WO2000031819A1 - Method and apparatus for switching high frequency signals - Google Patents

Method and apparatus for switching high frequency signals Download PDF

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Publication number
WO2000031819A1
WO2000031819A1 PCT/US1999/025643 US9925643W WO0031819A1 WO 2000031819 A1 WO2000031819 A1 WO 2000031819A1 US 9925643 W US9925643 W US 9925643W WO 0031819 A1 WO0031819 A1 WO 0031819A1
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WO
WIPO (PCT)
Prior art keywords
dielectric material
switch
membrane
providing
resistivity
Prior art date
Application number
PCT/US1999/025643
Other languages
French (fr)
Inventor
John C. Ehmke
Charles L. Goldsmith
Zhimin J. Yao
Susan M. Eshelman
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Raytheon Company
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Publication date
Application filed by Raytheon Company filed Critical Raytheon Company
Priority to AU13354/00A priority Critical patent/AU1335400A/en
Publication of WO2000031819A1 publication Critical patent/WO2000031819A1/en

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Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01PWAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
    • H01P1/00Auxiliary devices
    • H01P1/10Auxiliary devices for switching or interrupting
    • H01P1/12Auxiliary devices for switching or interrupting by mechanical chopper
    • H01P1/127Strip line switches
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01GCAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES OR LIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE
    • H01G5/00Capacitors in which the capacitance is varied by mechanical means, e.g. by turning a shaft; Processes of their manufacture
    • H01G5/16Capacitors in which the capacitance is varied by mechanical means, e.g. by turning a shaft; Processes of their manufacture using variation of distance between electrodes
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01GCAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES OR LIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE
    • H01G5/00Capacitors in which the capacitance is varied by mechanical means, e.g. by turning a shaft; Processes of their manufacture
    • H01G5/40Structural combinations of variable capacitors with other electric elements not covered by this subclass, the structure mainly consisting of a capacitor, e.g. RC combinations
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01HELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H59/00Electrostatic relays; Electro-adhesion relays
    • H01H59/0009Electrostatic relays; Electro-adhesion relays making use of micromechanics
    • H01H2059/0018Special provisions for avoiding charge trapping, e.g. insulation layer between actuating electrodes being permanently polarised by charge trapping so that actuating or release voltage is altered
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01HELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H59/00Electrostatic relays; Electro-adhesion relays
    • H01H59/0009Electrostatic relays; Electro-adhesion relays making use of micromechanics

Definitions

  • This invention relates generally to electronic devices and more particularly to a method and apparatus for switching high frequency signals.
  • Microelectromechanical microwave (MEMS) capacitive switches can be used for switching high frequency signals .
  • MEMS microwave capacitive switches are described in U.S. Patent 5,619,061 entitled, Micromechanical Microwave Swi tching, which is incorporated herein by reference. Such switches may be used for functions such as beam steering in a phased array radar.
  • MEMS capacitive switches generally are low loss devices because they include no active semiconductor components. The lack of active semiconductor components also makes MEMS capacitive switches relatively inexpensive.
  • microelectromechanical microwave capacitive switches show an inability to remain in a switched on position for more than a few seconds at low frequency bias voltages and show a bipolar response when exposed to high- frequency bias voltages.
  • Bipolar response refers to switching on at both zero and positive bias.
  • a method of forming a switch includes providing a conductive region, a membrane, and a dielectric material.
  • the method includes disposing a region of the dielectric material between the conductive region and the membrane such that a sufficient voltage applied between the conductive region and the membrane effects a capacitive coupling between the membrane and the conductive region.
  • the dielectric material has a resistivity sufficiently low to inhibit charge accumulation in the dielectric region during application of the voltage.
  • a switch includes a conductive region, a membrane, and a dielectric region.
  • the dielectric region is formed from a dielectric material and is disposed between the membrane and the conductive region. When a sufficient voltage is applied between the conductive region and the membrane, a capacitive coupling between the membrane and the conductive region is effected.
  • the dielectric material has a resistivity sufficiently low to inhibit charging in the dielectric region during operation of the switch.
  • Embodiments of the invention provide numerous technical advantages. For example, in one embodiment of the invention, a switch is provided that does not suffer from bipolar operation in response to high frequency stimulus and does not turn off inadvertently when it should be turned on in response to low frequency stimulus, which are disadvantages associated with some prior devices . Further, according to the invention, a switch is provided that can be repeatedly activated in response to a bias voltage having a fairly constant magnitude. Such switches provide more reliable operation and are desirable. Other technical advantages are readily apparent to one skilled in the art from the following figures, descriptions, and claims .
  • FIGURE 1 is a schematic drawing illustrating a top view of a microelectromechanical microwave capacitive switch according to the teachings of the present invention
  • FIGURE 2 is a side view of the microelectromechanical microwave capacitive switch illustrated in FIGURE 1 in an undeflected position
  • FIGURE 3 is a schematic drawing illustrating the microelectromechanical microwave capacitive switch of
  • FIGURE 1 in a deflected position
  • FIGURE 4 is a circuit diagram illustrating an effective electrical circuit at high frequency of the microelectromechanical microwave capacitive switch illustrated in FIGURES 1 through 3;
  • FIGURES 5A through 5C are a series of graphs illustrating a desired response and a conventional response for microelectromechanical microwave capacitive switches for high frequency stimulus;
  • FIGURES 6A through 6C are a series of graphs showing a desired response and a conventional response for microelectromechanical microwave capacitive switches in response to a low frequency stimulus;
  • FIGURES 7A through 7B are a series of graphs of switch repetition versus bias voltage illustrating an increasing bias voltage required with switch repetitions.
  • FIGURES 8A through 8C are a series of schematic drawings illustrating the formation of electric fields between a membrane and an electrode of the microelectromechanical microwave capacitive switch of FIGURE 1.
  • FIGURES 1 through 8 of the drawings like numerals being used for like and corresponding parts of the various drawings.
  • FIGURES 1 through 3 are schematic drawings illustrating one embodiment of a microelectromechanical microwave (MEMS) capacitive switch 10 according to the teachings of the present invention.
  • FIGURE 1 shows a top view of switch 10.
  • FIGURE 2 shows a side view along the lines 2-2 of FIGURE 1 for an undeflected position.
  • FIGURE 3 shows a side view along lines 2-2 of FIGURE 1 for a deflected position.
  • Switch 10 includes membrane posts 12 and 14.
  • Membrane post 12 and 14 are generally formed from any suitable conductive material; however, membrane posts 12 and 14 may also be insulative if desired.
  • Electrode 16 is connected to, or forms a part of, a transmission line 22. Transmission line 22 carries a high frequency signal.
  • dielectric region 18 is formed from silicon nitride (Si 3 N 4 ) . However, any suitable dielectric may be used. As described in greater detail below, dielectric region 18 is formed from a dielectric material having a sufficiently low resistivity to inhibit charge accumulation within dielectric region 18.
  • a membrane 20 is disposed between membrane support posts 12 and 14, as best illustrated in FIGURE 2. Membrane 20 is connected to a reference voltage, such as ground. According to one embodiment, membrane 20 is formed from a conductive material. A gap 19 exist between membrane 20 and dielectric region 18, as illustrated in FIGURE 2. In one embodiment, membrane posts 12 and 14, electrode 16, dielectric region 18, and membrane 20 are formed overlying a substrate 24.
  • FIGURE 4 is a simplified circuit diagram illustrating an effective circuit of microelectromechanical microwave capacitive switch 10. As illustrated, when microelectromechanical microwave capacitive switch 10 is closed, signals along transmission line 22 are shorted to ground. This closing of microelectromechanical switch 10 corresponds to the position of membrane 20 illustrated in FIGURE 3. As described above, this positioning of membrane 20 is effected by application of a bias voltage between electrode 16 and membrane 20.
  • the invention recognizes that, during application of a bias voltage, charge tends to be injected from either membrane 20 or electrode 16 into dielectric region 18. This charge, once injected, occupies trap sites within dielectric region 18 and creates a shielding effect that effectively lowers the electric field between electrode 16 and membrane 20. When the injected charge reaches sufficient levels, the electrostatic attraction between electrode 16 and membrane 20 is neutralized and membrane 20 returns to its rest, or up position. This results in a spontaneous and undesired release of microelectromechanical microwave capacitive switch 10. According to the teachings of the invention, reducing the resistivity of the material used for dielectric region 18 inhibits charge accumulation and effects a more desirable microelectromechanical microwave mechanical capacitive switch.
  • FIGURES 5A through 5C are a series of graphs illustrating the position of a microelectromechanical microwave capacitive switch in response to a high frequency stimulus.
  • Curve 26 in FIGURE 5A represents a high frequency stimulus for a bias voltage applied between electrode 16 and membrane 20.
  • Curve 28 in FIGURE 5B illustrates a desired response of microelectromechanical microwave capacitive switch 10.
  • an "Up" position indicates that membrane 20 is as illustrated in FIGURE 2 and a gap 19 is maintained between membrane 20 and dielectric region 18. In such a position, microelectromechanical microwave capacitive switch 10 allows signals to flow along transmission line 22.
  • microelectromechanical microwave capacitive switch 10 Conversely, a "Dn" position indicates that microelectromechanical microwave capacitive switch 10 is in a down position, being in contact with dielectric region 18. In such a position, microelectromechanical microwave capacitive switch 10 shorts high frequency signals to ground and therefore halts transmission of high frequency signals along transmission line 22.
  • Desired response curve 28 shows that microelectromechanical microwave capacitive switch is in a "Dn" position only when an appropriate bias voltage is applied between electrode 16 and membrane 20, corresponding to closing of the switch.
  • Curve 30 in FIGURE 5C illustrates a problem that occurs in some conventional microelectromechanical microwave capacitive switches. With operation as shown by curve 30, the switch toggles at a rate equal to twice the desired rate. This operation is undesirable.
  • the invention recognizes that the behavior of some conventional microelectromechanical microwave capacitive switches as exhibited by curve 30 occurs due to charge injection and accumulation, which is described in greater detail below in conjunction with FIGURES 8A through 8C.
  • FIGURES 6A through 6C are a series of graphs illustrating the operation of microelectromechanical microwave capacitive switches in response to a low frequency stimulus.
  • Curve 32 in FIGURE 6A illustrates an example of low frequency stimulus in which a positive bias voltage applied between electrodes 16 and membrane 20 generates the desired response illustrated by curve 34, shown in FIGURE 6B .
  • Curve 36 in FIGURE 6C illustrates a response resulting from some conventional microelectromechanical microwave capacitive switches in which the membrane of the microelectromechanical switch toggles back to an up position when it should be in a down position. Thus, after some period of time, the membrane returns to an "Up" position even when a bias voltage is maintained.
  • the invention recognizes that the behavior of some conventional microelectromechanical microwave capacitive switches as exhibited by curve 36 occurs due to charge injection and accumulation, which is described in greater detail in conjunction with FIGURES 8A through 8C.
  • FIGURES 7A and 7B are a series of graphs showing switch repetitions versus bias voltage.
  • curve 38 in FIGURE 7A the voltage required to displace membrane 20 downward to contact dielectric region 18 is illustrated as a function of the number of switch repetitions.
  • the bias voltage required to effect such contact increases as the number of times the switch is opened and closed increases.
  • curve 40 in FIGURE 7B the bias voltage required to displace membrane 20 to contact dielectric region 18 remains fairly constant after a few switch repetitions.
  • the behavior as illustrated by curve 38 is also attributed to charge injection and accumulation.
  • an external electric field due to a bias voltage applied between electrode 16 and membrane 20 has the same magnitude as the total electric field between electrode 16 and membrane 20 because there is no internally generated electric field within dielectric region 18.
  • electrical charges begin to accumulate within dielectric region 18. These electrical charges are injected into dielectric region 19 due to the applied bias voltage. These electrical charges generate an internal electric field that opposes the externally applied electric field.
  • the total electric field between membrane 20 and electrode 16 is reduced.
  • the total electric field between membrane 20 and electrode 16 is reduced to an extent that membrane 20 will return to an "open" position.
  • Charge accumulation is also responsible for the behavior of conventional microelectromechanical microwave mechanical capacitive switches in response to low frequency stimulation as exhibited by curve 38 in FIGURE 7A.
  • a bias voltage is applied between membrane 20 and electrode 16
  • a little more charge is injected into dielectric region 18.
  • This additional charge creates a stronger electric field opposing an externally applied electric field resulting from the bias voltage. Therefore, to attain an electric field sufficient to displace membrane 20 to contact dielectric region 18, a greater bias voltage is required for each successive switch repetition.
  • Charge accumulation is also responsible for the behavior of conventional microelectromechanical microwave mechanical capacitive switches in response to high frequency stimulation as exhibited by curve 30 in FIGURE 5C. This phenomena, which results in switching at twice the desired frequency, occurs due to charge accumulation resulting from charge injection by application of a bias voltage.
  • a bias voltage Upon application of a bias voltage, charge is injected into dielectric region 18. The bias voltage then returns to zero at a desired time, but the accumulated charge creates a net electric field in dielectric region 18. This net electric field causes a potential difference between electrode 16 and membrane 20, which causes membrane 20 to again displace toward electrode 16. This displacement occurs even though the externally applied bias voltage is zero. Therefore, switching occurs at twice the desired rate. This operation is referred to as bipolar operation.
  • dielectric region 18 is deposited with a material having an increased conductivity, or decreased resistivity, to inhibit charge accumulation in dielectric region 18 during operation of switch 10.
  • inhibit charge accumulation refers to preventing charge accumulation to an extent that microelectromechanical microwave mechanical capacitative switches, during standard operating conditions, generally do not exhibit bipolar response in response to high frequency stimulus or generally do not switch to an "Up” position when they should be in a "Dn” position in response to low frequency stimulus, but not necessarily both. Thus inhibition of charge accumulation occurs if one or more of these two behaviors is generally prevented.
  • dielectric layer 18 may be intentionally doped with an external dopant; the internal stoichiometry may be modified; pre or post processing steps can be introduced or modified; or other suitable techniques that increase the conductivity of dielectric region 18 may be utilized.
  • dielectric layer 18 may be intentionally doped with an external dopant; the internal stoichiometry may be modified; pre or post processing steps can be introduced or modified; or other suitable techniques that increase the conductivity of dielectric region 18 may be utilized.
  • silicon nitride (Si 3 N 4 ) is deposited stoichiometrically by plasma enhanced chemical vapor deposition.
  • the conductivity of SiN is sensitive to the Si/N ratio.
  • the resistivity of the silicon nitride used to form dielectric region 18 was reduced from lxlO 11 to lxlO 7 Ohm-cm. This resistivity occurs in the presence of an electrical field having a magnitude of 200 kilovolts per centimeter.

Abstract

A switch includes a conductive region, a membrane, and a dielectric region. The dielectric region is formed from a dielectric material and is disposed between the membrane and the conductive region. When a sufficient voltage is applied between the conductive region and the membrane, a capacitive coupling between the membrane nd the conductive region is effected. The dielectric material has a resistivity sufficiently low to inhibit charge accumulation in the dielectric region during operation of the switch.

Description

METHOD AND APPARATUS FOR SWITCHING HIGH FREQUENCY SIGNALS
TECHNICAL FIELD OF THE INVENTION
This invention relates generally to electronic devices and more particularly to a method and apparatus for switching high frequency signals.
BACKGROUND OF THE INVENTION
Microelectromechanical microwave (MEMS) capacitive switches can be used for switching high frequency signals . Examples of microelectromechanical microwave capacitive switches are described in U.S. Patent 5,619,061 entitled, Micromechanical Microwave Swi tching, which is incorporated herein by reference. Such switches may be used for functions such as beam steering in a phased array radar. MEMS capacitive switches generally are low loss devices because they include no active semiconductor components. The lack of active semiconductor components also makes MEMS capacitive switches relatively inexpensive.
A problem with some implementations of microelectromechanical microwave capacitive switches is that they show an inability to remain in a switched on position for more than a few seconds at low frequency bias voltages and show a bipolar response when exposed to high- frequency bias voltages. Bipolar response refers to switching on at both zero and positive bias. SUMMARY OF THE INVENTION
Accordingly, a need has arisen for an improved method and apparatus for method and apparatus for dielectric charges reduction in micromechanical microwave capacitive switches that address shortcomings of prior methods and apparatuses .
According to one embodiment of the invention, a method of forming a switch includes providing a conductive region, a membrane, and a dielectric material. The method includes disposing a region of the dielectric material between the conductive region and the membrane such that a sufficient voltage applied between the conductive region and the membrane effects a capacitive coupling between the membrane and the conductive region. The dielectric material has a resistivity sufficiently low to inhibit charge accumulation in the dielectric region during application of the voltage.
According to another embodiment of the invention, a switch includes a conductive region, a membrane, and a dielectric region. The dielectric region is formed from a dielectric material and is disposed between the membrane and the conductive region. When a sufficient voltage is applied between the conductive region and the membrane, a capacitive coupling between the membrane and the conductive region is effected. The dielectric material has a resistivity sufficiently low to inhibit charging in the dielectric region during operation of the switch.
Embodiments of the invention provide numerous technical advantages. For example, in one embodiment of the invention, a switch is provided that does not suffer from bipolar operation in response to high frequency stimulus and does not turn off inadvertently when it should be turned on in response to low frequency stimulus, which are disadvantages associated with some prior devices . Further, according to the invention, a switch is provided that can be repeatedly activated in response to a bias voltage having a fairly constant magnitude. Such switches provide more reliable operation and are desirable. Other technical advantages are readily apparent to one skilled in the art from the following figures, descriptions, and claims .
BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding on the present invention and the advantages thereof, reference is now made to the following descriptions taken in connection with the accompanying drawings in which:
FIGURE 1 is a schematic drawing illustrating a top view of a microelectromechanical microwave capacitive switch according to the teachings of the present invention;
FIGURE 2 is a side view of the microelectromechanical microwave capacitive switch illustrated in FIGURE 1 in an undeflected position; FIGURE 3 is a schematic drawing illustrating the microelectromechanical microwave capacitive switch of
FIGURE 1 in a deflected position;
FIGURE 4 is a circuit diagram illustrating an effective electrical circuit at high frequency of the microelectromechanical microwave capacitive switch illustrated in FIGURES 1 through 3;
FIGURES 5A through 5C are a series of graphs illustrating a desired response and a conventional response for microelectromechanical microwave capacitive switches for high frequency stimulus;
FIGURES 6A through 6C are a series of graphs showing a desired response and a conventional response for microelectromechanical microwave capacitive switches in response to a low frequency stimulus;
FIGURES 7A through 7B are a series of graphs of switch repetition versus bias voltage illustrating an increasing bias voltage required with switch repetitions; and
FIGURES 8A through 8C are a series of schematic drawings illustrating the formation of electric fields between a membrane and an electrode of the microelectromechanical microwave capacitive switch of FIGURE 1.
DETAILED DESCRIPTION OF THE INVENTION
The present invention and its advantages are best understood by referring to FIGURES 1 through 8 of the drawings, like numerals being used for like and corresponding parts of the various drawings.
FIGURES 1 through 3 are schematic drawings illustrating one embodiment of a microelectromechanical microwave (MEMS) capacitive switch 10 according to the teachings of the present invention. FIGURE 1 shows a top view of switch 10. FIGURE 2 shows a side view along the lines 2-2 of FIGURE 1 for an undeflected position. FIGURE 3 shows a side view along lines 2-2 of FIGURE 1 for a deflected position. Switch 10 includes membrane posts 12 and 14. Membrane post 12 and 14 are generally formed from any suitable conductive material; however, membrane posts 12 and 14 may also be insulative if desired. Disposed between membrane posts 12 and 14 is an electrode 16. Electrode 16 is connected to, or forms a part of, a transmission line 22. Transmission line 22 carries a high frequency signal. Overlying electrode 16 is a dielectric region 18. In one embodiment, dielectric region 18 is formed from silicon nitride (Si3N4) . However, any suitable dielectric may be used. As described in greater detail below, dielectric region 18 is formed from a dielectric material having a sufficiently low resistivity to inhibit charge accumulation within dielectric region 18. A membrane 20 is disposed between membrane support posts 12 and 14, as best illustrated in FIGURE 2. Membrane 20 is connected to a reference voltage, such as ground. According to one embodiment, membrane 20 is formed from a conductive material. A gap 19 exist between membrane 20 and dielectric region 18, as illustrated in FIGURE 2. In one embodiment, membrane posts 12 and 14, electrode 16, dielectric region 18, and membrane 20 are formed overlying a substrate 24. If a DC bias voltage is applied to electrode 16 and membrane 20 is held at ground, as illustrated in FIGURE 3, membrane 20 is deflected downward, due to an electric field created between membrane 20 and electrode 16 by the bias voltage, until it rests on dielectric region 18. This contact forms a capacitive coupling that effectively shorts high frequency signals between transmission line 22 and ground. Thus, transmission of a high frequency signal along transmission line 22 can be prevented by application of a bias voltage between electrode 16 and membrane 20. FIGURE 4 is a simplified circuit diagram illustrating an effective circuit of microelectromechanical microwave capacitive switch 10. As illustrated, when microelectromechanical microwave capacitive switch 10 is closed, signals along transmission line 22 are shorted to ground. This closing of microelectromechanical switch 10 corresponds to the position of membrane 20 illustrated in FIGURE 3. As described above, this positioning of membrane 20 is effected by application of a bias voltage between electrode 16 and membrane 20.
As described in greater detail below, the invention recognizes that, during application of a bias voltage, charge tends to be injected from either membrane 20 or electrode 16 into dielectric region 18. This charge, once injected, occupies trap sites within dielectric region 18 and creates a shielding effect that effectively lowers the electric field between electrode 16 and membrane 20. When the injected charge reaches sufficient levels, the electrostatic attraction between electrode 16 and membrane 20 is neutralized and membrane 20 returns to its rest, or up position. This results in a spontaneous and undesired release of microelectromechanical microwave capacitive switch 10. According to the teachings of the invention, reducing the resistivity of the material used for dielectric region 18 inhibits charge accumulation and effects a more desirable microelectromechanical microwave mechanical capacitive switch. FIGURES 5A through 5C are a series of graphs illustrating the position of a microelectromechanical microwave capacitive switch in response to a high frequency stimulus. Curve 26 in FIGURE 5A represents a high frequency stimulus for a bias voltage applied between electrode 16 and membrane 20. Curve 28 in FIGURE 5B illustrates a desired response of microelectromechanical microwave capacitive switch 10. For curve 28, an "Up" position indicates that membrane 20 is as illustrated in FIGURE 2 and a gap 19 is maintained between membrane 20 and dielectric region 18. In such a position, microelectromechanical microwave capacitive switch 10 allows signals to flow along transmission line 22. Conversely, a "Dn" position indicates that microelectromechanical microwave capacitive switch 10 is in a down position, being in contact with dielectric region 18. In such a position, microelectromechanical microwave capacitive switch 10 shorts high frequency signals to ground and therefore halts transmission of high frequency signals along transmission line 22.
Desired response curve 28 shows that microelectromechanical microwave capacitive switch is in a "Dn" position only when an appropriate bias voltage is applied between electrode 16 and membrane 20, corresponding to closing of the switch. Curve 30 in FIGURE 5C illustrates a problem that occurs in some conventional microelectromechanical microwave capacitive switches. With operation as shown by curve 30, the switch toggles at a rate equal to twice the desired rate. This operation is undesirable. The invention recognizes that the behavior of some conventional microelectromechanical microwave capacitive switches as exhibited by curve 30 occurs due to charge injection and accumulation, which is described in greater detail below in conjunction with FIGURES 8A through 8C.
FIGURES 6A through 6C are a series of graphs illustrating the operation of microelectromechanical microwave capacitive switches in response to a low frequency stimulus. Curve 32 in FIGURE 6A illustrates an example of low frequency stimulus in which a positive bias voltage applied between electrodes 16 and membrane 20 generates the desired response illustrated by curve 34, shown in FIGURE 6B . Curve 36 in FIGURE 6C illustrates a response resulting from some conventional microelectromechanical microwave capacitive switches in which the membrane of the microelectromechanical switch toggles back to an up position when it should be in a down position. Thus, after some period of time, the membrane returns to an "Up" position even when a bias voltage is maintained. The invention recognizes that the behavior of some conventional microelectromechanical microwave capacitive switches as exhibited by curve 36 occurs due to charge injection and accumulation, which is described in greater detail in conjunction with FIGURES 8A through 8C.
FIGURES 7A and 7B are a series of graphs showing switch repetitions versus bias voltage. In curve 38 in FIGURE 7A, the voltage required to displace membrane 20 downward to contact dielectric region 18 is illustrated as a function of the number of switch repetitions. As illustrated, the bias voltage required to effect such contact increases as the number of times the switch is opened and closed increases. A more desirable response is illustrated by curve 40 in FIGURE 7B in which the bias voltage required to displace membrane 20 to contact dielectric region 18 remains fairly constant after a few switch repetitions. The behavior as illustrated by curve 38 is also attributed to charge injection and accumulation.
FIGURES 8A through 8C illustrate the generation of an electric field between membrane 20 and electrode 16 for three time periods: time t = 0; time t = t1# > 0; and time t = t2 > tx. The cause of the above-described undesirable behaviors of some microelectromechanical microwave capacitive switches is further described in conjunction with FIGURE 8.
For time t = 0, an external electric field due to a bias voltage applied between electrode 16 and membrane 20 has the same magnitude as the total electric field between electrode 16 and membrane 20 because there is no internally generated electric field within dielectric region 18. However, at time tl7 electrical charges begin to accumulate within dielectric region 18. These electrical charges are injected into dielectric region 19 due to the applied bias voltage. These electrical charges generate an internal electric field that opposes the externally applied electric field. Thus, the total electric field between membrane 20 and electrode 16 is reduced. At some time t2 the total electric field between membrane 20 and electrode 16 is reduced to an extent that membrane 20 will return to an "open" position. Thus, the accumulation of a charge that is injected into dielectric region 19 by application of a bias voltage creates an electric field opposing the externally applied electric field generated by application of a bias voltage. This charge accumulation is responsible for the behavior of conventional microelectromechanical microwave mechanical capacitive switches as exhibited by curve 36 in FIGURE 6C.
Charge accumulation is also responsible for the behavior of conventional microelectromechanical microwave mechanical capacitive switches in response to low frequency stimulation as exhibited by curve 38 in FIGURE 7A. Each time a bias voltage is applied between membrane 20 and electrode 16, a little more charge is injected into dielectric region 18. This additional charge creates a stronger electric field opposing an externally applied electric field resulting from the bias voltage. Therefore, to attain an electric field sufficient to displace membrane 20 to contact dielectric region 18, a greater bias voltage is required for each successive switch repetition.
Charge accumulation is also responsible for the behavior of conventional microelectromechanical microwave mechanical capacitive switches in response to high frequency stimulation as exhibited by curve 30 in FIGURE 5C. This phenomena, which results in switching at twice the desired frequency, occurs due to charge accumulation resulting from charge injection by application of a bias voltage. Upon application of a bias voltage, charge is injected into dielectric region 18. The bias voltage then returns to zero at a desired time, but the accumulated charge creates a net electric field in dielectric region 18. This net electric field causes a potential difference between electrode 16 and membrane 20, which causes membrane 20 to again displace toward electrode 16. This displacement occurs even though the externally applied bias voltage is zero. Therefore, switching occurs at twice the desired rate. This operation is referred to as bipolar operation.
According to the teachings of the present invention, such problems associated with charge injection and accumulation may be addressed by depositing dielectric region 18 in such a way as to make it "leaky. " In other words, dielectric region 18 is deposited with a material having an increased conductivity, or decreased resistivity, to inhibit charge accumulation in dielectric region 18 during operation of switch 10. As used herein, according to one embodiment, "inhibit charge accumulation" refers to preventing charge accumulation to an extent that microelectromechanical microwave mechanical capacitative switches, during standard operating conditions, generally do not exhibit bipolar response in response to high frequency stimulus or generally do not switch to an "Up" position when they should be in a "Dn" position in response to low frequency stimulus, but not necessarily both. Thus inhibition of charge accumulation occurs if one or more of these two behaviors is generally prevented.
Forming dielectric region 18 with decreased resistivity allows migration of the injected charges through dielectric region 18 and avoids charge buildup. According to the invention, increasing the conductivity of dielectric region 18 may be achieved in several ways: dielectric layer 18 may be intentionally doped with an external dopant; the internal stoichiometry may be modified; pre or post processing steps can be introduced or modified; or other suitable techniques that increase the conductivity of dielectric region 18 may be utilized. Although the particular increases from standard conductivities associated with dielectric material used in conventional microelectromechanical microwave capacitive switches varies by application, bias voltage, and magnitude of electric field, increasing the conductivity by a factor of a 10,000 over standard values has been shown to be particularly advantageous and produced the above-described desirable results.
According to one embodiment of the invention, silicon nitride (Si3N4) is deposited stoichiometrically by plasma enhanced chemical vapor deposition. The conductivity of SiN is sensitive to the Si/N ratio. By increasing the silicon concentration in the film and making the film silicon-rich, the dielectric becomes leaky and prevents charge by accumulation problems . In one embodiment of the invention, the resistivity of the silicon nitride used to form dielectric region 18 was reduced from lxlO11 to lxlO7 Ohm-cm. This resistivity occurs in the presence of an electrical field having a magnitude of 200 kilovolts per centimeter.
Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions, and alterations can be made therein without departing from the spirit and scope of the present invention as defined by the appended claims .

Claims

WHAT IS CLAIMED IS:
1. A method of forming a switch, the method comprising: providing a conductive region; providing a membrane; providing a dielectric material; disposing a region of the dielectric material between the conductive region and the membrane such that a sufficient voltage applied between the conductive region and the membrane effects a capacitive coupling between the membrane and the conductive region; and wherein providing the dielectric material comprises providing a dielectric material having a resistivity sufficiently low to inhibit charge accumulation in the dielectric region during application of the voltage.
2. The method of Claim 1 wherein providing the dielectric material comprises providing a dielectric material having a resistivity sufficiently low to generally prevent bipolar operation of the switch.
3. The method of Claim 1 wherein providing the dielectric material comprises providing a dielectric material having a resistivity sufficiently low to generally prevent release of the capacitive coupling while the sufficient voltage is applied.
4. The method of Claim 1, wherein providing the dielectric material comprises providing a dielectric material having a resistivity less than approximately lxlO11 ohm-cm measured in an electric field of approximately 200kV/cm.
5. The method of Claim 1, wherein providing the dielectric material comprises providing silicon nitride having a resistivity less than approximately lxlO11 ohm-cm measured in an electric field of approximately 200kV/cm.
6. The method of Claim 1, wherein providing the dielectric material comprises providing a dielectric material having a resistivity of approximately lxlO7 Ohm-cm in an electric field having a strength of approximately 200kV/cm.
7. A switch comprising: a conductive region; a membrane; a dielectric region formed from a dielectric material, the dielectric region disposed between the membrane and the conductive region; wherein a sufficient voltage applied between the conductive region and the membrane effects a capacitive coupling between the membrane and the conductive region; and wherein the dielectric material has a resistivity sufficiently low to inhibit charge accumulation in the dielectric region during operation of the switch.
8. The switch of Claim 7, wherein the dielectric material further has a resistivity sufficiently low to generally prevent bipolar operation of the switch.
9. The switch of Claim 7, wherein the dielectric material further has a resistivity sufficiently low to generally prevent release of the capacitive coupling while the sufficient voltage is applied.
10. The switch of Claim 7, wherein the dielectric material has a resistivity less than approximately lxlO11 ohm-cm measured in an electric field of approximately 200kV/cm.
11. The switch of Claim 7, wherein the dielectric material comprises silicon nitride having a resistivity less than approximately lxlO11 ohm-cm measured in an electric field of approximately 200kV/cm.
12. The switch of Claim 7, wherein the dielectric material comprises silicon nitride having a resistivity of approximately lxlO7 ohm-cm measured at approximately 200kV/cm.
13. The switch of Claim 7, wherein the dielectric material further has a resistivity sufficiently low to generally prevent bipolar operation of the switch and sufficiently low to generally prevent release of the capacitive coupling while the sufficient voltage is applied.
14. A method of forming a capacitive switch, the method comprising: providing a substrate; disposing a conductive region overlying the substrate; disposing a dielectric region overlying the conductive region; disposing a membrane over the dielectric region such that a sufficient voltage applied between the conductive region and the membrane effects a capacitive coupling between the membrane and the conductive region; and wherein disposing a dielectric region overlying the conductive region comprises providing a dielectric material having a resistivity that inhibits charge accumulation in the dielectric region when the switch is operating.
15. The method of Claim 14 wherein providing the dielectric material comprises providing a dielectric material having a resistivity sufficiently low to generally prevent bipolar operation of the switch.
16. The method of Claim 14 wherein providing the dielectric material comprises providing a dielectric material having a resistivity sufficiently low to generally prevent release of the capacitive coupling while the sufficient voltage is applied.
17. The method of Claim 14, wherein providing the dielectric material comprises providing a dielectric material having a resistivity less than approximately lxlO11 ohm-cm measured in an electric field of approximately 200kV/cm.
18. The method of Claim 14, wherein providing the dielectric material comprises providing silicon nitride having a resistivity less than approximately lxlO11 ohm-cm measured in an electric field of approximately 200kV/cm.
19. The method of Claim 14, wherein providing the dielectric material comprises providing a dielectric material having a resistivity of approximately lxlO7 ohm-cm in an electric field having a strength of approximately 200kV/cm.
20. The method of Claim 14, wherein providing a dielectric material comprises providing a dielectric material having a resistivity sufficiently low to generally prevent bipolar operation of the switch and sufficiently low to generally prevent release of the capacitive coupling while the sufficient voltage is applied.
PCT/US1999/025643 1998-11-25 1999-11-01 Method and apparatus for switching high frequency signals WO2000031819A1 (en)

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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1308977A2 (en) * 2001-11-06 2003-05-07 Omron Corporation Electrostatic actuator, and electrostatic microrelay and other devices using the same
WO2007138102A1 (en) * 2006-05-31 2007-12-06 Thales Radiofrequency or hyperfrequency micro switch structure and method for producing one such structure
EP1950778A3 (en) * 2007-01-24 2009-03-11 Fujitsu Ltd. Drive control method and unit for micro machine device
US7903386B2 (en) 2007-03-30 2011-03-08 Fujitsu Limited Apparatus and method for drive controlling micro machine device
WO2010092406A3 (en) * 2009-02-13 2011-05-26 Wolfson Microelectronics Plc Mems device with leakage path
EP2495866A1 (en) * 2011-03-04 2012-09-05 Commissariat à l'Énergie Atomique et aux Énergies Alternatives Electrostatic actuator of a mobile structure with improved relief of trapped charges

Families Citing this family (102)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7550794B2 (en) * 2002-09-20 2009-06-23 Idc, Llc Micromechanical systems device comprising a displaceable electrode and a charge-trapping layer
US7471444B2 (en) * 1996-12-19 2008-12-30 Idc, Llc Interferometric modulation of radiation
US8928967B2 (en) 1998-04-08 2015-01-06 Qualcomm Mems Technologies, Inc. Method and device for modulating light
KR100703140B1 (en) 1998-04-08 2007-04-05 이리다임 디스플레이 코포레이션 Interferometric modulation and its manufacturing method
WO2003007049A1 (en) 1999-10-05 2003-01-23 Iridigm Display Corporation Photonic mems and structures
US6738600B1 (en) * 2000-08-04 2004-05-18 Harris Corporation Ceramic microelectromechanical structure
US6635919B1 (en) * 2000-08-17 2003-10-21 Texas Instruments Incorporated High Q-large tuning range micro-electro mechanical system (MEMS) varactor for broadband applications
WO2003017301A1 (en) * 2001-08-20 2003-02-27 Honeywell International Inc. Snap action thermal switch
US6630871B2 (en) * 2001-09-28 2003-10-07 Intel Corporation Center-mass-reduced microbridge structures for ultra-high frequency MEM resonator
US6919784B2 (en) 2001-10-18 2005-07-19 The Board Of Trustees Of The University Of Illinois High cycle MEMS device
US6794119B2 (en) * 2002-02-12 2004-09-21 Iridigm Display Corporation Method for fabricating a structure for a microelectromechanical systems (MEMS) device
WO2003107372A1 (en) * 2002-06-14 2003-12-24 International Business Machines Corporation Micro-electromechanical switch having a deformable elastomeric conductive element
US6933808B2 (en) * 2002-07-17 2005-08-23 Qing Ma Microelectromechanical apparatus and methods for surface acoustic wave switching
US6998946B2 (en) * 2002-09-17 2006-02-14 The Board Of Trustees Of The University Of Illinois High cycle deflection beam MEMS devices
US7781850B2 (en) 2002-09-20 2010-08-24 Qualcomm Mems Technologies, Inc. Controlling electromechanical behavior of structures within a microelectromechanical systems device
KR100470634B1 (en) * 2002-10-02 2005-03-10 한국전자통신연구원 Capacitive micro-electro-mechanical switch and a method of manufacturing the same
US6714169B1 (en) 2002-12-04 2004-03-30 Raytheon Company Compact, wide-band, integrated active module for radar and communication systems
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US7221495B2 (en) * 2003-06-24 2007-05-22 Idc Llc Thin film precursor stack for MEMS manufacturing
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US7142346B2 (en) * 2003-12-09 2006-11-28 Idc, Llc System and method for addressing a MEMS display
US7161728B2 (en) * 2003-12-09 2007-01-09 Idc, Llc Area array modulation and lead reduction in interferometric modulators
US7551159B2 (en) * 2004-08-27 2009-06-23 Idc, Llc System and method of sensing actuation and release voltages of an interferometric modulator
US7889163B2 (en) 2004-08-27 2011-02-15 Qualcomm Mems Technologies, Inc. Drive method for MEMS devices
US7515147B2 (en) * 2004-08-27 2009-04-07 Idc, Llc Staggered column drive circuit systems and methods
US7499208B2 (en) * 2004-08-27 2009-03-03 Udc, Llc Current mode display driver circuit realization feature
US7560299B2 (en) * 2004-08-27 2009-07-14 Idc, Llc Systems and methods of actuating MEMS display elements
US7369296B2 (en) 2004-09-27 2008-05-06 Idc, Llc Device and method for modifying actuation voltage thresholds of a deformable membrane in an interferometric modulator
US7405861B2 (en) * 2004-09-27 2008-07-29 Idc, Llc Method and device for protecting interferometric modulators from electrostatic discharge
US7675669B2 (en) 2004-09-27 2010-03-09 Qualcomm Mems Technologies, Inc. Method and system for driving interferometric modulators
US7626581B2 (en) * 2004-09-27 2009-12-01 Idc, Llc Device and method for display memory using manipulation of mechanical response
US7492502B2 (en) * 2004-09-27 2009-02-17 Idc, Llc Method of fabricating a free-standing microstructure
US7136213B2 (en) * 2004-09-27 2006-11-14 Idc, Llc Interferometric modulators having charge persistence
US7724993B2 (en) 2004-09-27 2010-05-25 Qualcomm Mems Technologies, Inc. MEMS switches with deforming membranes
US7545550B2 (en) * 2004-09-27 2009-06-09 Idc, Llc Systems and methods of actuating MEMS display elements
US7679627B2 (en) * 2004-09-27 2010-03-16 Qualcomm Mems Technologies, Inc. Controller and driver features for bi-stable display
US20060065622A1 (en) * 2004-09-27 2006-03-30 Floyd Philip D Method and system for xenon fluoride etching with enhanced efficiency
US7684104B2 (en) 2004-09-27 2010-03-23 Idc, Llc MEMS using filler material and method
US7532195B2 (en) * 2004-09-27 2009-05-12 Idc, Llc Method and system for reducing power consumption in a display
US20060065366A1 (en) * 2004-09-27 2006-03-30 Cummings William J Portable etch chamber
US20060067650A1 (en) * 2004-09-27 2006-03-30 Clarence Chui Method of making a reflective display device using thin film transistor production techniques
US8310441B2 (en) 2004-09-27 2012-11-13 Qualcomm Mems Technologies, Inc. Method and system for writing data to MEMS display elements
US7161730B2 (en) * 2004-09-27 2007-01-09 Idc, Llc System and method for providing thermal compensation for an interferometric modulator display
US8878825B2 (en) * 2004-09-27 2014-11-04 Qualcomm Mems Technologies, Inc. System and method for providing a variable refresh rate of an interferometric modulator display
US20060066594A1 (en) * 2004-09-27 2006-03-30 Karen Tyger Systems and methods for driving a bi-stable display element
US7310179B2 (en) * 2004-09-27 2007-12-18 Idc, Llc Method and device for selective adjustment of hysteresis window
US7553684B2 (en) * 2004-09-27 2009-06-30 Idc, Llc Method of fabricating interferometric devices using lift-off processing techniques
US20060066932A1 (en) * 2004-09-27 2006-03-30 Clarence Chui Method of selective etching using etch stop layer
US7373026B2 (en) * 2004-09-27 2008-05-13 Idc, Llc MEMS device fabricated on a pre-patterned substrate
US7417783B2 (en) * 2004-09-27 2008-08-26 Idc, Llc Mirror and mirror layer for optical modulator and method
US7843410B2 (en) 2004-09-27 2010-11-30 Qualcomm Mems Technologies, Inc. Method and device for electrically programmable display
US7327510B2 (en) * 2004-09-27 2008-02-05 Idc, Llc Process for modifying offset voltage characteristics of an interferometric modulator
US20060138604A1 (en) * 2004-12-27 2006-06-29 Northrop Grumman Corporation Low charging dielectric for capacitive MEMS devices and method of making same
TW200628877A (en) * 2005-02-04 2006-08-16 Prime View Int Co Ltd Method of manufacturing optical interference type color display
US7948457B2 (en) * 2005-05-05 2011-05-24 Qualcomm Mems Technologies, Inc. Systems and methods of actuating MEMS display elements
US7920136B2 (en) * 2005-05-05 2011-04-05 Qualcomm Mems Technologies, Inc. System and method of driving a MEMS display device
WO2006121784A1 (en) 2005-05-05 2006-11-16 Qualcomm Incorporated, Inc. Dynamic driver ic and display panel configuration
EP2495212A3 (en) 2005-07-22 2012-10-31 QUALCOMM MEMS Technologies, Inc. Mems devices having support structures and methods of fabricating the same
US7355779B2 (en) * 2005-09-02 2008-04-08 Idc, Llc Method and system for driving MEMS display elements
JP4919146B2 (en) * 2005-09-27 2012-04-18 独立行政法人産業技術総合研究所 Switching element
KR20080068821A (en) 2005-09-30 2008-07-24 퀄컴 엠이엠스 테크놀로지스, 인크. Mems device and interconnects for same
US20070126673A1 (en) * 2005-12-07 2007-06-07 Kostadin Djordjev Method and system for writing data to MEMS display elements
US8391630B2 (en) * 2005-12-22 2013-03-05 Qualcomm Mems Technologies, Inc. System and method for power reduction when decompressing video streams for interferometric modulator displays
US7795061B2 (en) 2005-12-29 2010-09-14 Qualcomm Mems Technologies, Inc. Method of creating MEMS device cavities by a non-etching process
US7916980B2 (en) 2006-01-13 2011-03-29 Qualcomm Mems Technologies, Inc. Interconnect structure for MEMS device
US7382515B2 (en) * 2006-01-18 2008-06-03 Qualcomm Mems Technologies, Inc. Silicon-rich silicon nitrides as etch stops in MEMS manufacture
US7652814B2 (en) 2006-01-27 2010-01-26 Qualcomm Mems Technologies, Inc. MEMS device with integrated optical element
US8194056B2 (en) * 2006-02-09 2012-06-05 Qualcomm Mems Technologies Inc. Method and system for writing data to MEMS display elements
US7547568B2 (en) * 2006-02-22 2009-06-16 Qualcomm Mems Technologies, Inc. Electrical conditioning of MEMS device and insulating layer thereof
US20070228156A1 (en) * 2006-03-28 2007-10-04 Household Corporation Interoperability facilitator
US7643203B2 (en) * 2006-04-10 2010-01-05 Qualcomm Mems Technologies, Inc. Interferometric optical display system with broadband characteristics
US7527996B2 (en) * 2006-04-19 2009-05-05 Qualcomm Mems Technologies, Inc. Non-planar surface structures and process for microelectromechanical systems
US7417784B2 (en) * 2006-04-19 2008-08-26 Qualcomm Mems Technologies, Inc. Microelectromechanical device and method utilizing a porous surface
US7711239B2 (en) * 2006-04-19 2010-05-04 Qualcomm Mems Technologies, Inc. Microelectromechanical device and method utilizing nanoparticles
US8049713B2 (en) * 2006-04-24 2011-11-01 Qualcomm Mems Technologies, Inc. Power consumption optimized display update
US7369292B2 (en) * 2006-05-03 2008-05-06 Qualcomm Mems Technologies, Inc. Electrode and interconnect materials for MEMS devices
US7321457B2 (en) * 2006-06-01 2008-01-22 Qualcomm Incorporated Process and structure for fabrication of MEMS device having isolated edge posts
US7702192B2 (en) 2006-06-21 2010-04-20 Qualcomm Mems Technologies, Inc. Systems and methods for driving MEMS display
US7777715B2 (en) 2006-06-29 2010-08-17 Qualcomm Mems Technologies, Inc. Passive circuits for de-multiplexing display inputs
US7763546B2 (en) 2006-08-02 2010-07-27 Qualcomm Mems Technologies, Inc. Methods for reducing surface charges during the manufacture of microelectromechanical systems devices
US7566664B2 (en) * 2006-08-02 2009-07-28 Qualcomm Mems Technologies, Inc. Selective etching of MEMS using gaseous halides and reactive co-etchants
US7706042B2 (en) 2006-12-20 2010-04-27 Qualcomm Mems Technologies, Inc. MEMS device and interconnects for same
US7535621B2 (en) 2006-12-27 2009-05-19 Qualcomm Mems Technologies, Inc. Aluminum fluoride films for microelectromechanical system applications
US7733552B2 (en) 2007-03-21 2010-06-08 Qualcomm Mems Technologies, Inc MEMS cavity-coating layers and methods
US7719752B2 (en) 2007-05-11 2010-05-18 Qualcomm Mems Technologies, Inc. MEMS structures, methods of fabricating MEMS components on separate substrates and assembly of same
US7625825B2 (en) * 2007-06-14 2009-12-01 Qualcomm Mems Technologies, Inc. Method of patterning mechanical layer for MEMS structures
US8068268B2 (en) 2007-07-03 2011-11-29 Qualcomm Mems Technologies, Inc. MEMS devices having improved uniformity and methods for making them
US7570415B2 (en) * 2007-08-07 2009-08-04 Qualcomm Mems Technologies, Inc. MEMS device and interconnects for same
US7729036B2 (en) * 2007-11-12 2010-06-01 Qualcomm Mems Technologies, Inc. Capacitive MEMS device with programmable offset voltage control
US7863079B2 (en) 2008-02-05 2011-01-04 Qualcomm Mems Technologies, Inc. Methods of reducing CD loss in a microelectromechanical device
CA2715283A1 (en) * 2008-02-11 2009-08-20 Qualcomm Mems Technologies, Inc. Method and apparatus for sensing, measurement or characterization of display elements integrated with the display drive scheme, and system and applications using the same
US8248358B2 (en) * 2009-03-27 2012-08-21 Qualcomm Mems Technologies, Inc. Altering frame rates in a MEMS display by selective line skipping
US8736590B2 (en) * 2009-03-27 2014-05-27 Qualcomm Mems Technologies, Inc. Low voltage driver scheme for interferometric modulators
US8054147B2 (en) * 2009-04-01 2011-11-08 General Electric Company High voltage switch and method of making
JP5418317B2 (en) * 2010-03-11 2014-02-19 富士通株式会社 Electrostatic actuator and driving method thereof
US8525185B2 (en) 2010-04-07 2013-09-03 Uchicago Argonne, Llc RF-MEMS capacitive switches with high reliability
US8659816B2 (en) 2011-04-25 2014-02-25 Qualcomm Mems Technologies, Inc. Mechanical layer and methods of making the same
KR20160051280A (en) * 2014-11-03 2016-05-11 삼성전기주식회사 Mems switch and method of manufacturing the same
CN111740187B (en) * 2019-03-25 2021-10-19 华为技术有限公司 Radio frequency switch and antenna

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0709911A2 (en) * 1994-10-31 1996-05-01 Texas Instruments Incorporated Improved switches

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3590792T (en) 1985-05-10 1987-07-16
US4905070A (en) * 1988-09-02 1990-02-27 Motorola, Inc. Semiconductor device exhibiting no degradation of low current gain
US5233459A (en) * 1991-03-06 1993-08-03 Massachusetts Institute Of Technology Electric display device
US5374843A (en) * 1991-05-06 1994-12-20 Silinconix, Inc. Lightly-doped drain MOSFET with improved breakdown characteristics
US5486804A (en) 1993-12-03 1996-01-23 Hughes Aircraft Company Integrated magnetoresistive sensor fabrication method and apparatus
US5771321A (en) * 1996-01-04 1998-06-23 Massachusetts Institute Of Technology Micromechanical optical switch and flat panel display
US5973623A (en) * 1997-10-21 1999-10-26 Stmicroelectronics, Inc. Solid state capacitive switch
US6127908A (en) * 1997-11-17 2000-10-03 Massachusetts Institute Of Technology Microelectro-mechanical system actuator device and reconfigurable circuits utilizing same
US6188301B1 (en) * 1998-11-13 2001-02-13 General Electric Company Switching structure and method of fabrication
US6307452B1 (en) * 1999-09-16 2001-10-23 Motorola, Inc. Folded spring based micro electromechanical (MEM) RF switch

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0709911A2 (en) * 1994-10-31 1996-05-01 Texas Instruments Incorporated Improved switches

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
GOLDSMITH C ET AL: "CHARACTERISTICS OF MICROMACHINED SWITCHES AT MICROWAVE FREQUENCIES", IEEE MTT-S INTERNATIONAL MICROWAVE SYMPOSIUM DIGEST,US,NEW YORK, IEEE, 1996, pages 1141 - 1144, XP000732544, ISBN: 0-7803-3247-4 *

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1308977A2 (en) * 2001-11-06 2003-05-07 Omron Corporation Electrostatic actuator, and electrostatic microrelay and other devices using the same
EP1308977A3 (en) * 2001-11-06 2005-01-19 Omron Corporation Electrostatic actuator, and electrostatic microrelay and other devices using the same
US7161273B2 (en) 2001-11-06 2007-01-09 Omron Corporation Antistatic mechanism of an electrostatic actuator
US7960662B2 (en) 2006-05-31 2011-06-14 Thales Radiofrequency or hyperfrequency micro-switch structure and method for producing one such structure
FR2901781A1 (en) * 2006-05-31 2007-12-07 Thales Sa RADIOFREQUENCY OR HYPERFREQUENCY MICRO-SWITCH STRUCTURE AND METHOD OF MANUFACTURING SUCH STRUCTURE
WO2007138102A1 (en) * 2006-05-31 2007-12-06 Thales Radiofrequency or hyperfrequency micro switch structure and method for producing one such structure
EP1950778A3 (en) * 2007-01-24 2009-03-11 Fujitsu Ltd. Drive control method and unit for micro machine device
US7961448B2 (en) 2007-01-24 2011-06-14 Fujitsu Limited Drive control method and unit for micro machine device
US7903386B2 (en) 2007-03-30 2011-03-08 Fujitsu Limited Apparatus and method for drive controlling micro machine device
WO2010092406A3 (en) * 2009-02-13 2011-05-26 Wolfson Microelectronics Plc Mems device with leakage path
CN102356042A (en) * 2009-02-13 2012-02-15 沃福森微电子股份有限公司 Mems device and process
TWI457270B (en) * 2009-02-13 2014-10-21 Wolfson Microelectronics Plc Mems device and process
EP2495866A1 (en) * 2011-03-04 2012-09-05 Commissariat à l'Énergie Atomique et aux Énergies Alternatives Electrostatic actuator of a mobile structure with improved relief of trapped charges
FR2972315A1 (en) * 2011-03-04 2012-09-07 Commissariat Energie Atomique ELECTROSTATIC ACTUATOR OF A MOBILE STRUCTURE WITH IMPROVED RELAXATION OF TRAPPED LOADS
US8860283B2 (en) 2011-03-04 2014-10-14 Commissariat a l'Energie et aux Energies Alternatives Electrostatic actuator of a mobile structure with improved relaxation of trapped charges

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US20020036304A1 (en) 2002-03-28
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US6391675B1 (en) 2002-05-21

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