Thin Film Ballasting Means (e.g., Polysilicon Resistor) Patents (Class 257/581)
  • Patent number: 10366964
    Abstract: A semiconductor device including a first semiconductor switching element having a first gate pad, a plurality of first emitter pads, and a first collector pad, a first wire for connecting adjacent pads out of the plurality of first emitter pads, a first output wire for connecting one of the plurality of first emitter pads to an output, a first controller for applying a gate voltage to the first gate pad, a first emitter wire that is directly connected to a first extraction pad which is any one pad of the plurality of first emitter pads, and is connected to the first controller to give a ground potential of the first controller, and a second semiconductor switching element having a second gate pad, a second emitter pad and a second collector pad connected to the output.
    Type: Grant
    Filed: April 23, 2018
    Date of Patent: July 30, 2019
    Assignee: Mitsubishi Electric Corporation
    Inventors: Taichi Obara, Rei Yoneyama, Masayuki Ando
  • Patent number: 9909939
    Abstract: Embodiments of a force sensing resistor (FSR) are disclosed. The FSR has one or more external conductive layers, applied to at least part of the contact surface of the FSR, so that when a conductive probe presses the FSR, initial zero-force contact with the FSR can be detected immediately. The external conductive layer or layers may be rigid sheet metal, flexible sheet metal, metallic-coated polymer, conductive polymer, conductive elastomer, or other conductive material. A lead or trace may be electrically coupled to the external conductive layer or layers to allow for ease of coupling to a circuit or circuit board.
    Type: Grant
    Filed: June 7, 2016
    Date of Patent: March 6, 2018
    Assignee: Adonit Co., Ltd.
    Inventors: Yu-Kuang Hou, Zachary Joseph Zeliff, Reinier Bloem, Michael A. Justice
  • Patent number: 8901626
    Abstract: A field effect transistor device includes a gate stack disposed on a substrate a first contact portion disposed on a first distal end of the gate stack, a second contact portion disposed on a second distal end of the gate stack, the first contact portion disposed a distance (d) from the second contact portion, and a third contact portion having a width (w) disposed in a source region of the device, the distance (d) is greater than the width (w).
    Type: Grant
    Filed: July 20, 2012
    Date of Patent: December 2, 2014
    Assignee: International Business Machines Corporation
    Inventors: Dechao Guo, Wilfried E. Haensch, Xinhui Wang, Keith Kwong Hon Wong
  • Patent number: 8748988
    Abstract: A semiconductor device has a semiconductor substrate, a field insulating film disposed on a surface of the semiconductor substrate, a base insulating film disposed on a surface of the field insulating film, and a resistor disposed on the base insulating film. The resistor is formed of a polycrystalline silicon film and has a resistance region and electrode lead-out regions disposed at both ends of the resistance region. A portion of the base insulating film below the resistance region projects with respect to portions of the base insulating film below the electrode lead-out regions so that a height difference occurs therebetween. The resistance region has a thickness thinner than that of each of the electrode lead-out regions.
    Type: Grant
    Filed: May 26, 2011
    Date of Patent: June 10, 2014
    Assignee: Seiko Instruments Inc.
    Inventor: Yuichiro Kitajima
  • Patent number: 8610215
    Abstract: An electronic device includes a semiconductor substrate and a dielectric layer over the substrate. A resistive link located over the substrate includes a first resistive region and a second resistive region. The first resistive region has a first resistivity and a first morphology. The second resistive region has a second resistivity and a different second morphology.
    Type: Grant
    Filed: September 19, 2008
    Date of Patent: December 17, 2013
    Assignee: Agere Systems LLC
    Inventors: Frank A. Baiocchi, James T. Cargo, John M. DeLucca, Barry J. Dutt, Charles Martin
  • Patent number: 7964469
    Abstract: In a method of manufacturing a semiconductor device, a first oxide film is formed in a convex shape on a field insulating film, a polycrystalline silicon film is formed on the first oxide film, and impurities are introduced into the polycrystalline silicon film. The polycrystalline silicon film into which the impurity is introduced is patterned so that a portion above the convex-shaped first oxide film becomes a resistance region of the resistor. A second oxide film is then formed on the patterned polycrystalline silicon film followed by the formation of a third oxide film on the second oxide film. The third oxide film and parts of the second oxide film and the polycrystalline silicon film are then removed to form a planarized surface including surface portions of the second oxide film and the polycrystalline silicon film.
    Type: Grant
    Filed: February 13, 2007
    Date of Patent: June 21, 2011
    Assignee: Seiko Instruments Inc.
    Inventor: Yuichiro Kitajima
  • Patent number: 7732896
    Abstract: A semiconductor apparatus comprises a plurality of transistor devices including a control terminal being inputted with a control signal and a first and a second terminals that a current flows therein according to the control signal, and a plurality of substrate conductive portions each formed in a region different from a region where the plurality of transistor devices are formed therein, wherein the transistor devices are connected to the substrate conductive portions, and each of the substrate conductive portion includes a semiconductor layer separated from other substrate conductive portions.
    Type: Grant
    Filed: July 5, 2006
    Date of Patent: June 8, 2010
    Assignee: NEC Electronics Corporation
    Inventor: Kouzi Hayasi
  • Patent number: 7615775
    Abstract: A semiconductor apparatus in which a conducting path formed from organic semiconductor molecules as a material has a novel structure and exhibits high mobility, and a manufacturing method for fabricating the same are provided. Fine particles that include a conductor or a semiconductor and organic semiconductor molecules, are alternately bonded through a functional group at both terminals of the organic semiconductor molecules to form a conducting path in a network form such that the conducting path in the fine particles and the conducting path in the organic semiconductor molecules are two-dimensionally or three-dimensionally linked together.
    Type: Grant
    Filed: July 2, 2003
    Date of Patent: November 10, 2009
    Assignee: Sony Corporation
    Inventors: Masaru Wada, Shinichiro Kondo, Ryouichi Yasuda
  • Patent number: 7414298
    Abstract: The invention relates to a process of forming a compact bipolar junction transistor (BJT) that includes forming a self-aligned collector tap adjacent the emitter stack and an isolation structure. A base layer is formed from epitaxial silicon that is disposed in the substrate.
    Type: Grant
    Filed: July 31, 2003
    Date of Patent: August 19, 2008
    Assignee: Intel Corporation
    Inventors: Shahriar Ahmed, Mark Bohr, Stephen Chambers, Richard Green
  • Patent number: 7365397
    Abstract: The semiconductor device comprises a resistance element 26 formed of polysilicon film formed on a silicon substrate 10, which includes a resistor part 26a having a resistance value set at a prescribed value, contact parts 26b formed on both sides of the resistor part 26a and connected to a line for applying a fixed potential, and a heat radiation part 26c connected to the contact part 26b, whereby the semiconductor device can include the resistance element having a small parasitic capacitance and good heat radiation.
    Type: Grant
    Filed: October 31, 2005
    Date of Patent: April 29, 2008
    Assignee: Fujitsu Limited
    Inventor: Hiroshi Nomura
  • Patent number: 7323762
    Abstract: A semiconductor package substrate with embedded resistors and a method for fabricating the same are proposed. Firstly, an inner circuit board having a first circuit layer thereon is provided, and a plurality of resistor electrodes are formed in the fist circuit layer. Then, a patterned resistive material is formed on the inner circuit board and electrically connected to the resistor electrodes to accurately define a resistance value of resistors. Subsequently, at least one insulating layer is coated on a surface of the circuit board having the patterned resistive material. At least one patterned second circuit layer is formed on the insulating layer and electrically connected to the resistor electrodes by a plurality of conductive vias formed in the insulating layer or plated through holes formed through the circuit board.
    Type: Grant
    Filed: November 1, 2004
    Date of Patent: January 29, 2008
    Assignee: Phoenix Precision Technology Corporation
    Inventors: Zao-Kuo Lai, Lin-Yin Wong
  • Patent number: 7250348
    Abstract: A method and apparatus for packaging semiconductor devices using patterned laminate films to reduce stress buffering. The method includes fabricating a semiconductor die having thin film resistors and bond pads formed on an active surface. A film layer is formed onto the active surface of the die, covering the thin film resistors and bond pads. The film layer is then patterned to create recesses in the film layer in the vicinity of the bond pads on the active surface of the die. The die then undergoes wire bonding and is next encapsulated in a molding compound. The film layer between the film resister and the molding compound reduces stress buffering created by the molding compound.
    Type: Grant
    Filed: November 12, 2004
    Date of Patent: July 31, 2007
    Assignee: National Semiconductor Corporation
    Inventors: Zabarulla Hanifah, Pradeep A/L P. Divakaran, Low Chian Inn, Lim Leong Heng
  • Patent number: 7180139
    Abstract: A pixel structure controlled by a scan line and a data line on a substrate is provided. The pixel structure comprises a thin film transistor, a resistance wire, a first pixel electrode, and a second pixel electrode, which are disposed on the substrate. Additionally, the thin film transistor is electrically connected to the scan line, the data line, and the resistance wire. Further, the first pixel electrode is electrically connected to the thin film transistor and the second pixel electrode is electrically connected to the thin film transistor by the resistance wire. Especially, a method of manufacturing a pixel structure is also provided.
    Type: Grant
    Filed: January 20, 2005
    Date of Patent: February 20, 2007
    Assignee: Au Optronics Corporation
    Inventor: Han-Chung Lai
  • Patent number: 7019337
    Abstract: Power semiconductor switching devices, power converters, integrated circuit assemblies, integrated circuitry, power current switching methods, methods of forming a power semiconductor switching device, power conversion methods, power semiconductor switching device packaging methods, and methods of forming a power transistor are described. One exemplary aspect provides a power semiconductor device including a semiconductive substrate having a surface; and a power transistor having a planar configuration and comprising a plurality of electrically coupled sources and a plurality of electrically coupled drains formed using the semiconductive substrate and adjacent the surface.
    Type: Grant
    Filed: November 7, 2003
    Date of Patent: March 28, 2006
    Assignee: Isothermal Systems Research, Inc.
    Inventors: Richard C. Eden, Bruce A. Smetana
  • Patent number: 6897545
    Abstract: The transistor includes an emitter region 17 disposed in a first isolating well 11, 150 formed in a semiconductor bulk. An extrinsic collector region 16 is disposed in a second isolating well 3, 150 formed in the semiconductor bulk SB and separated laterally from the first well by a bulk separator area 20. An intrinsic collector region is situated in the bulk separator area 20 in contact with the extrinsic collector region. An intrinsic base region 100 is formed which is thinner laterally than vertically and in contact with the intrinsic collector region and in contact with the emitter region through bearing on a vertical flank of the first isolating well facing a vertical flank of the second isolating well. An extrinsic base region 60 is formed which is substantially perpendicular to the intrinsic base region in the top part of the bulk separator area, and contact terminals C, B, E respectively in contact with the extrinsic collector region, the extrinsic base region, and the emitter region.
    Type: Grant
    Filed: May 9, 2002
    Date of Patent: May 24, 2005
    Assignee: STMicroelectronics S.A.
    Inventors: Olivier Menut, Herve Jaouen
  • Patent number: 6858917
    Abstract: A metal oxide semiconductor (MOS) bandgap voltage reference circuit with a plurality of dummy bipolar junction transistors (BJTs) coupled to the mismatched parasitic substrate BJTs for improving parasitic capacitance matching, thereby improving startup behavior of the bandgap reference circuitry.
    Type: Grant
    Filed: December 5, 2003
    Date of Patent: February 22, 2005
    Assignee: National Semiconductor Corporation
    Inventor: Paul David Ranucci
  • Patent number: 6767781
    Abstract: A bitline contact and method of forming bitline contact for a vertical DRAM array using a bitline contact mask. In the method, gate conductor lines are formed. An oxide layer is deposited over the gate conductor lines, and a bitline contact mask is formed over portions of the oxide layer. The bitline contact mask is etched, and a silicon layer is deposited on the substrate. A bitline layer is deposited on the silicon layer. A masking and etching operation is performed on the bitline layer. A M0 metal is deposited over the silicon layer and on sides of non etched portions of the bitline (M0) layer to form left and right bitlines.
    Type: Grant
    Filed: September 23, 2003
    Date of Patent: July 27, 2004
    Assignees: International Business Machines Corporation, Infineon Technologies North America Corp.
    Inventors: Larry A. Nesbit, Jonathan E. Faltermeier, Ramachandra Divakaruni, Wolfgang Bergner
  • Patent number: 6703685
    Abstract: The invention relates to a process of forming a compact bipolar junction transistor (BJT) that includes forming a self-aligned collector tap adjacent the emitter stack and an isolation structure. A base layer is formed from epitaxial silicon that is disposed in the substrate.
    Type: Grant
    Filed: December 10, 2001
    Date of Patent: March 9, 2004
    Assignee: Intel Corporation
    Inventors: Shahriar Ahmed, Mark Bohr, Stephen Chambers, Richard Green
  • Patent number: 6690082
    Abstract: The present invention provides a high dopant concentration diffused resistor, a method of manufacture therefor, and an integrated circuit including the same. In one embodiment of the invention, the high dopant concentration diffused resistor includes a doped tub located over a semiconductor substrate and a doped resistor region located in the doped tub, the doped resistor region forming a junction within the doped tub. In a related embodiment, the high dopant concentration diffused resistor further includes first and second terminals each contacting the doped tub and the doped resistor region, wherein the first and second terminals cause the doped tub and doped resistor region to have a zero potential difference at any point across the junction when a voltage is applied to the first and second terminals.
    Type: Grant
    Filed: September 27, 2002
    Date of Patent: February 10, 2004
    Assignee: Agere Systems Inc.
    Inventor: Kadaba R. Lakshmikumar
  • Patent number: 6656812
    Abstract: A vertical bipolar transistor includes a semiconductor substrate, an extrinsic collector layer in the semiconductor substrate, an intrinsic collector on the extrinsic collector, a lateral isolating region surrounding an upper part of the intrinsic collector, an offset extrinsic collector well, a base including a semiconductor region above the intrinsic collector and above the lateral isolating region including at least one silicon layer, and a doped emitter surrounded by the base. The doped emitter may include first and second parts. The first part may be formed from single-crystal silicon and in direct contact with the upper surface of the semiconductor region in a predetermined window in the upper surface above the intrinsic collector. The second part may be formed from polycrystalline silicon. The two parts of the emitter may be separated by a separating oxide layer spaced apart from the emitter-base junction of the transistor.
    Type: Grant
    Filed: November 21, 2000
    Date of Patent: December 2, 2003
    Assignee: STMicroelectronics SA
    Inventors: Michel Marty, Didier Dutartre, Alain Chantre, Sébastien Jouan, Pierre Llinares
  • Patent number: 6482710
    Abstract: A bipolar transistor according to the invention is provided with structure that an intrinsic base made of single crystal Si—Ge and a base leading-out electrode are connected via a link base made of polycrystal Si—Ge by doping at high concentration, further, a part immediately under the intrinsic base has the same conductive type as that of a collector and in a peripheral part, a single crystal Si—Ge layer having the same conductive type as that of a base is provided between the intrinsic base and a collector layer. Hereby, the reduction of the resistance of the link base between the intrinsic base and the base leading-out electrode and the reduction of capacitance between the collector and the base are simultaneously realized, and a self-aligned bipolar transistor wherein capacitance between an emitter and the base and capacitance between the collector and the base are respectively small, power consumption is small and high speed operation is enabled is acquired.
    Type: Grant
    Filed: March 20, 2001
    Date of Patent: November 19, 2002
    Assignees: Hitachi, Ltd., Hitachi Device Engineering Co., Ltd.
    Inventors: Katsuya Oda, Eiji Ohue, Masao Kondo, Katsuyoshi Washio, Masamichi Tanabe, Hiromi Shimamoto
  • Patent number: 6437419
    Abstract: A power semiconductor device has an integral source/emitter ballast resistor. The gate has partial gate structures spaced apart from each other. Emitter resistors are provided beneath sidewall spacers on the ends of the gate structures. The emitter resistors have little effect on the threshold voltage under normal operating conditions, but rapidly saturate the device during short circuit conditions. This in turn increases the short circuit withstand capability o the device.
    Type: Grant
    Filed: November 29, 1999
    Date of Patent: August 20, 2002
    Assignee: Fairchild Semiconductor Corporation
    Inventors: Anup Bhalla, Praveen Muraleedharan Shenoy
  • Publication number: 20020030184
    Abstract: A structure and a fabrication method of a flat panel display comprising address lines with mending layers. A first address line and a first mending layer are formed on a substrate. The first mending layer and the first address line are electrically insulated with each other, and the first mending layer is partitioned into different segments by the first address line. A first insulating layer is formed over the substrate to cover at least the first mending layer and the first address line. A second address line is formed on the first insulating layer over the first mending layer and crossing the first address line. A second insulating layer is formed over the substrate to cover at least the second address line. A second mending layer is formed on the second insulating layer over the second address line and crossing the first address line.
    Type: Application
    Filed: January 23, 2001
    Publication date: March 14, 2002
    Inventor: Biing-Seng Wu
  • Publication number: 20010021544
    Abstract: In a crystallization process of an amorphous semiconductor film, a first crystalline semiconductor film having crystalline regions, and dotted with amorphous regions within the crystalline regions, is obtained by performing heat treatment processing after introducing a metallic element which promotes crystallization on the amorphous semiconductor film. The amorphous regions are kept within a predetermined range by regulating the heat treatment conditions at this point. Laser annealing is performed on the first crystalline semiconductor film, to form a second crystalline semiconductor film. Electrical characteristics for a TFT manufactured based on the second crystalline semiconductor film can be obtained having less dispersion.
    Type: Application
    Filed: March 5, 2001
    Publication date: September 13, 2001
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hideto Ohnuma, Chiho Kokubo, Koichiro Tanaka, Naoki Makita, Shuhei Tsuchimoto
  • Publication number: 20010012648
    Abstract: A method of manufacturing a thin film transistor. A gate electrode is formed on a substrate. Then a first gate insulation layer is formed on the gate electrode and on the substrate. The first gate insulation layer is then cleaned to remove contaminates. After cleaning, a second gate insulation layer is then formed on the first gate insulation layer. Beneficially, the first and second gate insulation layers are of the same material. An active layer having an ohmic contact layer is then formed on the second insulation layer. Spaced apart source and drain electrodes are then formed on the ohmic contact.
    Type: Application
    Filed: December 15, 2000
    Publication date: August 9, 2001
    Inventor: Seong-Su Lee
  • Patent number: 6211562
    Abstract: A homojunction bipolar transistor with performance characteristics similar to more costly heterojunction or retrograde base transistors. The high emitter resistivity found in prior homojunction devices is circumvented using a low work function material layer in forming the emitter. This produces an economically viable high performance alternative to SiGe HBTs or SiGe retrograde base transistors.
    Type: Grant
    Filed: February 24, 1999
    Date of Patent: April 3, 2001
    Assignee: Micron Technology, Inc.
    Inventors: Leonard Forbes, Kie Y. Ahn
  • Patent number: 6130471
    Abstract: A ballasted transistor structure reduces thermal runaway. A heterojunction bipolar junction transistor array includes a plurality of transistors, each having an emitter, a base and a collector. Each of the bases is an alloy of silicon and germanium and each of the collectors and emitters is silicon. A ballast resistor, of doped silicon, that prevents thermal runaway, is electrically connected to each of the collectors.
    Type: Grant
    Filed: August 29, 1997
    Date of Patent: October 10, 2000
    Assignee: The Whitaker Corporation
    Inventor: Timothy Edward Boles
  • Patent number: 6013942
    Abstract: In order to avoid thermal runaway bipolar transistors, emitters are provided with ballast resistors. Elongate ballast resistors may be used, part of the lengths being connected for obtaining suitable resistance and design variability. The emitters are split up into a plurality of emitter portions, each with a separate emitter ballast resistor. The collector and base are correspondingly split up. The transistor is split up into unit cells, each comprising an emitter, a ballast resistor, a base, and a collector, which are respectively connected via respective common leads. This structure may advantageously be realized in a SOI technique, the galvanic isolation enabling unproblematic mixing of digital and analog and power devices in the same chip.
    Type: Grant
    Filed: April 3, 1998
    Date of Patent: January 11, 2000
    Assignee: Telefonakteibolaget LM Ericsson
    Inventors: Anders Soderbarg, Nils Ola Ogren, H.ang.kan Sjodin
  • Patent number: 5990539
    Abstract: A transistor component is suited for controlling large currents, even given high frequencies. The transistor component includes integrated emitter resistors which are arranged between partial-emitter regions and emitter-metal contacts. The integrated emitter resistors cause a stabilized, uniform current distribution both over the various partial-emitter regions, and within the partial-emitter regions, and bring about an improved current carrying capacity, as well as improved high-frequency properties, particularly in view of the finite magnitude of the extrinsic base resistance.
    Type: Grant
    Filed: August 5, 1998
    Date of Patent: November 23, 1999
    Assignee: Robert Bosch GmbH
    Inventors: Gerhard Conzelmann, Heinz Pfizenmaier, Wolfgang Appel, Volker Dudek, Helmut Schneider
  • Patent number: 5907180
    Abstract: The present invention, generally speaking, provides an apparatus and method whereby the current flow through an RF power transistor may be monitored without the use of any external parts. More particularly, in accordance with one embodiment of the invention, an RF power transistor includes a silicon die, a pair of interdigitated electrodes formed on the silicon die, each having a multiplicity of parallel electrode fingers and at least one bond pad. Regions of a first type of diffusion are formed beneath electrode fingers of one electrode of the pair of interdigitated electrodes, and regions of a second type of diffusion are formed beneath electrode fingers of another electrode of the pair of interdigitated electrodes. One electrode has multiple electrode fingers and multiple resistors formed on the silicon die, at least one resistor connected in series with each one of the electrode fingers.
    Type: Grant
    Filed: January 22, 1997
    Date of Patent: May 25, 1999
    Assignee: Telefonaktiebolaget L.M. Ericsson
    Inventors: Ted Johansson, Larry Leighton
  • Patent number: 5821602
    Abstract: Increased gain and improved stability are realized in using resistive emitter ballasting by including integrated capacitive elements in parallel with the resistive elements in the emitter circuit. A feature of the invention is an integrated capacitor structure having a small surface area to minimize parasitic capacitance, whereby resistor and capacitor surface areas of 100 square micrometers or less are obtained. Another feature of the invention is the use of a high dielectric material in realizing a resistor-capacitor impedance zero at a frequency much lower than the operating frequency of the transistor. For an operating frequency of 2 GHz and resistor values of 50-250 ohms, capacitance required is 3 pF or greater. Another feature of the invention is a method of fabricating the integrated resistive-capacitive element in either a low temperature process or a high temperature process which minimizes capacitor leakage when using a thin high dielectric insulative material between capacitor plates.
    Type: Grant
    Filed: November 25, 1996
    Date of Patent: October 13, 1998
    Assignee: Spectrian, Inc.
    Inventors: Francois Hebert, William McCalpin
  • Patent number: 5798561
    Abstract: A semiconductor device including a bipolar transistor is provided, which can reduce the base resistance of the transistor. This device includes a semiconductor base region having a first semiconductor active region of a first conductivity type in its inside. A first insulating layer is formed on the main surface of the substructure to cover the first active region. The first insulating layer has a first penetrating window exposing the first active region. A semiconductor contact region of a second conductivity type is formed on the first insulating layer. The contact region has an overhanging part which overhangs the first window. The second window is defined by the inner end of the overhanging part to be entirely overlapped with the first window. The contact region is made of a polycrystalline semiconductor. A second semiconductor active region of the second conductivity type is formed on the first active region in the first window.
    Type: Grant
    Filed: October 15, 1996
    Date of Patent: August 25, 1998
    Assignee: NEC Corporation
    Inventor: Fumihiko Sato
  • Patent number: 5760457
    Abstract: A bipolar transistor circuit element includes a semiconductor substrate; successively disposed on the substrate, a base layer, an emitter layer, and a collector layer; a bipolar transistor formed from parts of the collector, base, and emitter layers and including a base electrode electrically connected to the base layer and a base electrode pad for making an external connection to the base layer; a base ballasting resistor formed from a part of the base layer isolated from the bipolar transistor and electrically connecting the base electrode to the base electrode pad; and a base parallel capacitor connected in parallel with the base ballasting resistor wherein the base parallel capacitor includes part of the base input pad, a dielectric film disposed on part of the base electrode pad, and a second electrode disposed on the dielectric layer opposite the base electrode pad and electrically connected to the emitter electrode of the bipolar transistor.
    Type: Grant
    Filed: February 26, 1997
    Date of Patent: June 2, 1998
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Shigeru Mitsui, Takuji Sonoda, Teruyuki Shimura, Saburo Takamiya
  • Patent number: 5684326
    Abstract: An apparatus and method are provided for bypassing the emitter ballast resistors of a power transistor, thereby increasing transistor gain. In a power transistor of the interdigitated type, bypassing the emitter ballast resistors requires bypassing each individual ballast resistor with a capacitor in parallel. Bypassing is therefore done on the silicon chip. More particularly, in accordance with one embodiment of the invention, an RF power transistor includes a silicon die, an emitter ballast resistor formed on the silicon die, and a bypass capacitor formed on the silicon die and connected in parallel with the emitter ballast resistor. The resistor may be a diffused resistor, and the capacitor may be a metal-on-polysilicon capacitor.
    Type: Grant
    Filed: February 24, 1995
    Date of Patent: November 4, 1997
    Assignee: Telefonaktiebolaget L.M. Ericsson
    Inventors: Ted Johansson, Larry Leighton
  • Patent number: 5510642
    Abstract: An insular shaped polycrystalline silicon film is formed by adhering its entire bottom face to the surface of a insulation film which is formed on the main face of a silicon substrate. A resistance element which contains designated impurities is formed in the central part of the polycrystalline silicon film. A non-doping region which essentially does not contain impurities and is adheres to all the sides of the resistance element, is positioned on the peripheral region except for the central part of the polycrystalline silicon film. By performing heat treatment when a non-doping amorphous silicon pattern is formed on the insulating film, the amorphous silicon pattern is convened to a non-doping polycrystalline silicon pattern. By using this method, a semiconductor device which has only small variances in its resistance value, which provides more efficient heat radiation, and which enables higher integration of a silicon substrate can be obtained.
    Type: Grant
    Filed: December 16, 1994
    Date of Patent: April 23, 1996
    Assignee: NEC Corporation
    Inventor: Chihiro Ogawa
  • Patent number: 5444292
    Abstract: The ballast resistance of a semiconductor device is increased without decreasing the figure of merit of the device. The semiconductor device includes an emitter feeder, a first contact coupled to the emitter feeder, a second contact, a resistive medium connected between the first contact and the second contact, an emitter, and a further resistive medium connected between the second contact and the emitter. The ballast resistance of the semiconductor device is increased without decreasing the figure of merit of the device by increasing the distance between the first contact and the second contact.
    Type: Grant
    Filed: April 4, 1994
    Date of Patent: August 22, 1995
    Assignee: SGS-Thomson Microelectronics, Inc.
    Inventor: William P. Imhauser
  • Patent number: 5374844
    Abstract: A transistor structure incorporates a polysilicon layer which is doped with N-type dopants and is used as an emitter ballast resistor in an array of NPN transistors. In one embodiment, the polysilicon layer is also used as a diffusion source to form N-type emitter regions within a deep and high resistivity P-well, which acts as a relatively high value base ballast resistor for the transistor. In another embodiment, a standard base is used, contributing little base ballast resistance. A buried collector region carries collector current. Preferably, the emitter regions are formed as oblong strips. P-type base contact regions, also generally formed as oblong strips, are formed in the surface of this P-well parallel to the emitter regions. The dimensions of the base contact regions may be varied in order to achieve a constant base-emitter voltage along the entire length of each emitter strip.
    Type: Grant
    Filed: February 17, 1994
    Date of Patent: December 20, 1994
    Assignee: Micrel, Inc.
    Inventor: James C. Moyer
  • Patent number: 5298785
    Abstract: A multi-emitter type semiconductor device having multiple transistors coupled in parallel which utilize a common substrate. Between a selected emitter electrode and a base contact, a stabilizing resistive region is formed in the common substrate. In order to reduce the parasitic effects due to this region an additional emitter ballast resistor may be formed on the surface of an insulating layer over the substrate. This supplemental resistor formed on the insulating layer is made from polycrystalline silicon. Alternatively, the supplemental resistor can be combined with the resistance of the stabilizing region in a single resistor located on the surface of the insulating layer.
    Type: Grant
    Filed: April 18, 1991
    Date of Patent: March 29, 1994
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Shinichi Ito, Jiro Terashima