Having Multiple Emitter Or Collector Structure Patents (Class 438/342)
  • Patent number: 7176099
    Abstract: A hetero-junction bipolar transistor that satisfies high resistance required to avoid a potential breakdown includes: an n-type sub-collector layer 110 that is made of GaAs; an n-type first collector 121 that is made of a semiconductor material with a smaller avalanche coefficient than that of the sub-collector 110 and is formed on the sub-collector layer 110; a second collector layer 132 that is made of n-type or i-type GaAs with lower dopant concentration than that of the sub-collector layer 110 and is formed on the first collector layer 121; a p-type base layer 133 that is made of GaAs and is formed on the second collector layer 132; and emitter layer 134 that is made of a semiconductor material with a larger band gap than that of the base layer 133 and is formed on the base layer 133.
    Type: Grant
    Filed: April 7, 2005
    Date of Patent: February 13, 2007
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Keiichi Murayama, Akiyoshi Tamura, Masanobu Nogome
  • Patent number: 7098113
    Abstract: A power lateral PNP device is disclosed which includes an epitaxial layer; a first and second collector region embedded in the epitaxial layer; an emitter region between the first and second collector regions. Therefore slots are placed in each of the regions. Accordingly, in a first approach the standard process flow will be followed until reaching the point where contact openings and metal are to be processed. In this approach slots are etched that are preferably 5 to 6 um deep and 5 to 6 um wide. These slots are then oxidized and will be subsequently metalized. When used for making metal contacts to the buried layer or for ground the oxide is removed from the bottom of the slots by an anisotropic etch. Subsequently when these slots receive metal they will provide contacts to the buried layer where this is desired and to the substrate when a ground is desired. In a second approach the above-identified process is completed up through the slot process without processing the lateral PNPs.
    Type: Grant
    Filed: March 13, 2003
    Date of Patent: August 29, 2006
    Assignee: Micrel, Inc.
    Inventors: John Durbin Husher, Ronald L. Schlupp
  • Patent number: 7060583
    Abstract: In the inventive method for manufacturing a bipolar transistor having a polysilicon emitter, a collector region of a first conductivity type and, adjoining thereto, a basis region of a second conductivity type will be generated at first. At least one layer of an insulating material will now be applied, wherein the at least one layer is patterned such that at least one section of the basis region is exposed. Next, a layer of a polycrystalline semiconductor material of the first conductivity type, which is heavily doped with doping atoms, will be generated such that the exposed section is essentially covered. Now, a second layer of a highly conductive material on the layer of the polycrystalline semiconductor material will be generated in order to form an emitter double layer with the same.
    Type: Grant
    Filed: January 13, 2004
    Date of Patent: June 13, 2006
    Assignee: Infineon Technologies AG
    Inventors: Jakob Kriz, Martin Seck, Armin Tilke
  • Patent number: 7037799
    Abstract: Devices and methods are disclosed related to a bipolar transistor device and methods of fabrication. A top region is formed at a surface of and within a base region. The top region is formed by implanting a dopant of an opposite conductivity to that of the base region. However, the top region remains of the same conductivity type as the base region (e.g., n-type or p-type). This implanting, also referred to as counterdoping, increases resistivity of the top region and thus improves an emitter-base breakdown voltage. Additionally, this implanting does not have a substantial detrimental affect on a beta value, also referred to as an amplification property, or a collector emitter breakdown voltage, also referred to as BVceo, for the transistor. The beta value and the collector emitter breakdown voltage are mainly a function of a bottom portion of the base region.
    Type: Grant
    Filed: October 24, 2002
    Date of Patent: May 2, 2006
    Assignee: Texas Instruments Incorporated
    Inventor: Billy Bradford Hutcheson
  • Patent number: 6893932
    Abstract: A bipolar transistor includes a collector that is selected from the group SiC and SiC polytypes (4H, 6H, 15R, 3C . . . ), a base that is selected from the group Si, Ge and SiGe, at least a first emitter that is selected from the group Si, SiGe, SiC, amorphous-Si, amorphous-SiC and diamond-like carbon, and at least a second emitter that is selected from the group Si, SiGe, SiC, amorphous-Si, amorphous-SiC and diamond-like carbon. Direct-wafer-bonding is used to assemble the bipolar transistor. In an embodiment the bandgap of the collector, the bandgap of the at least a first emitter and the bandgap of the at least a second emitter are larger than the bandgap of the base.
    Type: Grant
    Filed: April 15, 2004
    Date of Patent: May 17, 2005
    Assignee: Astralux, Inc.
    Inventors: John Tarje Torvik, Jacques Isaac Pankove
  • Patent number: 6891230
    Abstract: The invention describes the fabrication and structure of an ESD protection device for integrated circuit semiconductor devices with improved ESD protection and resiliency. A vertical bipolar npn transistor forms the basis of the protection device. To handle the large current requirements of an ESD incident, the bipolar transistor has multiple base and emitter elements formed in an npn bipolar array. To assure turn-on of the multiple elements of the array the emitter fingers are continuously or contiguously connected with an unique emitter design layout. The contiguous emitter design provides an improved electrical emitter connection for the device, minimizing any unbalance that can potentially occur when using separate emitter fingers and improving the ability for the simultaneous turn on of the multiple emitter-base elements.
    Type: Grant
    Filed: March 2, 2004
    Date of Patent: May 10, 2005
    Assignee: Taiwan Semiconductor Manufacturing Company, Ltd.
    Inventor: Ta-Lee Yu
  • Patent number: 6838348
    Abstract: High-voltage bipolar transistors (30, 60) in silicon-on-insulator (SOI) integrated circuits are disclosed. In one disclosed embodiment, an collector region (28) is formed in epitaxial silicon (24, 25) disposed over a buried insulator layer (22). A base region (32) and emitter (36) are disposed over the collector region (28). Buried collector region (31) are disposed in the epitaxial silicon (24) away from the base region (32). The transistor may be arranged in a rectangular fashion, as conventional, or alternatively by forming an annular buried collector region (31). According to another disclosed embodiment, a high voltage transistor (60) includes a central isolation structure (62), so that the base region (65) and emitter region (66) are ring-shaped to provide improved performance. A process for fabricating the high voltage transistor (30, 60) simultaneously with a high performance transistor (40) is also disclosed.
    Type: Grant
    Filed: May 12, 2004
    Date of Patent: January 4, 2005
    Assignee: Texas Instruments Incorporated
    Inventors: Jeffrey A. Babcock, Gregory E. Howard, Angelo Pinto, Phillipp Steinmann, Scott G. Balster
  • Patent number: 6787427
    Abstract: A method of fabricating a SiGe heterojunction bipolar transistor (HBT) is provided which results in a SiGe HBT that has a controllable current gain and improved breakdown voltage. The SiGe HBT having these characteristics is fabricated by forming an in-situ P-doped emitter layer atop a patterned SiGe base structure. The in-situ P-doped emitter layer is a bilayer of in-situ P-doped a:Si and in-situ P-doped polysilicon. The SiGe HBT structure including the above mentioned bilayer emitter is also described herein.
    Type: Grant
    Filed: October 1, 2003
    Date of Patent: September 7, 2004
    Assignee: International Business Machines Corporation
    Inventors: David R. Greenberg, Basanth Jagannathan, Shwu-Jen Jeng, Joseph T. Kocis, Samuel C. Ramac, David M. Rockwell
  • Patent number: 6784064
    Abstract: A method of making a heterojunction bipolar transistor comprises the steps of: forming a mask layer on a compound semiconductor film by using a photomask for forming an emitter; and forming the emitter by wet-etching the compound semiconductor film by using the mask layer. The photomask has a pattern thereon for forming the emitter. The pattern is defined by a first area R associated with the shape of the emitter to be formed, and a plurality of second areas T1 to T4. Each of the second areas T1 to T4 includes first and second sides S1 and S2 meeting each other to form an acute angle therebetween, and a third side S3 in contact with the first area R. In each of the second areas T1 to T4, one side S3 of the two sides meeting each other to form a right angle therebetween is in contact with one side of the area R, whereas the other side S1 is connected to another side of the first area R to form a line segment.
    Type: Grant
    Filed: December 27, 2001
    Date of Patent: August 31, 2004
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Seiji Yaegashi, Kenji Kotani, Masaki Yanagisawa, Hiroshi Yano
  • Patent number: 6759303
    Abstract: A method for fabricating complementary vertical bipolar junction transistors of silicon-on-sapphire in fewer steps than required for true complimentary vertical bipolar junction transistors is disclosed. Initially a thin layer of silicon is grown on a sapphire substrate. The silicon is improved using double solid phase epitaxy. The silicon is then patterned and implanted with P+-type and N+-type dopants. Subsequently a micrometer scale N-type layer is grown that acts as the intrinsic base for both an PNP transistor and as the collector for an NPN transistor. The extrinsic base for the NPN is then formed and the emitter, collector and ohmic contact regions are next selectively masked and implanted. Conductive metal is then formed between protecting oxide to complete the complementary vertical bipolar junction transistors.
    Type: Grant
    Filed: March 5, 2002
    Date of Patent: July 6, 2004
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Eric N. Cartagena
  • Patent number: 6743691
    Abstract: A bipolar transistor device with a large current capacity is formed by connecting a plurality of transistor elements to each other in parallel, each transistor element having a collector layer, a base layer, and an emitter layer formed respectively in a semiconductor substrate. In the bipolar transistor device, the base layers of a plurality of the transistor elements are extended in parallel to each other and those base layers are separated from each other. In each separated base layer, a first base electrode is formed on a part of the base layer which is separated from an emitter junction with the emitter layer, and a second base electrode is formed on another portion of the base layer closer to the emitter junction than the first base electrode. To dispose the base electrodes of a plurality of the transistor elements in parallel to each other, a base wiring is connected to the first base electrodes of those elements electrically.
    Type: Grant
    Filed: December 27, 2001
    Date of Patent: June 1, 2004
    Assignee: Renesas Technology Corp.
    Inventors: Atsushi Kurokawa, Masao Yamane, Kazuhiro Mochizuki
  • Patent number: 6720625
    Abstract: The invention describes the fabrication and structure of an ESD protection device for integrated circuit semiconductor devices with improved ESD protection and resiliency. A vertical bipolar npn transistor forms the basis of the protection device. To handle the large current requirements of an ESD incident, the bipolar transistor has multiple base and emitter elements formed in an npn bipolar array. To assure turn-on of the multiple elements of the array the emitter fingers are continuously or contiguously connected with an unique emitter design layout. The contiguous emitter design provides an improved electrical emitter connection for the device, minimizing any unbalance that can potentially occur when using separate emitter fingers and improving the ability for the simultaneous turn on of the multiple emitter-base elements.
    Type: Grant
    Filed: October 8, 2002
    Date of Patent: April 13, 2004
    Assignee: Taiwan Semiconductor Manufacturing Company
    Inventor: Ta-Lee Yu
  • Patent number: 6709941
    Abstract: In a method for manufacturing a semiconductor device, an N type single-crystal silicon substrate having a first silicon oxide film and a P type poly-crystal silicon layer is provided. A silicon nitride film is formed on the P type poly-crystal silicon layer. A side wall of the silicon nitride film is formed in an opening in the P type poly-crystal silicon layer above a portion expected to provide an active region. The first silicon oxide film has an opening therein which is larger than the opening formed in the P type poly-crystal silicon layer. Then, an N type IV-group semiconductor mixed crystal layer having a smaller band gap than silicon to a desired thickness is grown on the single-crystal silicon substrate on which a surface of the portion expected to provide said active region is exposed. A non-doped single-crystal silicon layer is grown on the IV-group semiconductor mixed crystal layer to a desired thickness.
    Type: Grant
    Filed: November 6, 2002
    Date of Patent: March 23, 2004
    Assignee: Oki Electric Industry Co., Ltd.
    Inventor: Hirokazu Fujimaki
  • Patent number: 6682981
    Abstract: General purpose methods for the fabrication of integrated circuits from flexible membranes formed of very thin low stress dielectric materials, such as silicon dioxide or silicon nitride, and semiconductor layers. Semiconductor devices are formed in a semiconductor layer of the membrane. The semiconductor membrane layer is initially formed from a substrate of standard thickness, and all but a thin surface layer of the substrate is then etched or polished away. In another version, the flexible membrane is used as support and electrical interconnect for conventional integrated circuit die bonded thereto, with the interconnect formed in multiple layers in the membrane. Multiple die can be connected to one such membrane, which is then packaged as a multi-chip module. Other applications are based on (circuit) membrane processing for bipolar and MOSFET transistor fabrication, low impedance conductor interconnecting fabrication, flat panel displays, maskless (direct write) lithography, and 3D IC fabrication.
    Type: Grant
    Filed: February 5, 2001
    Date of Patent: January 27, 2004
    Assignee: Elm Technology Corporation
    Inventor: Glenn Joseph Leedy
  • Publication number: 20040005800
    Abstract: A socket connector (1) includes a base (10) defining an array of terminal cells (111), a number of conductive contacts (30) received in the respective terminal cells, a cover (20) slidably mounted on the base and a driving device (40) sandwiched between the cover and the base for driving the cover to move relative to the base. The cover has a supporting surface (211) for supporting a CPU (5) and defines an array of pin holes (213) corresponding to the terminal cells for insertion of pins (51) of the CPU therethrough. A standoff is formed on periphery edges of the supporting surface, and a number of small-dimensioned supporting posts (222) and large-dimensioned supporting posts (223) are formed on the supporting surface within the standoff for supporting the CPU mounted on the socket connector. The standoff and the supporting posts have the same height.
    Type: Application
    Filed: October 28, 2002
    Publication date: January 8, 2004
    Inventor: Sung-Pei Hou
  • Patent number: 6673703
    Abstract: A method of fabricating an integrated circuit including a monocrystalline silicon substrate, a layer of polycrystalline silicon on the top surface of the substrate and doped with at least two dopants with different rates of diffusion, in which method annealing is performed at a temperature and for a time such that a first dopant diffuses into a first zone and a second dopant diffuses into a second zone larger than the first zone.
    Type: Grant
    Filed: June 13, 2002
    Date of Patent: January 6, 2004
    Assignee: STMicroelectronics S.A.
    Inventors: Olivier Menut, Herve Jaouen
  • Patent number: 6664609
    Abstract: Disclosed is a circuit layout of a differential amplification circuit that constitutes a Gilbert cell, in which two multiple finger bipolar transistors forming a differential amplifier are positioned substantially axially symmetrical to each other. The longitudinal direction of each finger is orthogonal to the axis of symmetry. A wiring connected to an emitter electrode of each one of the transistors is laid so as to extend in a direction opposite to the other one of the transistors.
    Type: Grant
    Filed: March 21, 2002
    Date of Patent: December 16, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Junji Ito, Ikuo Imanishi
  • Patent number: 6563145
    Abstract: A compound collector double heterojunction bipolar transistor (CCHBT) incorporates a collector comprising two layers: a wide bandgap collector region (e.g., GaAs), and a narrow bandgap collector region (e.g., InGaP). The higher electric field is supported in the wide bandgap region, thereby increasing breakdown voltage and reducing offset voltage. At the same time, the use of wide bandgap material in the depleted portion of the collector, and a higher mobility material toward the end and outside of the depletion region, reduces series resistance as well as knee voltage.
    Type: Grant
    Filed: December 29, 1999
    Date of Patent: May 13, 2003
    Inventors: Charles E. Chang, Richard L. Pierson, Peter J. Zampardi, Peter M. Asbeck
  • Patent number: 6559023
    Abstract: A method for manufacturing a semiconductor device constituting an JGHT is provided that allows to manufacture the device using an inexpensive wafer and with high yields, and achieves low losses. Specifically, after an emitter electrode is formed, a reverse principal surface is polished to a specified thickness. The center line average height Ra of the polished surface is controlled to be not more than 1 &mgr;m, and the filtered center line waviness Wca is kept within 10 &mgr;m. The polished surface is selectively cleaned with an aqueous chemical solution to remove particles. To the cleaned surface, phosphorus ions arc implanted for forming a field-stop layer and boron ions are implanted for forming a collector layer. The wafer is then put into a diffusion furnace and annealed at a temperature from 300° C. to 550° C. to form a field-stop layer and a collector layer. Finally, a collector electrode is formed.
    Type: Grant
    Filed: February 11, 2002
    Date of Patent: May 6, 2003
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Masahito Otsuki, Seiji Momota, Mitsuaki Kirisawa, Takashi Yoshimura
  • Patent number: 6544830
    Abstract: A semiconductor device, such as a BiCMOS, includes a bipolar transistor having at least an emitter region. An emitter electrode is formed on the emitter region. Further, a wiring pattern is formed over the emitter region. A plurality of contact plugs are formed to electrically connect the emitter electrode with the wiring pattern. The contact plugs are partially embedded in the emitter electrode in order to prevent of reduction of the current amplification factor of the bipolar transistor.
    Type: Grant
    Filed: April 30, 2002
    Date of Patent: April 8, 2003
    Assignee: NEC Corporation
    Inventor: Hiroaki Yokoyama
  • Patent number: 6524921
    Abstract: The invention includes a bipolar transistor construction having a collector region, emitter region, and base region extending within a semiconductive material substrate. The construction further comprises separate access regions associated with the base region, emitter region and collector region, respectively. An n-type doped connecting region is comprised by the collector region and extends beneath the emitter and base regions. A p-type doped location is comprised by the base region and extends beneath the emitter region and above the n-type doped connecting region. An n-type doped intermediate location is within the emitter region and between the p-type doped location and the emitter access region. The invention also includes methods of forming bipolar transistors.
    Type: Grant
    Filed: March 8, 2002
    Date of Patent: February 25, 2003
    Assignee: Micron Technology, Inc.
    Inventor: Nathaniel J. Collins
  • Publication number: 20030020140
    Abstract: A modified bipolar transistor defined for providing a larger emitter current than a basic emitter current from a basic bipolar transistor is provided. The modified transistor has an improved emitter structure comprising plural divided sub-emitter regions electrically isolated and spatially separated from each other. The plural divided sub-emitter regions may typically have a uniform emitter size identical with a basic emitter size of the basic bipolar transistor. A set of the plural divided sub-emitter regions provides an intended emitter current distinctly larger than the basic emitter current by a highly accurate direct current amplification factor corresponding to an intended emitter-size magnification factor.
    Type: Application
    Filed: July 29, 2002
    Publication date: January 30, 2003
    Applicant: NEC CORPORATION
    Inventor: Masaru Ohki
  • Patent number: 6503809
    Abstract: A power transistor includes a plurality of emitter regions and a plurality of base contacts. In order to decrease base resistance, each of the plurality of emitter regions is adjacent to at least four base contacts. The entire transistor includes multiple emitter regions, e.g., greater than or equal to about 1,000 with no upper limit wherein the actual number of emitter regions is dependent on the desired current carrying capacity. The emitter regions are directly connected in parallel to the high current carrying metal layer of the transistor through vias or metal contact studs. The size of the emitter regions should be made as small as the process design rules will allow in order to allow an increase in the perimeter to area ratio of the emitter region which, for a given current, decreases the peak current density.
    Type: Grant
    Filed: March 9, 2001
    Date of Patent: January 7, 2003
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Lars Tilly, Per-Olof Magnus Brandt
  • Patent number: 6472286
    Abstract: The invention describes the fabrication and structure of an ESD protection device for integrated circuit semiconductor devices with improved ESD protection and resiliency. A vertical bipolar npn transistor forms the basis of the protection device. To handle the large current requirements of an ESD incident, the bipolar transistor has multiple base and emitter elements formed in an npn bipolar array. To assure turn-on of the multiple elements of the array the emitter fingers are continuously or contiguously connected with an unique emitter design layout. The contiguous emitter design provides an improved electrical emitter connection for the device, minimizing any unbalance that can potentially occur when using separate emitter fingers and improving the ability for the simultaneous turn on of the multiple emitter-base elements.
    Type: Grant
    Filed: August 9, 2000
    Date of Patent: October 29, 2002
    Assignee: Taiwan Semiconductor Manufacturing Company
    Inventor: Ta-Lee Yu
  • Patent number: 6423603
    Abstract: A transistor array including a plurality of transistors. Each transistor includes an emitter. An emitter region contact overlies each emitter region. At least one base region underlies each emitter region and is common to a plurality of transistors in the array. At least one base contact overlies the at least one base region and is associated with each transistor. A plurality of the base contacts are common to at least two transistors in the array. At least one collector reach through is associated with each transistor. A collector reach through contact overlies each collector reach through. A buried layer subcollector region of electrically conducting material electrically connects the collector reach through region to the collector pedestal region of each transistor.
    Type: Grant
    Filed: August 6, 2001
    Date of Patent: July 23, 2002
    Assignee: International Business Machines Corporation
    Inventors: Robert A. Groves, Dale K. Jadus, Dominique L. Nguyen-Ngoc, Keith M. Walter
  • Publication number: 20010017398
    Abstract: A substrate potential limiting device for an integrated circuit that includes a semiconductor substrate is provided. The device includes at least one unidirectional element connected between a substrate contact on the semiconductor substrate and a reference potential. The unidirectional element may be a bipolar transistor. The bipolar transistor includes a base and a collector connected to the at least one substrate contact and an emitter connected to the reference potential.
    Type: Application
    Filed: February 27, 2001
    Publication date: August 30, 2001
    Applicant: STMicroelectronics S.r. I.
    Inventor: Filippo Alagi
  • Publication number: 20010010963
    Abstract: A bipolar transistor is described whose I-V curve is such that it operates in two regions, one having low gain and low power consumption and another having higher gain and better current driving ability. Said transistor has a base region made up of two sub regions, the region closest to the emitter having a resistivity about an order a magnitude lower than the second region (which interfaces with the collector). A key feature of the invention is that the region closest to the collector is very uniformly doped, i.e. there is no gradient or built-in field present. In order to produce such a region, epitaxial growth along with boron doping is used rather than more conventional techniques such as ion implantation and/or diffusion.
    Type: Application
    Filed: March 13, 2001
    Publication date: August 2, 2001
    Applicant: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY
    Inventors: Jun-Lin Tsai, Ruey-Hsing Liu, Chiou-Shian Peng, Kuo-Chio Liu
  • Publication number: 20010009793
    Abstract: A semiconductor device including a bipolar transistor formed by epitaxial growth or ion implantation is provided has an epitaxial silicon collector layer, a base region directly under an emitter defined as an intrinsic base and a peripheral region thereof defined as an outer base region is formed by the step of implanting ions into the collector layer to form a high concentration collector region at a location close to a buried region using a photoresist to form an aperture, and the step of implanting ions into the collector layer to form a high concentration collector region directly beneath the base region after forming the base region.
    Type: Application
    Filed: February 26, 2001
    Publication date: July 26, 2001
    Applicant: NEC Corporation
    Inventor: Fumihiko Sato
  • Publication number: 20010009794
    Abstract: A power transistor includes a plurality of emitter regions and a plurality of base contacts. In order to decrease base resistance, each of the plurality of emitter regions is adjacent to at least four base contacts. The entire transistor includes multiple emitter regions, e.g., greater than or equal to about 1,000 with no upper limit wherein the actual number of emitter regions is dependent on the desired current carrying capacity. The emitter regions are directly connected in parallel to the high current carrying metal layer of the transistor through vias or metal contact studs. The size of the emitter regions should be made as small as the process design rules will allow in order to allow an increase in the perimeter to area ratio of the emitter region which, for a given current, decreases the peak current density.
    Type: Application
    Filed: March 9, 2001
    Publication date: July 26, 2001
    Inventors: Lars Tilly, Per-Olof Magnus Brandt
  • Patent number: 6236072
    Abstract: A power transistor includes a plurality of emitter regions and a plurality of base contacts. In order to decrease base resistance, each of the plurality of emitter regions is adjacent to at least four base contacts. The entire transistor includes multiple emitter regions, e.g., greater than or equal to about 1,000 with no upper limit wherein the actual number of emitter regions is dependent on the desired current carrying capacity. The emitter regions are directly connected in parallel to the high current carrying metal layer of the transistor through vias or metal contact studs. The size of the emitter regions should be made as small as the process design rules will allow in order to allow an increase in the perimeter to area ratio of the emitter region which, for a given current, decreases the peak current density.
    Type: Grant
    Filed: November 12, 1998
    Date of Patent: May 22, 2001
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Lars Tilly, Per-Olof Magnus Brandt
  • Patent number: 6228732
    Abstract: A method is disclosed for reproducibly and controllably enhancing the current gain of a bipolar junction transistor. Prior to depositing an extrinsic emitter region of polycrystalline silicon, the surface of a monocrystalline silicon substrate is nitridized to grow a layer of silicon nitride thereon. The interfacial layer of silicon nitride functions as a tunnel insulator to enhance the current gain of the transistor and as a diffusion barrier to prevent thickening of the tunnel insulator due to the growth of a native oxide layer while exposed to an oxygen-containing atmosphere. The ubiquitous native silicon oxide on the surface of the monocrystalline silicon substrate may be optionally removed either before nitridation or after nitridation.
    Type: Grant
    Filed: December 22, 1999
    Date of Patent: May 8, 2001
    Assignees: Sony Corporation, Sony Electronics Inc.
    Inventors: William F. Richardson, Anhkim Duong
  • 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: 6140694
    Abstract: An integrated injection logic device is provided in which each collector of an I2L gate is isolated by a field oxide ("FOX"), or by other suitable isolation such as, for example, an isolation trench. The connection of the base to the collectors, between the base contact region and the bottom of the collectors, is made underneath the field oxide using a buried p type layer (TN3 in the Figures illustrating the invention). Because both silicide and heavy implant p+ implant is present at the base contact point only, the recombination current is reduced. This reduces the current loss when compared to the current loss of the known device. Additionally, current gain is also improved by placing a deep base implant close to the emitter of the upside down NPN transistor in the integrated logic device. The area of the base and the area of the collectors is decoupled, i.e.
    Type: Grant
    Filed: December 30, 1998
    Date of Patent: October 31, 2000
    Assignee: Philips Electronics North America Corporation
    Inventors: Chun-Yu Chen, Gilles Marcel Ferru, Serge Bardy
  • Patent number: 6103584
    Abstract: A bipolar transistor designed to support a substantially uniform current density in base and collector regions to prevent the characteristic early fall-off of bipolar transistor current gain, and to improve the forward safe operating area performance. The advantages of the present invention are achieved by optimally spacing the neighboring emitters in relation to base thickness and further by maintaining a symmetrical topology by the self-aligned formation of emitters and base contacts. The spacing distance between the neighboring emitters does not exceed the base thickness. As a result, the current density below each emitter island is substantially uniform and the transistor as a whole can conduct a higher total current. Moreover, the transistor inhibits formation of current filaments and hot spots because the electric field in the collector region is uniform.
    Type: Grant
    Filed: April 27, 1999
    Date of Patent: August 15, 2000
    Assignee: Semicoa Semiconductors
    Inventors: Richard A. Metzler, Vladimir Rodov
  • Patent number: 6004855
    Abstract: A process for producing a small shallow-depth high-performance bipolar structure having low parasitic capacitance is disclosed wherein an active base region of a P-type material is first defined in a substrate, a portion of which is of N-type material in a device formation area surrounded by an isolating oxide regions, such as trenches or the like. An N-doped polysilicon layer is then defined over the active base region and over field oxide regions located atop the isolating trenches. This N-poly region, when treated, will provide an interdigitated collector with self aligning emitter region aligned over the active base region. After appropriate spaced isolation layers are placed, a P-poly layer is laid down and heat treated to cause the P-type doping material to diffuse into the substrate contact to the active base region. A thin buried collector layer, approximately 1.
    Type: Grant
    Filed: October 29, 1997
    Date of Patent: December 21, 1999
    Assignee: Synergy Semiconductor Corporation
    Inventors: Larry Joseph Pollock, George William Brown
  • Patent number: 5869381
    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: September 29, 1997
    Date of Patent: February 9, 1999
    Assignee: Spectrian, Inc.
    Inventors: Francois Hebert, William McCalpin