With Means To Reduce Transistor Action In Selected Portions Of Transistor (e.g., Heavy Base Region Doping Under Central Web Of Emitter To Prevent Secondary Breakdown) Patents (Class 257/583)
  • Patent number: 5539233
    Abstract: An npn transistor having a low collector-base breakdown voltage. An emitter region (104, 106) of a first conductivity type is located in a semiconductor substrate (102). A base region (14) of a second conductivity type is located within the emitter region (104,106) and a shallow collector region (18) of the first conductivity type is located within the base region (14). The shallow collector region (18) may be doped with arsenic and/or phosphorus such that the dopant concentration and depth of the shallow collector region (18) provide a low collector-base breakdown voltage.
    Type: Grant
    Filed: June 13, 1995
    Date of Patent: July 23, 1996
    Assignee: Texas Instruments Incorporated
    Inventors: Ajith Amerasekera, Amitava Chatterjee
  • 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: 5369298
    Abstract: A semiconductor device has a semiconductor substrate including a base region and an emitter region in the base region. The emitter region in the base region has a comb-teeth-shaped outer edge. The emitter region has a window through which the base region is exposed. The window has an extended ares to reach portions of the emitter region near the comb-teeth-shaped outer edge of the emitter region. Consequently, the area of junction between the window and the emitter region os increased to suppress concentration of electrical current in the window and to improve electrical characteristics such as secondary yield breakdown strength.
    Type: Grant
    Filed: July 8, 1993
    Date of Patent: November 29, 1994
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Ziro Honda, Yasushi Nomoto
  • Patent number: 5352911
    Abstract: This invention discloses a dual base heterojunction bipolar transistor for use in a number of different application. Current is introduced into one of the base contacts such that current is forced through the base region of the transistor to the other base contact. Because of the different resistances in the base, there will be a voltage potential between one side of the emitter mesa adjacent one of the base contacts and the other side of the emitter mesa adjacent the other base contact. This lateral voltage potential creates current crowding which forces the current density to travel to the perimeter of the transistor. Because the current travels mostly through the perimeter regions of the transistor, this concept can be used for testing for defects in the bulk of the base region by comparing the current gain without current crowding and with current crowding. Also, this concept can be used strictly as a gain control for a heterojunction bipolar transistor.
    Type: Grant
    Filed: October 28, 1991
    Date of Patent: October 4, 1994
    Assignee: TRW Inc.
    Inventor: Peter C. Grossman
  • Patent number: 5343069
    Abstract: An electronic switch, in particularly a transistor, has at least one barrier layer extending between regions of different doping concentrations within a semiconductor and is characterized in that the barrier layer has at least one voltage limiting zone (Z) having a radius of curvature (R) less than or at most equal to the diffusion depth (x.sub.JB) of the diffused junction.
    Type: Grant
    Filed: February 26, 1993
    Date of Patent: August 30, 1994
    Assignee: Robert Bosch GmbH
    Inventors: Christian Pluntke, Alfred Goerlach
  • Patent number: 5341020
    Abstract: An integrated array of minute transistors, or cells, either of the type having emitters in the form of a mesh and bases in the form of islands, or of the type having emitters in the form of islands and bases in the form of a mesh. When a transistor chip of conventional design was connected to an inductive load such as a transformer or motor and turned off, the outer cells of the chip were more susceptible to breakdown than the inner ones. In order to make all the cells equally resistive to turnoff voltages, a first set of base openings in an insulating film on the semiconductor substrate, through which are exposed the bases of the inner cells are made larger in size than a second set of base openings in the insulating film exposing the bases of the outer cells. Additionally, in a transistor chip having meshed emitters, the peripheral annular part of the mesh is made less in width than each strip of the inner part of the mesh.
    Type: Grant
    Filed: April 2, 1992
    Date of Patent: August 23, 1994
    Assignee: Sanken Electric Co., Ltd.
    Inventor: Kunio Sasahara
  • 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: 5327006
    Abstract: The occupation area and thickness of dielectrically isolated island-resident transistor structures, which employ a buried subcollector for providing low collector resistance at the bottom of the island, are reduced by tailoring the impurity concentration of a reduced thickness island region to provide a low resistance current path from an island location directly beneath the base region to the collector contact. The support substrate is biased at a voltage which is less than the collector voltage, so that the portion of the collector (island) directly beneath the emitter projection onto the base is depleted of carriers prior to the electric field at that location reaching BCVEO, so as not to effectively reduce BVCEO.
    Type: Grant
    Filed: September 5, 1991
    Date of Patent: July 5, 1994
    Assignee: Harris Corporation
    Inventor: James D. Beasom
  • Patent number: 5323055
    Abstract: A semiconductor device includes an insulating support layer on which are mounted, in succession, a conductive layer, a buried layer comprising first and second spaced portions and a semiconductor single crystal layer comprising spaced first and second portions respectively supported on the first and second spaced portions of the buried layer, the respective first and second portions having respective, first and second common sidewalls defining respective, first and second peripheries thereof and respectively comprising a transistor region and a collector electrode region. A remaining exposed surface portion of the conductive layer extends between the spaced, opposing portions of the sidewalls of the transistor and collector electrode regions.
    Type: Grant
    Filed: August 21, 1991
    Date of Patent: June 21, 1994
    Assignee: Fujitsu Limited
    Inventor: Tatsuya Yamazaki
  • Patent number: 5237183
    Abstract: The reverse breakdown voltage of a conventional insulated gate transistor is greatly increased by the addition of a lightly doped layer between the substrate and a buffer layer of the insulated gate transistor. The addition of the lightly doped layer does not increase the on resistance of the device, nor the cut-off time of the device. The lightly doped layer can be provided as an epitaxial layer along with the other epitaxial layers of the insulated gate transistor.
    Type: Grant
    Filed: December 14, 1989
    Date of Patent: August 17, 1993
    Assignee: Motorola, Inc.
    Inventors: Gary V. Fay, Bernard W. Boland
  • Patent number: 5235206
    Abstract: A method of manufacturing a vertical bipolar transistor including the steps of: providing a semiconductor substrate including a first region of a first conductivity type; forming an extrinsic base region of a second conductivity type in the surface of the first region, the extrinsic base region generally bounding a portion of the first region; forming by ion implantation a linking region of the second conductivity type in the surface of the bounded portion of the first region so as to electrically link generally opposing edges of the extrinsic base region through the linking region; forming an insulating spacer over the junction between the extrinsic base region and the linking region so as to generally bound a portion of the linking region within the portion of the first region; etching the surface of the bounded portion of the linking region a short distance into the linking region; forming by epitaxial growth a first layer of semiconductor material of the second conductivity type on the etched surface of t
    Type: Grant
    Filed: April 7, 1992
    Date of Patent: August 10, 1993
    Assignee: International Business Machines Corporation
    Inventors: Brian H. Desilets, Chang-Ming Hsieh, Louis L. Hsu
  • 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