MEMS device with over-travel stop structure and method of fabrication

A MEMS device comprises a substrate, a proof mass spaced apart from a surface of the substrate, and an over-travel stop structure. The over-travel stop structure includes a lateral stop structure and a cap coupled to the lateral stop structure. The MEMS device is fabricated to include relatively small gap sections and relatively large gap regions separating the lateral stop structure from the proof mass. The larger gap regions are covered by the cap and the smaller gap sections are exposed from the gap. During fabrication, removal of particles from the smaller gap sections is facilitated by their exposure from the cap and removal of particles from the larger gap regions underlying the cap is facilitated by their larger size. The lateral stop structure may be cross-shaped to limit deflection of the proof mass along two in-plane axes. The cap limits deflection of the proof mass along an out-of-plane axis.

ELECTRICALLY CONDUCTIVE BARRIERS FOR INTEGRATED CIRCUITS

Electrically conductive barriers for integrated circuits and integrated circuits and methods including the electrically conductive barriers. The integrated circuits include a semiconductor substrate, a semiconductor device supported by a device portion of the substrate, and a plurality of bond pads supported by a bond pad portion of the substrate. The integrated circuits also include an electrically conductive barrier that projects away from an intermediate portion of the substrate and is configured to decrease capacitive coupling between the device portion and the bond pad portion. The methods can include methods of manufacturing an integrated circuit. These methods include forming a semiconductor device, forming a plurality of bond pads, forming a plurality of electrically conductive regions, and forming an electrically conductive barrier. The methods also can include methods of operating an integrated circuit. These methods include applying an input electric signal, receiving an output electric signal, and applying a reference potential.

MEMS device with common mode rejection structure

A MEMS device includes a drive spring system coupling a pair of drive masses and a sense spring system coupling a pair of sense masses. The drive spring system includes a constrained stiff beam and flexures interconnecting the pair of drive masses. In response to drive movement of the drive masses the flexures enable pivotal movement of the constrained stiff beam about its center hinge point to enable anti-phase drive motion of the drive masses and to suppress in-phase motion of the drive masses. The sense spring system includes diagonally oriented stiff beams and a spring system that enable anti-phase sense motion of the sense masses while suppressing in-phase motion of the sense masses. Coupling masses interposed between the drive and sense masses decouple the drive motion of the drive masses from the sense motion of the sense masses.

Actively preventing charge induced leakage of semiconductor devices

A structure for preventing charge induced leakage of a semiconductor device includes a shield separated from a first interconnect by at least a first lateral spacing and separated from a second interconnect by at least a second lateral spacing. The first interconnect is connected to a first junction and the second interconnect is connected to a second junction. A shield bias is connected to the shield to terminate an electromagnetic field on the shield. The shield between the first and second lateral spacings has a minimum width to substantially prevent formation of a conductive channel between the first and second junctions. The shield may be formed over a portion of the first junction and over a portion of the second junction to substantially prevent formation of another conductive channel between the first and second junctions at a location that does not have the first and second lateral spacings.

MEMS device having variable gap width and method of manufacture

A MEMS device ( 40 ) includes a base structure ( 42 ) and a microstructure ( 44 ) suspended above the structure ( 42 ). The base structure ( 42 ) includes an oxide layer ( 50 ) formed on a substrate ( 48 ), a structural layer ( 54 ) formed on the oxide layer ( 50 ), and an insulating layer ( 56 ) formed over the structural layer ( 54 ). A sacrificial layer ( 112 ) is formed overlying the base structure ( 42 ), and the microstructure ( 44 ) is formed in another structural layer ( 116 ) over the sacrificial layer ( 112 ). Methodology ( 90 ) entails removing the sacrificial layer ( 112 ) and a portion of the oxide layer ( 50 ) to release the microstructure ( 44 ) and to expose a top surface ( 52 ) of the substrate ( 48 ). Following removal, a width ( 86 ) of a gap ( 80 ) produced between the microstructure ( 44 ) and the top surface ( 52 ) is greater than a width ( 88 ) of a gap ( 84 ) produced between the microstructure ( 44 ) and the structural layer ( 54 ).

System and method for calibrating an inertial sensor

A system ( 40 ) for calibrating an inertial sensor ( 20 ) includes a power source ( 42 ), a frequency measurement subsystem ( 44, 48 ), and a gain determination subsystem ( 52 ). A calibration process ( 110 ) using the system ( 40 ) entails applying ( 116 ) a bias voltage ( 66 ) to the inertial sensor ( 20 ), measuring ( 114 ) a drive resonant frequency ( 46 ), and measuring ( 118 ) a sense resonant frequency ( 50 ) of the inertial sensor ( 20 ) produced in response to the bias voltage ( 66 ). A gain value ( 32 ) is determined ( 124 ) for calibrating ( 144 ) the inertial sensor ( 20 ) using a relationship ( 140 ) between the sense resonant frequency ( 50 ) and the bias voltage ( 66 ) without imposing an inertial stimulus on the inertial sensor ( 20 ).

Multiple axis rate sensor

A microelectromechanical systems (MEMS) device includes at least two rate sensors ( 20, 50 ) suspended above a substrate ( 30 ), and configured to oscillate parallel to a surface ( 40 ) of the substrate ( 30 ). Drive elements ( 156, 158 ) in communication with at least one of the rate sensors ( 20, 50 ) provide a drive signal ( 168 ) exhibiting a drive frequency. One or more coupling spring structures ( 80, 92, 104, 120 ) interconnect the rate sensors ( 20, 50 ). The coupling spring structures enable oscillation of the rate sensors ( 20, 50 ) in a drive direction dictated by the coupling spring structures. The drive direction for the rate sensors ( 20 ) is a rotational drive direction ( 43 ) associated with a first axis ( 28 ), and the drive direction for the rate sensors ( 50 ) is a translational drive direction ( 64 ) associated with a second axis ( 24, 26 ) that is perpendicular to the first axis ( 28 ).

MEMS SENSOR WITH FOLDED TORSION SPRINGS

A microelectromechanical systems (MEMS) sensor () includes a substrate () and a suspension anchor () formed on a planar surface () of the substrate (). A first folded torsion spring () and a second folded torsion spring () interconnect the movable element () with the suspension anchor () to suspend the movable element () above the substrate (). The folded torsion springs () are each formed from multiple segments () that are linked together by bar elements () in a serpentine fashion. The folded torsion springs () have an equivalent shape and are oriented relative to one another in rotational symmetry about a centroid () of the suspension anchor (). 1. A microelectromechanical systems (MEMS) sensor comprising:a substrate;a movable element positioned in spaced apart relationship above a surface of said substrate;a suspension anchor formed on said surface of said substrate;a first folded torsion spring interconnecting said movable element with said suspension anchor; anda second folded torsion spring interconnecting said movable element with said suspension anchor, said first and second folded torsion springs having a substantially equivalent shape, and said second folded torsion spring being generally oriented in rotational symmetry relative to said first folded torsion spring about a centroid of said suspension anchor.2. A MEMS sensor as claimed in wherein said second folded torsion spring is located in an orientation that is rotated about said centroid of said suspension anchor approximately one hundred and eighty degrees relative to said first folded torsion spring.3. A MEMS sensor as claimed in wherein:said movable element is adapted for motion relative to a rotational axis positioned between first and second ends of said movable element;said centroid of suspension anchor is located at said rotational axis;said first folded torsion spring has a first end coupled to said suspension anchor; andsaid second folded torsion spring has a second end coupled to said ...

MEMS SENSOR WITH DUAL PROOF MASSES

A microelectromechanical systems (MEMS) sensor () includes a substrate () and suspension anchors () formed on a planar surface () of the substrate (). The MEMS sensor () further includes a first movable element () and a second movable element () suspended above the substrate (). Compliant members () interconnect the first movable element () with the suspension anchor and compliant members () interconnect the second movable element () with the suspension anchor (). The movable elements () have an equivalent shape. The movable elements may be generally rectangular movable elements () or L-shaped movable elements () in a nested configuration. The movable elements () are oriented relative to one another in rotational symmetry about a point location () on the substrate (). 1. A microelectromechanical systems (MEMS) sensor comprising:a substrate;a first movable element positioned in spaced apart relationship above a generally planar surface of said substrate; anda second movable element positioned in spaced apart relationship above said surface of said substrate, said first and second movable elements having a substantially equivalent shape and said second movable element being generally oriented in rotational symmetry relative to said first movable element about a point location on said planar surface of said substrate.2. A MEMS sensor as claimed in wherein said second movable element is located in an orientation that is rotated about said point location approximately one hundred and eighty degrees relative to said first movable element.3. A MEMS sensor as claimed in wherein:said first movable element is adapted for rotational motion in a first direction in response to acceleration along an axis perpendicular to said planar surface of said substrate, said rotational motion occurring about a first rotational axis positioned between first and second ends of said first movable element; andsaid second movable element is adapted for rotational motion in a second direction in ...

MEMS DEVICE WITH CENTRAL ANCHOR FOR STRESS ISOLATION

A MEMS device () includes a proof mass () coupled to and surrounding an immovable structure (). The immovable structure () includes fixed fingers () extending outwardly from a body () of the structure (). The proof mass () includes movable fingers (), each of which is disposed between a pair () of the fixed fingers (). A central area () of the body () is coupled to an underlying substrate (), with the remainder of the immovable structure () and the proof mass () being suspended above the substrate () to largely isolate the MEMS device () from package stress, Additionally, the MEMS device () includes isolation trenches () and interconnects () so that the fixed fingers (), the fixed fingers (), and the movable fingers () are electrically isolated from one another to yield a differential device configuration. 1. A microelectromechanical systems (MEMS) device comprising:a substrate;a first structure including a body and fixed fingers extending outwardly from an outer periphery of said body, wherein a central area of said body is coupled to said substrate and a remainder of said first structure is suspended over said substrate;a frame structure surrounding said first structure and suspended over said substrate, said frame structure being movably coupled to said first structure, said frame structure including a movable finger extending inwardly from an inner periphery of said frame structure, said movable finger being disposed between a pair of said fixed fingers;an anchor element extending through said body of said first structure and coupled to said substrate; anda signal trace electrically connecting said frame structure to said anchor element, and said frame structure, said signal trace, and said anchor element being electrically isolated from said first structure.2. A MEMS device as claimed in wherein said pair of fixed fingers includes a first fixed finger and a second fixed finger claim 1 , and said MEMS device further comprises at least one isolation trench ...

ANGULAR RATE SENSOR WITH DIFFERENT GAP SIZES

An angular rate sensor () includes conductive plates () mounted on a substrate (), and a structure () coupled to the substrate (). The structure () includes a drive mass () and a sense mass () suspended above the plates (). The sense mass () includes regions () separated by a sense axis of rotation (). Each of the regions () has an outer surface () and an inner surface (). An inner gap () exists between the inner surface () and plates (). An outer gap () exists between the outer surface () and the plate (). The outer gap () is larger than the inner gap (). Plates () may be electrodes for force feedback, frequency tuning, and/or quadrature compensation. Plates () may be electrodes for sensing angular velocity. 1. An angular rate sensor comprising:a substrate having a surface;conductive plates fixedly mounted on said surface, said conductive plates including a first electrode and a second electrode;a drive mass flexibly coupled to said substrate surface, said drive mass being configured to move with an oscillatory motion;a sense mass having first and second regions separated by an axis of rotation, wherein a first gap exists between a first portion of said sense mass and said first electrode, and a second gap exists between a second portion of said sense mass and said second electrode, said second gap being larger than said first gap; andflexible support elements connecting said sense mass to said drive mass.2. An angular rate sensor as claimed in wherein each of said first and second regions includes a first surface and a second surface laterally displaced from said axis of rotation such that said first surface is interposed between said axis of rotation and said second surface claim 1 , said first surface having a corrugation formed thereon claim 1 , said first gap existing between said corrugation and said first electrode claim 1 , and said second gap existing between said second surface and said second electrode.3. An angular rate sensor as claimed in wherein said ...

Inertial sensor with off-axis spring system

An inertial sensor ( 20 ) includes a drive mass ( 30 ) configured to undergo oscillatory motion and a sense mass ( 32 ) linked to the drive mass ( 30 ). On-axis torsion springs ( 58 ) are coupled to the sense mass ( 32 ), the on-axis torsion springs ( 58 ) being co-located with an axis of rotation ( 22 ). The inertial sensor ( 20 ) further includes an off-axis spring system ( 60 ). The off-axis spring system ( 60 ) includes off-axis springs ( 68, 70, 72, 74 ), each having a connection interface ( 76 ) coupled to the sense mass ( 32 ) at a location on the sense mass ( 32 ) that is displaced away from the axis of rotation ( 22 ). Together, the on-axis torsion springs ( 58 ) and the off-axis spring system ( 60 ) enable the sense mass ( 32 ) to oscillate out of plane about the axis of rotation ( 22 ) at a sense frequency that substantially matches a drive frequency of the drive mass ( 30 ).

MEMS SENSOR WITH STRESS ISOLATION AND METHOD OF FABRICATION

A MEMS sensor () includes a support structure () suspended above a surface () of a substrate () and connected to the substrate () via spring elements (). A proof mass () is suspended above the substrate () and is connected to the support structure () via torsional elements (). Electrodes (), spaced apart from the proof mass (), are connected to the support structure () and are suspended above the substrate (). Suspension of the electrodes () and proof mass () above the surface () of the substrate () via the support structure () substantially physically isolates the elements from deformation of the underlying substrate (). Additionally, connection via the spring elements () result in the MEMS sensor () being less susceptible to movement of the support structure () due to this deformation. 1. A micro electromechanical systems (MEMS) sensor comprising:a substrate;a support structure suspended above a surface of said substrate and connected to said substrate via a support element;a proof mass suspended above said substrate and flexibly connected to said support structure via a flexible support element, said proof mass being adapted for motion about an axis between first and second ends of said proof mass; andan electrode suspended above said substrate and connected to said support structure, said electrode being spaced apart from said proof mass.2. A MEMS sensor as claimed in wherein said support structure comprises at least one isolation joint claim 1 , said at least one isolation joint electrically isolating said electrode from said proof mass.3. A MEMS sensor as claimed in wherein:said electrode is a first electrode;said proof mass includes a first section formed between said axis and said first end and a second section formed between said axis and said second end, said first electrode being spaced apart from said first section of said proof mass; andsaid MEMS sensor further comprises a second electrode suspended above said substrate and connected to said support ...

PRESSURE SENSOR WITH DIFFERENTIAL CAPACITIVE OUTPUT

A MEMS pressure sensor device is provided that can provide both a linear output with regard to external pressure, and a differential capacitance output so as to improve the signal amplitude level. These benefits are provided through use of a rotating proof mass that generates capacitive output from electrodes configured at both ends of the rotating proof mass. Sensor output can then be generated using a difference between the capacitances generated from the ends of the rotating proof mass. An additional benefit of such a configuration is that the differential capacitance output changes in a more linear fashion with respect to external pressure changes than does a capacitive output from traditional MEMS pressure sensors. 1. A micro-electromechanical system (MEMS) pressure sensor comprising: a moveable element adapted for motion relative to a rotational axis offset between first and second ends thereof to form a first section between the rotational axis and the first end and a second section between the rotational axis and the second end,', 'the first section comprising an extended portion spaced away from the rotational axis, and', 'the second section comprising an extended portion spaced away from the rotational axis at a length approximately equal to a length of the extended portion of the first section, such that the rotational axis is at a center of mass of the moveable element;, 'a rotating proof mass, wherein the rotating proof mass comprises'}a diaphragm configured to deform in response to a first fluid pressure external to a package comprising the diaphragm and the rotating proof mass; and 'the rotating proof mass is configured to rotate in response to deformation of the diaphragm.', 'a linkage configured to couple a surface of the diaphragm internal to the package to a point along the first section of the rotating proof mass, wherein'}2. The MEMS pressure sensor of wherein the second section of the moveable element further comprises:a counterweight ...

METHOD AND SYSTEM FOR CALIBRATING AN INERTIAL SENSOR

A calibration system () configured for communication with an inertial sensor () includes a signal generator () and processing system (). A calibration process () performed using the calibration system () includes applying () an electrical stimulus () to the inertial sensor (), receiving an output signal () from the sensor () produced in response to the electrical stimulus () and determining a sensitivity () of the inertial sensor () to the electrical stimulus () in response to the output signal () and an applied voltage of the electrical stimulus (). A sensitivity () of the inertial sensor () to an inertial stimulus is calculated using the sensitivity () and a measured resonant sensitivity () of the inertial sensor (), and the calculated sensitivity () is utilized to adjust a gain value () for the inertial sensor () to calibrate the sensor (). 1. A method for calibrating an inertial sensor comprising:applying an electrical stimulus to said inertial sensor;receiving an output signal from said inertial sensor produced in response to said electrical stimulus;determining a first sensitivity of said inertial sensor in response to said received output signal and an applied voltage of said electrical stimulus;calculating a second sensitivity for said inertial sensor using said first sensitivity and a resonant frequency of said inertial sensor; andutilizing said second sensitivity to adjust a gain value for said inertial sensor to calibrate said inertial sensor.2. A method as claimed in wherein said inertial sensor includes an acceleration sensor having a sense mass that is movable in response to acceleration of said acceleration sensor along a sense axis claim 1 , said sense axis being approximately parallel to a lateral plane of said acceleration sensor claim 1 , and said applying operation applies said electrical stimulus between said sense mass and a fixed sense electrode to generate an electrostatic force that moves said sense mass along said sense axis to simulate ...

MEMS SENSOR DEVICES HAVING A SELF-TEST MODE

A micro-electro-mechanical system (MEMS) device comprises a micro-electro-mechanical system (MEMS) sensor; a detector circuit; a controller circuit coupled with the MEMS sensor; a first connection arranged between a first output of the MEMS sensor and a first input of the detector circuit; a second connection arranged between a second output of the MEMS sensor and a second input of the detector circuit; and a first switch arranged in the first connection. The controller circuit is configured to open the first switch during a first test mode so as to connect only a single input of the detector circuit with an output of the MEMS sensor. A further switch may be provided to connect two outputs of the MEMS sensor to a single input of the detector circuit. 1. A micro-electro-mechanical system (MEMS) device comprisinga MEMS sensor;a detector circuit;a controller circuit coupled with the MEMS sensor;a first connection coupled to a first output of the MEMS sensor and a first input of the detector circuit;a second connection coupled to a second output of the MEMS sensor and a second input of the detector circuit; anda first switch arranged in the first connection, and configured to be controlled by the controller circuit,wherein the controller circuit is configured to open the first switch during a first test mode so as to connect only a single input of the detector circuit with an output of the MEMS sensor.4. The MEMS device according to claim 1 , further comprisinga third connection between the first output of the MEMS device and the second input of the detector circuit; anda third switch arranged in the third connection, and configured to be controlled by the controller circuit,wherein the controller circuit is configured to close the third switch during the first test mode so as to connect only a single input of the detector circuit with both outputs of the MEMS sensor.5. The MEMS device according to claim 4 , further comprisinga fourth connection between the second ...

INERTIAL SENSOR WITH SPLIT ANCHORS AND FLEXURE COMPLIANCE BETWEEN THE ANCHORS

An inertial sensor includes a movable mass, a torsion element, and a suspension system suspending the movable mass apart from a surface of a substrate. The torsion element is coupled to the movable mass for enabling motion of the movable mass about an axis of rotation in response to a force imposed upon the movable mass in a direction perpendicular to the surface of the substrate. The suspension system includes first and second anchors attached to the substrate and displaced away from the axis of rotation, a beam connected to the movable mass via the torsion element, a first folded spring coupled between the first anchor and a first beam end of the beam, and a second folded spring coupled between the second anchor and a second beam end of the beam. 1. An inertial sensor comprising:a movable mass spaced apart from a surface of a substrate;a torsion element coupled to the movable mass and configured to enable motion of the movable mass about an axis of rotation in response to a force imposed upon the movable mass in a direction that is perpendicular to the surface of the substrate; and{'claim-text': ['a first anchor attached to the substrate;', 'a first folded spring having first and second spring ends, the first spring end being coupled to the first anchor;', 'a second anchor attached to the substrate, each of the first and second anchors being displaced away from the axis of rotation;', 'a second folded spring having third and fourth spring ends, the third spring end being coupled to the second anchor;', 'a beam connected to the movable mass via the torsion element, the beam having first and second beam ends, the first beam end being coupled to the second spring end of the first folded spring, and the second beam end being coupled to the fourth spring end of the second folded spring; and', 'a coupler positioned at and aligned with the axis of rotation, wherein a midpoint of the beam between the first and second beam ends is connected to the coupler, and the torsion ...

MICROELECTROMECHANICAL SYSTEM DEVICES HAVING CRACK RESISTANT MEMBRANE STRUCTURES AND METHODS FOR THE FABRICATION THEREOF

Methods for fabricating crack resistant Microelectromechanical (MEMS) devices are provided, as are MEMS devices produced pursuant to such methods. In one embodiment, the method includes forming a sacrificial body over a substrate, producing a multi-layer membrane structure on the substrate, and removing at least a portion of the sacrificial body to form an inner cavity within the multi-layer membrane structure. The multi-layer membrane structure is produced by first forming a base membrane layer over and around the sacrificial body such that the base membrane layer has a non-planar upper surface. A predetermined thickness of the base membrane layer is then removed to impart the base membrane layer with a planar upper surface. A cap membrane layer is formed over the planar upper surface of the base membrane layer. The cap membrane layer is composed of a material having a substantially parallel grain orientation. 1. A Microelectromechanical Systems (MEMS) device , comprising:a substrate; a base membrane layer; and', 'a cap membrane layer formed over the base membrane layer and having outer edge regions, the cap membrane layer comprising a material having a substantially parallel grain orientation at the outer edge regions of the cap membrane layer; and, 'a multi-layer membrane structure formed on the substrate, the multi-layer membrane structure comprisinga cavity at least partially enclosed by the multi-layer membrane structure.2. The MEMS device of wherein the cap membrane layer and the base membrane layer each comprise polycrystalline silicon.3. The MEMS device of wherein a height of the multi-layer membrane structure is less than or equal to a width and a length thereof4. The MEMS device of wherein the multi-layer membrane structure comprises claim 1 , in cross-section claim 1 , opposing anchor regions and a flexible diaphragm region extending between the opposing anchor regions.5. The MEMS device of further comprising an electrode positioned beneath the flexible ...

Redundant sensor system with self-test of electromechanical structures

A sensor system includes first and second MEMS structures and a processing circuit. The first and second MEMS structures are configured to produce first and second output signals, respectively, in response to a physical stimulus. A method performed by the processing circuit entails receiving the first and second output signals and detecting a defective one of the first and second MEMS structures from the first and second output signals by determining that the first and second output signals are uncorrelated to one another. The method further entails utilizing only the first or the second output signal from a non-defective one of the MEMS structures to produce a processed output signal when one of the MEMS structures is determined to be defective and utilizing the first and second output signals from both of the MEMS structures to produce the processed output signal when neither of the MEMS structures is defective.

INERTIAL SENSOR SAMPLING WITH COMBINED SENSE AXES

A sensor system includes a transducer for sensing a physical stimulus along at least two orthogonal axes and an excitation circuit. The transducer includes a movable mass configured to react to the physical stimulus and multiple differential electrode pairs of electrodes. Each of the electrode pairs is configured to detect displacement of the movable mass along one of the orthogonal axes. The excitation circuit is connectable to the electrodes in various electrode connection configurations, with different polarity schemes, that enable excitation and sampling of each of the orthogonal axes during every sensing period. For each sensing period, a composite output signal is produced that includes the combined information sensed along each of the orthogonal axes. The individual sense signals for each orthogonal axis may be extracted from the composite output signals. 1. A sensor system comprising: a movable mass configured to react to the physical stimulus;', 'first and second electrodes that are immovable relative to the movable mass, the first and second electrodes being configured as a first differential electrode pair for detecting a first displacement of the movable mass along the first axis in response to the physical stimulus; and', 'third and fourth electrodes that are immovable relative to the movable mass, the third and fourth electrodes being configured as a second differential electrode pair for detecting a second displacement of the movable mass along the second axis in response to the physical stimulus; and, 'a transducer configured to sense a physical stimulus along a first axis and a second axis, the second axis being orthogonal to the first axis, the transducer including;'} during a first sensing period, a first terminal of the excitation circuit is coupled to the first and third electrodes and a second terminal of the excitation circuit is coupled to the second and fourth electrodes in a first connection configuration; and', 'during a second sensing ...

REDUNDANT SENSOR SYSTEM WITH SELF-TEST OF ELECTROMECHANICAL STRUCTURES

A sensor system includes first and second MEMS structures and a processing circuit. The first and second MEMS structures are configured to produce first and second output signals, respectively, in response to a physical stimulus. A method performed by the processing circuit entails receiving the first and second output signals and detecting a defective one of the first and second MEMS structures from the first and second output signals by determining that the first and second output signals are uncorrelated to one another. The method further entails utilizing only the first or the second output signal from a non-defective one of the MEMS structures to produce a processed output signal when one of the MEMS structures is determined to be defective and utilizing the first and second output signals from both of the MEMS structures to produce the processed output signal when neither of the MEMS structures is defective. 1. A method of testing first and second microelectromechanical systems (MEMS) structures in a MEMS sensor system , the first MEMS structure being configured to produce a first output signal in response to a first physical stimulus , and the second MEMS structure being configured to produce a second output signal in response to a second physical stimulus , the method comprising:receiving the first and second output signals at a processing circuit; anddetecting defective one of the first and second MEMS structures from the first and second output signals by determining that the first and second output signals are uncorrelated to one another.2. The method of claim 1 , further comprising utilizing only the first output signal or the second output signal from a non-defective one of the first and second MEMS structures to produce a processed output signal when the detecting operation detects the defective one of the first and second MEMS structures.3. The method of claim 2 , further comprising increasing a voltage gain of the first output signal or the second ...

MICROELECTROMECHANICAL SYSTEM DEVICES HAVING CRACK RESISTANT MEMBRANE STRUCTURES AND METHODS FOR THE FABRICATION THEREOF

Methods for fabricating crack resistant Microelectromechanical (MEMS) devices are provided, as are MEMS devices produced pursuant to such methods. In one embodiment, the method includes forming a sacrificial body over a substrate, producing a multi-layer membrane structure on the substrate, and removing at least a portion of the sacrificial body to form an inner cavity within the multi-layer membrane structure. The multi-layer membrane structure is produced by first forming a base membrane layer over and around the sacrificial body such that the base membrane layer has a non-planar upper surface. A predetermined thickness of the base membrane layer is then removed to impart the base membrane layer with a planar upper surface. A cap membrane layer is formed over the planar upper surface of the base membrane layer. The cap membrane layer is composed of a material having a substantially parallel grain orientation. 1. A method for fabricating a Microelectromechanical (MEMS) device , the method comprising:forming a sacrificial body over a substrate; forming a base membrane layer over and around the sacrificial body such that the base membrane layer has a non-planar upper surface;', 'removing a predetermined thickness of material from a top of the base membrane layer to impart the base membrane layer with a planar upper surface; and', 'forming a cap membrane layer over the planar upper surface of the base membrane layer, the cap membrane layer comprising polycrystalline silicon having a substantially parallel grain orientation at the interface between the cap membrane layer and the base membrane layer; and, 'producing a multi-layer membrane structure on the substrate, wherein producing comprisingremoving at least a portion of the sacrificial body to form an inner cavity within the multi-layer membrane structure.2. The method of wherein the base membrane layer is formed by depositing polycrystalline silicon over and around the sacrificial body.3. The method of wherein an ...

Stiction resistant mems device and method of operation

A MEMS device ( 20 ) includes a movable element ( 20 ) suspended above a substrate ( 22 ) by a spring member ( 34 ) having a spring constant ( 104 ). A spring softening voltage ( 58 ) is applied to electrodes ( 24, 26 ) facing the movable element ( 20 ) during a powered mode ( 100 ) to decrease the stiffness of the spring member ( 34 ) and thereby increase the sensitivity of the movable element ( 32 ) to an input stimulus ( 46 ). Upon detection of a stiction condition ( 112 ), the spring softening voltage ( 58 ) is effectively removed to enable recovery of the movable element ( 32 ) from the stiction condition ( 112 ). A higher mechanical spring constant ( 104 ) yields a stiffer spring ( 34 ) having a larger restoring force ( 122 ) in the unpowered mode ( 96 ) in order to enable recovery from the stiction condition ( 112 ). A feedback voltage ( 56 ) can be applied to feedback electrodes ( 28, 30 ) facing the movable element ( 32 ) to provide electrical damping.

Inertial sensor with suspension spring structure surrounding anchor

An inertial sensor includes a substrate, a movable element having an edge, and a suspension system retaining the movable element in spaced apart relationship above a surface of the substrate. The suspension system includes an anchor attached to the surface of the substrate, the anchor having a first side laterally spaced apart from the edge of the movable element, and a spring structure having a first attach point coupled to the first side of the anchor and a second attach point coupled to the edge of the movable element. The spring structure includes beam sections serially adjoining one another, the beam sections extending from the first side of the anchor and surrounding the anchor to couple to the edge of the movable element. The spring structure makes no more than one coil around the anchor to position the first attach point in proximity to the second attach point.

SPRING SYSTEM FOR MEMS DEVICE

A spring system () links a pair of drive masses () of a MEMS device (). The spring system () includes stiff beams () oriented to form a parallelogram arrangement (). The beams are oriented diagonal to a drive direction () of the masses (). Diagonally opposing corners () of the parallelogram arrangement () are coupled to the drive masses (). A spring () is coupled to a corner () and a spring () is coupled to a diagonally opposing corner () of the parallelogram arrangement. The springs () are interconnected with a sense frame () surrounding the drive masses. The beams and side springs are stiff to substantially prevent in-phase motion () of the drive masses. However, rotationally compliant flexures (), allow the arrangement () to collapse and expand to enable anti-phase motion () of the drive masses. 1. A microelectromechanical systems (MEMS) device comprising:a first movable mass;a second movable mass; and a set of stiff beams oriented relative to one another to form a parallelogram arrangement, said beams being oriented diagonal to a drive direction of said first and second movable masses, wherein a first corner of said parallelogram arrangement is configured to couple to said first movable mass and a second corner of said parallelogram arrangement is configured to couple to said second movable mass, said second corner being diagonally opposite said first corner;', 'a first side spring coupled to a third corner of said parallelogram arrangement; and', 'a second side spring coupled to a fourth corner of said parallelogram arrangement, said fourth corner being diagonally opposite said third corner., 'a spring system for coupling said first movable mass to said second movable mass, said spring system comprising2. A MEMS device as claimed in wherein said spring system further comprises:a first flexure arrangement interconnecting a first beam and a second beam of said parallelogram arrangement at said first corner;a second flexure arrangement interconnecting a third beam ...

PRESSURE SENSOR WITH DIFFERENTIAL CAPACITIVE OUTPUT

A MEMS pressure sensor device is provided that can provide both a linear output with regard to external pressure, and a differential capacitance output so as to improve the signal amplitude level. These benefits are provided through use of a rotating proof mass that generates capacitive output from electrodes configured at both ends of the rotating proof mass. Sensor output can then be generated using a difference between the capacitances generated from the ends of the rotating proof mass. An additional benefit of such a configuration is that the differential capacitance output changes in a more linear fashion with respect to external pressure changes than does a capacitive output from traditional MEMS pressure sensors. 115-. (canceled)16. A micro electro-mechanical system (MEMS) pressure sensor comprising: a moveable element adapted for motion relative to first and second rotational axes offset between first and second ends and from the other rotational axis,', 'a first section of the moveable element is formed between the first rotational axis and the first end and comprises an extended portion spaced away from the first rotational axis and the second rotational axis,', 'a second section of the moveable element is formed between the second rotational axis and the second end and comprises an extended portion spaced away from the second rotational axis and the first rotational axis,', 'a length of the extended portion of the second section is approximately equal to a length of the extended portion of the first section, and', 'a third section is formed between the first rotational axis and the second rotational axis;, 'a rotating proof mass, wherein the rotating proof mass comprises'}a first diaphragm configured to deform in response to a first fluid pressure external to a package comprising the first diaphragm and the rotating proof mass;a second diaphragm configured to deform in response to a second fluid pressure external to the package;a first linkage configured ...

MULTIPLE AXIS RATE SENSOR

A microelectromechanical systems (MEMS) device includes at least two rate sensors () suspended above a substrate (), and configured to oscillate parallel to a surface () of the substrate (). Drive elements () in communication with at least one of the rate sensors () provide a drive signal () exhibiting a drive frequency. One or more coupling spring structures () interconnect the rate sensors (). The coupling spring structures enable oscillation of the rate sensors () in a drive direction dictated by the coupling spring structures. The drive direction for the rate sensors () is a rotational drive direction () associated with a first axis (), and the drive direction for the rate sensors () is a translational drive direction () associated with a second axis () that is perpendicular to the first axis (). 1. A microelectromechanical systems (MEMS) device comprising:a first rate sensor;a second rate sensor, said first and second rate sensors being configured to oscillate parallel to a planar surface;drive elements in communication with at least one of said first and second rate sensors for providing a drive signal exhibiting a drive frequency; anda first coupling spring structure interconnecting said first and second rate sensors, said first coupling spring structure enabling oscillation of said first and second rate sensors at said drive frequency in a drive direction dictated by said coupling spring structure, wherein said drive direction for said first rate sensor is a first drive direction associated with a first axis and said drive direction for said second rate sensor is a second drive direction associated with a second axis, said second axis being perpendicular to said first axis.2. A MEMS device as claimed in wherein each of said first and second rate sensors comprises:a drive frame having a central opening; anda sense mass positioned in said central opening and flexibly coupled to said drive frame, wherein said first coupling spring structure is interconnected ...

MEMS DEVICE HAVING VARIABLE GAP WIDTH AND METHOD OF MANUFACTURE

A MEMS device () includes a base structure () and a microstructure () suspended above the structure (). The base structure () includes an oxide layer () formed on a substrate (), a structural layer () formed on the oxide layer (), and an insulating layer () formed over the structural layer (). A sacrificial layer () is formed overlying the base structure (), and the microstructure () is formed in another structural layer () over the sacrificial layer (). Methodology () entails removing the sacrificial layer () and a portion of the oxide layer () to release the microstructure () and to expose a top surface () of the substrate (). Following removal, a width () of a gap () produced between the microstructure () and the top surface () is greater than a width () of a gap () produced between the microstructure () and the structural layer (). 1. A microelectromechanical systems (MEMS) device comprising:a base structure including a substrate having a first dielectric layer formed thereon, a first structural layer formed on said first dielectric layer, and a second dielectric layer formed over said first structural layer, wherein an exposed region of a top surface of said substrate is exposed from each of said first dielectric layer, said first structural layer, and said second dielectric layer; anda proof mass suspended above said base structure to yield a first gap between said proof mass and said exposed region of said top surface of said substrate and a second gap between said proof mass and said first structural layer, a first width of said first gap being greater than a second width of said second gap.2. The MEMS device of wherein said exposed region is located at a non-sensing region for said MEMS device.3. The MEMS device of wherein said proof mass is adapted for motion relative to an axis of rotation offset between first and second ends thereof to form a first section between said axis of rotation and said first end and a second section between said axis of rotation ...

System and method for calibrating an inertial sensor

A system ( 40 ) for calibrating an inertial sensor ( 20 ) includes a power source ( 42 ), a frequency measurement subsystem ( 44, 48 ), and a gain determination subsystem ( 52 ). A calibration process ( 110 ) using the system ( 40 ) entails applying ( 116 ) a bias voltage ( 66 ) to the inertial sensor ( 20 ), measuring ( 114 ) a drive resonant frequency ( 46 ), and measuring ( 118 ) a sense resonant frequency ( 50 ) of the inertial sensor ( 20 ) produced in response to the bias voltage ( 66 ). A gain value ( 32 ) is determined ( 124 ) for calibrating ( 144 ) the inertial sensor ( 20 ) using a relationship ( 140 ) between the sense resonant frequency ( 50 ) and the bias voltage ( 66 ) without imposing an inertial stimulus on the inertial sensor ( 20 ).

Single axis inertial sensor with suppressed parasitic modes

A single axis inertial sensor includes a proof mass spaced apart from a surface of a substrate. The proof mass has first, second, third, and fourth sections. The third section diagonally opposes the first section relative to a center point of the proof mass and the fourth section diagonally opposes the second section relative to the center point. A first mass of the first and third sections is greater than a second mass of the second and fourth sections. A first lever structure is connected to the first and second sections, a second lever structure is connected to the second and third sections, a third lever structure is connected to the third and fourth sections, and a fourth lever structure is connected to the fourth and first sections. The lever structures enable translational motion of the proof mass in response to Z-axis linear acceleration forces imposed on the sensor.

Mems device with over-travel stop structure and method of fabrication

A MEMS device comprises a substrate, a proof mass spaced apart from a surface of the substrate, and an over-travel stop structure. The over-travel stop structure includes a lateral stop structure and a cap coupled to the lateral stop structure. The MEMS device is fabricated to include relatively small gap sections and relatively large gap regions separating the lateral stop structure from the proof mass. The larger gap regions are covered by the cap and the smaller gap sections are exposed from the gap. During fabrication, removal of particles from the smaller gap sections is facilitated by their exposure from the cap and removal of particles from the larger gap regions underlying the cap is facilitated by their larger size. The lateral stop structure may be cross-shaped to limit deflection of the proof mass along two in-plane axes. The cap limits deflection of the proof mass along an out-of-plane axis.

Inertial sensor with trim capacitance and method of trimming offset

An inertial sensor ( 20 ) includes a movable element ( 24 ) coupled to a substrate ( 28 ) and adapted for motion about a rotational axis ( 34 ). The sensor ( 20 ) further includes a trim elements ( 36, 38 ). The trim elements ( 36, 38 ) are spaced away from a surface ( 26 ) of the substrate ( 28 ) and are symmetrically positioned on opposing sides of the rotational axis ( 34 ). The trim elements ( 36, 38 ) are largely insensitive to acceleration about the rotational axis ( 34 ), but are sensitive to asymmetrical bending of the substrate ( 28 ). Trim signals ( 72, 74 ) are received via the trim elements ( 36, 38 ) and sense signals ( 68, 70 ) are received via sense elements ( 50, 52 ). The trim signals ( 72, 74 ) are applied to the sense signals ( 68, 70 ) to trim an offset error in an output signal of the inertial sensor ( 20 ) to produce a compensated sense signal ( 144 ).

Sensor with combined sense elements for multiple axis sensing

A MEMS sensor includes a movable element spaced apart from a surface of a substrate and fixed sense elements attached to the substrate, where all of the fixed sense elements are oriented parallel to one another. The movable element includes movable sense elements adjacent to the fixed sense elements. The movable element is adapted to undergo motion in response to mutually orthogonal forces, each of the forces being substantially parallel to the surface of the substrate. The fixed sense elements detect the motion of the movable element, and differential logic is applied to determine the magnitudes of the mutually orthogonal forces.

MICROELECTROMECHANICAL SYSTEM DEVICES HAVING CRACK RESISTANT MEMBRANE STRUCTURES AND METHODS FOR THE FABRICATION THEREOF

Methods for fabricating crack resistant Microelectromechanical (MEMS) devices are provided, as are MEMS devices produced pursuant to such methods. In one embodiment, the method includes forming a sacrificial body over a substrate, producing a multi-layer membrane structure on the substrate, and removing at least a portion of the sacrificial body to form an inner cavity within the multi-layer membrane structure. The multi-layer membrane structure is produced by first forming a base membrane layer over and around the sacrificial body such that the base membrane layer has a non-planar upper surface. A predetermined thickness of the base membrane layer is then removed to impart the base membrane layer with a planar upper surface. A cap membrane layer is formed over the planar upper surface of the base membrane layer. The cap membrane layer is composed of a material having a substantially parallel grain orientation. 1. A Microelectromechanical Systems (MEMS) device , comprising:a substrate; a base membrane layer; and', 'a cap membrane layer formed over the base membrane layer and having outer edge regions, the cap membrane layer comprising a material having a substantially parallel grain orientation at the outer edge regions of the cap membrane layer; and, 'a multi-layer membrane structure formed on the substrate, the multi-layer membrane structure comprisinga cavity at least partially enclosed by the multi-layer membrane structure.2. The MEMS device of wherein the cap membrane layer and the base membrane layer each comprise polycrystalline silicon.3. The MEMS device of wherein a height of the multi-layer membrane structure is less than or equal to a width and a length thereof4. The MEMS device of wherein the multi-layer membrane structure comprises claim 1 , in cross-section claim 1 , opposing anchor regions and a flexible diaphragm region extending between the opposing anchor regions.5. The MEMS device of further comprising an electrode positioned beneath the flexible ...

Inertial sensor with single proof mass and multiple sense axis capabiliity

An inertial sensor includes a movable element having a mass that is asymmetric relative to a rotational axis and anchors attached to the substrate. First and second spring systems are spaced apart from the surface of the substrate. Each of the first and second spring systems includes a pair of beams, a center flexure interposed between the beams, and a pair of end flexures. One of the end flexures is interconnected between one of the beams and one of the anchors and the other end flexure is interconnected between one of the beams and the movable element. The beams are resistant to deformation relative to the center flexure and the end flexures. The first and second spring systems facilitate rotational motion of the movable element about the rotational axis and the spring systems facilitate translational motion of the movable element substantially parallel to the surface of the substrate.

FLEXURE WITH ENHANCED TORSIONAL STIFFNESS AND MEMS DEVICE INCORPORATING SAME

A flexure for a MEMS device includes an elongated beam and a protrusion element extending outwardly from a sidewall of the elongated beam. A MEMS inertial sensor includes a movable element spaced apart from a surface of a substrate, an anchor attached to the substrate, and a spring system. The spring system includes first and second beams, a center flexure between the first and second beams, a first end flexure interconnected between an end of the first beam and the anchor, and a second end flexure interconnected between an end of the second beam and the movable element. Each of the end flexures includes the elongated beam having first and second ends, and the sidewall defining a longitudinal dimension of the elongated beam, and the protrusion element extending from the sidewall of the elongated beam, the protrusion element being displaced away from the first and second ends of the beam. 1. A microelectromechanical systems (MEMS) device comprising: an elongated beam having a sidewall defining a longitudinal dimension of the elongated beam; and', 'a protrusion element extending outwardly from the sidewall of the elongated beam., 'a flexure spaced apart from a surface of a substrate, the flexure including2. The MEMS device of wherein the protrusion element is a cantilevered arrangement extending from the sidewall of the elongated beam substantially parallel to the surface of the substrate.3. The MEMS device of wherein each of the elongated beam and the protrusion element exhibit a thickness that is perpendicular to the surface of the substrate.4. The MEMS device of wherein the elongated beam exhibits a beam width in a direction that is orthogonal to the longitudinal dimension and to the thickness claim 3 , the beam width being less than each of the longitudinal dimension and the thickness.5. The MEMS device of wherein the protrusion element is a T-shaped structure having a base and a crossmember claim 1 , a first end of the base being coupled to the sidewall of the ...

MEMS DEVICE WITH COMMON MODE REJECTION STRUCTURE

A MEMS device includes a drive spring system coupling a pair of drive masses and a sense spring system coupling a pair of sense masses. The drive spring system includes a constrained stiff beam and flexures interconnecting the pair of drive masses. In response to drive movement of the drive masses the flexures enable pivotal movement of the constrained stiff beam about its center hinge point to enable anti-phase drive motion of the drive masses and to suppress in-phase motion of the drive masses. The sense spring system includes diagonally oriented stiff beams and a spring system that enable anti-phase sense motion of the sense masses while suppressing in-phase motion of the sense masses. Coupling masses interposed between the drive and sense masses decouple the drive motion of the drive masses from the sense motion of the sense masses. 1. A microelectromechanical systems (MEMS) device comprising:a planar substrate;a drive assembly anchored to said planar substrate, said drive assembly including a first drive mass and a second drive mass; anda stiff beam interconnecting said first drive mass with said second drive mass, a lengthwise dimension of said stiff beam being oriented perpendicular to a drive direction of said first and second drive masses, said drive direction being substantially parallel to said planar substrate, wherein said stiff beam pivots about an axis that is substantially perpendicular to said planar substrate in response to drive motion of said first and second drive masses in said drive direction.2. The MEMS device of further comprising:a first elastic element coupled between a first end of said stiff beam and said first drive mass; anda second elastic element coupled between a second end of said stiff beam and said second drive mass, said first and second elastic elements being oriented transverse to said stiff beam.3. The MEMS device of wherein said stiff beam and said first and second elastic elements are configured to enable said first and ...

Combined environmental parameter sensor

A combination sensor and corresponding method of measuring a plurality of environmental parameters uses a pressure sensor disposed on an integrated circuit die; a humidity sensor disposed on the integrated circuit die; and a circuit coupled to and shared by the pressure sensor and the humidity sensor to facilitate pressure and humidity sensing.

Single proof mass, 3 axis MEMS transducer

A transducer is provided herein which comprises an unbalanced proof mass ( 51 ), and which is adapted to sense acceleration in at least two mutually orthogonal directions. The proof mass ( 51 ) has first ( 65 ) and second ( 67 ) opposing sides that are of unequal mass.

Flexure with enhanced torsional stiffness and MEMS device incorporating same

A flexure for a MEMS device includes an elongated beam and a protrusion element extending outwardly from a sidewall of the elongated beam. A MEMS inertial sensor includes a movable element spaced apart from a surface of a substrate, an anchor attached to the substrate, and a spring system. The spring system includes first and second beams, a center flexure between the first and second beams, a first end flexure interconnected between an end of the first beam and the anchor, and a second end flexure interconnected between an end of the second beam and the movable element. Each of the end flexures includes the elongated beam having first and second ends, and the sidewall defining a longitudinal dimension of the elongated beam, and the protrusion element extending from the sidewall of the elongated beam, the protrusion element being displaced away from the first and second ends of the beam.

Mems sensor with folded torsion springs

A microelectromechanical systems (MEMS) sensor (40) includes a substrate (46) and a suspension anchor (54) formed on a planar surface (48) of the substrate (46). A first folded torsion spring (58) and a second folded torsion spring (60) interconnect the movable element (56) with the suspension anchor (54) to suspend the movable element (56) above the substrate (46). The folded torsion springs (58, 60) are each formed from multiple segments (76) that are linked together by bar elements (78) in a serpentine fashion. The folded torsion springs (58, 60) have an equivalent shape and are oriented relative to one another in rotational symmetry about a centroid (84) of the suspension anchor (54).

Inertial sensor with off-axis spring system

An inertial sensor ( 20 ) includes a drive mass ( 30 ) configured to undergo oscillatory motion and a sense mass ( 32 ) linked to the drive mass ( 30 ). On-axis torsion springs ( 58 ) are coupled to the sense mass ( 32 ), the on-axis torsion springs ( 58 ) being co-located with an axis of rotation ( 22 ). The inertial sensor ( 20 ) further includes an off-axis spring system ( 60 ). The off-axis spring system ( 60 ) includes off-axis springs ( 68, 70, 72, 74 ), each having a connection interface ( 76 ) coupled to the sense mass ( 32 ) at a location on the sense mass ( 32 ) that is displaced away from the axis of rotation ( 22 ). Together, the on-axis torsion springs ( 58 ) and the off-axis spring system ( 60 ) enable the sense mass ( 32 ) to oscillate out of plane about the axis of rotation ( 22 ) at a sense frequency that substantially matches a drive frequency of the drive mass ( 30 ).

Microelectromechanical system devices having crack resistant membrane structures and methods for the fabrication thereof

Methods for fabricating crack resistant Microelectromechanical (MEMS) devices are provided, as are MEMS devices produced pursuant to such methods. In one embodiment, the method includes forming a sacrificial body over a substrate, producing a multi-layer membrane structure on the substrate, and removing at least a portion of the sacrificial body to form an inner cavity within the multi-layer membrane structure. The multi-layer membrane structure is produced by first forming a base membrane layer over and around the sacrificial body such that the base membrane layer has a non-planar upper surface. A predetermined thickness of the base membrane layer is then removed to impart the base membrane layer with a planar upper surface. A cap membrane layer is formed over the planar upper surface of the base membrane layer. The cap membrane layer is composed of a material having a substantially parallel grain orientation.

MEMS device and method of reducing stiction in a MEMS device

A MEMS device includes a substrate; a movable mass suspended in proximity to the substrate; and at least one suspension structure coupled to the movable mass for performing a mechanical spring function. The at least one suspension structure has portions that move in tandem when the MEMS device is subject to at least one stimulus in a sensing direction, and further includes at least one link between the portions that move in tandem.

MEMS device with central anchor for stress isolation

A MEMS device (20) includes a proof mass (32) coupled to and surrounding an immovable structure (30). The immovable structure (30) includes fixed fingers (36, 38) extending outwardly from a body (34) of the structure (30). The proof mass (32) includes movable fingers (60), each of which is disposed between a pair (62) of the fixed fingers (36, 38). A central area (42) of the body (34) is coupled to an underlying substrate (24), with the remainder of the immovable structure (30) and the proof mass (32) being suspended above the substrate (24) to largely isolate the MEMS device (20) from package stress. Additionally, the MEMS device (20) includes isolation trenches (80) and interconnects (46, 50, 64) so that the fixed fingers (36), the fixed fingers (38), and the movable fingers (60) are electrically isolated from one another to yield a differential device configuration.

Z-axis inertial sensor with extended motion stops

A sensor includes a movable element adapted for rotational motion about a rotational axis due to acceleration along an axis perpendicular to a surface of a substrate. The movable element includes first and second ends, a first section having a first length between the rotational axis and the first end, and a second section having a second length between the rotational axis and the second end that is less than the first length. A motion stop extends from the second end of the second section. The first end of the first section includes a geometric stop region for contacting the surface of the substrate at a first distance away from the rotational axis. The motion stop for contacting the surface of the substrate at a second distance away from the rotational axis. The first and second distances facilitate symmetric stop performance between the geometric stop region and the motion stop.

Method for testing pressure sensors

Pressure sensors that are fabricated to sense low pressures are tested and calibrated by providing a controlled gas flow or leak to create a pressure during testing. Rather than placing the pressure sensor in a sealed environment, a controlled leak of a gas is used to induce a stable and controllable pressure region over the pressure sensor during testing. The stable low pressure region is monitored via a sensing tube.

Circuit and method of compensating for membrane stress in a sensor

A circuit and method for correcting a sense signal of a sensor (100) where the sense signal is reduced by a negative nonlinear error component introduced by membrane stress in a sensor structure (101). A first transducer (103) is disposed at a location (203) having substantial bending stress to produce a sense signal having a linear component and the nonlinear error component. A second transducer (102) is disposed at a location (202) with substantially zero bending stress to produce a sense signal having the nonlinear error component but a substantially zero linear component. The sense signal from the second transducer (102) is added to the sense signal from the first transducer (103) to correct the nonlinear error for producing a linear output sense signal (V OUT ) of the sensor (100) which is representative of the physical condition.

Z-axis accelerometer with at least two gap sizes and travel stops disposed outside an active capacitor area

capacitive sensor with stress relief that compensates for package stress

A microelectromechanical systems (MEMS) capacitive sensor ( 52 ) includes a movable element ( 56 ) pivotable about a rotational axis ( 68 ) offset between ends ( 80, 84 ) thereof. A static conductive layer ( 58 ) is spaced away from the movable element ( 56 ) and includes electrode elements ( 62, 64 ). The movable element ( 56 ) includes a section ( 74 ) between the rotational axis ( 68 ) and one end ( 80 ) that exhibits a length ( 78 ). The movable element ( 56 ) further includes a section ( 76 ) between the rotational axis ( 68 ) and the other end ( 84 ) that exhibits a length ( 82 ) that is less than the length ( 78 ) of the section ( 74 ). The section ( 74 ) includes slots ( 88 ) extending through movable element ( 56 ) from the end ( 80 ) toward the rotational axis ( 68 ). The slots ( 88 ) provide stress relief in section ( 74 ) that compensates for package stress to improve sensor performance.

Flexure with enhanced torsional stiffness and mems device incorporating same

Montagem do dispositivo mems e método de embalagem do mesmo

MONTAGEM DE DISPOSITIVOS DE MEMS E MÉTODO DE ACONDICIONAMENTO DOS MESMOS. Uma montagem (220) inclui um molde de MEMS (222) e um molde de circuito integrado (IC) (224) fixados a um substrato (226). O molde de MEMS (222) inclui um dispositivo de MEMS (237) formado sobre um substrato (242). Um processo de acondicionamento (264) implica na formação do dispositivo de MEMS (237) sobre o substrato (242) e remoção de uma porção de material do substrato (237) que circunda o dispositivo (237) para formar uma plataforma de substrato em cantilever (246) suspensa acima do substrato (226) na qual reside o dispositivo de MEMS (237). O molde de MEMS (222) está eletricamente interconectado ao molde de IC (224). Um elemento tampão (314) pode ser posicionado sobrejacente à plataforma (246). É aplicado composto de moldagem (32) para encapsular o molde de MEMS (222), o molde de IC (224), e o substrato (226). A seguir ao encapsulamento, o elemento tampão (314) pode ser removido, e uma cobertura (236) pode ser acoplada ao substrato (242) sobrejacente a uma região ativa (244) do dispositivo de MEMS (237)

Inertial sensor sampling with combined sense axes

A sensor system includes a transducer for sensing a physical stimulus along at least two orthogonal axes and an excitation circuit. The transducer includes a movable mass configured to react to the physical stimulus and multiple differential electrode pairs of electrodes. Each of the electrode pairs is configured to detect displacement of the movable mass along one of the orthogonal axes. The excitation circuit is connectable to the electrodes in various electrode connection configurations, with different polarity schemes, that enable excitation and sampling of each of the orthogonal axes during every sensing period. For each sensing period, a composite output signal is produced that includes the combined information sensed along each of the orthogonal axes. The individual sense signals for each orthogonal axis may be extracted from the composite output signals.

Capacitor assembly with shielded connections and method for forming the same

A capacitor assembly ( 82 ) is formed on a substrate ( 20 ). The capacitor assembly a first conductive plate ( 38 ) and a second conductive plate ( 60 ) formed over the substrate such that the second conductive plate is separated from the first conductive plate by a distance. A conductive trace ( 40 ) is formed over the substrate that is connected to the first conductive plate and extends away from the capacitor assembly. A conductive shield ( 62 ) is formed over at least a portion of the conductive trace that is separated from the first and second conductive plates to control a fringe capacitance between the second conductive plate and the conductive trace.

Integrated cmos capacitive pressure sensor

A capacitive pressure sensor (10) utilizes a diaphragm (38) that is formed along with forming gates (56,57) of active devices on the same semiconductor substrate (11).

A method of adding mass to MEMS structures

A method of adding mass to mems structures

A proof mass (11) for a MEMS device is provided herein. The proof mass comprises a base (13) comprising a semiconductor material, and at least one appendage (15) adjoined to said base by way of a stem (21). The appendage (15) comprises a metal (17) or other such material that may be disposed on a semiconductor material (19). The metal increases the total mass of the proof mass (11) as compared to a proof mass of similar dimensions made solely from semiconductor materials, without increasing the size of the proof mass. At the same time, the attachment of the appendage (15) by way of a stem (21) prevents stresses arising from CTE differentials in the appendage from being transmitted to the base, where they could contribute to temperature errors.

A method of adding mass to mems structures

A proof mass (11) for a MEMS device is provided herein. The proof mass comprises a base (13) comprising a semiconductor material, and at least one appendage (15) adjoined to said base by way of a stem (21). The appendage (15) comprises a metal (17) or other such material that may be disposed on a semiconductor material (19). The metal increases the total mass of the proof mass (11) as compared to a proof mass of similar dimensions made solely from semiconductor materials, without increasing the size of the proof mass. At the same time, the attachment of the appendage (15) by way of a stem (21) prevents stresses arising from CTE differentials in the appendage from being transmitted to the base, where they could contribute to temperature errors.

Integrated cmos capacitive pressure sensor

A capacitive pressure sensor (10) utilizes a diaphragm (38) that is formed along with forming gates (56,57) of active devices on the same semiconductor substrate (11).

Integrated cmos capacitive pressure sensor

デュアルプルーフマスを有するｍｅｍｓセンサ

【課題】熱により誘起された高ひずみおよび測定精度の低下を生じないＭＥＭＳセンサを提供する。 【解決手段】 微小電気機械システム（ＭＥＭＳ）センサ２０は、基板２６と、基板２６の平坦面２８に形成されたサスペンションアンカー３４、３６とを備える。ＭＥＭＳセンサ２０は、基板２６上に吊らされる、第１可動素子および第２可動素子をさらに備える。可撓性部材４２、４４が第１可動素子３８をサスペンションアンカー３４に相互接続し、可撓性部材４６、４８が第２可動素子４０をサスペンションアンカー３６に相互接続する。可動素子３８、４０は同一の形状を有する。可動素子は矩形または入れ子構成におけるＬ形状可動素子１０８、１１０であってよい。可動素子３８、４０は、基板２６における点位置９４の周りに互いに回転対称に配向される。 【選択図】図１

System for reading pressure of a pressure sensor and method therefor

A method for reading pressure may include reading, by a first device, an acceleration of a pressure sensor, wherein the pressure sensor is encapsulated in a medium, and wherein the acceleration alters a reading of the pressure sensor and reading, by a second device, a pressure reading from the pressure sensor. If an output criteria is met, an adjusted pressure reading is produced. A system for reading pressure includes a first device coupled to the pressure sensor and configured to read an acceleration of the pressure sensor. A second device may be configured to read a pressure from the pressure sensor wherein, if an output criteria is met, to adjust the measured pressure of the pressure sensor, based on the measured acceleration, to produce an adjusted pressure reading. An output device is configured to receive an output of the second device and to output an output pressure reading.

System for reading pressure of a pressure sensor and method therefor

A method for reading pressure may include reading, by a first device, an acceleration of a pressure sensor, wherein the pressure sensor is encapsulated in a medium, and wherein the acceleration alters a reading of the pressure sensor and reading, by a second device, a pressure reading from the pressure sensor. If an output criteria is met, an adjusted pressure reading is produced. A system for reading pressure includes a first device coupled to the pressure sensor and configured to read an acceleration of the pressure sensor. A second device may be configured to read a pressure from the pressure sensor wherein, if an output criteria is met, to adjust the measured pressure of the pressure sensor, based on the measured acceleration, to produce an adjusted pressure reading. An output device is configured to receive an output of the second device and to output an output pressure reading.

MEMS device having variable gap width and method of manufacture

Sensor having free fall self-test capability and method therefor

Sensor having free fall self-test capability and method therefor

A transducer (20) includes a movable element (24), a self-test actuator (22), and a sensing element (56, 58). The sensing element (56, 58) detects movement of the movable element (24) from a first position (96) to a second position (102) along an axis perpendicular to a plane of the sensing element (56, 58). The second position (102) results in an output signal (82) that simulates a free fall condition. A method (92) for testing a protection feature of a device (70) having the transducer (20) entails moving the movable element (24) to the first position (102) to produce a negative gravitational force detectable at the sensing element (56, 68), applying a signal (88) to the actuator (22) to move the movable element (24) to the second position (102) by the electrostatic force (100) , and ascertaining an enablement of the protection feature in response to the simulated free fall.

具有自由下落自我測試能力之感測器及其方法

Mems accelerometer with vertical stops

A MEMS device includes a substrate, a set of spring, and a proof mass suspended above and coupled to the substrate by the springs. Each spring includes a corresponding anchor on the substrate and a beam extending away from that anchor. Each beam has a fixed end that is coupled to the anchor by a first linkage at one end of the beam proximal to the anchor and a free end that is coupled to the proof mass by a second linkage at an end of the beam that is distal to the anchor. The anchors are arranged symmetrically around a center of the proof mass. The proof mass translates vertically with respect to the substrate and when a vertical displacement of the proof mass toward the substrate reaches a predefined value, the free end of each spring contacts the substrate and prevents the proof mass from contacting the substrate.

Mems accelerometer with vertical stops

A MEMS device includes a substrate, a set of spring, and a proof mass suspended above and coupled to the substrate by the springs. Each spring includes a corresponding anchor on the substrate and a beam extending away from that anchor. Each beam has a fixed end that is coupled to the anchor by a first linkage at one end of the beam proximal to the anchor and a free end that is coupled to the proof mass by a second linkage at an end of the beam that is distal to the anchor. The anchors are arranged symmetrically around a center of the proof mass. The proof mass translates vertically with respect to the substrate and when a vertical displacement of the proof mass toward the substrate reaches a predefined value, the free end of each spring contacts the substrate and prevents the proof mass from contacting the substrate.

Electrically conductive barriers for integrated circuits

Electrically conductive barriers for integrated circuits and integrated circuits and methods including the electrically conductive barriers. The integrated circuits include a semiconductor substrate, a semiconductor device supported by a device portion of the substrate, and a plurality of bond pads supported by a bond pad portion of the substrate. The integrated circuits also include an electrically conductive barrier that projects away from an intermediate portion of the substrate and is configured to decrease capacitive coupling between the device portion and the bond pad portion. The methods can include methods of manufacturing an integrated circuit. These methods include forming a semiconductor device, forming a plurality of bond pads, forming a plurality of electrically conductive regions, and forming an electrically conductive barrier. The methods also can include methods of operating an integrated circuit. These methods include applying an input electric signal, receiving an output electric signal, and applying a reference potential.