WO2016192371A1

WO2016192371A1 - Integrated sensor device and manufacturing method thereof

Info

Publication number: WO2016192371A1
Application number: PCT/CN2015/097313
Authority: WO
Inventors: 孙艳美
Original assignee: 歌尔声学股份有限公司
Priority date: 2015-05-29
Filing date: 2015-12-14
Publication date: 2016-12-08
Also published as: CN105043439A

Abstract

An integrated sensor device and manufacturing method thereof comprises a first substrate (1) and a second substrate (3) having a back cavity (5), and one side of the second substrate (3) having the back cavity (5) is connected above the first substrate (1); an upper end of the first substrate (1) is provided with a first sensitive structure (4) located in the back cavity (5), and an upper end of the second substrate (3) is provided with a second sensitive structure (6). The first substrate (1) and the first sensitive structure (4) of the integrated sensor device form a first sensor, and the second substrate (3) and the second sensitive structure (6) form a second sensor. Integrating two sensors in a vertical direction reduces a transverse dimension of the entire package. Furthermore, using the second substrate (3) in the second sensor as a package cover of the first sensor provides a good protective effect to the first sensitive structure (4). Further, the height of the entire package is reduced and the dimension of the entire package is decreased, thereby satisfying miniaturization development of the modern electronic product.

Description

Sensor integrated device and production method thereof

Technical field

The present invention relates to the field of sensor measurement, and more particularly to an integrated device for a sensor; the present invention also relates to a method of producing a sensor integrated device.

Background technique

In recent years, with the development of science and technology, the volume of electronic products such as mobile phones and notebook computers is decreasing, and the performance requirements of these portable electronic products are getting higher and higher, which requires electronic components compatible with them. The volume must also decrease.

As a measuring device, sensors have been widely used in electronic products such as mobile phones and notebook computers. Many system manufacturers hope that these measuring devices can further reduce the size of the chips to maintain the miniaturization of such electronic products while maintaining the existing performance. . The current problem is that the packaging process of each sensor is relatively mature, the process capability is approaching the limit, and it is difficult to further reduce the size of the chip according to the requirements of the system manufacturer.

Summary of the invention

It is an object of the present invention to provide a new technical solution for a sensor integrated device.

According to a first aspect of the present invention, there is provided a sensor integrated device comprising a first substrate and a second substrate having a back cavity, the second substrate having one side of the back cavity connected to the first substrate Above; wherein the upper end of the first substrate is provided with a first sensitive structure in the back cavity, and the upper end of the second substrate is provided with a second sensitive structure.

Preferably, the first sensitive structure is a movable mass structure of an inertial measurement sensor.

Preferably, the second sensitive structure is a varistor film layer of a pressure sensor.

Preferably, the back cavity penetrates the upper and lower ends of the second substrate, and the second sensitive structure is suspended above the back cavity.

Preferably, the back cavity is a trapezoidal groove closed at an upper end, and is disposed at an upper end of the second substrate There is a closed cavity at the lower end, and the second sensitive structure is suspended above the cavity.

Preferably, the first substrate and the second substrate are single crystal silicon materials, and the two are bonded together by a bonding layer.

The invention also provides a production method of the above sensor integrated device, comprising the following steps:

a) providing a first sensitive structural layer on the upper surface of the first substrate, and constructing the first sensitive structural layer as the first sensitive structure;

b) providing a second sensitive structural layer on the upper surface of the second substrate, and configuring the second sensitive structural layer as a second sensitive structure; etching a lower cavity on the lower surface of the second substrate;

c) fixing the lower surface of the second substrate to the upper surface of the first substrate, and encapsulating the first sensitive structure on the first substrate in the back cavity of the second substrate.

The present invention also provides another method for producing the above sensor integrated device, comprising the following steps:

a) providing a second sensitive structural layer on the upper surface of the second substrate, and constructing the second sensitive structural layer as a second sensitive structure; etching a lower cavity on the lower surface of the second substrate;

b) providing a first sensitive structural layer on the upper surface of the first substrate, and constructing the first sensitive structural layer as a first sensitive structure;

a) providing a first sensitive structural layer on the upper surface of the first substrate, and constructing the first sensitive structural layer as a first sensitive structure;

b) etching the lower surface of the second substrate to form a back cavity closed at the upper end, etching the upper surface of the second substrate to form a cavity closed at the lower end, and suspending the cavity on the upper surface of the second substrate a second sensitive structural layer above and a second sensitive structural layer as a second sensitive structure;

a) forming a back cavity closed at the upper end on the lower surface of the second substrate, etching a cavity closed at the lower end on the upper surface of the second substrate, and suspending the cavity on the upper surface of the second substrate a second sensitive structural layer above and a second sensitive structural layer as a second sensitive structure;

In the sensor integrated device of the present invention, the first substrate and the first sensitive structure constitute a first sensor, and the second substrate and the second sensitive structure constitute a second sensor, and the first sensor and the second sensor may be accelerometers, Gyroscopes, pressure sensors, and the like are well known to those skilled in the art. Integrating the two sensors in the vertical direction not only reduces the lateral dimension of the overall package; but the second substrate in the second sensor acts as a package cover for the first sensor, which can be very useful for the first sensitive structure Good protection; it also reduces the height of the entire package, reduces the size of the overall package, and meets the miniaturization of modern electronic products.

The inventors of the present invention have found that in the prior art, the packaging process of each sensor has been relatively mature, and the process capability has reached the limit, and it is difficult to further reduce the size of the chip according to the requirements of the system manufacturer. Therefore, the technical task to be achieved by the present invention or the technical problem to be solved is not thought of or expected by those skilled in the art, so the present invention is a new technical solution.

Other features and advantages of the present invention will become apparent from the Detailed Description of the <RTIgt;

DRAWINGS

The accompanying drawings, which are incorporated in FIG

1 is a schematic structural view of a sensor integrated device of the present invention.

2 to 4 are schematic views showing the production process of the sensor integrated device of FIG. 1.

FIG. 5 is a schematic structural view of a sensor integration device according to another embodiment of the present invention.

6 and FIG. 7 are diagrams showing the second sensitive structure, the back cavity, and the cavity on the second substrate in FIG. Schematic diagram of production process.

detailed description

Various exemplary embodiments of the present invention will now be described in detail with reference to the drawings. It should be noted that the relative arrangement of the components and steps, numerical expressions and numerical values set forth in the embodiments are not intended to limit the scope of the invention unless otherwise specified.

The following description of the at least one exemplary embodiment is merely illustrative and is in no way

Techniques, methods and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail, but the techniques, methods and apparatus should be considered as part of the specification, where appropriate.

In all of the examples shown and discussed herein, any specific values are to be construed as illustrative only and not as a limitation. Thus, other examples of the exemplary embodiments may have different values.

It should be noted that similar reference numerals and letters indicate similar items in the following figures, and therefore, once an item is defined in one figure, it is not required to be further discussed in the subsequent figures.

Referring to FIG. 1, in order to reduce the size of a package, the present invention provides a sensor integrated device including a first substrate 1 and a second substrate 3 disposed above the first substrate 1, wherein the second The substrate 3 has a back cavity 5 which can be formed on the second substrate 3, for example by etching known to those skilled in the art. The second substrate 3 has a side of the back cavity 5 connected above the first substrate 1 such that the lower end of the back cavity 5 is encapsulated by the first substrate 1.

In the present invention, both the first substrate 1 and the second substrate 3 may be made of a single crystal silicon material, and the first substrate 1 and the second substrate 3 may be connected by SI-SI bonding through the bonding layer 2 Together, the bonding layer 2 is preferably made of a silicon dioxide material.

The sensor integrated device of the present invention is provided with a first sensitive structure 4 at the upper end of the first substrate 1, and the first sensitive structure 4 is located in the back cavity 5 of the second substrate 3, so that the first sensitive structure 4 It is encapsulated by the second substrate 3. The first sensitive structure 4 is a measuring device of the sensor, through which the required measurement data is obtained by the first sensitive structure 4. In a specific embodiment of the present invention, the first sensitive structure 4 may be a movable mass structure in an inertial measurement sensor, when When subjected to inertia, the movable mass structure is deflected or translated, and finally the inertial force is output as an electrical signal. The inertial measurement sensor may be a structure well known to those skilled in the art such as an accelerometer or a gyroscope, and the detailed structure, manufacturing method, and operation principle thereof will not be described herein.

In the sensor integrated device of the present invention, a second sensitive structure 6 is disposed at an upper end of the second substrate 3. The second sensitive structure 6 is a measuring device of the sensor, through which the required measurement data is obtained by the second sensitive structure 6. In a specific embodiment of the invention, the second sensitive structure 6 may be a varistor film layer of a pressure sensor. Referring to FIG. 1, the second sensitive structure 6 may be made of a single crystal silicon material, and a silicon dioxide layer 7 is disposed between the second sensitive substrate 6 and the second substrate 3. The silicon oxide layer 7 is bonded together and the insulation between the second substrate 3 and the second sensitive structure 6 is achieved by the silicon dioxide layer 7. The second sensitive structure 6 injects impurities by means of heavily doping and light doping, for example, implanting boron elements to form P+, P-, and finally forming the second sensitive structure 6 into a varistor film layer. The specific structure, manufacturing method, and working principle of the varistor film layer are common knowledge of those skilled in the art, and are not described herein again.

In a specific embodiment of the present invention, the back cavity 5 penetrates the upper and lower ends of the second substrate 3, and the second sensitive structure 6 is disposed at the upper end of the second substrate 3 and suspended in the back cavity 5. Above, thereby blocking the upper end of the back cavity 5, referring to Fig. 1, the lower end of the back cavity 5 is encapsulated by the first substrate 1. Thereby, the back chamber 5 is enclosed as a closed chamber, which can serve as the cover of the first sensitive structure 4, can prevent foreign matter from entering the first sensitive structure 4, and can provide a vacuum environment, The damping of the movement of the first sensitive structure 4 is reduced.

In the sensor integrated device of the present invention, the first substrate and the first sensitive structure constitute a first sensor, and the second substrate and the second sensitive structure constitute a second sensor, and the first sensor and the second sensor may be accelerometers, A sensor structure known to those skilled in the art, such as a gyroscope or a pressure sensor. Integrating the two sensors in the vertical direction not only reduces the lateral dimension of the overall package; but the second substrate in the second sensor acts as a package cover for the first sensor, which can be very useful for the first sensitive structure Good protection; it also reduces the height of the entire package, reduces the size of the overall package, and meets the miniaturization of modern electronic products.

In another specific implementation structure of the present invention, referring to FIG. 5, the back cavity 5 is closed at the upper end. The trapezoidal groove is provided at the upper end of the second substrate 3 with a cavity 8 closed at the lower end, that is, the back cavity 5 and the cavity 8 are spaced apart from each other and are not connected together. The second sensitive structure 6 is disposed at the upper end of the second substrate 3 and suspended above the cavity 8; the first sensitive structure 4 is disposed at the upper end of the first substrate 1 and located at the back cavity of the second substrate 3. 5, thereby completely isolating the first sensitive structure 4 and the second sensitive structure 6 for better protection.

The invention also provides a method for producing a sensor integrated device, comprising the following steps:

a) firstly, a first sensitive structural layer is disposed on the upper surface of the first substrate 1, and the first sensitive structural layer is configured as the first sensitive structure 4, with reference to FIG. 2; in particular, first, for example, by a single Depositing a bonding layer 2 on the upper surface of the first substrate 1 composed of a crystalline silicon wafer, and etching the bonding layer 2 into a desired shape; then bonding the first sensitive structural layer to the first layer through the bonding layer 2 a substrate 1 and etching the first sensitive structure layer into a predetermined first sensitive structure 4 according to actual needs to form a measuring device of the first sensor;

b) providing a second sensitive structure layer on the upper surface of the second substrate 3, and constructing the second sensitive structure layer as the second sensitive structure 6; etching the back cavity 5 on the second substrate 3, referring to FIG. In the actual application, a silicon dioxide layer 7 is further disposed between the second substrate 3 and the second sensitive structure layer, wherein the second substrate 3 and the second sensitive structural layer are all made of a single crystal silicon material. The two are bonded together through the silicon dioxide layer 7 and insulated from each other. The second substrate 3, the silicon dioxide layer 7, and the second sensitive structure layer integrally constitute a SOI silicon wafer in the prior art. The second sensitive structural layer of the upper layer of the SOI wafer is constructed as a predetermined second sensitive structure 6, and is etched on the second substrate 3 of the lower layer of the SOI wafer to form the back cavity 5.

For example, when the second sensitive structure is a varistor film layer, impurities may be implanted on the second sensitive structure layer by heavy doping or light doping, for example, boron is implanted to form P+, P-, and finally The second sensitive structural layer is constructed as a piezoresistive film layer.

c) Finally, the lower surface of the second substrate 3 may be bonded to the upper surface of the first substrate 1 through the bonding layer 2, and the first sensitive structure 4 on the first substrate 1 is encapsulated in the second liner In the back cavity 5 of the bottom 3.

In the steps a) and b) of the above production method, first, the first sensitive structure 4 is formed on the first substrate 1, and then the second sensitive structure 6 is formed on the second substrate 3. However, it is also possible for a person skilled in the art to first form a second sensitive structure on the second substrate 3. 6. The back cavity 5, after which the first sensitive structure 4 is formed on the first substrate 1, this sequence of step changes has no substantial effect on the resulting sensor integrated device.

The invention also provides a production method of another sensor integrated device, which is basically the same as the above production method, the only difference being the step b), in the embodiment, the step b) is as follows:

Forming an upper end closed back cavity 5 on the lower surface of the second substrate 3, and etching a lower end closed cavity 8 on the upper surface of the second substrate 3, wherein the back cavity 5 and the cavity 8 are separated from each other;

A second sensitive structural layer suspended above the cavity 8 is disposed on the upper surface of the second substrate 3, and the second sensitive structural layer is configured as the second sensitive structure 6, see FIGS. 6 and 7.

In this embodiment, first, the first sensitive structure 4 is formed on the first substrate 1, and then the second sensitive structure 6, the back cavity 5, the cavity 8, and the like are formed on the second substrate 3. However, it is also possible for a person skilled in the art to first form the cavity 8, the second sensitive structure 6, the back cavity 5 on the second substrate 3, and then form the first sensitive structure on the first substrate 1. 4. This change in the sequence of steps has no substantial effect on the resulting sensor integrated device.

While the invention has been described in detail with reference to the preferred embodiments of the present invention, it is understood that It will be appreciated by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims

A sensor integrated device, comprising: a first substrate (1) and a second substrate (3) having a back cavity (5), the second substrate (3) having one side of the back cavity (5) Connected above the first substrate (1); wherein the upper end of the first substrate (1) is provided with a first sensitive structure (4) in the back cavity (5), the second substrate (3) The upper end is provided with a second sensitive structure (6).
The sensor integrated device according to claim 1, characterized in that said first sensitive structure (4) is a movable mass structure of an inertial measurement sensor.
The sensor integrated device according to claim 1 or 2, characterized in that the second sensitive structure (6) is a varistor film layer of a pressure sensor.
The sensor integrated device according to claim 1, wherein the back cavity (5) penetrates the upper and lower ends of the second substrate (3), and the second sensitive structure (6) is suspended in the back cavity ( 5) above.
The sensor integrated device according to claim 1, wherein the back cavity (5) is a trapezoidal groove closed at an upper end, and a cavity closed at a lower end is provided at an upper end of the second substrate (3) (8) The second sensitive structure (6) is suspended above the cavity (8).
The sensor integrated device according to claim 1, wherein the first substrate (1) and the second substrate (3) are single crystal silicon materials, and the two are bonded by a bonding layer (2). together.
A method of manufacturing a sensor integrated device according to claim 1, comprising the steps of:

a) providing a first sensitive structural layer on the upper surface of the first substrate (1), and constructing the first sensitive structural layer as the first sensitive structure (4);

b) providing a second sensitive structural layer on the upper surface of the second substrate (3) and configuring the second sensitive structural layer as the second sensitive structure (6); etching on the lower surface of the second substrate (3) Forming a back cavity (5);

c) fixing the lower surface of the second substrate (3) on the upper surface of the first substrate (1), and encapsulating the first sensitive structure (4) on the first substrate (1) on the second substrate ( 3) in the back cavity (5).
A method of manufacturing a sensor integrated device according to claim 1, comprising the steps of:

a) providing a second sensitive structural layer on the upper surface of the second substrate (3) and configuring the second sensitive structural layer as the second sensitive structure (6); etching on the lower surface of the second substrate (3) Forming a back cavity (5);

b) providing a first sensitive structural layer on the upper surface of the first substrate (1), and constructing the first sensitive structural layer as a first sensitive structure (4);

c) fixing the lower surface of the second substrate (3) on the upper surface of the first substrate (1), and encapsulating the first sensitive structure (4) on the first substrate (1) on the second substrate ( 3) in the back cavity (5).
A method of manufacturing a sensor integrated device according to claim 1, comprising the steps of:

a) providing a first sensitive structural layer on the upper surface of the first substrate (1), and constructing the first sensitive structural layer as a first sensitive structure (4);

b) etching the lower surface of the second substrate (3) to form a back cavity (5) closed at the upper end, and etching the upper surface of the second substrate (3) to form a cavity (8) closed at the lower end, The upper surface of the two substrates (3) is provided with a second sensitive structural layer suspended above the cavity (8), and the second sensitive structural layer is configured as a second sensitive structure (6);

c) fixing the lower surface of the second substrate (3) on the upper surface of the first substrate (1), and encapsulating the first sensitive structure (4) on the first substrate (1) on the second substrate ( 3) in the back cavity (5).
A method of manufacturing a sensor integrated device according to claim 1, comprising the steps of:

a) etching the lower surface of the second substrate (3) to form a back cavity (5) closed at the upper end, and etching the upper surface of the second substrate (3) to form a cavity (8) closed at the lower end, The upper surface of the two substrates (3) is provided with a second sensitive structural layer suspended above the cavity (8), and the second sensitive structural layer is configured as a second sensitive structure (6);

b) providing a first sensitive structural layer on the upper surface of the first substrate (1), and constructing the first sensitive structural layer as a first sensitive structure (4);

c) fixing the lower surface of the second substrate (3) on the upper surface of the first substrate (1), and encapsulating the first sensitive structure (4) on the first substrate (1) on the second substrate ( 3) in the back cavity (5).