Means To Reduce Sensitivity To Physical Deformation Patents (Class 257/420)
-
Patent number: 6051866Abstract: A single mask, low temperature reactive ion etching process for fabricating high aspect ratio, released single crystal microelectromechanical structures independently of crystal orientation.Type: GrantFiled: August 11, 1998Date of Patent: April 18, 2000Assignee: Cornell Research Foundation, Inc.Inventors: Kevin A. Shaw, Z. Lisa Zhang, Noel C. MacDonald
-
Patent number: 6043524Abstract: A sensor (100) includes a fixed gate field-effect transistor (138) that produces a quiescent signal (V.sub.QUIESC1) in a channel (336) when a control signal (V.sub.CONTROL) is applied to a source (332) of the FGFET. A movable gate field-effect transistor (MGFET) (108) produces a sense signal (V.sub.ACCEL) in a channel (316) in response to a physical condition of the sensor when the control signal is applied to a source (312) of the MGFET such that the sense signal is proportional to the quiescent signal. The difference between the currents in the FGFET and MGFET is amplified by a differential amplifier (230) to produce the output signal (V.sub.OUT) of the sensor. The difference between a reference signal (V.sub.RATIO) and the quiescent signal is amplified in an amplifier (206) to produce the control signal that adjusts the output signal to be proportional to the reference signal.Type: GrantFiled: February 3, 1997Date of Patent: March 28, 2000Assignee: Motorola, Inc.Inventors: Eric D. Joseph, Barun K. Kar
-
Patent number: 6028332Abstract: A semiconductor type yaw rate sensor has a substrate, a beam structure formed from a semiconductor material and having at least one anchor portion disposed on the substrate, a weighted portion located above the substrate a predetermined gap therefrom, and a beam portion which extends from the anchor portion and supports the weighted portion. A movable electrode is formed onto the weighted portion, and a fixed electrode is formed on the substrate in such a manner that the fixed electrode faces the movable electrode. When a drive voltage is applied between the movable electrode and the fixed electrode, the beam structure is forcibly caused to vibrate in a direction that is horizontal relative to a substrate surface plane. In this yaw rate sensor, a strain gauge to monitor forced vibration of the beam structure is formed in the beam portion. As a result, the forced vibration of the beam structure can be monitored with a simple structure.Type: GrantFiled: June 29, 1998Date of Patent: February 22, 2000Assignee: Denso CorporationInventors: Kazuhiko Kano, Makiko Fujita, Yoshinori Ohtsuka
-
Patent number: 6025638Abstract: Process for making an integrated circuit module and product thereof including a carrier supporting a plurality of precisely aligned semiconductor circuit chips having uniform thicknesses.Type: GrantFiled: June 1, 1998Date of Patent: February 15, 2000Assignee: International Business Machines CorporationInventors: H. Bernhard Pogge, Subramania S. Iyer
-
Patent number: 6005275Abstract: A semiconductor device comprises a semiconductor acceleration sensor having a cantilever made of a semiconductor material, a supporter for supporting the cantilever, and diffused resistors disposed on the cantilever. An acceleration detecting device detects a displacement of the cantilever based on acceleration forces applied to the cantilever and on changes of resistance values of the diffused resistors.Type: GrantFiled: August 23, 1995Date of Patent: December 21, 1999Assignee: Seiko Instruments Inc.Inventors: Masataka Shinogi, Yutaka Saitoh, Yoshifumi Yoshida, Hirofumi Harada, Kenji Katoh
-
Patent number: 6001666Abstract: This invention relates to the manufacture of a strain gauge sensor using the piezoresistive effect, comprising a structure (1) made of a monocrystalline material acting as support to at least one strain gauge (2) made of a semiconducting material with a freely chosen doping type. The strain gauge (2) is an element made along a crystallographic plane determined to improve its piezoresistivity coefficient. The structure (1) is a structure etched along a crystallographic plane determined to improve its etching. The strain gauge (2) is fixed to the structure (1) by bonding means capable of obtaining said sensor.Type: GrantFiled: March 24, 1997Date of Patent: December 14, 1999Assignee: Commissariat a l'Energie AtomiqueInventors: Bernard Diem, Sylvie Viollet-Bosson, Patricia Touret
-
Patent number: 5994758Abstract: A functional circuit group consisting of a plurality of functional circuits is formed at a surface of a substrate and a resistance element group consisting of a plurality of resistance elements connected to the functional circuits is arranged outside the functional circuit group on the substrate. The resistance element group is arranged in a region extending from an inner line, which is distant by one-third of a distance between the outer edge of the substrate and the center thereof from the same outer edge, up to the same outer edge. The resistance element group is a group in which a plurality of resistance elements, each having the same shape and size, are arranged at a constant distance between two of any adjacent pair.Type: GrantFiled: December 18, 1997Date of Patent: November 30, 1999Assignee: NEC CorporationInventor: Shigeru Hayashi
-
Patent number: 5986316Abstract: A diffusion gauge is formed in a surface of a silicon substrate which has a plane orientation of (110). The diffusion gauge is disposed so that a main current thereof flows along a <110> direction perpendicular to a direction in which large stress biased in one direction generates in the surface of the silicon substrate due to distortion of a base for fixing the silicon substrate. Therefore, even when the large biased stress generates in the surface of the silicon substrate, because the <110> direction in which the main current of the diffusion gauge flows is perpendicular to the direction in which the biased stress generates, there is a little change in a resistance value of the diffusion gauge. As a result, a detection error caused by the distortion of the base can be reduced.Type: GrantFiled: November 26, 1997Date of Patent: November 16, 1999Assignee: Denso CorporationInventors: Inao Toyoda, Yasutoshi Suzuki, Nobukazu Oba, Hiroaki Tanaka
-
Patent number: 5949119Abstract: A device having at least one element of a floating rigid microstructure element made of a structure layer(s) and a rigidity lining which increases its resistance to flexing and to torsion. The increased rigidity of the microstructure element allows the thickness and/or the width to be reduced, particularly of the structure layer(s) and hence allows an increase in the thermal resistance.Type: GrantFiled: December 23, 1998Date of Patent: September 7, 1999Assignee: Commissariat a l'Energie AtomiqueInventor: Michel Vilain
-
Patent number: 5949118Abstract: An etching method for a silicon substrate, which can easily smooth the etching surface of the (110)-oriented silicon, is disclosed. A container is filled with KOH solution. In the KOH solution is immersed a (110)-oriented silicon wafer having a PN junction and is also disposed a platinum electrode plate to face the silicon wafer. To between a platinum electrode of the silicon wafer and the platinum electrode plate are connected a constant voltage power source, an ammeter and a contact in series. A controller starts etching from one surface on which the PN junction is formed, and terminates voltage application when the specified time lapses after the formation of an anodic oxide film is equilibrated with the etching of the anodic oxide film on the etching surface on the PN junction part.Type: GrantFiled: April 24, 1996Date of Patent: September 7, 1999Assignee: Nippondenso Co., Ltd.Inventors: Minekazu Sakai, Tsuyoshi Fukada, Koki Mizuno, Yasutoshi Suzuki, Yoshitsugu Abe, Hiroshi Tanaka, Motoki Ito, Kazuhisa Ikeda, Hiroshi Okada
-
Patent number: 5945605Abstract: A non-invasive sensor assembly device includes a pedestal mounted sensor die for stress isolation of the sensor die from external stresses, a substrate and die porting configuration to limit exposure of the sensor assembly to only the interior of the sensor die and a connecting tube to provide significant isolation of the sensor assembly and its constituent parts from the fluid stream, and an inert coating conformally deposited on the inside surfaces of the die, pedestal, and connecting tube that are in contact with the fluid media to thereby provide complete isolation of the sensor assembly from the media.Type: GrantFiled: November 19, 1997Date of Patent: August 31, 1999Assignee: SenSym, Inc.Inventors: Francis S. Julian, Raymond P. Hui, James H. Hoffman, Christos D. Cartsonas
-
Patent number: 5914507Abstract: A micromechanical device or microactuator based upon the piezoelectric, pyroelectric, and electrostrictive properties of ferroelectric thin film ceramic materials such as PZT. The microdevice has a device substrate and a deflectable component. The deflectable component is mounted for deflection on the device substrate and has a sensor/actuator. The sensor/actuator has first and second electrodes and a piezoelectric thin film disposed between the first and second electrodes. The thin film is preferably PZT. The sensor/actuator is disposed on a sensor/actuator substrate. The sensor/actuator substrate is formed of a material selected for being resistive to attack by hydrofluoric acid vapor. The invention also relates to a method for fabricating such micromechanical devices or microactuators.Type: GrantFiled: October 30, 1996Date of Patent: June 22, 1999Assignee: Regents of the University of MinnesotaInventors: Dennis L. Polla, Joon Han Kim
-
Patent number: 5914521Abstract: A sensor (11) has a movable plate (16) that moves in response to an external acceleration. The movable plate (16) has a finger (17) that is capacitively coupled to fingers (13,14) that are attached to a substrate (12). A travel stop (19) is used to stop the movable plate (16) before the finger (17) on the movable plate (16) collides into the fingers (13,14) on the substrate (12).Type: GrantFiled: July 30, 1997Date of Patent: June 22, 1999Assignee: Motorola, Inc.Inventors: Ronald James Gutteridge, Daniel Nicolas Koury, Jr., Daniel Joseph Koch, Jonathan Hale Hammond
-
Patent number: 5912499Abstract: An integrated pressure sensitive transducer incorporating a pressure sensitive structure having a silicon substrate, and at least one monocrystalline silicon diaphragm deformable in a direction perpendicular to the substrate. The diaphragm, which is joined to the substrate at its periphery by means of an etched insulating layer, has a centered insulating stud which bears on the substrate in order to increase the rigidity of the diaphragm. Completing the transducer and for measuring the deformation of the diaphragm is at least one first electrode located in the substrate facing a high deformation region of the diaphragm and remote from the periphery of the diaphragm and the insulating stud, and at least one second electrode facing at least one low deformation region of the diaphragm and in the vicinity of the periphery and/or the insulating stud.Type: GrantFiled: December 22, 1995Date of Patent: June 15, 1999Assignee: Commissariat A L'Energie AtomiqueInventors: Bernard Diem, Marie-Therese Delaye
-
Patent number: 5903038Abstract: A semiconductor sensing device (10) for sensing a lateral acceleration includes a field effect transistor (132) fabricated along a sidewall (114) of a trench (112) formed in a substrate (11). A movable gate (12) overlies a channel region (138) of the field effect transistor (132). In response to a lateral acceleration perpendicular to the sidewall (114) of the trench (112), the movable gate (12) moves relative to the substrate (11) in a direction substantially perpendicular to the sidewall (114). The conductive state of the channel region (138) depends on the distance between the movable gate (12) and the channel region (138) and changes in response to the lateral acceleration Thus, the motion of the movable gate (12) modulates a current flowing in the field effect transistor (132). The lateral acceleration is sensed by sensing the current flowing in the field effect transistor (132).Type: GrantFiled: June 30, 1997Date of Patent: May 11, 1999Assignee: Motorola, Inc.Inventors: Zuoying Lisa Zhang, Shang-Hui Larry Tu, Guang Xuan Li
-
Patent number: 5894144Abstract: In a semiconductor acceleration sensor, a weight and thin beam parts adjacent to the weight are formed on a substrate, a moving electrode is formed on the weight, and a fixed electrode is formed at a position of the other substrate opposed to the moving electrode. Both the electrodes come in contact with each other and conduct as a result of acceleration on the weight, whereby the semiconductor acceleration sensor operates. The fixed electrode or the moving electrode is formed with a projection toward the opposed electrode and the projection and the electrode come in contact with each other and conduct by action of acceleration with a predetermined spacing held between both the electrodes for preventing occurrence of chattering caused by the electrostatic attraction force between both the electrodes.Type: GrantFiled: October 30, 1997Date of Patent: April 13, 1999Assignees: Akebono Brake Industry Co., Ltd.,, Nihon Inter Electronic CorporationInventors: Masatomo Mori, Takashi Kunimi, Masahiro Nezu, Tadao Matsunaga, Rokurou Naya, Shougo Suzuki
-
Patent number: 5889312Abstract: A semiconductor device includes a thermal oxide film for isolation, a semiconductor region that becomes an element forming region with the circumference thereof surrounded by the oxide film and diffused resistance layers in the semiconductor region and provides a structure for controlling resistance value variation of diffused resistors originated in a stress generated at time of forming the oxide film for isolation. A distance between an end portion on a longer side closest to a thermal oxide film of the diffused layer and an end of the thermal oxide film is apart from each other by a predetermined value determined by stress distribution in the semiconductor region or by at least 4 .mu.Type: GrantFiled: July 10, 1997Date of Patent: March 30, 1999Assignee: Hitachi, Ltd.Inventors: Hideo Miura, Yasunobu Tanizaki, Eiji Wakimoto, Shinji Sakata, Makoto Ogasawara, Hiroo Masuda, Jun Murata, Noriaki Okamoto
-
Patent number: 5883419Abstract: A transistor in accordance with the invention comprises an ultra-thin Mo--C film functioning as a channel for an electron flow with two ends of the thin metal film functioning as source and drain terminals of the transistor, respectively; a piezoelectric film formed on the Mo--C film, for producing a force in accordance with an applied electric field provided by a gate voltage; and an electrode film formed on the piezoelectric film functioning as a gate of the transistor to which the gate voltage is applied to produce the applied electric field; and wherein a resistance of the Mo--C film between the source and drain terminals changes in accordance with the force produced in response to the applied gate voltage. This transistor can be used as an element of the three dimensional integrated circuit with a laminated structure.Type: GrantFiled: May 1, 1997Date of Patent: March 16, 1999Assignee: Electronics and Telecommunications Research InstituteInventors: Seong-Jae Lee, Kyoung-Wan Park, Min-Cheol Shin
-
Patent number: 5828115Abstract: A polysilicon ground plane is formed over dielectric layers and under a suspended, movable mass in a surface micromachined device. The process includes steps of forming a diffused region in a substrate, forming the dielectric layers over the substrate, forming the ground plane over dielectric layers, and forming a body having a suspended mass, a first anchor extending from the mass down to the diffused region, and a second anchor extending from the down to the ground plane. The two anchors are formed simultaneously. The ground plane, which can be formed with only three additional steps over prior processes, serves as a ground plane to control changes and also as a local interconnect.Type: GrantFiled: November 22, 1996Date of Patent: October 27, 1998Assignee: Analog Devices, Inc.Inventor: Theresa A. Core
-
Patent number: 5828116Abstract: The present invention provides an improved method of wire-bonding on a semiconductor chip, especially a small acceleration sensor chip which is mounted on a substrate with an adhesive having low stress characteristics such as a silicon resin. Further, the present invention provides a semiconductor device having a structure in which the improved method of wire bonding is easily applicable. The wire-bonding is performed by giving ultrasonic vibrations to the wires and the pads on which the wires are bonded while imposing pressure thereon. The vibration is given in a direction along a radial line extending from the center of the semiconductor chip.Type: GrantFiled: January 21, 1997Date of Patent: October 27, 1998Assignee: Denso CorporationInventor: Kenichi Ao
-
Patent number: 5818093Abstract: A semiconductor device (8) has a movable gate (20) over a semiconductor substrate (14) having a top surface (30). Source and drain regions (16-19) are in the substrate, and a channel region (24,25) is between the source and drain regions. The gate is suspended above the source and drain regions such that the gate is movable in a plane substantially parallel to the top surface of the substrate. In one embodiment the device is an accelerometer having the gate connected to a beam (10) with an aspect ratio between 2:1 and 10:1. Also, the gate can have first and second levels (22,23) corresponding to first and second threshold voltages of the channel region.Type: GrantFiled: January 25, 1996Date of Patent: October 6, 1998Assignee: Motorola, Inc.Inventors: Ronald J. Gutteridge, Margaret L. Kniffin, Zuoying L. Zhang, Raymond M. Roop
-
Patent number: 5808331Abstract: A semiconductor device (15) having a sensor (11) and a transistor (10) formed on a monolithic semiconductor substrate (16). The sensor (11) has a source region (41), a drain region (42), and a microstructure (12) which is formed from a conductive layer (28). The microstructure (12) modulates a channel region between the source and drain regions (41,42). The transistor has a gate structure, a portion of which is formed from the same conductive layer (28) used to form the microstructure (12). Anneal steps are performed on the conductive layer (28) to remove stress prior to the formation of source and drain regions (34,36) of the transistor (10). A self-test structure (14) is formed adjacent to the microstructure (12) which is used to calibrate and verify the operation of the sensor (11).Type: GrantFiled: July 16, 1997Date of Patent: September 15, 1998Assignee: Motorola, Inc.Inventors: Zuoying L. Zhang, Barun K. Kar, Guang X. Li, Ronald J. Gutteridge, Eric D. Joseph
-
Patent number: 5786621Abstract: A novel apparatus and technique or characterizing materials at submicron scale and for characterizing micromechanical devices integrates test specimens with the testing device. The test specimen is a micromechanical structure made of the material to be characterized or may be a device under evaluation. A microloading instrument is a microelectromechanical structure incorporating a stable, planar frame to which is connected a multiplicity of comb-type capacitive actuators. A variable drive voltage applied across the actuator plates selectively moves the frame structure along a longitudinal axis in a controlled fashion. The frame is mounted to a fixed substrate by means of laterally extending spring arms which position the capacitor plates and guide the motion of the frame along the longitudinal axis. The micro loading instrument is calibrated by buckling a long slender beam cofabricated with the instrument.Type: GrantFiled: June 21, 1996Date of Patent: July 28, 1998Assignee: Cornell Research Foundation, Inc.Inventors: Muhammed T. A. Saif, Noel C. MacDonald
-
Patent number: 5780885Abstract: Process for the production of accelerometers using the silicon on insulator method. The process comprises the following stages: a) producing a conductive monocrystalline silicon film on a silicon substrate and separated from the latter by an insulating layer; b) etching the silicon film and the insulating layer up to the substrate in order to fix the shape of the mobile elements and the measuring device; c) producing electric contacts for the measuring devices; d) partial elimination of the insulating layer in order to free the mobile elements, the remainder of the insulating layer rendering integral the substrate and the moving elements.Type: GrantFiled: August 15, 1996Date of Patent: July 14, 1998Assignee: Commissariat a l'Energie AtomiqueInventors: Bernard Diem, Marie-Therese Delaye
-
Patent number: 5770883Abstract: A pair of signal voltages outputted from a bridge circuit composed of plural strain gauges are linearly amplified individually by a pair of amplifiers, whereupon a difference between the pair of signal voltages is detected. The pair of amplifiers are formed respectively in regions that are symmetrical with each other on a chip. As a result, variations in the output characteristics between the amplifiers are decreased.Type: GrantFiled: September 19, 1996Date of Patent: June 23, 1998Assignee: Nippondenso Co., Ltd.Inventors: Koki Mizuno, Hiroshi Okada, Inao Toyoda, Masakazu Kanosue, Yasutoshi Suzuki, Kenichi Yokoyama
-
Patent number: 5747858Abstract: An electronic component includes a substrate (11) having a device surface (13) and opposite ends (14, 15) adjacent to the device surface (13), an electronic device (16) supported by the device surface (13), and an interconnect substrate (30) overlying a first end (14) of the substrate (11) and electrically coupled to the electronic device (16). The electronic component can be manufactured by inserting the second end (15) of the substrate (11) into one of a plurality of holes (23) in a carrier (20) wherein the device surface (13) and the carrier (20) form an angle greater than approximately five degrees.Type: GrantFiled: September 30, 1996Date of Patent: May 5, 1998Assignee: Motorola, Inc.Inventor: George W. Hawkins
-
Patent number: 5723894Abstract: An electrical connection structure interconnects a first circuit member and a second circuit member and comprises a cantilever, a conductive needle, a terminal pad and a fixing element. The cantilever is formed in the semiconductor substrate and has an end remote from the semiconductor substrate. The conductive needle is at the end of the cantilever and is electrically connected to the first circuit member. The terminal pad is located on the second circuit member opposite the conductive needle tip when the first circuit member and the second circuit member are juxtaposed. The terminal pad is electrically connected to the second circuit member. The fixing element fixes the first circuit member juxtaposed to the second circuit member in a way that stresses the cantilever to apply a contact force between the conductive needle and the terminal pad.Type: GrantFiled: July 3, 1996Date of Patent: March 3, 1998Assignee: Hewlett-Packard CompanyInventors: Toshiaki Ueno, Mitsuchika Saito
-
Patent number: 5698888Abstract: A metal-semiconductor type field effect transistor has a Y-letter shaped gate electrode standing on an active layer, and the Y-letter shaped gate electrode prevents piezoelectric charges induced beneath both ends of the wing portions thereof from undesirable merger so as to restrict variation of the threshold regardless of the orientation of the Y-letter shaped gate electrode.Type: GrantFiled: April 24, 1996Date of Patent: December 16, 1997Assignee: NEC CorporationInventor: Muneo Fukaishi
-
Patent number: 5656846Abstract: An acceleration sensor is provided with damping means on an upper surface and/or an lower surface of a movable portion of a sensor body and/or opposite regions surrounded by the movable portion and a rim of the sensor body in order to provide damping of a vibration to the movable portion of the sensor body. The damping means includes a material having a large mechanical damping constant, for example, a plastic, a gel, an inorganic material, and micro capsules. In a fabrication process of the acceleration sensor, a supporting film is provided on the movable portion of the sensor body, the damping material is provided on the supporting film and the movable portion of the sensor body is subjected to etching so as to form a weight and a diaphragm.Type: GrantFiled: March 7, 1995Date of Patent: August 12, 1997Assignee: NEC CorporationInventor: Keizo Yamada
-
Patent number: 5640039Abstract: A method and apparatus for providing a conductive plane beneath a suspended microstructure. A conductive region is diffused into a substrate. A dielectric layer is added, covering the substrate, and then removed from a portion of the conductive region. A spacer layer is deposited over the dielectric and exposed conductive region. A polysilicon layer is deposited over the spacer layer, and formed into the shape of the suspended microstructure. After removal of the spacer layer, the suspended microstructure is left free to move above an exposed conductive plane. The conductive plane is driven to the same potential as the microstructure.Type: GrantFiled: December 1, 1994Date of Patent: June 17, 1997Assignee: Analog Devices, Inc.Inventors: Kevin Hin-Leung Chau, Roger T. Howe, Richard S. Payne, Yang Zhao, Theresa A. Core, Steven J. Sherman
-
Patent number: 5637905Abstract: A high-temperature, integrated, pressure sensor includes a single crystal semiconductor substrate that is provided with a recess in a first surface thereof, the recess bounded by a rim. A first coil structure is positioned within the recess and a pressure diaphragm, comprising a single-crystal semiconductor wafer is bounded about its periphery to the rim of the semiconductor substrate. The bonding is created by a glass interlayer between the pressure diaphragm and the semiconductor substrate. A second coil structure is positioned on the underside of the pressure diaphragm and is separated from the first coil structure. Electrical circuitry is connected to both coil structures and provides an output indicative of changes in inductive coupling between the coils.Type: GrantFiled: February 1, 1996Date of Patent: June 10, 1997Assignee: New Jersey Institute of TechnologyInventors: William N. Carr, Robert S. Okojie
-
Patent number: 5635739Abstract: A micromechanical accelerometer comprises a mass of monocrystalline silicon in which a substantially symmetrical plate attached to a silicon frame by flexible linkages is produced by selective etching. The plate has a plurality of apertures patterned and etched therethrough to speed further etching and freeing of the plate and flexible linkages, suspending them above a void etched beneath. The plate is capable of limited motion about an axis created by the flexible linkages. An accelerometer comprised of a substantially symmetrical, linkage supported plate configuration is implemented as an angular accelerometer paired with an auxiliary linear accelerometer, which is used to compensate for the linear sensitivity of the angular sensor, to achieve an instrument that is insensitive to linear acceleration and responds to angular acceleration.Type: GrantFiled: April 25, 1995Date of Patent: June 3, 1997Assignee: The Charles Stark Draper Laboratory, Inc.Inventors: Paul Grieff, Burton Boxenhorn, Marc S. Weinberg
-
Patent number: 5627397Abstract: A semiconductor acceleration sensor according to the present invention performs acceleration detection by means of detecting increase or decrease in electrical current flowing between fixed electrodes formed on a semiconductor substrate taking a movable section in a movable state supported on the semiconductor substrate as a gate electrode. Two transistor structures are utilized in this detection. Current between fixed electrodes in one transistor structure increases when the movable section is subjected to acceleration and is displaced. At that time, current between fixed electrodes in the other transistor structure decreases. These two transistor structures are disposed proximately. By means of this proximate disposition, fluctuations in characteristics of both transistors are reduced, and by means of acceleration detection by differential type, temperature characteristics of the two transistors can be canceled favorably.Type: GrantFiled: March 13, 1995Date of Patent: May 6, 1997Assignee: Nippondenso Co., Ltd.Inventors: Kazuhiko Kano, Yukihiro Takeuchi, Takamoto Watanabe, Kenichi Ao, Masakazu Kanosue, Hirofumi Uenoyama, Kenichi Nara
-
Patent number: 5619050Abstract: A semiconductor acceleration sensor capable of reducing a leakage current and manufacturing method thereof is disclosed. A beam structure is disposed on a silicon substrate. The beam structure has a movable section, and the movable section is disposed spaced at a prescribed distance above silicon substrate. A movable electrode section is formed in one portion of movable section. Fixed electrodes made of an impurity diffusion layer are formed in silicon substrate to correspond to both sides of a movable electrode section. A peripheral circuit is formed in silicon substrate. The beam structure and the peripheral circuit are electrically connected by an electroconductive thin film, made of polysilicon. Then, when a voltage is applied to the beam structure, and a voltage is applied to both fixed electrodes, an inversion layer is formed, and an electrical current flows between the fixed electrodes.Type: GrantFiled: March 6, 1995Date of Patent: April 8, 1997Assignee: Nippondenso Co., Ltd.Inventors: Hirofumi Uenoyama, Kenichi Ao, Masakazu Kanosue, Yasutoshi Suzuki, Yukihiro Takeuchi
-
Patent number: 5614742Abstract: A high precision micromechanical accelerometer comprises a layered structure of five (5) semiconductor wafers insulated from one another by thin oxide layers. The accelerometer is formed by first connecting a coverplate and a baseplate to associated insulating plates. Counter-electrodes, produced by anisotropic etching from the respective insulating plates, are fixed to the coverplate and the baseplate respectively. The counter-electrodes are contactable through the cover or baseplate via contact windows. A central wafer contains a unilaterally linked mass (pendulum) that is also produced by anisotropic etching and which serves as a movable central electrode of a differential capacitor. The layered structure is hermetically sealed by semiconductor fusion bonding. A stepped gradation from the top is formed at a wafer edge region for attaching contact pads to individual wafers to permit electrical contacting of individual wafers. The invention permits fabrication of a .mu.Type: GrantFiled: January 2, 1996Date of Patent: March 25, 1997Assignee: LITEF GmbHInventors: Thomas Gessner, Martin Hafen, Eberhard Handrich, Peter Leinfelder, Bruno Ryrko, Egbert Vetter, Maik Wiemer
-
Patent number: 5602411Abstract: A micromechanical component includes a fixed micromechanical structure having a pair of capacitor plates being formed of one or more conductive layers, and a movable micromechanical structure being formed of a dielectric layer to be introduced into or removed from an interstice between the plates. A capacitance change is obtained through the resilient or freely movable dielectric, so that the component can be inserted as a proportional or a non-proportional force sensor. A microsystem with an integrated circuit and a micromechanical component with a movable dielectric, as well as a production method for the component and the microsystem, are also provided.Type: GrantFiled: April 28, 1995Date of Patent: February 11, 1997Assignee: Siemens AktiengesellschaftInventor: Thomas Zettler
-
Patent number: 5587601Abstract: A pressure sensor assembly including semiconductor transducer elements disposed upon a diaphragm support structure, wherein the support structure is comprised of a plurality of substrate layers anodically bonded together. A groove is disposed in the support structure creating an area of reduced thickness within the support structure. The ares of reduced thickness acts as a stress concentration region. As such, the transducer elements are disposed within the ares of reduced thickness so as to efficiently monitor any deformations experienced by the support structure. The groove that creates the ares of reduced thickness is formed in each of the substrate layers, prior to bonding into the overall structure, as such a very accurately tolerance groove can be formed into the structure which greatly increases the reliability of the structure.Type: GrantFiled: June 5, 1995Date of Patent: December 24, 1996Assignee: Kulite Semiconductor Products, Inc.Inventor: Anthony D. Kurtz
-
Patent number: 5583373Abstract: A preferred embodiment of an integrated semiconductor device includes a semiconductor die having a hole therethrough. A paddle member includes a handle member connected between the paddle member and the semiconductor die to suspend the paddle member in the hole. A cap layer is bonded to the semiconductor die to completely cover the hole, the paddle member, and the handle member. The second surface of the semiconductor die is bonded to the lead frame.Type: GrantFiled: October 12, 1995Date of Patent: December 10, 1996Assignee: National Semiconductor CorporationInventors: James V. Ball, Robert A. Pease
-
Patent number: 5572067Abstract: An integrated circuit chip die (12) is manufactured with sacrificial structures (16) placed at the areas of die that are likely to experience cracks. According to one embodiment of the invention, these sacrificial structures are placed at the corners of the die. The sacrificial structures are constructed with metal lines (22, 24) that resist propagation of cracks into the area of the die containing electronic devices. The metal lines form lattice steps so that the surface of the die will more tightly bond to the molding compound that makes up the die package.Type: GrantFiled: October 6, 1994Date of Patent: November 5, 1996Assignee: Altera CorporationInventor: Guru Thalapaneni
-
Patent number: 5572057Abstract: Adverse effects due to electrostatic force between a semiconductor substrate and a movable electrode are avoided with a new structure. A movable electrode of beam structure is disposed at a specified interval above a p-type silicon substrate. Fixed electrodes, each composed of an impurity diffusion layer, are disposed on both sides of the movable electrode on the p-type silicon substrate; these fixed electrodes are self-aligningly with respect to the movable electrode. The movable electrode is displaced in accompaniment to the action of acceleration, and acceleration is detected by change (fluctuation) in current between the fixed electrodes generated by means of this displacement. Additionally, an electrode for movable electrode upward-movement use is disposed above the movable electrode, a potential difference is given between the movable electrode and the electrode for movable electrode upward-movement use, and attractive force of the movable electrode to the silicon substrate is alleviated.Type: GrantFiled: December 21, 1994Date of Patent: November 5, 1996Assignee: Nippondenso Co., Ltd.Inventors: Toshimasa Yamamoto, Yukihiro Takeuchi, Yoshinori Ohtsuka, Kazuhiko Kano
-
Patent number: 5545912Abstract: An enclosure (8) for an electronic device (26) such as, for example, an accelerometer. The enclosure (8) includes a conductive semiconductor substrate (12) underlying the electronic device (26), a conductive cap (16) overlying the electronic device (26), and a power supply (25) having one or more outputs (27, 29) each with a substantially fixed potential wherein one output is electrically coupled to the conductive semiconductor substrate (12) and another output to the conductive cap (16). In a preferred embodiment, substrate ( 12 ) and cap (16) are coupled to the same power supply output (27). This coupling substantially eliminates the adverse effects of parasitic capacitances of the substrate (12) and cap (16) to reduce measurement error and EMI when a capacitive accelerometer is used as the electronic device (26).Type: GrantFiled: October 27, 1994Date of Patent: August 13, 1996Assignee: Motorola, Inc.Inventors: Ljubisa Ristic, Daniel N. Koury, John E. Schmiesing, Ronald J. Gutteridge, Henry G. Hughes
-
Patent number: 5541437Abstract: In an acceleration sensor having movable gates and a movable electrode and having a signal processing portion, the movable gates generate a differential voltage from acceleration in one direction and its output signal is fed back to the movable electrode. The balance of the movable portion is kept using an electrostatic force which cancels the acceleration acting on the movable portion, and signal detection is stabilized using closed loop control. Since signal detection is on a differential basis, acceleration can be detected in only one direction. Since a change in current is detected as a voltage difference, no carrier wave is required. Since MISFETs having movable gates are formed in pairs, there is no influence of temperature drifts. The use of a differential signal similarly cancels the influence of fluctuations of the power supply. Configuration of an acceleration sensor is thus simplified.Type: GrantFiled: March 14, 1995Date of Patent: July 30, 1996Assignee: Nippondenso Co., Ltd.Inventors: Takamoto Watanabe, Shigeru Nonoyama, Yukihiro Takeuchi
-
Patent number: 5536963Abstract: A micromechanical structure or microactuator based upon the piezoelectric, pyroelectric, and electrostrictive properties of ferroelectric thin film ceramic materials such as PZT with a thickness between 0.1 and 10 micrometers. The thin film ceramic material is sandwiched between first and second electrodes and may contain an intermediate electrically insulating thin film. This structure with electrodes is formed on a deformable or movable structure integral to a semiconductor or bulk ceramic substrate. Electrical connection is established between the upper and lower electrodes. A potential difference or voltage is established between the electrical interconnection points to produce a force, movement, or mechanical deformation. The invention also relates to a method for making such micromechanical structures or microactuators.Type: GrantFiled: May 11, 1994Date of Patent: July 16, 1996Assignee: Regents of the University of MinnesotaInventor: Dennis L. Polla
-
Patent number: 5528069Abstract: A sensing transducer (10,30) and a method therefor uses a Schottky junction (12) having a conductive layer (16) disposed on a semiconductor substrate (14). The conductive layer (16) is generally formed from the reaction of a metal with a portion of the semiconductor substrate (14). One example of the conductive layer (16) is a metal silicide layer. In one pressure sensing approach, a substantially constant reverse current (I.sub.1) is applied to the Schottky junction (12). The change in reverse output voltage of the junction (12) is proportional to the change in pressure on the junction (12) itself, and can thus be used to sense pressure. This output voltage change is significantly higher than that achieved with prior pressure transducers and permits the output signal of the transducer (10,30) according to the present invention to be substantially used without extra amplification or other conditioning.Type: GrantFiled: September 15, 1995Date of Patent: June 18, 1996Assignee: Motorola, Inc.Inventors: Dragan A. Mladenovic, Mahesh Shah
-
Patent number: 5514898Abstract: A semiconductor device comprises a piezoresistive pressure sensor (12), which has a membrane (14), which is constituted by a conducting epitaxy layer (16), which is applied to a conducting semiconductor substrate (18) of the opposite conductivity. On the outer surface (20) of the membrane facing away from the semiconductor substrate (18) at least one piezoresistor (22) is incorporated. Between the semiconductor substrate (18) and the epitaxy layer (16) an annularly structured intermediate layer (28) is incorporated, which defines a region (26'), adjoining the inner surface (24) of the membrane, of an opening (26) extending through the semiconductor substrate (18). This opening (26) is produced by anisotropic semiconductor etching, the intermediate layer (28) having a conductivity which is opposite to that of the semiconductor substrate so that this intermediate layer (28) functions as an etch stopping means and is not attacked by the etchant.Type: GrantFiled: April 3, 1995Date of Patent: May 7, 1996Assignee: Texas Instruments Deutschland GmbHInventor: Siegbert Hartauer
-
Patent number: 5500761Abstract: A method and apparatus for modulating an optical signal using a micromechanical modulator are disclosed. The modulator comprises a membrane, which consists of at least one layer, and a substrate, spaced to form an air gap. The layers of the membrane are characterized in that there is a relationship between the refractive indices of the layers and the refractive index of the substrate. The membrane is suspended in a first position over the substrate by a flexible support arrangement. Bias is applied to the membrane and the substrate to create an electrostatic force to move the membrane towards the substrate to a second position. The reflectivity of the device to an optical signal changes as the membrane moves from the first position to the second position, thereby modulating the signal.Type: GrantFiled: January 27, 1994Date of Patent: March 19, 1996Assignee: AT&T Corp.Inventors: Keith W. Goossen, James A. Walker
-
Patent number: 5500549Abstract: A semiconductor yaw rate sensor, which can be structured easily by means of an IC fabrication process, such that a yaw rate detection signal due to a current value is obtained by means of a transistor structure and a method of producing the same is disclosed. A weight supported by beams is disposed at a specified interval from a surface of a semiconductor substrate, and movable electrodes and excitation electrodes are formed integrally with the weight. Fixed electrodes for excitation use are fixed to the substrate in correspondence to the excitation electrodes. Along with this, source electrodes as well as drain electrodes are formed by means of a diffusion layer on a surface of the substrate at positions opposing the movable electrodes, such that drain current changes in correspondence with displacement of the movable electrodes by means of Corioli's force due to yaw rate, and the yaw rate is detected by this current.Type: GrantFiled: December 13, 1994Date of Patent: March 19, 1996Assignee: Nippondenso Co., Ltd.Inventors: Yukihiro Takeuchi, Kozo Shibata, Yoshinori Ohtsuka, Kazuhiko Kano, Toshimasa Yamamoto
-
Patent number: 5459351Abstract: An absolute pressure sensor subassembly includes a top cap bonded to a pressure sensor die and enclosing a reference vacuum. The subassembly is initially held in place within a housing by a vacuum or sublimeable solid adhesive while wire bonds from the subassembly to the housing leads are completed. A self-contained adhesive drop on the inner surface of the housing cover contacts the sensor subassembly when the cover is placed on the housing body and the sensor subassembly is supported by the adhesive drop.Type: GrantFiled: June 29, 1994Date of Patent: October 17, 1995Assignee: Honeywell Inc.Inventor: Terrence D. Bender
-
Patent number: 5444286Abstract: A semiconductor pressure sensor has a package base provided with an adhesive supporting portion for supporting nearly the entire lengths of inner portions of outer leads. Since nearly the entire lengths of the inner portions in a package are supported, the inner portions do not resonate even if the semiconductor pressure sensor vibrates, thereby preventing detachment of the wires bonded to the ends of the inner portions.Type: GrantFiled: February 3, 1994Date of Patent: August 22, 1995Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Motomi Ichihashi
-
Patent number: 5442227Abstract: The main surface of a semiconductor substrate, on which a field effect transistor is formed, coincides with the (nm0) lattice plane of the substrate and drain electrode thereof is oriented to flow drain current in a direction parallel to the [mn0] or [mn0] axis, wherein n and m independently represent an arbitrary integer, provided that n and m are not 0 at the same time, and that the quotient n/m (m is not zero) is not an integer. Accordingly, the plane orientation of the substrate and the direction of the drain current have a relationship such that no piezoelectric charges are induced in the channel region of the field effect transistor. Therefore, substantially no piezoelectric charges are generated even when a stress is produced in the dielectric layer formed on the substrate. Moreover, deterioration and variation in the electric characteristics due to the variation in the thickness of the dielectric layer are minimized.Type: GrantFiled: January 11, 1994Date of Patent: August 15, 1995Assignee: NEC CorporationInventors: Muneo Fukaishi, Hikaru Hida