With Bipolar Transistor Patents (Class 257/477)
  • Patent number: 6989557
    Abstract: A bipolar junction transistor (BJT) includes a dielectric layer formed on a predetermined region of a substrate, an opening formed in the dielectric layer and a portion of the substrate being exposed, a heavily doped polysilicon layer formed on a sidewall of the opening to define a self-aligned base region in the opening, an intrinsic base doped region formed within the substrate and in a bottom of the opening by implanting through the self-aligned base region, a spacer formed on the heavily doped polysilicon layer to define a self-aligned emitter region in the opening, and an emitter conductivity layer being filled with the self-aligned emitter region and a PN junction being formed between the emitter conductivity layer and the intrinsic base doped region.
    Type: Grant
    Filed: May 14, 2004
    Date of Patent: January 24, 2006
    Assignee: United Microelectronics Corp.
    Inventor: Anchor Chen
  • Patent number: 6972442
    Abstract: One embodiment is a method for fabricating the base of a bipolar transistor where the method comprises placing a first wafer in an undoped epi chamber. Next a first undoped base layer is grown over the first wafer. After growing the first undoped base layer, the first wafer is transferred from the undoped epi chamber into a separate doped epi chamber. A first doped base layer is then grown over the first undoped based layer in the doped epi chamber. While the first wafer is being processed in the doped epi chamber, a second wafer can be processed in the undoped epi chamber. Another embodiment is a structure produced by the disclosed method and yet another embodiment comprises a transfer chamber, a transfer arm, a bake chamber, and a separate undoped epi chamber and a doped epi chamber for practicing the disclosed method.
    Type: Grant
    Filed: December 7, 2002
    Date of Patent: December 6, 2005
    Assignee: Newport Fab, LLC
    Inventor: Klaus F. Schuegraf
  • Patent number: 6949764
    Abstract: A bipolar transistor structure is described incorporating an emitter, base, and collector having a fully depleted region on an insulator of a Silicon-On-Insulator (SOI) substrate without the need for a highly doped subcollector to permit the fabrication of vertical bipolar transistors on semiconductor material having a thickness of 300 nm or less and to permit the fabrication of SOI BiCMOS. The invention overcomes the problem of requiring a thick semiconductor layer in SOI to fabricate vertical bipolar transistors with low collector resistance.
    Type: Grant
    Filed: November 19, 2004
    Date of Patent: September 27, 2005
    Assignee: International Business Machines Corporation
    Inventor: Tak Hung Ning
  • Patent number: 6933751
    Abstract: A logic gate is described that has an N-type region, which may be an N-well or N-tub, forming a cathode of one or more Schottky diodes and a collector of an NPN bipolar transistor. Accordingly, the Schottly diodes and transistor do not need to be isolated from one another, resulting in a very compact logic gate. The logic gate forms a portion of a NAND function in one embodiment. One or more Schottky diodes between the collector and base of the bipolar transistor act as a clamp to prevent the transistor from saturating. The clamp diodes can also be used to adjust the output voltage of the gate to ensure downstream transistors can be fully turned off.
    Type: Grant
    Filed: September 18, 2003
    Date of Patent: August 23, 2005
    Assignee: Micrel, Inc.
    Inventors: Thomas S. Wong, Robert W. Bechdolt, Phi Thai
  • Patent number: 6921958
    Abstract: A semiconductor device which IGBT (Z1) and a control circuit (B1) for driving the IGBT (Z1) are formed on the same semiconductor substrate by using a junction isolation technology, includes an input terminal (P1) for inputting a drive signal of the IGBT (Z1), a Schottky barrier diode (D2) having an anode connected to the input terminal (P1) and a cathode connected to an input terminal (B11) of the control circuit (B1), and a p-channel MOSFET (T1) for shorting both ends of the Schottky barrier diode (D2) when the voltage of the drive signal input to the input terminal (P1) is higher than a predetermined voltage, thereby latch-up of the parasitic element is prevented and a transmission loss of the input signal can be reduced.
    Type: Grant
    Filed: October 21, 2003
    Date of Patent: July 26, 2005
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Yukio Yasuda
  • Patent number: 6852580
    Abstract: The invention provides a bias circuit for suppressing change with temperature of an idle current of a power transistor and a semiconductor device including the bias circuit. The bias circuit includes a first bipolar transistor having an emitter, a base and a collector, and at least one Schottky diode connected to the base of the first bipolar transistor, and the at least one Schottky diode is provided for supplying a base potential for suppressing a collector current of the first bipolar transistor from changing in accordance with temperature change.
    Type: Grant
    Filed: May 20, 2002
    Date of Patent: February 8, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Manabu Yanagihara, Tsuyoshi Tanaka, Akihisa Sugimura
  • Patent number: 6849871
    Abstract: A bipolar transistor structure is described incorporating an emitter, base, and collector having a fully depleted region on an insulator of a Silicon-On-Insulator (SOI) substrate without the need for a highly doped subcollector to permit the fabrication of vertical bipolar transistors on semiconductor material having a thickness of 300 nm or less and to permit the fabrication of SOI BiCMOS. The invention overcomes the problem of requiring a thick semiconductor layer in SOI to fabricate vertical bipolar transistors with low collector resistance.
    Type: Grant
    Filed: January 10, 2001
    Date of Patent: February 1, 2005
    Assignee: International Business Machines Corporation
    Inventor: Tak Hung Ning
  • Patent number: 6838709
    Abstract: A bipolar transistor includes the first group of transistors 610a, the second group of transistors 610b, the third group of transistors 610c and the fourth group of transistors 610d. The groups of transistors have unit transistors with emitters, bases and collectors that are connected electrically in parallel and the number of unit transistors is different from group to group and 2, 4, 8, and 16, respectively.
    Type: Grant
    Filed: October 9, 2003
    Date of Patent: January 4, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Shinichi Sonetaka, Yasuyuki Toyoda, Kazuhiro Arai, Yorito Ota
  • Patent number: 6809400
    Abstract: This disclosure describes a structure for transistor devices formed from compound semiconductor materials; and particularly for heterojuntion bipolar transistors (HBTs); and more particularly for the collector structure of a double HBT (DHBT). The invention enables high output power at high frequency operation, of high frequency operation at high output power.
    Type: Grant
    Filed: March 14, 2003
    Date of Patent: October 26, 2004
    Inventors: Eric Harmon, Jerry Woodall, Hironori Tsukamoto, David Salzman
  • Patent number: 6744111
    Abstract: A three-terminal semiconductor transistor device comprises a semiconductor base region in contact with a first electric terminal, a conductive emitter region in contact with the semiconductor base region, forming a first Schottky barrier junction at the interface of the conductive emitter region and the semiconductor base region. The conductive emitter region is in contact with a second electric terminal. The three-terminal semiconductor transistor device further includes a conductive collector region in contact with the semiconductor base region, forming a second Schottky barrier junction at the interface of the conductive collector region and the semiconductor base region. The conductive collector region is in contact with a third electric terminal. The tunneling currents through the first and the second Schottky barrier junctions are substantially controlled by the voltage of the semiconductor base region.
    Type: Grant
    Filed: May 15, 2003
    Date of Patent: June 1, 2004
    Inventor: Koucheng Wu
  • Publication number: 20040061195
    Abstract: Hithereto, there was a problem involving that the VF and IR characteristics of a Schottky barrier diode were in a tradeoff relationship, and an increase in leak current was unavoidable to implement low VF. In some preferred embodiments, a plurality of P+-type orthohexagonal semiconductor regions are provided in a Schottky junction region. Since they are spaced from one another equidistantly, depletion layers are spread from the P+-type semiconductor regions when a reverse voltage is applied, and are fully filled in an epitaxial layer. As a result, a leak current occurring at the Schottky junction interface can be prevented from leaking to the cathode side. Even when a high leak current occurs, it can be intercepted by the depletion layers, so that the tradeoff relationship between VF and IR can be eliminated. Thus, a low VF can be implemented without consideration for IR.
    Type: Application
    Filed: September 30, 2003
    Publication date: April 1, 2004
    Applicant: Sanyo Electric Co., Ltd.
    Inventors: Tetsuya Okada, Mitsuhiro Yoshimura
  • 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: 6703283
    Abstract: A process for forming at least one interface region between two regions of semiconductor material. At least one region of dielectric material comprising nitrogen is formed in the vicinity of at least a portion of a boundary between the two regions of semiconductor material, thereby controlling electrical resistance at the interface.
    Type: Grant
    Filed: February 4, 1999
    Date of Patent: March 9, 2004
    Assignee: International Business Machines Corporation
    Inventors: Arne W. Ballantine, Douglas D. Coolbaugh, Jeffrey Gilbert, Joseph R. Greco, Glenn R. Miller
  • Patent number: 6573582
    Abstract: A bipolar transistor is formed on a semiconductor substrate. A Schottky diode is formed in the collector region of the bipolar transistor. The collector region and the semiconductor substrate are isolated in potential from each other by potential isolating layers.
    Type: Grant
    Filed: November 13, 2001
    Date of Patent: June 3, 2003
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Yasunori Yamashita, Fumitoshi Yamamoto, Tomohide Terashima
  • Patent number: 6525388
    Abstract: A heterojunction bipolartansistor is fabricated on a semi-insulating substrate, and has a mesa structure, wherein an emitter signal line of titanium-platinum-gold alloy is held in contact with the collector layer as well as the emitter layer for forming a Schottky barrier diode connected between the emitter and the collector so that surge current flows before damage of the p-n junction of the heterojunction bipolar transistor.
    Type: Grant
    Filed: November 9, 2000
    Date of Patent: February 25, 2003
    Assignee: NEC Compound Semiconductor Devices, Ltd.
    Inventor: Hidenori Shimawaki
  • Publication number: 20030015765
    Abstract: A bipolar transistor is formed on a semiconductor substrate. A Schottky diode is formed in the collector region of the bipolar transistor. The collector region and the semiconductor substrate are isolated in potential from each other by potential isolating layers.
    Type: Application
    Filed: November 13, 2001
    Publication date: January 23, 2003
    Applicant: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Yasunori Yamashita, Fumitoshi Yamamoto, Tomohide Terashima
  • Publication number: 20020119591
    Abstract: A tunnel diode has a quantum well having at least one layer of semiconductor material. The tunnel diode also has a pair of injection layers on either side of the quantum well. The injection layers comprise a collector layer and an emitter layer. A barrier layer is positioned between each of the injection layers and the quantum well. The quantum well has an epitaxial relationship with the emitter layer. An amount of one element of the well layer is increased to increase the lattice constant a predetermined amount. The lattice constant may have a reduction in the conduction band energy. A second element is added to the well layer to increase the conduction band energy but not to change the lattice constant. By controlling the composition in this matter, the negative resistance, and thus the effective mass, may be controlled for various diode constructions.
    Type: Application
    Filed: February 15, 2002
    Publication date: August 29, 2002
    Inventor: Joel N. Schulman
  • Patent number: 6417554
    Abstract: A three layer IGBT which cannot latch on is provided with a trench gate and a Schottky contact to the depletion region surrounding the trench gate. An emitter contact is connected to base diffusion regions which are diffused into the depletion region. The depletion region is formed atop an emitter region which emits carriers into the depletion region in response to the turn on of the gate and the injection of carriers from the Schottky gate.
    Type: Grant
    Filed: April 27, 2000
    Date of Patent: July 9, 2002
    Assignee: International Rectifier Corporation
    Inventor: Iftikhar Ahmed
  • Patent number: 6252282
    Abstract: The invention relates to a semiconductor device including a preferably discrete bipolar transistor with a collector region, a base region, and an emitter region which are provided with connection conductors. A known means of preventing a saturation of the transistor is that the latter is provided with a Schottky clamping diode. The latter is formed in that case in that the connection conductor of the base region is also put into contact with the collector region. In a device according to the invention, the second connection conductor is exclusively connected to the base region, and a partial region of that portion of the base region which lies outside the emitter region, as seen in projection, lying below the second connection conductor is given a smaller flux of dopant atoms. The bipolar transistor in a device according to the invention is provided with a pn clamping diode which is formed between the partial region and the collector region.
    Type: Grant
    Filed: February 9, 1999
    Date of Patent: June 26, 2001
    Assignee: U.S. Philips Corporation
    Inventors: Godefridus A. M. Hurkx, Holger Schligtenhorst, Bernd Sievers
  • Patent number: 6046486
    Abstract: Mixer circuitry having a semiconductor body formed therein mixer circuitry having an oscillator having a heterojunction bipolar transistor and a mixer having a Schottky diode. The heterojunction transistor has a collector region formed in one portion of doped layer of the semiconductor body and the diode has a metal electrode is Schottky contact with another portion of such doped layer. The mixer is includes a diode and a DC biasing circuit, comprising a constant current, for biasing such diode to predetermined operating point substantially invariant with power of an input signal fed to such mixer.
    Type: Grant
    Filed: August 21, 1998
    Date of Patent: April 4, 2000
    Assignee: Raytheon Company
    Inventors: Brian J. McNamara, John P. Wendler, Kamal Tabatabaje-Alavi
  • Patent number: 6037646
    Abstract: A Schottky barrier diode and a method for fabricating a Schottky barrier diode that utilizes HBT active device layers. The Schottky barrier diode is formed with a vertically integrated profile on a GaAs substrate, with a subcollector layer and a collector layer. A suitable dielectric material is deposited on top of the collector layer. Vias are formed in the collector layer and subcollector layer for the barrier and ohmic contacts. The collector via is relatively deeply etched into the collector layer to lower the series resistance between the barrier and ohmic contacts, which results in relatively higher cut-off frequency performance.
    Type: Grant
    Filed: May 30, 1997
    Date of Patent: March 14, 2000
    Assignee: TRW Inc.
    Inventors: Aaron K. Oki, Donald K. Umemoto, Liem T. Tran, Dwight C. Streit
  • Patent number: 5930636
    Abstract: A Schottky barrier diode and a method for fabricating a Schottky barrier diode that utilizes HBT active device layers. The Schottky barrier diode is formed with a vertically integrated profile on a GaAs substrate, with a subcollector layer and a collector layer. A suitable dielectric material is deposited on top of the collector layer. Vias are formed in the collector layer and subcollector layer for the barrier and ohmic contacts. The collector via is relatively deeply etched into the collector layer to lower the series resistance between the barrier and ohmic contacts, which results in relatively higher cut-off frequency performance.
    Type: Grant
    Filed: May 13, 1996
    Date of Patent: July 27, 1999
    Assignee: TRW Inc.
    Inventors: Aaron K. Oki, Donald K. Umemoto, Liem T. Tran, Dwight C. Streit
  • Patent number: 5889317
    Abstract: A leadframe for an IC package and a method of manufacturing the same are provided. The leadframe can be manufactured in such a manner as to provide suitable bondability, molding compound characteristic, and solderability. The leadframe includes a base structure made from a conductive material. A silver plating is formed over the base structure of the leadframe, and a palladium plating is formed over the silver plating. Depending on actual requirements, a copper layer and a nickel plating can be formed between the silver plating and the base structure of the leadframe, and a palladium/nickel plating can be found between the silver and palladium platings. Further, a gold layer can be formed over the palladium plating. The palladium plating and the palladium/nickel plating can be formed all over the leadframe or selectively formed only in the external-lead area of the leadframe.
    Type: Grant
    Filed: June 6, 1997
    Date of Patent: March 30, 1999
    Assignee: Sitron Precision Co., Ltd.
    Inventors: Chih-Kung Huang, Wei-Jen Lai
  • Patent number: 5763918
    Abstract: The preferred embodiment of the present invention overcomes the limitations of the prior art and provides a device and method to decrease the latch-up susceptibility of an ESD structure by suppressing the injection of minority carriers that cause transistor action to occur. This is accomplished, for example, by using a metal contact to the n-substrate or n-well in place of or in parallel with the prior art p-diffusion. Using such a metal contact forms a Schottky Barrier Diode (SBD) with the ESD structure. Since the SBD is a majority-carrier device, negligible minority carriers are injected when the SBD is in forward bias, thereby reducing the likelihood of latch-up.
    Type: Grant
    Filed: October 22, 1996
    Date of Patent: June 9, 1998
    Assignee: International Business Machines Corp.
    Inventors: Badih El-Kareh, James Gardner Ryan, Hiroyoshi Tanimoto
  • Patent number: 5760424
    Abstract: An integrated circuit arrangement includes an IGBT, provided with a secondary contact connected with the drift area, and a diode connected between the secondary contact and the anode of the IGBT. The cathode of the diode is connected with the anode of the IGBT and the anode of the diode is connected with the secondary contact of the IGBT. In this way the pn-junction of the IGBT, formed through the drift area and the channel area, can be used as an internal free-running diode of the IGBT.
    Type: Grant
    Filed: February 12, 1996
    Date of Patent: June 2, 1998
    Assignee: Siemens Aktiengesellschaft
    Inventor: Klaus-Guenter Oppermann
  • Patent number: 5583348
    Abstract: A method for making a schottky diode structure (10) simultaneously with a polysilicon contact structure (31,33) to a transistor is provided. In a single process step, a polysilicon layer is patterned to expose a single crystal semiconductor region (22a) over one portion of a substrate, while leaving portions the polysilicon layer (31, 33, 29) intact over other portions of the substrate (22b). Multi-layer metal electrodes are deposited and patterned to form a rectifying schottky contact to the exposed single crystal region (22a), and to form an ohmic contact to the exposed polysilicon (31, 33, 29).
    Type: Grant
    Filed: December 3, 1991
    Date of Patent: December 10, 1996
    Assignee: Motorola, Inc.
    Inventor: Lalgudi M. G. Sundaram
  • Patent number: 5567969
    Abstract: Disclosed is an integrated transistor structure having increased conductance and operating speed including a complementary insulated gate field effect transistor pair, each including a source and a drain region with a gate contact positioned therebetween, ohmic contacts to the sources, and a rectifying junction contact to each of the drain regions. The gates of the two transistors are interconnected and function as the input terminal, and the two rectifying contacts are interconnected as the output of the device. The structure includes a semiconductor substrate having slow diffusant dopants therein or implanted metal ions of cobalt, molybdenum, or tungsten. The structure further includes an epitaxial semiconductor layer with resistance on the order of 0.5 to 1.0 ohm cm and a thickness of 1.5 to 5.0 .mu.m. The device regions for the field effect transistor pair are formed in the epitaxial semiconductor layer.
    Type: Grant
    Filed: April 20, 1995
    Date of Patent: October 22, 1996
    Inventor: John H. Hall
  • Patent number: 5536966
    Abstract: An improved Schottky transistor structure (6), including a bipolar transistor structure (7) and a Schottky diode structure (8), is formed by retrograde diffusing relatively fast diffusing atoms to form a localized retrograde diode well (9) as the substrate for the Schottky diode structure. An expanded buried collector layer (11) formed of relatively slow diffusing atoms underlies the base and collector regions of the bipolar transistor structure (7) and the retrograde diode well (9). A diode junction (10) is formed by expanding the base contact of the bipolar transistor structure to include the surface of the retrograde diode well. Preferably, the diode junction is a Platinum-Silicide junction.
    Type: Grant
    Filed: August 15, 1994
    Date of Patent: July 16, 1996
    Assignee: National Semiconductor Corporation
    Inventors: Murray J. Robinson, Christopher C. Joyce, Timwah Luk
  • Patent number: 5438218
    Abstract: A semiconductor device is provided having a first semiconductor region comprising an n-type semiconductor and a second semiconductor region of an n-type semiconductor having a higher resistivity than the first semiconductor region. An insulation film is provided adjacent to the semiconductor region having an aperture therein, and an electrode region is provided in the aperture. A third semiconductor region comprising a p-type semiconductor is provided at a junction between the insulation film and the electrode region. The electrode comprises a monocrystalline metal and constitutes a Schottky junction with the semiconductor region. An ohmic electrode comprising aluminum is arranged on the electrode region.
    Type: Grant
    Filed: April 30, 1993
    Date of Patent: August 1, 1995
    Inventors: Yoshio Nakamura, Shin Kikuchi, Shigeru Nishimura
  • Patent number: 5331186
    Abstract: A high-cut-off frequency, high-speed HBT is obtained by suppressing the diffusion of impurities to the utmost by lowering a heat treatment temperature in the step subsequent to the formation of a high concentration base layer. A base electrode for a base layer is made of a metal or an intermetallic compound which extends the emitter layer to reach at least a part of the base layer. The metal or intermetallic compound forms Schottky barrier with an emitter layer having a wide forbidden width ,and ohmic contacts with the base layer with a narrow forbidden band. The barrier potential of the Schottky junction formed between the intermetallic compound or metal and the emitter layer is higher than the diffusion potential of a pn junction between the base layer and the emitter layer.
    Type: Grant
    Filed: March 5, 1992
    Date of Patent: July 19, 1994
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Kouhei Morizuka
  • Patent number: 5296406
    Abstract: A Schottky diode is presented which has reduced minority carrier injection and reduced diffusion of the metallization into the semiconductor. These improvements are obtained by interposing a layer comprising a mixture of silicon and chromium between the anode metallization layer and the semiconductor in a Schottky diode. The layer including chromium acts an effective barrier against the diffusion of the metallization layer into the semiconductor, and at the same time reduces the amount of minority carrier injection into the substrate. The layer including chromium requires no addition photolithograpic masks because it can be plasma etched using the metallization layer as a mask after that layer has been patterned.
    Type: Grant
    Filed: July 7, 1993
    Date of Patent: March 22, 1994
    Assignee: Linear Technology Corporation
    Inventors: John E. Readdie, Benjamin H. Kwan, Jeng Chang
  • Patent number: 5177584
    Abstract: A bipolar SRAM which includes a forward bipolar transistor and a reverse bipolar transistor on an identical semiconductor substrate, is disclosed. Concretely, the base region of the reverse bipolar transistor is formed at a deeper position of the substrate than the base region of the forward bipolar transistor, thereby to heighten the cutoff frequency f.sub.T of the reverse bipolar transistor.
    Type: Grant
    Filed: January 28, 1991
    Date of Patent: January 5, 1993
    Assignee: Hitachi, Ltd.
    Inventors: Akihisa Uchida, Yuji Yatsuda, Katsumi Ogiue, Kazuo Nakazato, Takahiro Onai
  • Patent number: 5175597
    Abstract: A semiconducting component with a Schottky junction with stacked electrodes has a lower electrode forming an emitter or source, a central electrode forming a base or grid and an upper electrode forming either a collector or a drain. Semiconductor material is between the upper electrode and the lower electrode. The central control electrode is in the form of several adjacent conducting fingers. An insulating material is in the region directly below the fingers between the control electrode and the lower electrode, thereby reducing parasitic capacitance between the control electrode and the lower electrode.
    Type: Grant
    Filed: June 13, 1991
    Date of Patent: December 29, 1992
    Assignee: Thomson-CSF
    Inventors: Gerard Cachier, Jacques Gremillet
  • Patent number: 5166760
    Abstract: A semiconductor device is provided wherein a first diode having a pn junction and a second diode having a combination of a Schottky barrier and a pn junction in a current-passing direction are provided side by side in a direction perpendicular to the current-passing direction. When a forward current with a current density J.sub.F is passed into the second diode, the relation ##EQU1## is established in a forward voltage V.sub.F range of 0.1 (V) to 0.3 (V), where k represents the Boltzmann constant (.apprxeq.1.38.times.10.sup.-23 J/K), T represents the absolute temperature, and q represents the quantity of electron charges (.apprxeq.1.6.times.10.sup.-19 C).
    Type: Grant
    Filed: February 11, 1992
    Date of Patent: November 24, 1992
    Assignees: Hitachi, Ltd., Hitachi Haramachi Semiconductor Ltd.
    Inventors: Mutsuhiro Mori, Yasumiti Yasuda, Naoki Sakurai, Hidetoshi Arakawa, Hiroshi Owada