Lateral Bipolar Transistor Structure Patents (Class 257/557)
  • Patent number: 5478760
    Abstract: A process for fabricating a bipolar junction transistor by forming a trench in a silicon substrate. A lightly-doped base region is formed adjacent to the sidewalls of the trench, and a heavily-doped base region is formed under the bottom of the trench. Silicon oxide layers are formed along the sidewalls and bottom of the trench with a contact window provided to expose part of the lightly-doped base region. A polysilicon layer is formed in the trench, and is heavily doped by a dopant which in turn diffuses into the lightly-doped base region through the contact window to form an emitter region. A collector region is formed in the upper surface of the lightly-doped base region.
    Type: Grant
    Filed: March 27, 1995
    Date of Patent: December 26, 1995
    Assignee: United Microelectronics Corp.
    Inventor: Sheng-Hsing Yang
  • Patent number: 5465006
    Abstract: This invention pertains to a lateral bipolar transistor comprising an emitter, a base and a collector. The transistor exhibits improved function and overall size reduction, due to the base and emitter structure. An island forms both the base and emitter regions in the transistor structure with the base region being above the collector region, below the emitter region, and surrounded by a dielectric region. The emitter is surrounded by emitter isolation walls, which are formed approximately 0.2 microns above the plane of the dielectric region, such that any manufacturing variances will not cause the emitter isolation walls to contact the dielectric region and pinch-off the base region from the base junction region. This structure also allows the size of the base-emitter junction to be decreased without increasing the parasitic characteristics of the transistor.
    Type: Grant
    Filed: July 15, 1994
    Date of Patent: November 7, 1995
    Assignee: Hewlett-Packard Company
    Inventor: Yaw-Hwang Chen
  • Patent number: 5448104
    Abstract: A back gate bias voltage is applied to the underside of a lateral bipolar transistor to desensitize a portion of the collector-base depletion region to changes in the collector-base voltage. Emitter-collector current flows through an active base region bypassing the portion of the collector-base depletion region that remains sensitive to the collector bias. This allows for a control over the charge in the active base region by the back gate bias, generally independent of the collector-base bias. The transistor is preferably implemented in a silicon-on-insulator-on-silicon (SOIS) configuration, with the back gate bias applied to a doped silicon substrate. The base doping concentration and the thickness of the underlying insulator are preferably selected to produce an inversion layer in the base region adjacent the insulating layer, thereby reducing the collector access resistance.
    Type: Grant
    Filed: September 14, 1994
    Date of Patent: September 5, 1995
    Assignee: Analog Devices, Inc.
    Inventor: Kevin J. Yallup
  • Patent number: 5442226
    Abstract: In a semiconductor device, an emitter electrode has a polysilicon layer provided in a first contact hole and on a first insulating film. The polysilicon layer is in contact with an emitter region and is covered with a metal layer. A second contact hole is provided on a part of a second insulating film located on a substantially flat portion of the metal layer. A third contact hole is provided in those portions of the first insulating film and a second insulating layer which are located on a base region.
    Type: Grant
    Filed: April 26, 1993
    Date of Patent: August 15, 1995
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takeo Maeda, Hiroshi Gojohbori, Takeo Nakayama
  • Patent number: 5426328
    Abstract: A process is disclosed which simultaneously forms high quality complementary bipolar transistors, relatively high voltage CMOS transistors, relatively low voltage CMOS transistors, DMOS transistors, zener diodes and thin-film resistors, or any desired combination of these, all on the same integrated circuit chip. The process uses a small number of masking steps, forms high performance transistor structures, and results in a high yield of functioning die. Isolation structures, bipolar transistor structures, CMOS transistor structures, DMOS transistor structures, zener diode structures, and thin-film resistor structures are also disclosed.
    Type: Grant
    Filed: April 11, 1994
    Date of Patent: June 20, 1995
    Assignee: Siliconix incorporated
    Inventors: Hamza Yilmaz, Richard K. Williams, Michael E. Cornell, Jun W. Chen
  • Patent number: 5424575
    Abstract: A semiconductor device has an electrically insulating substrate and a semiconductor layer formed on the insulating substrate. A plurality of semiconductor regions are defined so as to be joined to each other to form at least two homojunctions in the semiconductor layer. A lead conductor for one of the semiconductor regions which is required to have a small thickness has a specific structure such that the lead conductor is in contact with the one semiconductor region at the main surface of the semiconductor layer for electrical connection therebetween and extends over that portion of the semiconductor layer which contributes to definition of at least one of the semiconductor regions other than the first-mentioned one semiconductor region.
    Type: Grant
    Filed: June 1, 1992
    Date of Patent: June 13, 1995
    Assignee: Hitachi, Ltd.
    Inventors: Katsuyoshi Washio, Tohru Nakamura, Takahiro Onai, Masatada Horiuchi, Takashi Uchino
  • Patent number: 5422502
    Abstract: A lateral bipolar transistor is provided in which the active base region comprises a layer of a material providing a predetermined valence band offset relative to the emitter and collector regions, to enhance transport of carriers from the emitter to the collector in a lateral manner. In particular, a silicon hetero-junction lateral bipolar transistor (HLBT) is provided. The lateral bipolar transistor structure and method of fabrication of the transistor is compatible with a bipolar-CMOS integrated circuit. Preferably the base region comprises a silicon-germanium alloy or a silicon-germanium superlattice structure comprising a series of alternating layers of silicon and silicon-germanium alloy.
    Type: Grant
    Filed: December 9, 1993
    Date of Patent: June 6, 1995
    Assignee: Northern Telecom Limited
    Inventor: Stephen J. Kovacic
  • Patent number: 5420457
    Abstract: A semiconductor device comprising a semiconductor substrate with a base region, a collector region and an emitter region in a lateral arrangement. The base region having a first conductivity type, and the collector and emitter regions having a second conductivity type. A first conductor layer is patterned over the substrate with a base contact portion, a collector contact portion and an emitter contact portion, with the base contact portion, the collector contact portion and the emitter contact portion contacting the base region, the collector region and the emitter region, respectively. A second conductor layer is patterned over a portion of the base region and is electrically coupled to the emitter contact portion, whereby the second conductor layer functions as an electrostatic shield for the base region.
    Type: Grant
    Filed: November 12, 1993
    Date of Patent: May 30, 1995
    Assignee: AT&T Corp.
    Inventor: Muhammed A. Shibib
  • Patent number: 5404043
    Abstract: A sidewall construction is utilized in the fabrication of semiconductor devices comprising planar type bipolar transistors wherein the width of the sidewall construction can be accuracy controlled which, in turn, controls accuracy the channel length of the base of the planar type bipolar transistors. This technique provides ways of preventing short circuiting between the formed transistor collector and emitter regions of the planar type bipolar transistors. The sidewall construction can also be employed in fabrication combination planar type bipolar/MIS type transistors resulting in higher density of these structures over the prior art laterally positioned structures.
    Type: Grant
    Filed: October 20, 1993
    Date of Patent: April 4, 1995
    Assignee: Seiko Epson Corporation
    Inventor: Toshihiko Higuchi
  • Patent number: 5382815
    Abstract: A Conductor Insulator Semiconductor (CIS) heterojunction transistor. The CIS transistor is on silicon (Si) substrate. A layer of n type Si is deposited on the substrate. A trench is formed through the n type Si layer, and may extend slightly into the substrate. The trench is filled with an insulator, preferably SiO.sub.2. A layer of p type Si.sub.1-z Ge.sub.z (where z is the mole fraction of Ge and 0.1.ltoreq.z.ltoreq.0.9) is deposited on the n type Si layer. A p.sup.+ base contact region is defined in the p type Si.sub.1-z Ge.sub.z region above the oxide filled trench. A n type dopant is ion implanted into both the Si.sub.1-z Ge.sub.z and n Si layers and may extend slightly into the substrate, forming a collector region. A thin oxide layer is deposited on the Si.sub.1-z Ge.sub.z layer and a low work function metal such as Al, Mg, Mn, or Ti is selectively deposited on the thin oxide and to define an emitter. Alternatively, the emitter may be p.sup.+ polysilicon.
    Type: Grant
    Filed: December 23, 1993
    Date of Patent: January 17, 1995
    Assignee: International Business Machines Corporation
    Inventors: Shaikh N. Mohammad, Robert B. Renbeck, Keith M. Walter
  • Patent number: 5355015
    Abstract: A lateral pnp transistor for use in programmable logic arrays. The lateral pnp has a layer of oxide disposed between a polysilicon layer and the base along the base width. The oxide layer prevents diffusion of the N+ dopant contained in the polysilicon layer into the N- base region. The base region thus remains N- and the resulting transistor has improved breakdown voltage characteristics while retaining the speed advantages of polysilicon contact layers. The lateral pnp transistor is manufactured by a method which requires minimal deviation from other methods used to manufacture lateral pnp transistors.
    Type: Grant
    Filed: November 27, 1991
    Date of Patent: October 11, 1994
    Assignee: National Semiconductor Corporation
    Inventors: Brian McFarlane, Frank Marazita, John E. Readdie
  • Patent number: 5347156
    Abstract: A lateral transistor includes a semiconductor substrate, a buried layer formed on the semiconductor substrate, an epitaxial layer formed on the buried layer in such a manner that the epitaxial layer is a p-type or n-type (first conductivity-type), a diffusion zone having a second conductivity-type opposite to the first conductivity-type and including an emitter zone and collector zone formed on the epitaxial layer, and a base zone. The base zone includes an epitaxial layer interposed between the emitter zone and the collector zone. The collector zone is formed within a well zone in such a manner that the well zone has the same type conductivity as the collector zone and a lower concentration than the collector zone.
    Type: Grant
    Filed: June 18, 1992
    Date of Patent: September 13, 1994
    Assignee: Rohm Co., Ltd.
    Inventor: Hisashi Sakaue
  • Patent number: 5341021
    Abstract: A contact hole for guiding an emitter electrode of bipolar transistors continuously arrayed and a contact hole for guiding a base electrode are positioned not to be arranged in the continuous array direction of the bipolar transistors. Also, the emitter electrode and the base electrode are respectively drawn from these contact holes in two directions different from the continuous array direction of the bipolar transistors. At least one of the base electrode and the emitter electrode is formed on a conductive layer of a polycide structure contacting an active region in a substrate to be connected.
    Type: Grant
    Filed: March 9, 1992
    Date of Patent: August 23, 1994
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takeo Maeda, Hiroshi Momose
  • Patent number: 5341023
    Abstract: A lateral bipolar transistor has an extrinsic base layer on either side of a centrally disposed emitter layer and an intrinsic base and a collector oriented perpendicularly to the extrinsic base and collector layers.
    Type: Grant
    Filed: June 18, 1992
    Date of Patent: August 23, 1994
    Assignee: International Business Machines Corporation
    Inventors: Chang-Ming Hsieh, Louis L. C. Hsu, Shaw-Ning Mei, Ronald W. Knepper, Lawrence F. Wagner, Jr.
  • Patent number: 5329147
    Abstract: When a field effect transistor is used to control the current through an inductive load, the flyback voltage is felt through the vertical pnp transistor at the drain, which onducts to the substrate. This current represents a power loss and a source of heat. This invention supplies a second lateral transistor which conducts this current back to the power supply.
    Type: Grant
    Filed: January 4, 1993
    Date of Patent: July 12, 1994
    Assignee: Xerox Corporation
    Inventors: Tuan A. Vo, Mohamad M. Mojaradi, Aram Nahidipour
  • Patent number: 5321301
    Abstract: The present invention relates to a semiconductor device which comprises: an n.sup.- type buried collector provided on an n type silicon epitaxial layer disposed in an emitter opening; an n.sup.- type silicon collector disposed on said collector; a p.sup.+ type single crystal silicon intrinsic base layer; and an n.sup.+ type single crystal silicon emitter wherein said p.sup.+ type single crystal silicon intrinsic base layer is connected with a p.sup.+ type base electrode polycrystalline silicon through a p.sup.+ type polycrystalline silicon graft base.
    Type: Grant
    Filed: April 7, 1993
    Date of Patent: June 14, 1994
    Assignee: NEC Corporation
    Inventors: Fumihiko Sato, Tsutomu Tashiro
  • Patent number: 5298440
    Abstract: A bipolar lateral device is disclosed having a high BV.sub.ceo. The device is formed according to a single polysilicon process. In one embodiment silicide is excluded from the surface of the N+ doped polysilicon protecting the N- base width region of the device and the resulting device has a BV.sub.ceo of 8 to 10 V. In another embodiment, the silicide is excluded from the surface of the polysilicon protecting the n-base width region and the polysilicon is maintained as intrinsic polysilicon. The resulting device has a BV.sub.ceo of about 20 V. The devices are useful as voltage clamping devices in programmable logic circuits which must withstand a collector to emitter reverse bias voltage that is sufficient to program either vertical fuse or lateral fuse devices.
    Type: Grant
    Filed: January 22, 1993
    Date of Patent: March 29, 1994
    Assignee: National Semiconductor Corporation
    Inventors: Rick C. Jerome, Brian McFarlane, Frank Marazita
  • Patent number: 5286986
    Abstract: In a semiconductor device, a charge transfer device, a bipolar transistor, and a MOSFET are formed on a single chip, and the peripheral portion of the charge transfer device is surrounded by an N.sup.+ -type region. Since the charge transfer device block is surrounded by the N.sup.+ -type region and the N.sup.+ -type buried layer, leaked charge of clocks from the charge transfer device is absorbed by the N.sup.+ -type region and the N.sup.+ -type buried layer.
    Type: Grant
    Filed: February 18, 1992
    Date of Patent: February 15, 1994
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kazuo Kihara, Minoru Taguchi
  • Patent number: 5276638
    Abstract: A bipolar memory array and memory cell. The memory cell has a pair of cross coupled NPN storage transistors and a pair of PNP load transistors. The collector of each of the load transistors is connected to one of the storage transistors. A base, common to both load transistors, are connected to a drain line. The word line is connected to an emitter common to both of the load transistors. The cell is connected to a bit line pair through Schottky Barrier Diodes (SBD's) or, alternatively, through emitters of transistors which share a common base and a common collector with the cross coupled storage transistors.
    Type: Grant
    Filed: July 31, 1991
    Date of Patent: January 4, 1994
    Assignee: International Business Machines Corporation
    Inventor: Robert C. Wong
  • Patent number: 5237198
    Abstract: A lateral PNP transistor having either of the collector or the emitter diffusion layers layered with an n.sup.+ type diffusion layer, is shown. The added layer serves to increase the static electricity withstand stress along a transistor discharging path. A low withstand stress contributes to transistor damage at high breakdown voltages. When an n.sup.+ diffusion layer is formed within a diffusion layer in a lateral PNP transistor the transistor behaves as a combination of two transistors, PNP and NPN, selectively configured.
    Type: Grant
    Filed: April 1, 1992
    Date of Patent: August 17, 1993
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Ho-Jin Lee
  • Patent number: 5218228
    Abstract: A method is disclosed which produces a high voltage MOS transistor with a deep retrograde N-well region, which includes a buried layer, said deep retrograde well region acting to increase the breakdown voltage of the MOS transistor and reduce the current gain of the inherent parasitic bipolar transistor. To achieve a high degree of control over the impurity concentration of the buried layer without affecting the impurity concentration in the N-well region, two dopants species are diffused or implanted in the N+ buried layer: one, a slow diffusing dopant, such as antimony or arsenic, and the other, a more rapidly diffusing dopant, such as phosphorus. A P- type epitaxial layer is grown over the buried layer and an N-well is formed in the epitaxial layer over the buried layer.
    Type: Grant
    Filed: March 11, 1992
    Date of Patent: June 8, 1993
    Assignee: Siliconix Inc.
    Inventors: Richard K. Williams, Robert W. Busse, Richard A. Blanchard
  • Patent number: 5198692
    Abstract: In a semiconductor device including a bipolar transistor having a base region formed in a collector region, and an emitter region formed in the base region, the emitter region comprises a high concentration region in contact with the base region, and a low concentration region provided between the base region and the high concentration region. The low concentration region is formed by introducing an impurity with a mask including a large opening. In addition, the high concentration region is formed by introducing an impurity with a mask including a small opening.
    Type: Grant
    Filed: June 14, 1991
    Date of Patent: March 30, 1993
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Hisayo Momose