for defining out-of-plane movement of the mass
- G01P2015/084—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values being provided with a particular type of spring-mass-system for defining the displacement of a seismic mass due to an external acceleration for defining out-of-plane movement of the mass the mass being suspended at more than one of its sides, e.g. membrane-type suspension, so as to permit multi-axis movement of the mass
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P15/00—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration
- G01P15/02—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses
- G01P15/08—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values
- G01P2015/0805—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values being provided with a particular type of spring-mass-system for defining the displacement of a seismic mass due to an external acceleration
- G01P2015/0822—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values being provided with a particular type of spring-mass-system for defining the displacement of a seismic mass due to an external acceleration for defining out-of-plane movement of the mass
- G01P2015/084—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values being provided with a particular type of spring-mass-system for defining the displacement of a seismic mass due to an external acceleration for defining out-of-plane movement of the mass the mass being suspended at more than one of its sides, e.g. membrane-type suspension, so as to permit multi-axis movement of the mass
- G01P2015/0842—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values being provided with a particular type of spring-mass-system for defining the displacement of a seismic mass due to an external acceleration for defining out-of-plane movement of the mass the mass being suspended at more than one of its sides, e.g. membrane-type suspension, so as to permit multi-axis movement of the mass the mass being of clover leaf shape
Definitions
- the present invention relates to a bending conversion element (or element) used in a semiconductor acceleration sensor having a double-supported beam structure used for automobiles, aircraft, home appliances, and the like, a method for manufacturing the same, and an acceleration sensor having such an element.
- a bending conversion element or element
- an acceleration sensor having such an element.
- an accelerometer can determine the X-, Y-, and Z-axis components of the acting acceleration independently in an X-Y-Z coordinate system consisting of three mutually orthogonal coordinate axes. Can be used to detect acceleration.
- US Patent No. 5,485,749 discloses a semiconductor acceleration sensor as described above. This sensor detects the mechanical radius of the member caused by acceleration.
- the acceleration sensor 500 has a bending conversion element 502 and a bottom cover 504.
- the radius conversion element 502 includes a frame (or a frame) 506 and a sheet-shaped member 508.
- the frame 506 has an upper surface 510 and a lower surface 512, and the lower surface 512 is supported by a support member 514.
- the sheet-shaped member 508 has a radiusable portion 515 and a central portion 516 (a portion surrounded by a dashed line in FIG. 18), and the radiusable portion 515 includes a central portion 515. Extending outward from 16 and the inner edge of frame 5 2 5 1 8 (Shown by a broken line in FIG. 18).
- the central portion 5 16 of the sheet-like member 508 is connected with a weight 52 0 below it, which is integrally connected to the central portion 5 16 via its neck portion 5 22.
- the inward side surface 5 2 4 of the support member 5 14 faces the outward side surface 5 2 6 of the weight 5 20 with the first gap 5 2 8 therebetween.
- the second gap 5330 is present between the flexible portion 515 and the weight 520, and is connected to the first gap 528. Furthermore, there is a third gap 532 force s surrounded by the frame 506 and the flexible portion 515.
- the radiusable portion 5 15 has a plurality of piezoresistors 5 3 4 and wires (not shown) connected thereto on the surface.
- the bottom cover 504 has a peripheral portion 541 that defines a concave portion 540 surrounding the weight 520 corresponding to the weight 520, and the support member 514 force s of the bottom cover 504 It is connected to the periphery by suitable means (eg, anodic bonding).
- the bottom cover 504 functions as a stop to prevent the weight from being excessively displaced and the sheet-shaped member 508 from being damaged when excessive acceleration acts on the sensor.
- an acceleration sensor 500 has a plurality of piezoresistors 534, an X—Y—Z coordinate system composed of three mutually orthogonal coordinate axes (the X axis and the Y axis Acceleration sensor for detecting acceleration by independently determining the X-axis, Y-axis, and Z-axis components of the acting acceleration.
- an X—Y—Z coordinate system composed of three mutually orthogonal coordinate axes (the X axis and the Y axis Acceleration sensor for detecting acceleration by independently determining the X-axis, Y-axis, and Z-axis components of the acting acceleration.
- the interconnection between the frame 506 and the sheet-like member 508 and between the sheet-like member 508 and the overlap 520 is performed by accelerating the sensor 500, specifically, the element 502. Acts, the weight 52 0 is displaced relative to the frame 5 06 By doing so, at least a part of the radiusable portion 5 15 having the piezoresistance 5 3 4 is elastically deformed (note that the center of the sheet-shaped member 5 0 8 connected to the neck 5 2 2). (The part 5 16 is not substantially deformed.) Therefore, the change in the resistance value of the piezoresistor 5 34 4 is converted into an electric signal, and by detecting the signal, the acceleration acting on the sensor is obtained. Can be measured.
- FIG. 20 (a) First, silicon nitride films 62 and 604 are formed on both main surfaces of a first silicon substrate 600 on which a support member 5 14 and a weight 5 20 are to be formed.
- FIG. 20 (b) Next, the silicon nitride film 602 corresponding to the second void 530 is removed to remove the opening 606, and the portion corresponding to the first void 528 is removed.
- the opening 608 is formed by removing the silicon nitride film 604.
- Fig. 20 (c) After the recesses 610 and 612 are formed by engraving from the openings 606 and 608, the remaining silicon nitride film 602 is removed and the first silicon One side main surface of the control board 600 is exposed, and a second silicon board 616 is bonded thereon to form a part of the concave portion 6100 as a second gap 5330, and the remaining portion is formed. The upper surface of the weight neck part 5 2 2 and the support member 5 14.
- Fig. 20 (d) When the sensor finally becomes a sensor, the second silicon substrate 616 is thinned by grinding or etching so that the flexible portion 515 is bent when a predetermined acceleration is applied. Thickness (t) and the second silicon substrate And a frame 506.
- FIG. 20 (e) Next, a piezo resistor 6 18 having a conductivity type opposite to that of the second silicon substrate 6 16 is attached to the sheet-shaped member 508 of the thinned second silicon substrate 6 16. It is formed by impurity diffusion.
- Fig. 20 (f) Next, after forming a wiring (not shown) connected to the piezoresistor 6 18, the first space reaching the second gap 5 30 from the recess 6 12 by anisotropic etching. An air gap 528 is formed so that the weight 520 is integrally connected to and supported by the central portion 516 of the second silicon substrate 616 via the neck portion 522.
- a desired portion of the second silicon substrate 6 16 is etched to form a third gap 532 (not shown), whereby the bending conversion element 502 is obtained. Note that the silicon nitride film 604 at the bottom of the first silicon substrate may be removed as needed.
- a portion corresponding to the second void is once formed as a sacrificial layer of polysilicon, and after forming the first void 528, It is also known to introduce another etchant from there to etch the sacrificial layer (Japanese Patent Application Laid-Open No. 7-23442 and corresponding foreign patent applications (if any) and US patents). Nos. 5, 395, 802).
- the acceleration to be detected is converted into a flexure of a radiusable portion which is at least a part of the sheet-like member, and a resistance value of a piezo resistor formed in the radiusable portion is changed by the flexure.
- the change ultimately converts the acceleration into an electrical signal. Therefore, the sensitivity of the semiconductor acceleration sensor is governed by the thickness of the deflectable portion, especially the thickness of the sheet-shaped member. That is, the sensitivity becomes worse as the radiusable portion becomes thicker, and is affected by variations in the thickness of the radiusable portion. Therefore, in the manufacturing process of the semiconductor acceleration sensor, it is important to control the thickness of the sheet member uniformly and accurately.
- a capacitance type acceleration sensor As another type of acceleration sensor, a capacitance type acceleration sensor is also known.
- the operating principle of this sensor is similar to that of a piezoresistive sensor in that it is based on the mechanical radius generated by the action of acceleration. However, this deflection is converted into relative displacement between two opposing members, and the piezoresistive sensor is used in that this displacement changes the capacitance between the electrodes provided on the members. And different. Therefore, in a capacitance-type acceleration sensor, the electrodes are arranged so as to face members that are displaced by acceleration acting on the sensor and members that are not displaced.
- FIG. 21 Such a capacitive acceleration sensor 700 is shown in FIG. 21 (a schematic partial cutaway perspective view) and FIG. 22 (a schematic cross-sectional view along a diagonal line C-C ′ in FIG. 21).
- the bending conversion element 720 of the speed sensor 700 is replaced by a piezoresistance instead of the upper surface of the weight 5200.
- Ru substantially the same der the case of FIG.
- the capacitance-type bending conversion element 702 is used together with a top cover 7400 (not shown in FIG. 21) disposed thereon.
- Top cover 7 4 0 is to prevent double Rino excessive displacement, by it connection, a force to prevent damage to the oar viewed possible section?, At least the sheet-like member, the portion preferably excluding the side of the frame on the element And has a concave portion on the inside corresponding to.
- Such a top cover is combined with elements for a piezoresistive acceleration sensor or for a capacitive calo velocity sensor.
- the top cover of the element for the capacitive acceleration sensor has an electrode as described later.
- the top cover 7400 has an electrode 742 arranged so as to face the electrode 734 when arranged on the element 7 02.
- the acceleration to be detected is applied to the sensor, the weight 5 2 0 force to the sheet-like member 5 0 8 having a scull viewed enable portion 5 1 5? So connected, weight 5 2 0 It is displaced relative to the support member 514 and the cover 740 disposed thereon, and as a result, the distance between the electrode 744 on the weight and the electrode 744 disposed on the cover facing the weight.
- the acceleration can be detected by the change in the capacitance between these electrodes, which changes with the change in the capacitance.
- the thickness of the deflectable portion 5 15 becomes thinner, and when the shape of the deflectable portion is long, the longer the length is, the smaller the acceleration becomes. It is easily deformed, and as a result, sensor sensitivity is improved. Also, if the thickness of the bendable portion varies, the sensitivity varies. Therefore, in any type of acceleration sensor, providing a semiconductor acceleration sensor or a deflection conversion element having a radius capable portion that is controlled appropriately and has a small variation in the thickness of the flexible portion is provided by the sensitivity of the sensor. It is desirable from the viewpoint of improvement of the sensor and variation between sensors. Therefore, in the manufacturing process of the conversion element, it is important to control the thickness of the flexible portion uniformly and accurately. If the form of the bendable part is long, It is desirable to be able to make it longer.
- the weight is connected to the central portion of the sheet-like member, the radiusable portion of the sheet-like member is connected to the frame, and the force supported by the support member is increased.
- a semiconductor acceleration sensor having a cantilever structure can be manufactured.
- the second silicon substrate 616 is thinned to a thickness (t) corresponding to a predetermined sheet-like member.
- the thickness in the plane of the second silicon substrate greatly varies, so that it is difficult to make the thickness of the radiusable portion 515 uniform.
- the bonding of silicon substrates is complicated, and two silicon substrates are required, which increases the manufacturing cost.
- the present invention is based on the examination of the above-mentioned problems, and an object of the present invention is to solve the above-mentioned problems and accurately form the thickness of a sheet-shaped member, particularly, a radiusable portion thereof. It is an object of the present invention to provide a radius conversion element for a semiconductor acceleration sensor having a doubly supported structure and a method for manufacturing the same, and an acceleration sensor using such an element. Further, the present invention also provides an embodiment having preferable features in such a device, a manufacturing method, and a sensor, and the advantages brought by the present invention will be apparent by referring to the following description and accompanying drawings. Will be.
- the present invention A radius conversion element used for an acceleration sensor for detecting an acting acceleration
- a sheet-like member having a plurality of deflectable portions and a central portion, wherein each deflectable portion extends between at least a portion of the inner edge portion of the frame and the central portion, and Sheet-like members connected together,
- a weight having a neck portion integrally connected to the central portion of the sheet-like member, and hanging from the sheet-like member through the neck portion;
- a support member that supports the lower surface of the frame, with the inner side facing the side of the weight with the first gap therebetween.
- a second gap connected to the first gap is defined between each radiusable portion of the sheet-shaped member and the weight
- a third gap is defined between the frame and the sheet member and / or in the sheet member
- At least two radially deformable portions are elastically deformed, so that the weight is displaced relative to the frame, so that the frame and the sheet-like member,
- the shape member and the weight are joined to each other, and the weight and the support member are configured using a semiconductor substrate,
- the second gap is formed by removing a sacrificial layer provided on the semiconductor substrate,
- the frame and the sheet-like member provide an element formed by an epitaxial layer provided on a semiconductor substrate.
- This element for example, in the X-Y-Z coordinate system consisting of three mutually orthogonal coordinate axes, separates the X, Y and Z components of the acting acceleration. It can be used for an acceleration sensor that detects acceleration by estimating it vertically, for example, a piezo-type or capacitance-type acceleration sensor, in which case the X-axis and Y-axis extend on the upper surface of the sheet-like member. Stipulated.
- the radius conversion element means an element for converting a radius acting on the sensor into an electrical output in the piezoresistive or capacitive acceleration sensor as described above. I do.
- a weight and a support member are formed from a single semiconductor substrate, and the frame and the sheet-like member are formed from an epitaxial layer grown on a semiconductor substrate.
- the weight, the frame, the sheet-like member, and the support member form a structure in which, when acceleration is applied to the element, at least a part of the bendable portion of the sheet-like member is deformed (or flexed) monotonically. It is connected.
- the side faces of the weight are defined by the first gap and the second gap, and the weight is constricted at the neck by the center of the sheet-shaped member. It has a structure connected to the part. That is, when considering the cross section of the weight parallel to the semiconductor substrate, the cross section of the neck portion is smaller than the cross sectional area of the other portion, and the cross section of the neck portion is located at the center of the cross section of the other portion. .
- the shape of the weight is not particularly limited.
- the weight may be substantially a square prism except for the neck portion, and the neck portion may be concentric with the square pillar.
- the neck portion is preferably as small as possible, and the cross-sectional area of the weight is preferably as large as possible. If a small weight is sufficient, such as the natural force S, there is no need to increase the weight.
- the weight may be constituted only by the semiconductor substrate, or may be constituted by the semiconductor substrate and a part of the epitaxy layer formed thereon.
- the deflectable portion of the sheet-shaped member has at least one piezoresistive in at least two portions that are elastically deformed when acceleration is applied, These piezoresistors have wires connected to them.
- This wiring may be any wiring capable of transmitting an output or information relating to an electric signal obtained by converting a change in the resistance value of the piezoresistor, for example, a metal wiring and / or a diffusion wiring.
- This wiring may be directly connected to the electrode pad if it is a metal wiring, or may be connected to the electrode pad via a metal wiring if it is a diffusion wiring. Through this electrode pad, the device is connected to a device that measures piezoresistance.
- the location where the piezoresistor is arranged is not particularly limited as long as the radius of the radiusable portion can be electrically detected. In fact, various arrangements are possible, but it is preferable to arrange them in a portion of the deflectable portion where elastic deformation (or deformation) is concentrated.
- Regarding the specific arrangement of the piezoresistors see US Pat. No. 5,485,749, JP-A-6-331636, JP-A-6-109755. Official gazette and Japanese Patent Application Laid-Open No. Hei 7—2 3 4 2 42 The corresponding foreign patent applications (if any) are disclosed and reference can be made to the arrangement of the piezoresistors of the present invention. The contents of these patent documents constitute a part of the present specification by this citation.
- an acceleration sensor can be obtained by combining such an element with the above-described bottom cover and top cover. Therefore, the present invention includes the above-described element and the bottom cover and the top cover. Piezoresistive acceleration sensor.
- the bottom and top covers have recesses on the inside, as described above, to prevent damage to the elements, especially the deflectable parts, if excessive acceleration is applied to the sensor.
- the radially deformable portion when acceleration acts, at least the radially deformable portion is displaced by being elastically deformed.
- One part has at least one electrode for capacitance measurement, and this electrode has a wiring connected thereto.
- This wiring may be any wiring capable of transmitting the output related to the measurement of the capacitance, for example, a metal wiring may be used. Further, this wiring may be directly connected to the electrode pad when the wiring is a metal wiring, or may be connected to the electrode pad and the pad via the metal wiring when the wiring is a diffusion wiring. May be. Through this electrode pad, the device is connected to a device for measuring the capacitance.
- the electrodes for capacitance measurement are arranged, as long as the electrodes can be relatively displaceable while facing the electrodes of the top cover arranged on the element.
- Various arrangements are possible, but it is preferable to arrange them in a portion where displacement caused by deformation of the radiusable portion is large.
- it may be arranged on a part of the upper side surface near the outer peripheral portion of the weight (for example, electrode 734).
- European Patent Publication (A1) No. 0 4 6 1 2 65 This can be referred to for the arrangement of the electrodes for capacitance measurement of the present invention.
- the contents of these patent documents constitute a part of this specification by this citation.
- an acceleration sensor By combining such an element with the top cover and, if necessary, the bottom cover described above, an acceleration sensor can be obtained, and thus the present invention comprises the above-described element and the top cover and the bottom cover Provided is a capacitive acceleration sensor comprising:
- the bottom and top covers, as described above, have recesses on the inside to prevent the elements, especially the deflectable parts, from being damaged if excessive acceleration acts on the sensor.
- the top cover has an electrode facing the electrode provided on the element.
- the present invention provides a method for manufacturing a bending transducer used for an acceleration sensor of the present invention described above or in detail below,
- FIG. 1 is a schematic partially cutaway perspective view of a piezo-type acceleration sensor element according to the present invention.
- FIG. 2 is a top view of the device of FIG.
- FIGS. 3A to 3I are schematic sectional views showing a series of manufacturing steps of the device of the present invention.
- FIG. 3A to 3I are schematic sectional views showing a series of manufacturing steps of the device of the present invention.
- 4 (a) to 4 (c.) are schematic partially cutaway perspective views showing a process of manufacturing the device of FIG.
- FIG. 5 (.a) to (1) are top views schematically showing the shape and arrangement of the etchant inlet.
- FIGS. 6 (a) and 6 (b) are schematic partial cutaway perspective views of another embodiment of the device of the present invention.
- FIGS. 7A to 7I are schematic sectional views showing another series of manufacturing steps of the device of the present invention.
- 8 (a) to 8 (e) are schematic partially cutaway perspective views showing a process of manufacturing the device of FIG.
- FIG. 9 is a schematic sectional view showing another embodiment of the first gap.
- 10 (a) to 10 (h) are schematic cross-sectional views showing a series of processes for forming the element having the first void shown in FIG.
- FIGS. 11A to 11H are schematic cross-sectional views illustrating a method for manufacturing a device of the present invention including a process of forming a wiring protection layer.
- FIGS. 12A to 12E are schematic cross-sectional views illustrating a method for manufacturing an element of the present invention including another process of forming a wiring protective layer.
- FIGS. 13A to 13D are schematic cross-sectional views illustrating a method for manufacturing an element of the present invention, which includes still another step of forming a wiring protective layer.
- 14 (a) to 14 (c) are schematic cross-sectional views of a substrate showing an example of a process of forming a sacrificial layer having a low impurity concentration near the surface.
- FIGS. 15 (a) to 15 (d) are schematic cross-sectional views of a substrate showing another example of a process of forming a sacrificial layer having a low impurity concentration near the surface.
- Figures 16 (a) to (e) show the formation of a sacrificial layer with low impurity concentration near the surface. It is a typical sectional view of a substrate which shows another example of a process.
- FIG. 17 is a cross-sectional view schematically showing an apparatus for manufacturing a porous silicon layer as a sacrificial layer.
- Figure 18 is a schematic perspective view of a conventionally known piezoresistive acceleration sensor.
- FIG. 19 is a schematic sectional view of the acceleration sensor shown in FIG.
- 20 (a) to (f) are cross-sectional views schematically showing a series of manufacturing processes of the acceleration sensor shown in FIG.
- FIG. 21 is a schematic partial cutaway perspective view of a conventionally known capacitive acceleration sensor.
- FIG. 22 is a schematic sectional view of the acceleration sensor shown in FIG.
- the semiconductor substrate used may be a silicon substrate, and its conductivity type may be either N-type or P-type, from which the weight and the support member are formed.
- the semiconductor substrate for example, an N-type substrate having a (100) plane orientation can be used.
- the impurity concentration of the substrate 1 0 X 1 0 1 7 cm- 3 following ones (e.g. 1 X 1 0 1 4 c m - 3 ⁇ 1 X 1 0 1 6 c m - 3 ones). Is desirable.
- the etching rate is reduced to about 1/150 or less, and the high-concentration impurity layer is removed by etching, compared to the case of a high-concentration impurity layer having a higher concentration.
- the thickness of the substrate is not particularly limited, and can be appropriately selected depending on the use of the sensor. Normally, a board that is equivalent to or slightly thicker than the board that has been used for an acceleration sensor is good. For example, a substrate having a thickness of 400 / m to 600 m can be used.
- a sacrificial layer is formed on one main surface of the substrate.
- the term “sacrifice layer” refers to a method for manufacturing the device of the present invention. The force that is present in the process is used to mean the layer that is ultimately removed and creates voids.
- the sacrificial layer extends outward from a portion corresponding to the center of the semiconductor substrate.
- the central portion of the semiconductor substrate is a portion that becomes a neck portion of the weight, and is finally a portion that is connected to the central portion of the sheet-shaped member, and no sacrifice layer is formed on that portion.
- the shape of the central portion of the substrate is not particularly limited, and may be, for example, a circle or a rectangle (a rectangle or a square). In particular, it is preferable that the center of gravity of the weight is located below the center of the substrate, particularly below the center of the center.
- the sacrificial layer extends from the outer edge in a direction away from a central outer edge of the substrate.
- the sacrificial layer may extend from the entire outer edge (i.e., the entire periphery of the central portion) to completely surround the portion, or may extend from a portion of the central outer edge.
- the sacrificial layer may be annular.
- the central portion of the substrate may be circular, and the sacrificial layer may be an annular portion between the concentric circle and the central portion formed by the concentric circle.
- the central portion is an inner square, and the sacrificial layer is formed by an outer square concentric with and in the same direction as the sacrificial layer, and may be an annular portion between the inner square and the outer square.
- the sacrificial layer may be a portion formed between a circular central portion and an outer square, or a portion formed by a combination of the opposite portions. You may use rectangles instead of squares and ellipses instead of circles.
- the sacrificial layer may be a substantially elongate layer spaced at equal angles (eg, 90 °) around the central portion.
- the sacrificial layer is in the form of four beams facing each other at the center (ie, cross-shaped at the center).
- the sacrificial layer may extend radially from the center, and the number is not limited. Usually, four are sufficient.
- the long sacrificial layer preferably extends symmetrically (point symmetry with respect to the center of the substrate or line symmetry with respect to a diagonal line of the substrate) from the center of the substrate.
- the thickness of the sacrificial layer substantially corresponds to the distance between the deflectable portion and the upper surface of the weight (therefore, the thickness of the second gap), and accordingly, is appropriately determined according to the use of the sensor. select. For example, it may be 5 to 15 ⁇ m.
- the sacrificial layer has a conductivity type opposite to or the same as that of the impurities in the substrate main body, and has a higher impurity concentration than the substrate, that is, a high-concentration impurity layer is formed on the surface of the substrate.
- a porous silicon layer it can be obtained by forming a porous silicon layer on the substrate surface.
- the impurity concentration of the high-concentration impurity layer can easily select the impurity concentration of the high-concentration impurity layer based on the etching conditions, the etching distance, and the like in consideration of the impurity concentration of the substrate body. For example, when the impurity concentration of the substrate body is about 1.0 X 10 14 to about 1.0 X 10 16 cm- 3 , the impurity concentration of the high-concentration impurity layer is about 1.0 X 10 1 It may be from 8 to about 1.0 X 1020 cm -3 (or the solid solubility limit).
- a porous silicon layer as a sacrificial layer is formed by forming a silicon oxide film on a silicon substrate, forming an opening corresponding to the portion where the sacrificial layer is to be formed on the silicon oxide film, and forming a P-type through the opening.
- the electrolyte solution eg, Anodizing in a solution containing hydrofluoric acid.
- the formation of the sacrificial layer of a predetermined shape can be performed by deposition and thermal diffusion after masking with a photoresist, or by ion implantation and annealing, and the thickness and impurity concentration of the sacrificial layer are controlled at the time of formation. It can be implemented by appropriately selecting operating conditions.
- step (2) an epitaxial layer is formed on the entire surface of the substrate on which the sacrificial layer has been formed. Since this epitaxy layer finally constitutes the sheet-like member of the element, it is necessary to have a thickness that can be elastically deformed so that acceleration can be detected with a predetermined sensitivity. The smaller the thickness, the higher the sensitivity because it can be deformed even with a small acceleration, but it is more susceptible to breakage, and vice versa. Therefore, it is necessary to select this thickness based on the intended use of the device.
- the method of forming the epitaxial layer is well known to those skilled in the art. Regarding the formation of the epitaxy layer on the porous silicon layer, reference can be made to Japanese Patent Application Laid-Open No.
- step (3) various types of etching are performed to form the sheet-like member, the support member, the weight, the first gap, the second gap, and the third gap.
- the order of the sub-steps (3—a) to (3—c) in step (3) is not particularly limited, unless the sub-step (3—c) is performed first.
- the substrate is etched to form the support member, the side surfaces of the weight, and the first gap therebetween. This etches the substrate from the side of the second major surface of the substrate (ie, the major surface without the epitaxial layer) and removes a portion of the substrate. In this etching, the first gap is on the side of the weight.
- the method is performed such that the first gap is present around the surface, and the first gap is surrounded by the support member.
- the substrate is a square sheet
- the support member is a wall member that surrounds the square at four sides of the square, and has a square cross section (in parallel to the main surface of the substrate) inside the square member. Cross section), and the first void exists between them.
- the cross section of the weight does not necessarily have to be rectangular, and may be, for example, a circle or a rectangle.However, in order to make the volume of the weight as large as possible, if the shape of the substrate is square, the weight Is preferably square. When the shape of the substrate is rectangular, the cross section of the weight is preferably a rectangle similar to the rectangle.
- Sub-step (3—b) is the second step in the epitaxial layer as a through-opening.
- the gap By forming the gap, a flexible portion is formed so that a part of the epitaxial layer can be finally elastically deformed, and the frame is also defined. This is due to the fact that the sheet has a partially elongated shape by having a through-opening sheet form rather than a flat and wide sheet form of the epitaxy layer, resulting in an elastic deformation. Based on becoming easier.
- the remaining epitaxy layer by forming the third void forms a frame and a sheet-like member (for example, see FIG. 6 (b)).
- the epitaxy layer remaining by forming the third gap in this sub-step includes a weight upper portion (41 in FIG. 1 or FIG.
- Sub-step (3-c) etches away the sacrificial layer to form a second void and a weight neck. If the first gap and the third gap are not formed, the second gap cannot be formed, so that this substep cannot be performed first.
- a force using an etching the response Ji in a gap shaped and dimensioned to form in any of the sub-steps anisotropic Etchingu (reactive ion etching (RIE:? Reactive Ion Etching )) Or isotropic etching.
- anisotropic etching is used to form the first and third gaps
- isotropic etching is used to form the second gap.
- step (3) may further comprise the sub-step (3-d) of forming at least one piezoresistor in at least one radiusable portion of the epitaxy layer.
- a wiring connected to the resistor may be further formed.
- the process (3) is based on the fact that the capacitance measuring electrode is a part of the epitaxy layer, which is displaced relatively to the frame when an acceleration is applied.
- the method may further include a sub-step (3-e) of forming a portion constituting a weight (i.e., an upper portion of the weight). Before or after forming this electrode, or At the same time, a wiring connected thereto may be further formed.
- this electrode may be formed on the weight. In this case, the electrode is formed after the formation of the third gap.
- Substep (3-d) or (3-e) may be performed at any stage of step (3) except for the last embodiment.
- the wiring connected to the piezoresistor is preferably a diffusion wiring.
- the capacitance type electrode is preferably a metal wiring. When etching is performed after such piezoresistors or electrodes and possibly existing wiring are formed, the piezoresistors or electrodes and possibly existing electrodes are used to avoid the effects of etching performed later.
- the epitaxial layer including the wiring to be formed is protected by a protective film, for example, a silicon oxide film and / or a silicon nitride film. Therefore, the step (3) further includes, after the sub-step (3-d) or (3-e), a sub-step (3-f-1) of providing a protective layer covering the piezoresistor or the electrode and the existing wiring. May include.
- This protective layer may be at least one film, but when two films are formed one on top of the other, there is an advantage that the flatness of the substrate can be ensured by reversing the warping directions of these films.
- another wiring for example, a metal wiring, And a pad electrode connected thereto may be provided on the element.
- a pad electrode When providing such wiring and pad electrodes, remove the above-mentioned protective layer located on the desired location of the piezoresistance or capacitance measuring electrode or on the desired location of the wiring connected to it.
- the effects of etching can be avoided. Therefore, after the sub-step (3-d) or (3-e), the sub-step (3-f-1) is performed, and then another wiring and an electrode pad are formed.
- a sub-step (3-f-2) of forming a wiring protection layer for protecting these may be included.
- step (3) of the method of the present invention when forming an electrode, wiring or electrode pad for measuring piezoresistance or capacitance, is affected by etching performed later (for example, damage).
- a sub-step (3-f) of forming a wiring protection layer to protect the etching before the etching may be included.
- the removal of the sacrificial layer may be performed after forming the first void reaching the sacrificial layer, or after forming the third void reaching the sacrificial layer, or This may be performed after the formation of the first and third voids.
- an etchant for etching and removing the sacrificial layer can be introduced through the gap. In this case, the introduction of the etchant can be performed through the first gap and / or the third gap.
- the third gap is formed by a portion of the epitaxy layer located above the sacrificial layer to be removed (for example, bending).
- the epitaxy layer which is a possible portion
- the third void may be formed by any etching method depending on its shape, but is generally performed by anisotropic etching.
- the sacrificial layer has a long shape
- the epitaxy layer portion (similarly long shape) on the sacrificial layer is formed in a radiusable portion by removing the sacrificial layer
- the sacrificial layer is formed along the bendable portion to be formed.
- a third void is formed in the epitaxy layer at least partially outside, in contact with, and preferably along its entire length.
- etching can be performed in a direction perpendicular to the longitudinal direction (that is, in the width direction of the long flexible portion) from a portion along the longitudinal direction of the possible portion, the etching distance is shortened (accordingly, the time for etching removal is shortened). Can be).
- the third gap may be formed so as to penetrate a portion of the epitaxial layer corresponding to the flexible portion to be formed. Even in this case, for the same reason, it is preferable that the third gap is provided along the longitudinal direction of the radiusable portion. If the sacrificial layer extends outward from the entire outer edge of the central portion of the substrate, the third gap is removed by etching other than the flexible layer portion and the portion of the epitaxy layer corresponding to the portion to be left as a frame. It is also preferable that the sacrificial layer is exposed at the bottom of the third gap, and then the sacrificial layer is removed by etching through the third gap.
- the third air gap may be formed by subjecting the epitaxial layer to direct anisotropic etching or RIE, or a second high-concentration impurity layer in the epitaxial layer (the first high-concentration impurity layer is a sacrificial layer provided on the substrate). ) May be formed by removing this by etching. Third by any method Whether to form a gap is determined by the shape and dimensions of the third gap to be formed. Third gap, the portion particularly reach it forces? Sacrificial layer becomes Etsuchanto inlet. In particular, if the etchant inlet is formed by RIE, the radius can be formed with high accuracy.
- the opening of the third gap located on the opposite side of the epitaxial layer from the substrate is automatically etched when the anisotropic etching for forming the third gap progresses to the sacrificial layer. It is preferable to select the etching conditions so that the etching stops at a time. This selection can be performed by controlling the opening size and shape of the mask at the time of anisotropic etching based on the anisotropic etching characteristics.
- the cross section along the epitaxy layer of the third void that is, the shape of the etchant inlet is circular, oval, rectangular (especially one with four rounded corners) or a combination thereof.
- the cross section along the epitaxy layer of the third void that is, the shape of the etchant inlet is circular, oval, rectangular (especially one with four rounded corners) or a combination thereof.
- the etching of the first high-concentration impurity layer which is the sacrificial layer, is performed. Can be continuously performed, thereby shortening the manufacturing process.
- the concentration on the surface of the layer be lower than the concentration on the inside. That is, the impurity concentration distribution in the thickness direction of the impurity layer has a maximum value at a certain location inside the surface. In this way, the growth of the epitaxial layer on the substrate having the high concentration impurity layer is started. Initially, the amount of impurities that escape from the high concentration impurity layer into the growth atmosphere can be reduced.
- the impurity concentration on the surface of the high-concentration impurity layer is 5 ⁇ 10 19 cm ⁇ 3 or less, and 1 ⁇ 10 17 cm 3 or more.
- Such an impurity layer can be formed by forming the impurity layer in advance by deposition and thermal diffusion of the impurity to the substrate, and thereafter, by wet oxidation or pyrogenic oxidization.
- the impurity concentration at the surface portion of the impurity layer can be made relatively lower than that at the inner portion by directly injecting the impurity ions into the substrate and annealing.
- another impurity having a conductivity type opposite to that of the impurity used is doped in the vicinity of the surface of the impurity layer to reduce the impurity concentration at the surface of the impurity layer.
- the density can be made relatively smaller than the density of the inner part.
- At least the impurity concentration of the first conductivity type in the substrate and the epitaxy layer in the epitaxy layer may be taken into the epitaxy layer by the photo-doping during epitaxy growth.
- the concentration is higher than the concentration of the second impurity constituting the layer, the conductivity type of the substrate can be prevented from being inverted by canceling the N-type and P-type impurities.
- the cross section of the first gap passing through the center of the substrate and perpendicular to the substrate is such that the distance between the support member and the weight is in the direction from the bottom of the weight toward the neck (with respect to the substrate).
- the first gap is composed of a first part close to the bottom of the weight and a second part located above it, and the taper angle of the first part Is smaller than the taper angle of the second part. That is, between the inner side surface of the support member and the side surface of the weight.
- the gap becomes smaller as approaching the epitaxial layer.
- Such an element is formed by forming a first portion by mechanical grinding or chemical treatment before etching and then forming a second portion by anisotropic etching when forming the first void. Can be manufactured.
- the piezoresistor or capacitance measuring electrode
- the piezoresistor or capacitance measuring electrode
- the piezoresistor or capacitance measuring electrode
- a wiring protection layer is formed so as to cover the pad, and thereafter, the sacrificial layer is removed by etching, and then at least the wiring protection layer on the electrode pad is removed by etching and exposed.
- the sacrificial layer is removed by etching, so the piezoresistor (or electrode for capacitance measurement), the wiring and the electrodes, and the head are corroded or etched by the etchant for removing the etching of the sacrificial layer. Disconnection can be prevented, and chip yield including reliability can be improved.
- the wiring protection layer to be formed may be, for example, a chromium film, a silicon nitride film, or a fluorine-based resin (including its composition).
- the wiring protection layer of the silicon nitride film can be formed by, for example, a plasma CVD method.
- a silicon nitride film is used as a protective layer, alloy spikes may occur if the temperature of the aluminum generally used for wiring exceeds 500 ° C. It is preferable to form the silicon nitride film at a low temperature, for example, at 300 ° C. or less.
- a fluorine-based resin is used as the spring distribution protective layer, it is advantageous because the fluorine-based resin does not substantially disappear when the sacrificial layer is removed by etching.
- CYTOP CYTOP
- CTL- 8 0 9 M manufactured by Asahi Glass Co., Ltd.
- fluorine-based resin C 6 F ⁇ 0 0
- tris par full O b heptyl Amin and Can be used as the wiring protective layer.
- the wiring protective layer can be applied by spin-coating a chromium film by sputtering or vapor deposition, and when a fluorinated resin is used, the resin is dissolved in an appropriate solvent.
- the wiring protection layer is formed, before the etching removal, only the wiring protection layer on the electrode pad is pattern-etched to a desired thickness to reduce the thickness, and after the sacrificial layer is removed by etching, the wiring protection layer is removed.
- the entire surface can be etched to expose only the electrode pads. In this case, portions other than the electrode pads are covered with the wiring protective layer, and the moisture resistance of the sensor can be improved.
- the surface of the spring distribution protective layer has irregularities, and the strength of the substrate is reduced, so that pattern processing (for example, photolithography) becomes difficult.
- the etching for forming the first gap is stopped before reaching the sacrificial layer, and a portion of the semiconductor substrate is slightly left under the sacrificial layer.
- An etchant inlet reaching the sacrifice layer is formed as a third gap, an etchant is introduced from the etchant inlet to remove the sacrifice layer by etching, and then the semiconductor substrate slightly remaining under the sacrifice layer is removed by etching. Good. In this case, the substrate is not easily broken when the sacrificial layer is removed by etching.
- the removal of the semiconductor substrate remaining under the sacrificial layer can be performed by anisotropic etching using an alkaline etchant or RIE.
- the bottom surface of the weight is If the force is possible to reduce the thickness of the body it is advantageous? A. This is because a thinner bottom cover with a flat shape (ie, no recess) can be used. Such etching may be performed simultaneously with the removal of the semiconductor substrate remaining under the sacrificial layer.
- FIG. 1 is a partially cutaway perspective view of an example of the bending conversion element (for a piezoresistive type acceleration sensor) of the present invention manufactured by the method of the present invention, and FIG. 2 (when viewed from above in FIG. 1). Shown in a top view.
- the bending conversion element 10 of the present invention has a frame 12 and a sheet-like member 14.
- the frame 12 has an upper surface 16 and a lower surface 18, and the lower surface 18 is supported by a support member 20.
- the sheet-like member 14 is substantially composed of a deflectable portion 15, a center portion 22 and a weight upper portion 41, and the deflectable portion 15 extends outward from the center portion 22 to form a frame 1. 2 and is integrally connected to the inner edge 2 4 (shown by a broken line in FIG. 1).
- the central part 22 of the sheet-like member 14 has a weight body 26 thereunder, which is integrated with the central part 22 via its net part 28 (see FIG. 3 (i)). linked.
- the weight body 26 has a weight upper part 41 thereon, which together form a weight 26 'of the element.
- the inward side surface 30 of the support member 20 faces the outward side surface 34 of the weight 26 across the first gap 36.
- the second gap 38 force exists between the radiusable portion 15 and the weight body 26, which is connected to the first gap 36.
- a gap 39 exists between the upper weight portion 41 and the flexible portion 15 and a gap 43 exists between the frame 12 and the upper weight portion 41.
- the sheet-shaped member 14, particularly the radiusable portion 15 has a plurality of piezoresistors 42 (omitted in FIG. 2) and wires (not shown) connected thereto on the surface. Note that the gap 43 and the first gap 36 are connected to form a slit form, the second gap 38 is connected to the first gap 36 and the third gap 40, and thus these gaps are one. Make up the void.
- FIG. 3 sequentially shows a method of manufacturing the device 10 in a cross-sectional view when the device 10 shown in FIGS. 1 and 2 is cut along a line along the line BB ′.
- FIG. 3 (a) First, a single-crystal silicon substrate 50 of N-type conductivity is prepared as a semiconductor substrate.
- a device for example, 5 mm X 5 mm
- a circular substrate having a diameter of 4 inches is used, and a plurality (for example, 200 to 300 pieces) of adjacent ones are integrated.
- Devices for example, when the substrate is viewed from above, adjacent to the top, bottom, left, and right
- dicing This is a well-known matter generally performed in the field of semiconductor devices.
- the device of the present invention and the method for manufacturing the same have been described with reference to a single device for simplicity, it is obvious to those skilled in the art that this can be applied to the manufacture of a plurality of devices.
- the shape of the substrate may be substantially rectangular or square in the sense of manufacturing a single device.
- Fig. 3 (b) Next, forces extending from the four sides 52 of the rectangular or square central portion 23 of the silicon substrate 50 toward the outer edge of the substrate, and four substantially terminating before the outer edge 54 Then, a long rectangular sacrificial layer 56 is formed on the first main surface 58 of the substrate 50.
- a long rectangular sacrificial layer 56 is formed on the first main surface 58 of the substrate 50.
- P-type impurities such as boron are masked.
- the ion implantation is performed at a high concentration in the non-existing portion and annealing is performed to form a portion having a high P-type impurity concentration.
- FIG. 3 (.c) Next, an epitaxial layer 60 of N-type conductivity is formed on the entire main surface 58 of the substrate 50. Since this epitaxy layer 60 finally constitutes the sheet-like member 14 (and the frame 12), the elastically deformable portion 15 when the acceleration acts is used. Thickness. Thereafter, a P-type impurity is introduced into a portion corresponding to the third gap 40 (for example, by diffusing impurities such as boron) to form a portion 62 having a high impurity concentration. Fig.
- piezo-resistors 64 and 66 are formed in a part of the epitaxial layer 60, which becomes a bendable part that can bend when acceleration is applied, that converts resistance change due to the radius into an electric signal. I do. This is formed by diffusing a P-type impurity such as boron having a P-type conductivity opposite to that of the epitaxial layer 60 into such a portion of the epitaxial layer 60. Note that the piezoresistor 66 can be used for offset or as one of the piezoresistors forming a bridge.
- FIG. 3 (e) Next, a wiring section 68 electrically connected to the piezoresistors 64 and 66 is formed by deposition and thermal diffusion or ion implantation.
- FIG. 3 (f) Next, the exposed surface side of the epitaxial layer 60 and the second main surface of the substrate are covered with a silicon nitride film 70. Thereafter, in order to form the first gap 36, a portion of the silicon nitride film corresponding to the opening 72 of the first gap is removed. It is preferable to form a silicon oxide film before forming the silicon nitride film 70.
- hydroxyl is passed through the opening 72 on the second main surface of the silicon substrate 50.
- the silicon substrate 50 is removed by anisotropic etching using an alkaline solution such as potassium iodide, and the first void 36 reaching the sacrificial layer 56 and the side surfaces 30 and Form the sides 3 4 of the weights 26.
- the etching speed is anisotropic etching which is fast in the thickness direction of the silicon substrate 50 and slow in the direction perpendicular thereto. Therefore, since the sacrificial layer 56 extends in the vertical direction with respect to the thickness direction of the silicon substrate 50, the anisotropic etching stops almost without being etched.
- a part of the silicon nitride film 70 on the first main surface side is removed, and an electrode 74 electrically connected to the piezoresistors 64 and 66 via the wiring section 68 is deposited. Alternatively, it is formed by sputtering.
- the sacrifice layer 56 is removed by introducing an etchant from the first gap 36 for isotropic etching in which etching is performed in all directions, and a frame having both ends of the epitaxial layer 60 is formed.
- a sheet-like member 14 supported by 12 and having a weight 26 hanging from a central portion 22 of the sheet-like member via a neck portion 28 is formed from the epitaxy layer 60.
- An acidic solution containing hydrofluoric acid may be used for the etching in this case.
- the etching speed of the isotropic etching is higher in the sacrificial layer 56 with a higher impurity concentration than in the epitaxial layer 60 with a lower impurity concentration, and therefore, only the sacrificial layer 56 is selectively removed. Is done. Thereby, the second gap 38 is formed.
- the portion 62 having a high impurity concentration formed in the process diagram 3 (c) is removed by isotropic etching following the sacrificial layer 56, and the sheet-like member 14 and the frame 12 are removed.
- a third void 40 defined by the following formula is formed.
- the third gap 40 may be in the form of a slit constituted by the gaps 39 and 43 as in the embodiment shown in FIG.
- the distance between the side surface of the support member and the side surface of the weight can be made as small as possible.
- the gap can be made thinner, and the first gap can be arranged as far as possible outside the substrate.
- Weight can be increased).
- the sacrificial layer is formed and removed, the connection between the weight and the sheet-like member can be achieved at the constricted neck portion, so that the substrate having a predetermined size can be bent.
- the distance from the center of the part to the frame can be increased.
- the radiusable portion has a substantially beam shape as shown in Fig. 1, the length of the radiusable portion can be increased in addition to the bending being concentrated on the radiusable portion. Therefore, the sensitivity of the sensor is improved.
- the portion of the sheet-like member 14 except for the central portion 22 and the upper weight portion 41 of the cross-shaped portion does not have a substrate under the portion, and only the epitaxy layer 60 has As configured, that part can be substantially deformed (or deflected) when acceleration is applied.
- Another piezoresistor 66 having the same structure as the piezoresistor 64 is formed on the upper surface of the frame 12 as described above, and the piezoresistor 64 and another piezoresistor 66 are connected to each other to form a bridge.
- a circuit (not shown) is formed. By measuring the resistance of the piezoresistor 64 using a bridge circuit, acceleration having three-axis components is detected.
- the sheet-like member 14 is formed by anisotropic etching from the second main surface of the silicon substrate 50, and is provided so as to partially surround the central part 22 of the sheet-like member 14 force silicon substrate 50.
- the isotropic etching of the epitaxial layer 60 which is formed by removing the sacrificial layer 56 that has been removed by isotropic etching, and forms the sheet-like member 14, does not proceed because the impurity concentration is low. Since the operation is stopped, the thickness of the sheet-like member 14 is accurately formed, and a semiconductor acceleration sensor having a double-supported beam structure with little sensitivity variation can be stably manufactured.
- the portion that can actually be elastically deformed (that is, the portion that can be radiused) has a beam form, and when the sensitivity and sensitivity are not so important, the beam width is increased. And / or the length may be reduced.
- the conductivity type of the substrate and the epitaxial layer 60 is N-type.
- the conductivity type may be P-type.
- the piezoresistor 64 may be N-type.
- a predetermined sacrificial layer 88 and an epitaxy layer 82 are formed on a substrate 96.
- the epitaxy layer 8 excluding the parts that eventually become the sheet-like members (including the central part 92 and the radiusable part 106) 80 and the frame 90.
- the portion 84 of 2 is removed by RIE or anisotropic etching to form an etchant inlet.
- the third void 86 is formed, and the sacrificial layer 88 is exposed at the bottom surface.
- the sacrificial layer 88 is removed by wet isotropic etching to form the sheet-like member 80 and the frame 90, and the neck portion 93
- the weight 94 and the support member 95 having the shape are formed.
- the sacrificial layer 88 which is a high-concentration impurity layer, can be directly etched.
- the etching of the sacrificial layer 88 located below the long portion of 80 that is, the radiusable portion 106
- the etching can be performed in the direction of the arrow shown in FIG.
- the third gap 86 along the epitaxial layer 82 is formed.
- the cross-sectional shape is substantially square except that only the corner portion 97 near the central portion 92 is convex inward, but this cross-sectional shape may be any suitable shape. Examples are shown in schematic top views in FIGS. 5 (a) to (1). Yet another embodiment is shown in schematic partial cutaway perspective views in FIGS. 6 (a) and 6 (b).
- the portions (indicated by diagonal lines) of the epitaxial layer 82 excluding the sheet-like member 80 and the portion to become the frame 90 are removed by etching to form the etchant inlet 86.
- an etchant is introduced from there and the sacrificial layer 88 is removed by etching, convection can be performed quickly without the stagnation phenomenon of the etchant, and as a result, it is included in the etchant in the locally closed space. It has the advantage that it is not affected by the fluctuation of the liquid composition due to the autocatalytic decomposition reaction of nitric acid.
- the sheet-like member 80 can be formed accurately without deteriorating the selectivity of the sacrificial layer 88 and the epitaxial layer 82. Further, with respect to the etching of the sacrificial layer portion located below the bendable portion 106, compared to the case of etching along the longitudinal direction 104 of the bendable portion 106 in the illustrated embodiment, Since etching can be performed in a vertical direction (the direction of the arrow in FIG. 4 (b) or FIG. 6 (b)), the etching distance can be reduced. If the etchant inlet 86 is formed simultaneously with the formation of the first void 100 by anisotropic etching, the etchant inlet 86 can be formed without increasing the number of steps.
- FIG. 5 (b) to (1) are schematic plan views showing the state of the semiconductor acceleration sensor element according to another embodiment of the present invention as viewed from above, and show the shape and arrangement of the etch inlet 86. Show.
- Fig. 5 (b) when viewed from above the etchant inlet 86 shown in Fig. 5 (a).
- the rounded corners of the curved shape improve the mechanical strength against stress concentration at the end of the sheet-like member beam-shaped flexible portion 106 reaching the frame 90. be able to.
- FIG. 5 (c) shows an embodiment in which the etchant inlet 86 shown in FIG. 5 (a) is formed only at a portion adjacent to the radiusable portion 106, whereby the lower portion of the radiusable portion 106 and its lower portion are formed. Only the sacrifice layer 13 in the vicinity is removed by etching, and the portion of the epitaxial layer (the portion surrounded by the etchant inlet 86 and the frame 90) 108 is not removed, and the sacrifice layer exists thereunder. Otherwise, the substrate in that portion remains, so that high sensitivity can be achieved by increasing the volume of the weight.
- a slit is formed inside the flexible portion 106 and at least partially between the portion 108 and the frame 90 by RIE or the like so that the flexible portion 106 has flexibility. It is necessary to have more.
- FIG. 5 (d) is obtained by dividing the etchant inlet 86 shown in FIG. 5 (c) into a plurality of rectangular portions, and can achieve the same effect as in FIG. 5 (c).
- the radiusable portion 106 is partially connected to the portion of the epitaxy layer 108 that is connected to the frame 90, the viscosity of the resist is high when the resist is applied by rotating the wafer at high speed. Thereby, the sheet-shaped member 80 can be prevented from being bent or broken, and the mechanical strength in handling surface (workability) is excellent.
- the force was rectangular Etsuchanto inlet 86 so as to form a plurality? Need not be limited to this, for example, it may be a Etsuchanto inlet oval.
- Figs. 5 (e) to 5 (h) show the possible radius in Figs. 5 (a) to 5 (d).
- An etching inlet 110 is further formed in the active part 106, whereby the sacrificial layer 8 8. is etched from the side and the center of the flexible part 106, thereby shortening the etching time. Can be done.
- the shape of the etchant inlet 110 may be any shape such as a circle, an ellipse, a rectangle, or a shape having four rounded corners as viewed from above. mouth
- a plurality of etchant introduction ports 110 may be formed on a center line parallel to the longitudinal direction of the flexible portion 106. If appropriate, the description of FIGS. 5 (a) to 5 (d) above also applies to the cases of FIGS. 5 (e) to 5 (h), respectively.
- FIGS. 5 (i) to 5 (1) show that in FIG. 5 (a) to FIG. 5 (d), an etchant inlet 1 1 2 is further formed over substantially the entire length in the longitudinal direction of the radiusable ⁇ ⁇ 06. With this, the sacrificial layer 88 is etched over the entire length in the direction perpendicular to the longitudinal direction from the side and the center of the squeezable portion 106, so that the etching time can be shortened.
- the shape of the etchant inlet 1 1 2 may be any shape such as an elliptical shape, a rectangular shape, or a shape in which the four corners of the rectangle are rounded. Considering the stress concentration at the point, it is desirable that the ellipse and the rectangle have rounded corners. If appropriate, the description of FIGS. 5 (a) to 5 (d) above also applies to the cases of FIGS. 5 (i) to 5 (1), respectively.
- Fig. 5 (a), Fig. 5 (b), Fig. 5 (e), Fig. 5 (f), Fig. 5 (i) and Fig. 5 (j) show the case of Fig. 6 (b).
- portions of the epitaxial layer 82 except for the sheet ⁇ ! Dog member 80 and the frame 90 are removed by etching.
- FIG. 5 (c), FIG. 5 (d), and FIG. 5 (g), 5 (h), 5 (k) and 5 (1) 6A only a portion of the epitaxial layer 82 adjacent to the frame 90 is etched to form a slit 87 connected to the third gap and the first gap.
- the weight of 94 can be increased to improve sensitivity.
- an etchant inlet 110 or 112 is further formed in the flexible portion 106 in FIG. 6 (a). This is the same as the configuration.
- the dimensions of the etch inlet 86 (especially 84 If the etching is designed to automatically stop at the point where the sacrificial layer 88 is reached in consideration of the anisotropic etching characteristics, the weight 94 is etched due to excessive etching, and the sensitivity is thereby improved. Can be prevented from lowering. This design can be implemented by controlling the opening size of the mask during anisotropic etching.
- the weight can be changed to four beam-shaped flexible portions 106 (FIG. 6 (a)) or eight beam-shaped flexible portions 106. (Fig. 6 (b)), but it is not limited to this.
- how many beams are required to support the weight such as a 12 beam section and a 16 beam section May be used.
- the epitaxy layer 82 is
- the upper weight portion does not exist.
- FIG. 7 is a cross-sectional view illustrating a process of manufacturing the bending conversion element for a semiconductor acceleration sensor according to the present embodiment.
- FIG. 8 is a schematic perspective view showing a state in a certain stage of the manufacturing process shown in FIGS. 7 (b) to 7 (i) in a partially cut-off state.
- FIG. 7 (a) The device according to the present embodiment is formed on a single-crystal silicon substrate 150 as an N-type semiconductor substrate having a plane orientation of (100) and a thickness of, for example, 400 or 600 m.
- a silicon oxide film 152 is formed by thermal oxidation or the like, and an opening 154 is formed by etching the silicon oxide film 152 using a photoresist (not shown) patterned in a predetermined shape as a mask. Then, remove the photoresist by plasma assing or the like. At this time, the openings 154 are portions extending outward from the four sides surrounding the substantially square central portion 156 of the single crystal silicon substrate 150 (therefore, the length extending partially surrounding the central portion). Is formed at the portion where the bendable portion (specifically, the beam portion) 158 is to be formed and at the vicinity thereof along the longitudinal direction. Therefore, the width of the radiusable portion 158 is smaller than the width of the opening 154.
- the opening 154 does not need to be limited to the illustrated form, and as described above, a portion completely surrounding the central portion 156 of the single-crystal silicon substrate 150 (that is, an annular portion). May be formed.
- P-type impurities such as boron (B) are deposited and thermally diffused or ion-implanted and annealed using the silicon oxide film 152 having the openings 154 as a mask.
- a P-type buried sacrificial layer 160 is formed as a high-concentration impurity sacrificial layer.
- the impurity concentration of the P-type buried sacrificial layer 160 is preferably, for example, not less than 1.0 ⁇ 10 17 cm ⁇ 3 and not more than the solid solubility limit.
- FIG. 7 (b) Next, the silicon oxide film 152 is removed by etching. Then, on the surface of the single-crystal silicon substrate 150 on which the P-type buried sacrificial layer 160 was formed, it corresponds to a radiusable portion 158 that can elastically bend when acceleration is applied.
- An N-type epitaxial layer 162 is formed with a thickness to be formed, and the photoresist (not shown) patterned in a predetermined shape is used as a mask to correspond to the flexible portion 1558 of the epitaxial layer 162. In certain places, such as boron (B)?
- a piezoresistor 164 is formed by deposition and thermal diffusion of the type impurity, or ion implantation and annealing (see FIG. 8 (a)).
- a diffusion wiring 166 is formed so as to be electrically connected to the piezoresistor 164 by deposition and thermal diffusion of a P-type impurity or by ion implantation and annealing. And remove the photoresist.
- a boron-containing material (particularly, a portion adjacent to the sheet portion of the epitaxial layer 162, particularly the deflectable portion 158) is used.
- the P-type impurity layer 168 reaching the P-type buried sacrificial layer 162 is formed by depositing and thermally diffusing a P-type impurity such as B) or ion implantation and annealing, and forming a photoresist. (See Fig. 8 (b)).
- the impurity layer 168 is formed in a portion adjacent to the radiusable portion 158.
- the present invention is not limited to this. It may be formed so as to be connected to the sacrifice layer 160 at locations except the radiusable portion 158, the central portion 188 and the frame 186.
- the piezoresistor 164 and the diffusion wiring 166 are formed, and then the impurity layer 168 is formed.
- the piezoresistor 168 is formed after the impurity layer 168 is formed. 64 and the diffusion wiring 166 may be formed.
- a silicon oxide film 170 is formed on the single crystal silicon substrate 150 and the epitaxial layer 162, and a protective film such as a silicon nitride film is formed on the silicon oxide film 170.
- a protective film such as a silicon nitride film is formed on the silicon oxide film 170.
- Fig. 7 (f) Next, using the protective film 172 in which the opening 176 is formed as a mask, the anisotropy of the single crystal silicon substrate 150 using an alkaline etchant such as K0H solution By performing the etching, a first void 178 reaching the P-type buried sacrificial layer 160 is formed.
- an alkaline etchant such as K0H solution
- the portion corresponding to the impurity layer 168 of the silicon oxide film 170 and the protective film 172 on the P-type impurity layer 168 is removed by etching to remove the third void.
- An opening (not shown) for the formation is formed, and a hydrofluoric acid / nitric acid based etchant is introduced from this opening to etch away the P-type impurity layer 168 and to introduce an etchant as a third void. Mouth 180 is formed.
- a hydrofluoric acid / nitric acid based etchant is introduced from the etchant introduction port 180 to etch away the P-type buried sacrificial layer 160 to form a second void 1802.
- the etching of the sacrificial layer 160 may be performed through the first gap 178 and the third gap 180.
- FIG. 7 (i) Next, the silicon oxide film 170 at a desired position on the diffusion wiring 166 and the protective film 172 formed on the silicon oxide film 170 are removed by etching. A contact hole (not shown) is formed, the contact hole is buried, and a metal wiring such as aluminum (A 1) is electrically connected to the piezoresistor 164 via the diffusion wiring 166. After forming 184, the silicon oxide film 170 on the single crystal silicon substrate 150 and the protective film 172 formed thereon are removed by etching (see FIG. 8 (d)).
- the portion excluding the portion that becomes the radiusable portion 158, the center portion 188, and the frame 186, and if necessary, the monocrystalline silicon substrate under the portion. Reactive ion etching of part of 150
- RIE Reactive Ion Etching
- a sheet-like member (158 + 188) with both ends connected to the frame, and a weight (17) suspended from the center (188) 4 is obtained, and the device of the present invention is obtained (see FIG. 8E).
- the boundary between the deflectable section 1558 and the frame 1886 and the boundary between the deflectable section 1558 and the center section 188 have curved edges (radius) to avoid stress concentration. It is desirable that it be processed into a shape.
- an etchant inlet 180 is formed in a portion of the epitaxy layer 162 adjacent to the radiusable portion 158 in the beam form, and an etchant is introduced therefrom to introduce an F-shaped implant. Since the embedded sacrificial layer 160 is removed by etching, convection swiftly occurs without the etchant stagnation phenomenon, and as a result, fluctuations in the liquid composition due to the autocatalytic decomposition reaction of nitric acid in a locally closed space are caused. Without being affected, the flexible portion 158 can be formed accurately without deteriorating the selectivity of the P-type buried sacrificial layer 160 and the epitaxial layer 162.
- the P-type impurity layer 168 is a high-concentration impurity layer like the P-type buried sacrificial layer 160
- the impurity layer 168 and the buried sacrificial layer 160 are removed by etching. Can be performed continuously, and the process can be shortened. Further, in the present embodiment, etching can be performed in a direction perpendicular to the longitudinal direction of the flexible portion 158 instead of etching in the longitudinal direction of the flexible portion 158. Can be.
- FIG. 9 is a schematic side cross-sectional view of the element 200 used in the semiconductor acceleration sensor according to one embodiment of the present invention. For example, as shown in FIG. It is substantially similar to the sectional view shown.
- the element 200 has a first void 202, which is formed by a first part 204 formed by a mechanical or chemical method and anisotropically. It consists of a second part 206 formed by etching.
- first part 204 formed by a mechanical or chemical method and anisotropically.
- second part 206 formed by etching.
- the side face 210 of the weight 208 and the side face 214 of the support member 212 are tapered and narrow, and the angle formed by them becomes the first part (e ⁇ is the first part).
- 2 part is smaller than 2 ).
- the opening 216 is inevitably considerably large (as shown by the dashed line), which causes a problem that the volume of the weight is reduced. In this aspect, such a problem is solved.
- the element as illustrated it is possible to increase the volume of the weight without increasing the area of the opening portion 21 of the first gap defined between the weight and the support member. This means that the sensitivity of the sensor can be increased without increasing the chip area of the acceleration sensor.
- the first portion is further divided into a plurality of portions. Mechanically or chemically ground to split into sub-parts May be.
- the first portion 204 is formed by mechanically grinding the semiconductor substrate 218 to, for example, almost the center.
- the frontage shape of the first portion 204, particularly the distance between the side surfaces, is such that the opening of the second portion necessary for forming the second portion 206 in the next step can be secured.
- the mechanical grinding for forming the first portion include a method using a dicing tool and a method of colliding particles at a high speed (for example, a sand blast method). In the sandplast method, fine particles of sand are sprayed on the sample at high pressure to scrape the sample.
- the first portion may be formed by using a chemical reaction, for example, reactive ion etching (RIE) can be used.
- RIE reactive ion etching
- the second portion 206 is formed by anisotropic etching with an aqueous solution such as an aqueous solution of a hydroxylating aqueous solution. Etching is performed up to the sacrificial layer functioning as an etching stop layer when the sacrificial layer exists in the second void 220. If not, the etching is stopped when the second gap 220 is reached.
- the first portion 204 serves as an etching mask for forming the second portion 206 and an inlet for an etchant.
- an etchant ethylenediamine pyrocatechol, hydrazine or the like may be used in addition to an aqueous potassium hydroxide solution.
- Mechanical grinding has the advantage that the removal rate is higher than etching, so that thicker substrates can be machined and, consequently, the volume (and hence weight) of the weight can be increased.
- reactive ion etching is one of the semiconductor processing technologies, and has the advantage that it can be used in the same environment as other processing used for manufacturing a device.
- 1 can be made smaller than mechanical grinding. Can be ground at a closer angle to the substrate 218), resulting in an opening 216 There is also an advantage that the force J can be reduced to substantially 0 °.
- the semiconductor substrate 218 used is an N-type one having a (100) plane orientation.
- the semiconductor substrate 218 preferably has an impurity concentration of 1.0 ⁇ 10 17 cm ⁇ 3 or less.
- the thickness of the substrate is larger than that generally used as a substrate (for example, about 100 m thick).
- the diffusion step for forming the sacrificial layer 230 deposition and thermal diffusion, or ion implantation and annealing are performed. Here, this is performed by doping impurities such as boron at a high concentration.
- the diffusion depth is set according to the application.
- This sacrificial layer 230 may be made of N-type high-concentration impurities using antimony, phosphorus or the like.
- the sacrificial layer 230 functions as both an etching stop layer and a sacrificial layer in the present invention.
- the epitaxial layer 232 forms a frame and a sheet-like member of the bending conversion element. Since the layer 232 is formed by epitaxy, the thickness can be easily and accurately controlled.
- a piezoresistor 2 3 4 is deposited on the portion of the epitaxial layer 2 3 2 which will become a radiusable portion by depositing and thermally diffusing a P-type impurity such as boron, or by ion implantation and annealing. Form.
- the diffusion wiring 236 for outputting the change in the resistance value of the piezoresistor 234 is deposited and thermally diffused with a P-type impurity such as boron, or ion implantation and annealing. By processing, it is formed at the portion of the epitaxy layer 2 32 that can be radiused. The impurity concentration in this case is higher than the piezoresistive formation process (Fig. 10 (c)).
- a protective mask 238 for protecting the epitaxial layer 2 32, the piezoresistor 2 3 4 and the diffused wiring 2 36, and a formation for forming the weight 2 50 A mask 240 is formed.
- the first portion 242 is formed by mechanically grinding the semiconductor substrate 218 to, for example, almost the center of the semiconductor substrate 218.
- a dicing saw is used for mechanical grinding.
- the dimensions of the opening 244 of the first part 242 should be such that the opening 2245 necessary for forming the second part 246 of the next process is secured.
- the second portion 246 is formed by anisotropic etching using an aqueous solution such as an aqueous hydration aqueous solution. Etching is performed up to the sacrificial layer 230 functioning as an etching stop layer.
- the first part 242 serves as an etching mask for forming the second part 246 and an inlet for the etching liquid.
- the silicon oxide film and the silicon nitride film at the desired locations on the diffusion wiring are removed to form contact holes, and the metal wiring 248 is formed by sputtering or evaporation. It is formed so as to be in contact with 36.
- the metal wiring 248 is formed by sputtering or evaporation. It is formed so as to be in contact with 36.
- heat treatment such as sintering. Gold, chrome, or the like may be used for the metal wiring 248.
- FIG. 10 (h) Finally, the sacrificial layer 230 serving as an etching stop layer is etched and removed to form a second void 255.
- a solution of hydrofluoric acid: nitric acid: acetic acid 1: 1 to 3: 8 is used.
- a low-concentration impurity diffusion layer having a density of 1.0 ⁇ 10 17 cm ⁇ 3 or less reduces the etching rate to about 1/150 with respect to a diffusion layer having a higher impurity concentration. Only the low concentration impurity diffusion layer can be selectively left.
- the sacrificial layer 230 diffused at a high concentration can be selectively removed by etching, and the weight 250 is supported.
- the members 25 2 are separated.
- the first void is divided into a plurality of, for example, two parts, these parts are formed using anisotropic etching in the last part, and mechanical grinding or RIE in other parts.
- FIG. 11 is a schematic cross-sectional view showing a manufacturing process of the acceleration sensor.
- Fig. 11 (a) First, thermal oxidation or the like is performed on a single-crystal silicon substrate 300 as a ⁇ -type semiconductor substrate having a plane orientation of (100) and a thickness of, for example, 400 to 600 ⁇ m.
- a silicon oxide film 302 is formed by etching, and an opening 304 is formed by etching the silicon oxide film 302 using a photoresist (not shown) patterned into a predetermined shape as a mask. Then, the photoresist is removed by plasma assing or the like. At this time, the opening 304 is formed in a portion surrounding the substantially square central portion 303 of the single-crystal silicon substrate 300.
- the silicon oxide film 302 in which the opening 304 is formed as a mask deposition and thermal diffusion of P-type impurities such as polon (B), or ion implantation and annealing are performed.
- P-type impurities such as polon (B), or ion implantation and annealing
- a silicon nitride film may be formed, and this may be used as a mask to perform deposition and thermal diffusion, or ion implantation and annealing.
- FIG. 11B Next, the silicon oxide film 302 is removed by etching. Thereafter, an N-type epitaxy layer 310 is formed on the side of the single-crystal silicon substrate 300 on which the P-type buried sacrificial layer 308 is formed, and a flexible portion to be formed from the epitaxy layer 310 is formed.
- the piezoresistor 312 is formed by depositing and thermally diffusing a P-type impurity such as boron (B) in the portion corresponding to 338, or by performing ion implantation and annealing.
- the epitaxial layer 310 finally becomes a sheet-like member including the bendable portion 338, it is formed to have a thickness that elastically bends when an acceleration is applied.
- diffusion wiring 3 1 4 is performed by depositing and thermally diffusing a higher concentration P-type impurity, or by ion implantation and annealing to electrically connect to the piezo resistor 3 12. Is formed, and a silicon oxide film 316 is formed on the exposed surfaces of the single crystal silicon substrate 300 and the epitaxial layer 310.
- a protective film 318 such as a silicon nitride film is formed on the silicon oxide film 316 by a CVD method or the like, and one of the protective film 318 and the silicon oxide film 316 is formed. The portion is removed by etching using RIE (Reactive Ion Etching) or the like to form an opening 320 for a first void 322 surrounding a weight 336 described later.
- RIE reactive Ion Etching
- Fig. 11 (e) Next, using the protective film 318 in which the opening 320 is formed as a mask, the single-crystal silicon substrate 300 is transformed into an alkali-based material such as a potassium hydroxide (KOH) solution. By performing anisotropic etching using an etchant, a first void 322 reaching the P-type buried sacrificial layer 308 is formed.
- KOH potassium hydroxide
- FIG 11 (f) Next, the silicon oxide film 3 16 and the protective film 3 18 at predetermined positions on the diffusion wiring 3 14 are removed by etching, and the aluminum oxide (A 1) or the like is removed by sputtering or evaporation. Metal wiring, ⁇ ⁇ 3 2 4 and an electrode pad (not shown) are formed so as to be electrically connected to the diffusion wiring 3 14, A wiring protection film 326 such as a chromium film, a silicon nitride film, or a fluororesin film is formed on the surface side of the single crystal silicon layer 300 on which the metal wire 324 is formed.
- a wiring protection film 326 such as a chromium film, a silicon nitride film, or a fluororesin film is formed on the surface side of the single crystal silicon layer 300 on which the metal wire 324 is formed.
- the metal wiring 3 2 4 When general aluminum is used as the metal wiring 3 2 4, if the temperature exceeds 500 ° C., a problem such as alloy spikes may occur. Therefore, a wiring protection film 3 2 6 made of a silicon nitride film is applied. In doing so, the plasma
- a part of the wiring protection film 3 26, the protection film 3 18, the silicon oxide film 3 16 and the epitaxy layer 310 is subjected to RIE, anisotropic etching or isotropic etching. Etching is removed by etching to form a third void 328 including an etchant inlet reaching the P-type buried sacrificial layer 308, and an etchant made of an acidic solution containing hydrofluoric acid or the like is formed from the etchant inlet.
- FIG. 11 (h) Next, the silicon oxide film 316 and the protective film 318 on the bottom surface side of the wiring protective film 326 and the weight 338 are removed by etching. Finally, a stove (or bottom cover) 342 having a concave portion 34 at a position corresponding to the weight 336 is joined to the support member 332 by anodic bonding or the like, and the acceleration of the present invention is improved. A sensor is obtained.
- FIG. 12 shows another embodiment in which the wiring protection layer is formed.
- the steps up to the formation of the silicon oxide film 316 are the same as those in FIG.
- Fig. 12 (a) Then, the silicon oxide film 3 16 at a desired location on the diffusion wiring 3 14 is removed by etching, and the diffusion wiring 3 is formed by sputtering or evaporation. A metal wiring 3 24 made of aluminum or the like and an electrode pad (not shown) are formed so as to be electrically connected to 14.
- a wiring protection film 3 26 made of a silicon nitride film is formed on the silicon oxide film 3 16 on both sides by CVD, etc., and the wiring protection film 3 26 and the silicon oxide film are formed.
- an opening 320 for the first void 3222 is formed.
- the wiring protection film 326 is formed so as to cover the metal wiring 324 and the electrode pad (not shown).
- the single crystal silicon substrate 300 reaches the sacrifice layer 308 by anisotropic etching using the wiring protective film 326 in which the opening 322 is formed as a mask. First voids 3 2 2 are formed.
- a stono which has a concave portion 34 at a position corresponding to the weight 3 36 (or the bottom cover) 3 42
- the sensor of the present invention is obtained by joining to the support member 332 by joining or the like.
- the wiring protective film 3 26 is entirely removed.
- the present invention is not limited to this. Only the wiring protective film 3 26 on the electrode pad is subjected to pattern etching in advance. After removing the sacrificial layer 308 by etching, the entire surface of the wiring protective film 326 is etched to reduce the thickness. Only the electrode pads may be exposed. As a result, portions other than the electrode pads are covered with the silicon nitride film, and the moisture resistance of the sensor element can be improved.
- the reason why only the wiring protective film 32 6 on the electrode pad was thinned in advance by pattern etching is that after the sacrificial layer 308 was removed by etching, the surface of the substrate became uneven.
- the first voids 32 2 are partially formed to leave the substrate portion 350 between the sacrificial layer 310 and the first voids 32 2, and then the sacrificial layer 310 Then, the remaining substrate portion 350 may be removed.
- the weight 336 and the support member 332 are not separated, so that the substrate is not destroyed in this step, and the yield of the substrate is greatly improved. Can be.
- Figure 13 (a) Anisotropic etching of single-crystal silicon substrate 300 using Al-based etchant such as potassium hydroxide (KOH) solution to form first voids 3 2 2 . At this time, the etching is stopped before reaching the first void 3 2 2 force sacrificial layer 3 08, and a single crystal silicon substrate portion 350 having a thickness of, for example, several tens of Z ⁇ m is formed under the sacrificial layer 3 08. Let it remain.
- Al-based etchant such as potassium hydroxide (KOH) solution
- Fig. 13 (b) Next, the silicon oxide film 316 and the protective film 318 at desired locations on the diffusion wiring 314 are removed by etching and electrically connected to the diffusion wiring 314. Like sputtering or evaporation aluminum (A 1) and the like and an electrode pad (not shown) are formed, and a chromium film and silicon nitride are formed on the surface of the single crystal silicon substrate 300 where the metal wiring 324 is formed. A wiring protective film 326 such as a film or a fluororesin film is formed. Fig. 13. (c) Next, as in the case of Fig.
- a third void 328 is formed, and an etchant made of an acidic solution containing hydrofluoric acid or the like is introduced from the etchant inlet, thereby forming a sacrificial layer.
- 308 is removed by isotropic etching to form a second void 330.
- the single crystal silicon substrate portion 350 left under the sacrificial layer 308 is removed by etching by anisotropic etching, RIE, or the like, and the first gap 32 2 and the second gap 330 are removed. Connect.
- the shape of the single-crystal silicon substrate portion 350 left under the buried sacrificial layer 308 after etching differs depending on the method of etching.
- Anisotropic etching using an alkaline etchant is the same as that of RIE.
- the taper angle (in Fig. 9 becomes larger. Therefore, when the area occupied by the element is determined, RIE can be used to increase the weight size s. This means that when RIE is used, the chip size can be made smaller by using RIE than by using wet anisotropic etching.
- the silicon oxide film 316 and the protective film 318 on the bottom surface of the portion to be the weight 336 are removed by etching, and then the protective film 318 on the support member 332 is used as a mask.
- Anisotropic etching using a force-based etchant or RIE is used to etch the bottom surface of the single crystal silicon substrate portion 350 and the portion that will become the weight 336 remaining under the buried sacrificial layer 308 Remove.
- the thickness of the weight 336 is reduced, and the flat stopper 342 is joined to the support member 332 by means of positive joining (see FIG. 13D).
- Figure 14 shows the sacrificial layer formation method when the final buried sacrificial layer depth target is 1.
- FIG. 14 (a) First, a field oxide film 362 having a thickness of about 12000A is formed on the surface of an N-type silicon substrate 360 by thermal oxidation or the like. This oxide film is patterned into a predetermined shape by photolithography and etching to form an opening 364.
- Figure 14 (b) Subsequently, using the field oxide film 362 as a mask, boron, which is a P-type impurity, is deposited on the surface of the silicon substrate 360, and the depth is reduced to about 5 by thermal diffusion in a nitrogen atmosphere. A high-concentration F-type impurity layer 366 of about m is formed. Subsequently, a silicon oxide film 368 of about 3500 A is formed on the substrate surface of the opening 364 by wet oxidation or pyrogenic oxidation. For example, the impurity concentration on the surface of the high-concentration P-type impurity layer 366 when only thermal diffusion is performed in a nitrogen atmosphere is about 1 ⁇ 10 20 cm ⁇ 3, but it is either pet oxidation or pyrogenic. With the addition of oxidation, it is reduced to about 4 x 10 19 cm- 3 .
- FIG. 14 (c) Next, the field oxide film 362 and the silicon oxide film 368 are completely removed by wet etching, and an N-type epitaxial layer 370 is deposited. At this time, boron is also diffused through the interface with the silicon substrate 360 on the epitaxial layer 370 side, and a final buried diffusion layer 372 is formed.
- the diffusion of boron toward the epitaxial layer when wet oxidation or pyrogenic oxidation was not carried out, it was about 4-5 / m, while when wet oxidation or pyrogenic oxidation was carried out, it was about 3.5 / m.
- the thickness of the inversion layer formed by doping is about 5 m when not performing nitric acid or pyrogenic oxidation, whereas the thickness of the inversion layer is approximately 5 m when performing nitriding or pyrogenic oxidation. To about 2.5 / m.
- the peak concentration in the inversion layer was 10 16 cm- 3 in the case where the nitric acid or pyridonic oxidation was not performed, whereas the peak concentration was in the case of carrying out the oxidation or Pairoje nick oxide decreases respectively to 1 0 1 5 cm one three.
- FIG. 15 shows another example of an embodiment in which the impurity concentration on the surface of the sacrifice layer is smaller than that on the inside.
- FIG. 15 (a) First, a field oxide film 362 of about 5000 A is formed on the surface of the N-type silicon substrate 360 by thermal oxidation or the like. This oxide film is patterned into a predetermined shape by photolithography and etching to form an opening 364.
- FIG. 15 (b) Subsequently, using the field oxide film 362 as a mask, boron as a P-type impurity is ion-implanted into the surface of the silicon substrate 360.
- FIG. 15 (c) A silicon oxide film 365 and a high-concentration P-type impurity layer 366 thereunder are formed by annealing in an oxygen atmosphere.
- the peak of the distribution of impurities in the thickness direction immediately after ion implantation appears slightly deeper than the surface of the implantation surface due to the so-called channeling effect, but this distance depends on the type of impurity and the time of implantation. Is determined by the acceleration energy. For example, when boron is ion-implanted at an acceleration energy of 100 keV, a peak appears at a position about 0.25 deeper than the implantation surface. Considering the case where the peak concentration is the same, the deeper the peak position, the higher the concentration on the substrate surface. The degree will be lower. In the embodiment of FIG.
- the sacrificial layer remains exposed at the opening, but if the anneal process is performed in the oxygen atmosphere, the opening is covered with the silicon oxide film. It is preferable because the impurity introduced easily escapes into the inside of this oxide film, and the impurity concentration on the substrate surface becomes lower than that when no oxide film exists.
- FIG. 16 shows another method of forming a sacrificial layer when the final buried sacrificial layer depth target is 10 m.
- phosphorus which is an N-type impurity, is ion-implanted using the field oxide film 362 as a mask.
- FIG. 16 (d) Next, a high-concentration P-type impurity layer 366 having a depth of about 5 m is formed by annealing in a nitrogen atmosphere. In this case, it is necessary to optimally set the phosphorus ion implantation conditions so that the conductivity type does not reverse in the high-concentration P-type impurity layer 366.
- FIG. 16 (e) Next, the field oxide film 362 and the silicon oxide film 365 are completely removed by wet etching over the entire surface, and an N-type epitaxial layer 3700 is deposited. At this time, the impurities are also diffused through the interface with the silicon substrate 360 on the epitaxial layer 370 side, and a final buried sacrificial layer 372 is formed. Since boron as a P-type impurity and phosphorus as an N-type impurity are both present near the surface of the sacrificial layer 372, each of the impurities simultaneously escapes into the atmosphere when forming the epitaxial layer, Both are taken into the epitaxial layer, and the two are offset, so that the formation of the inversion layer can be suppressed.
- each impurity is simultaneously epitaxially transmitted through the silicon substrate 360 surface. Since they are diffused to the layer 370 side, both are offset, and the depth of the P-type impurity layer formed in the epitaxial layer can be suppressed.
- the impurity concentration of at least the epitaxy layer of the substrate and the epitaxy layer is incorporated into the epitaxy layer by auto-doping during epitaxy growth. Higher than the concentration of impurities constituting the sacrificial layer.
- the impurity concentration is 1 ⁇ 1
- the concentration of impurities actually incorporated into the epitaxial layer by autodoping is about 8 ⁇ 10 15 cm— 3.
- the impurity concentration of the repetitive layer for a silicon substrate having an impurity concentration exceeding the impurity concentration of the substrate used, for example, 1 ⁇ 10 16 cm ⁇ 3 is 1 ⁇ 10 1 Epitaxial growth to be 6 cm -3
- an impurity concentration of 1 ⁇ 10 15 cm 3 is required on the outermost surface of the epitaxial layer (the surface on which the piezoresistance is formed)
- a silicon substrate having an impurity concentration of 1 ⁇ 10 16 cm ⁇ 3 is required.
- the epitaxial layer forming process even if the epitaxial growth is performed so that the impurity concentration continuously changes from 1 ⁇ 10 16 cm ⁇ 3 to 1 ⁇ 10 15 cm ⁇ 3, Good.
- a silicon oxide film 402 is formed on one main surface of a semiconductor substrate (for example, a single crystal silicon substrate) 400, an opening 404 is formed in a portion where a sacrificial layer is to be formed, and a P-type (
- the buried layer 406 is formed by diffusing impurities that may be boron (for example, boron) or N-type (for example, phosphorus).
- the substrate is disposed as a diaphragm (or a partition film) in an electrolytic cell 410 containing an electrolytic solution 408 composed of a hydrofluoric acid solution or the like, and a porous silicon layer 406 ′ as a sacrificial layer is formed by anodization.
- the portion other than the buried layer 406 is a protective film such as a silicon oxide film. It is preferably covered with.
- a silicon substrate 400 is arranged between two platinum electrodes 4 12 and 4 14 to which external DC power can be applied.
- the application of an external power supply generates fluorine ions in the electrolytic solution, which reacts with the silicon atoms of the buried layer 406 as an impurity layer and reacts with silicon tetrafluoride (Si). F 4 ) and hydrogen are generated, thereby dissolving a part of the impurity layer.
- pores are formed in the impurity layer to form a porous silicon layer.
- the substrate can be washed with water, dried and subjected to the next process.
- a silicon nitride film or a fluorine resin-based material can be used as a mask in the electrolytic solution treatment.
- the porous silicon thus obtained can be used for producing the device of the present invention.
- the present invention also provides, in addition to the above-described piezoresistive acceleration sensor, a radius conversion element used for a capacitance type acceleration sensor, a manufacturing method thereof, and an acceleration sensor using the same.
- the elements used for the capacitance type acceleration sensor are substantially different only in having an electrode for capacitance measurement instead of the piezo resistance. Therefore, from the above description of the element for a piezoresistive acceleration sensor of the present invention, the configuration of the element used for the capacitance type acceleration sensor and the manufacturing method thereof will be apparent to those skilled in the art. It is also known to those skilled in the art that a capacitance type acceleration sensor can be obtained by bonding a top cover having an electrode facing an electrode for capacitance measurement of the element on the element. it is obvious.
- the specific arrangement of the electrodes on the element may be the same as that shown in FIG. 21, for example, and the electrodes 734 (only one shown) are arranged as shown by broken lines in FIG. May do it.
Description
Claims
Priority Applications (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
KR1019980708419A KR100301097B1 (ko) | 1997-02-21 | 1997-10-22 | 가속도센서용소자및그제조방법 |
EP97909576A EP0899574B1 (en) | 1997-02-21 | 1997-10-22 | Acceleration sensor element and method of its manufacture |
AU47220/97A AU4722097A (en) | 1997-02-21 | 1997-10-22 | Acceleration sensor element and method of its manufacture |
DE69729941T DE69729941T2 (de) | 1997-02-21 | 1997-10-22 | Beschleunigungsmesselement sowie verfahren zu seiner herstellung |
US09/147,155 US6293149B1 (en) | 1997-02-21 | 1997-10-22 | Acceleration sensor element and method of its manufacture |
CA002251957A CA2251957C (en) | 1997-02-21 | 1997-10-22 | Acceleration sensor element and method of its manufacture |
Applications Claiming Priority (8)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP03727197A JP3277839B2 (ja) | 1997-02-21 | 1997-02-21 | 加速度センサ及びその製造方法 |
JP9/37271 | 1997-02-21 | ||
JP20426997 | 1997-07-30 | ||
JP9/204269 | 1997-07-30 | ||
JP23411497 | 1997-08-29 | ||
JP9/234114 | 1997-08-29 | ||
JP23411697 | 1997-08-29 | ||
JP9/234116 | 1997-08-29 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1998037425A1 true WO1998037425A1 (fr) | 1998-08-27 |
Family
ID=27460389
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP1997/003811 WO1998037425A1 (fr) | 1997-02-21 | 1997-10-22 | Element detecteur d'acceleration et son procede de production |
Country Status (7)
Country | Link |
---|---|
US (1) | US6293149B1 (ja) |
EP (1) | EP0899574B1 (ja) |
KR (1) | KR100301097B1 (ja) |
AU (1) | AU4722097A (ja) |
CA (1) | CA2251957C (ja) |
DE (1) | DE69729941T2 (ja) |
WO (1) | WO1998037425A1 (ja) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2428153A1 (de) | 2010-09-08 | 2012-03-14 | Miele & Cie. KG | Haushaltgerät, insbesondere grifflose Geschirrspülmaschine |
Families Citing this family (37)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
AU2001253093A1 (en) * | 2000-04-04 | 2001-10-15 | Rosemount Aerospace Inc. | Three axis accelerometer |
US6528340B2 (en) * | 2001-01-03 | 2003-03-04 | Honeywell International Inc. | Pressure transducer with composite diaphragm |
DE10111149B4 (de) * | 2001-03-08 | 2011-01-05 | Eads Deutschland Gmbh | Mikromechanischer kapazitiver Beschleunigungssensor |
EP1245528A1 (en) * | 2001-03-27 | 2002-10-02 | Delta Danish Electronics, Light & Acoustics | A unitary flexible microsystem and a method for producing same |
JP4890689B2 (ja) * | 2001-07-24 | 2012-03-07 | オリンパス株式会社 | 三次元構造体の製造方法及び揺動体の製造方法 |
JP2003172745A (ja) * | 2001-09-26 | 2003-06-20 | Hitachi Metals Ltd | 半導体加速度センサ |
US6763719B2 (en) * | 2002-03-25 | 2004-07-20 | Hitachi Metals, Ltd. | Acceleration sensor |
JP4216525B2 (ja) * | 2002-05-13 | 2009-01-28 | 株式会社ワコー | 加速度センサおよびその製造方法 |
US20040016981A1 (en) * | 2002-07-26 | 2004-01-29 | Matsushita Electric Works, Ltd. | Semiconductor acceleration sensor using doped semiconductor layer as wiring |
JP2004198280A (ja) * | 2002-12-19 | 2004-07-15 | Hitachi Metals Ltd | 加速度センサ |
TW589752B (en) * | 2003-05-28 | 2004-06-01 | Au Optronics Corp | Semiconductor acceleration sensor |
EP1491901A1 (en) | 2003-06-25 | 2004-12-29 | Matsushita Electric Works, Ltd. | Semiconductor acceleration sensor and method of manufacturing the same |
JP2005049130A (ja) * | 2003-07-30 | 2005-02-24 | Oki Electric Ind Co Ltd | 加速度センサ及び加速度センサの製造方法 |
JP4416460B2 (ja) * | 2003-09-16 | 2010-02-17 | トレックス・セミコンダクター株式会社 | 加速度センサー |
JP2005283402A (ja) * | 2004-03-30 | 2005-10-13 | Fujitsu Media Device Kk | 慣性センサ |
JP4683897B2 (ja) * | 2004-10-14 | 2011-05-18 | Okiセミコンダクタ株式会社 | 加速度センサチップパッケージ及びその製造方法 |
JP2006125887A (ja) * | 2004-10-26 | 2006-05-18 | Fujitsu Media Device Kk | 加速度センサ |
JP2006275896A (ja) * | 2005-03-30 | 2006-10-12 | Yokohama Rubber Co Ltd:The | 半導体加速度センサ |
US7371601B2 (en) | 2005-05-12 | 2008-05-13 | Delphi Technologies, Inc. | Piezoresistive sensing structure |
US7180019B1 (en) * | 2006-06-26 | 2007-02-20 | Temic Automotive Of North America, Inc. | Capacitive accelerometer or acceleration switch |
JP2008224254A (ja) * | 2007-03-08 | 2008-09-25 | Oki Electric Ind Co Ltd | センサ装置、センサ装置の製造方法 |
US20090133908A1 (en) * | 2007-11-28 | 2009-05-28 | Goodner Michael D | Interconnect structure for a microelectronic device, method of manfacturing same, and microelectronic structure containing same |
JP5108617B2 (ja) * | 2008-05-13 | 2012-12-26 | 大日本印刷株式会社 | 加速度センサ |
WO2010061777A1 (ja) * | 2008-11-25 | 2010-06-03 | パナソニック電工株式会社 | 加速度センサ |
US20100162823A1 (en) * | 2008-12-26 | 2010-07-01 | Yamaha Corporation | Mems sensor and mems sensor manufacture method |
JP5724342B2 (ja) | 2009-12-10 | 2015-05-27 | 大日本印刷株式会社 | パターン配置方法並びにシリコンウェハ及び半導体デバイスの製造方法 |
WO2011161917A1 (ja) * | 2010-06-25 | 2011-12-29 | パナソニック株式会社 | 加速度センサ |
KR20120131789A (ko) * | 2011-05-26 | 2012-12-05 | 삼성전기주식회사 | 관성센서 |
US8558330B2 (en) * | 2011-10-31 | 2013-10-15 | Taiwan Semiconductor Manufacturing Co., Ltd. | Deep well process for MEMS pressure sensor |
DE102012200929B4 (de) * | 2012-01-23 | 2020-10-01 | Robert Bosch Gmbh | Mikromechanische Struktur und Verfahren zur Herstellung einer mikromechanischen Struktur |
KR101299730B1 (ko) * | 2012-05-31 | 2013-08-22 | 삼성전기주식회사 | 센서 |
KR101985936B1 (ko) * | 2012-08-29 | 2019-06-05 | 에스케이하이닉스 주식회사 | 불휘발성 메모리 소자와 그 제조방법 |
KR101454123B1 (ko) * | 2013-08-29 | 2014-10-22 | 삼성전기주식회사 | 가속도 센서 |
JP6212000B2 (ja) * | 2014-07-02 | 2017-10-11 | 株式会社東芝 | 圧力センサ、並びに圧力センサを用いたマイクロフォン、血圧センサ、及びタッチパネル |
JP2018179575A (ja) * | 2017-04-05 | 2018-11-15 | セイコーエプソン株式会社 | 物理量センサー、電子機器、および移動体 |
JP6420442B1 (ja) * | 2017-10-16 | 2018-11-07 | 株式会社ワコー | 発電素子 |
KR102505956B1 (ko) | 2021-10-14 | 2023-03-03 | 국방과학연구소 | 가속도 센서 |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0714382U (ja) * | 1993-08-06 | 1995-03-10 | 住友精密工業株式会社 | 静電容量型加速度センサ |
JPH07234242A (ja) * | 1994-02-23 | 1995-09-05 | Matsushita Electric Works Ltd | 半導体加速度センサ及びその製造方法 |
JPH08236784A (ja) * | 1995-02-23 | 1996-09-13 | Tokai Rika Co Ltd | 加速度センサ及びその製造方法 |
JPH08274349A (ja) * | 1995-01-31 | 1996-10-18 | Matsushita Electric Works Ltd | 加速度センサ及び加速度センサの製造方法 |
JPH0945937A (ja) * | 1995-07-26 | 1997-02-14 | Matsushita Electric Works Ltd | 3軸加速度センサの製造方法 |
JPH09153626A (ja) * | 1995-11-30 | 1997-06-10 | Matsushita Electric Works Ltd | 3軸半導体加速度センサの製造方法 |
Family Cites Families (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4882933A (en) | 1988-06-03 | 1989-11-28 | Novasensor | Accelerometer with integral bidirectional shock protection and controllable viscous damping |
JPH0797644B2 (ja) | 1988-09-19 | 1995-10-18 | 日産自動車株式会社 | 半導体加速度センサ及びその製造方法 |
EP0461265B1 (en) | 1989-12-28 | 1995-05-10 | Wacoh Corporation | Acceleration sensors |
JP3043477B2 (ja) | 1991-07-17 | 2000-05-22 | 和廣 岡田 | 静電容量の変化を利用したセンサ |
JP3157030B2 (ja) | 1992-01-31 | 2001-04-16 | キヤノン株式会社 | 半導体基体とその作製方法 |
DE69331816T2 (de) | 1992-01-31 | 2002-08-29 | Canon Kk | Verfahren zur Herstellung eines Halbleitersubstrats |
JP2940293B2 (ja) | 1992-03-31 | 1999-08-25 | 日産自動車株式会社 | 半導体加速度センサの製造方法 |
JPH05340957A (ja) | 1992-06-08 | 1993-12-24 | Fujikura Ltd | 半導体センサの製造方法および半導体センサ |
JP3265641B2 (ja) | 1992-09-25 | 2002-03-11 | 松下電工株式会社 | 半導体加速度センサ |
JP3391841B2 (ja) | 1993-05-26 | 2003-03-31 | 松下電工株式会社 | 半導体加速度センサ |
JPH0714382A (ja) | 1993-06-15 | 1995-01-17 | Mitsubishi Electric Corp | マイクロコンピュータ |
-
1997
- 1997-10-22 WO PCT/JP1997/003811 patent/WO1998037425A1/ja active IP Right Grant
- 1997-10-22 US US09/147,155 patent/US6293149B1/en not_active Expired - Fee Related
- 1997-10-22 CA CA002251957A patent/CA2251957C/en not_active Expired - Fee Related
- 1997-10-22 DE DE69729941T patent/DE69729941T2/de not_active Expired - Lifetime
- 1997-10-22 KR KR1019980708419A patent/KR100301097B1/ko not_active IP Right Cessation
- 1997-10-22 AU AU47220/97A patent/AU4722097A/en not_active Abandoned
- 1997-10-22 EP EP97909576A patent/EP0899574B1/en not_active Expired - Lifetime
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0714382U (ja) * | 1993-08-06 | 1995-03-10 | 住友精密工業株式会社 | 静電容量型加速度センサ |
JPH07234242A (ja) * | 1994-02-23 | 1995-09-05 | Matsushita Electric Works Ltd | 半導体加速度センサ及びその製造方法 |
JPH08274349A (ja) * | 1995-01-31 | 1996-10-18 | Matsushita Electric Works Ltd | 加速度センサ及び加速度センサの製造方法 |
JPH08236784A (ja) * | 1995-02-23 | 1996-09-13 | Tokai Rika Co Ltd | 加速度センサ及びその製造方法 |
JPH0945937A (ja) * | 1995-07-26 | 1997-02-14 | Matsushita Electric Works Ltd | 3軸加速度センサの製造方法 |
JPH09153626A (ja) * | 1995-11-30 | 1997-06-10 | Matsushita Electric Works Ltd | 3軸半導体加速度センサの製造方法 |
Non-Patent Citations (1)
Title |
---|
See also references of EP0899574A4 * |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2428153A1 (de) | 2010-09-08 | 2012-03-14 | Miele & Cie. KG | Haushaltgerät, insbesondere grifflose Geschirrspülmaschine |
US8758524B2 (en) | 2010-09-08 | 2014-06-24 | Miele & Cie. Kg | Household appliance without a handle |
US9267319B2 (en) | 2010-09-08 | 2016-02-23 | Miele & Cie. Kg | Method for operating a door-opening mechanism of a household appliance |
Also Published As
Publication number | Publication date |
---|---|
DE69729941T2 (de) | 2005-08-25 |
EP0899574A1 (en) | 1999-03-03 |
US6293149B1 (en) | 2001-09-25 |
CA2251957A1 (en) | 1998-08-27 |
KR100301097B1 (ko) | 2001-09-22 |
EP0899574B1 (en) | 2004-07-21 |
AU4722097A (en) | 1998-09-09 |
DE69729941D1 (de) | 2004-08-26 |
KR20000064964A (ko) | 2000-11-06 |
CA2251957C (en) | 2003-07-01 |
EP0899574A4 (en) | 1999-06-16 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
WO1998037425A1 (fr) | Element detecteur d'acceleration et son procede de production | |
US6629465B1 (en) | Miniature gauge pressure sensor using silicon fusion bonding and back etching | |
US6743654B2 (en) | Method of fabricating pressure sensor monolithically integrated | |
US5589810A (en) | Semiconductor pressure sensor and related methodology with polysilicon diaphragm and single-crystal gage elements | |
EP0672899B1 (en) | Semiconductor pressure sensor with single-crystal silicon diaphragm and single-crystal gage elements and fabrication method therefor | |
KR101654391B1 (ko) | 압전저항기를 갖춘 장치를 형성하는 방법 | |
US5172205A (en) | Piezoresistive semiconductor device suitable for use in a pressure sensor | |
WO2020177339A1 (zh) | 压力传感器及其制造方法 | |
JP3191770B2 (ja) | 半導体加速度センサ及びその製造方法 | |
KR100904994B1 (ko) | 압력센서 제조방법 및 그 구조 | |
JP2000155030A (ja) | 角速度センサの製造方法 | |
JP3629185B2 (ja) | 半導体センサ及びその製造方法 | |
JP3405219B2 (ja) | 半導体加速度センサ素子及びその製造方法 | |
CN210559358U (zh) | 压力传感器 | |
JP3494022B2 (ja) | 半導体加速度センサの製造方法 | |
JP3551745B2 (ja) | 半導体加速度センサの製造方法 | |
JP2001044449A (ja) | 力検出センサ及び力検出センサの製造方法 | |
JPH0337534A (ja) | 半導体歪検出装置 | |
JP3473462B2 (ja) | 半導体加速度センサ及びその製造方法 | |
JP5309652B2 (ja) | 加速度センサ | |
JPH09153626A (ja) | 3軸半導体加速度センサの製造方法 | |
JP3405222B2 (ja) | 半導体加速度センサ素子及びその製造方法 | |
JP3493980B2 (ja) | 半導体加速度センサの製造方法 | |
Hornung et al. | Resonator Fabrication | |
JPH0694557A (ja) | 半導体圧力センサ |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): AL AM AT AU AZ BA BB BG BR BY CA CH CN CU CZ DE DK EE ES FI GB GE GH HU ID IL IS KE KG KR KZ LC LK LR LS LT LU LV MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SI SK SL TJ TM TR TT UA UG US UZ VN YU ZW |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): GH KE LS MW SD SZ UG ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN ML MR NE SN TD TG |
|
ENP | Entry into the national phase |
Ref document number: 2251957 Country of ref document: CA Kind code of ref document: A Ref document number: 2251957 Country of ref document: CA |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1997909576 Country of ref document: EP Ref document number: 09147155 Country of ref document: US |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1019980708419 Country of ref document: KR |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
WWP | Wipo information: published in national office |
Ref document number: 1997909576 Country of ref document: EP |
|
REG | Reference to national code |
Ref country code: DE Ref legal event code: 8642 |
|
WWP | Wipo information: published in national office |
Ref document number: 1019980708419 Country of ref document: KR |
|
WWG | Wipo information: grant in national office |
Ref document number: 1019980708419 Country of ref document: KR |
|
WWG | Wipo information: grant in national office |
Ref document number: 1997909576 Country of ref document: EP |