Making Regenerative-type Switching Device (e.g., Scr, Igbt, Thyristor, Etc.) Patents (Class 438/133)
  • Patent number: 7202114
    Abstract: A complementary SCR-based structure enables a tunable holding voltage for robust and versatile ESD protection. The structure are n-channel high-holding-voltage low-voltage-trigger silicon controller rectifier (N-HHLVTSCR) device and p-channel high-holding-voltage low-voltage-trigger silicon controller rectifier (P-HHLVTSCR) device. The regions of the N-HHLVTSCR and P-HHLVTSCR devices are formed during normal processing steps in a CMOS or BICMOS process. The spacing and dimensions of the doped regions of N-HHLVTSCR and P-HHLVTSCR devices are used to produce the desired characteristics. The tunable HHLVTSCRs makes possible the use of this protection circuit in a broad range of ESD applications including protecting integrated circuits where the I/O signal swing can be either within the range of the bias of the internal circuit or below/above the range of the bias of the internal circuit.
    Type: Grant
    Filed: January 11, 2005
    Date of Patent: April 10, 2007
    Assignees: Intersil Americas Inc., The University of central Florida
    Inventors: Javier A. Salcedo, Juin J. Liou, Joseph C. Bernier, Donald K. Whitney, Jr.
  • Patent number: 7195958
    Abstract: The present invention provides a novel ESD structure for protecting an integrated circuit (IC) from ESD damage and a method of fabricating the ESD structure on a semiconductor substrate. The ESD structure of the present invention has lower trigger voltage and lower capacitance, and takes smaller substrate area than prior art ESD structures. The low trigger voltage is provided by a small N+P diode or a P+N diode which has a PN junction with a much lower breakdown voltage than a PN junction between a N+ (or P+) source/drain region and a P-well (or N-well). All of the diffusion regions in the ESD device of the present invention can be formed using ordinary process steps for fabricating the MOS devices in the IC and does not require extra masking steps in addition to those required to fabricate the IC.
    Type: Grant
    Filed: June 30, 2004
    Date of Patent: March 27, 2007
    Assignee: Altera Corporation
    Inventors: Cheng Huang, Yowjuang (Bill) Liu
  • Patent number: 7195959
    Abstract: A thyristor-based semiconductor memory device may comprise at least a region thereof, e.g., a p-base region, having high ionization energy impurity, such as a dopant. This high ionization energy impurity within a base region may be operable to compensate for a gain-versus-temperature dependence of a constituent bipolar transistor of the thyristor element of a thyristor-based memory device. In particular embodiments, the high ionization energy impurity may include a donor and/or acceptor in silicon.
    Type: Grant
    Filed: October 4, 2004
    Date of Patent: March 27, 2007
    Assignee: T-Ram Semiconductor, Inc.
    Inventors: James D. Plummer, Zachary K. Lee, Kevin J. Yang, Farid Nemati
  • Patent number: 7186594
    Abstract: A high voltage ESD-protection structure is used to protect delicate transistor circuits connected to an input or output of an integrated circuit bond pad from destructive high voltage ESD events by conducting at a controlled breakdown voltage that is less than a voltage that may cause destructive breakdown of the input and/or output circuits. The ESD-protection structure is able to absorb high current from these ESD events without snapback that would compromise operation of the higher voltage inputs and/or outputs of the integrated circuit. The ESD-protection structure will conduct when an ESD event occurs at a voltage above a controlled breakdown voltage of an electronic device, e.g., diode, in the ESD protection structure. Conduction of current from an ESD event having a voltage above the electronic device controlled breakdown voltage may be through another electronic device, e.g.
    Type: Grant
    Filed: July 18, 2005
    Date of Patent: March 6, 2007
    Assignee: Microchip Technology Inc.
    Inventors: Randy L. Yach, Gregg Dix
  • Patent number: 7161230
    Abstract: An insulated gate bipolar transistor has a P-type collector region containing a P-type impurity such as boron. A relatively thin N-type buffer region containing arsenic in a relatively high concentration is formed on the collector region via an anti-diffusion region. The anti-diffusion region is provided in such a way that its thickness is the same as or slightly smaller than the distance over which the P-type impurity is diffused from the collector region toward the buffer region in a device fabrication process.
    Type: Grant
    Filed: November 19, 2004
    Date of Patent: January 9, 2007
    Assignee: Sanken Electric Co., Ltd.
    Inventors: Katsuyuki Torii, Ryoji Takahashi
  • Patent number: 7154152
    Abstract: A semiconductor device has a p-type substrate, a low-concentration n-type region formed in the p-type substrate, a first high-concentration p-type region formed in the low-concentration n-type region and connected to a first electrode, a first high-concentration n-type region formed in the low-concentration n-type region and connected via a resistive element to the first electrode, a low-concentration p-type region formed contiguously with the first high-concentration n-type region, a second high-concentration n-type region and a second high-concentration p-type region formed in the p-type substrate and connected to a second electrode, and an element separator portion formed between the low-concentration p-type region and the second high-concentration n-type region. This makes it possible to control the switching characteristic of the electrostatic protection circuit with high accuracy and thus to cope with the thinning of the gate oxide film protected by the protection circuit.
    Type: Grant
    Filed: March 5, 2004
    Date of Patent: December 26, 2006
    Assignee: Rohm Co., Ltd.
    Inventor: Toshiaki Kojima
  • Patent number: 7144797
    Abstract: A semiconductor device includes a graded junction termination extension. A method for fabricating the device includes providing a semiconductor layer having a pn junction, providing a mask layer adjacent to the semiconductor layer, etching the mask layer to form at least two laterally adjacent steps associated with different mask thicknesses and substantially planar step surfaces, and implanting a dopant species through the mask layer into a portion of the semiconductor layer adjacent to the termination of the pn junction. The semiconductor layer is annealed to activate at least a portion of the implanted dopant species to form the graded junction termination extension.
    Type: Grant
    Filed: September 24, 2004
    Date of Patent: December 5, 2006
    Assignee: Rensselaer Polytechnic Institute
    Inventors: Tat-Sing Paul Chow, Peter Losee, Santhosh Balachandran
  • Patent number: 7135359
    Abstract: Large area silicon carbide devices, such as light-activated silicon carbide thyristors, having only two terminals are provided. The silicon carbide devices are selectively connected in parallel by a connecting plate. Silicon carbide thyristors are also provided having a portion of the gate region of the silicon carbide thyristors exposed so as to allow light of an energy greater than about 3.25 eV to activate the gate of the thyristor. The silicon carbide thyristors may be symmetric or asymmetrical. A plurality of the silicon carbide thyristors may be formed on a wafer, a portion of a wafer or multiple wafers. Bad cells may be determined and the good cells selectively connected by a connecting plate.
    Type: Grant
    Filed: May 14, 2004
    Date of Patent: November 14, 2006
    Assignee: Cree, Inc.
    Inventors: Anant Agarwal, Sei-Hyung Ryu, John W. Palmour
  • Patent number: 7105410
    Abstract: A contact process for a semiconductor device containing a base region of a first conductivity type formed on a semiconductor substrate comprises formation of a first shallow layer of the first conductivity type on the base region, deposition of an insulator on the first shallow layer, etching the insulator and first shallow layer to form a contact hole, thermally driving the first shallow layer more deeply into said base region, formation of a second shallow layer of a second conductivity type on the base region at the bottom of the contact hole, filling a metal in the contact hole to contact the sidewall of the first shallow layer and the second shallow layer.
    Type: Grant
    Filed: April 9, 2004
    Date of Patent: September 12, 2006
    Assignee: Analog and Power Electronics Corp.
    Inventors: Wei-Jye Lin, Ming-Jang Lin, Chorng-Wei Liaw
  • Patent number: 7095119
    Abstract: A semiconductor device is equipped with fuses each made of a conductive material vertically extended through an insulator layer employed in the semiconductor device. Holes are formed which vertically penetrate the insulator layer. Sidewalls are formed on their corresponding wall surfaces of the holes. The holes formed with the sidewalls are buried with a conductive material.
    Type: Grant
    Filed: January 22, 2004
    Date of Patent: August 22, 2006
    Assignee: Oki Electric Industry Co., Ltd.
    Inventor: Shunji Takase
  • Patent number: 7067850
    Abstract: A device (10) comprises a semiconductor diode (12) and a switchable element (14) positioned in stacked adjacent relationship so that the semiconductor diode (12) and the switchable element (14) are electrically connected in series with one another. The switchable element (14) is switchable from a low-conductance state to a high-conductance state in response to the application of a forming voltage to the switchable element (14).
    Type: Grant
    Filed: October 16, 2001
    Date of Patent: June 27, 2006
    Assignee: Midwest Research Institute
    Inventors: Howard M. Branz, Qi Wang
  • Patent number: 7064358
    Abstract: An embodiment is a Electro Static Discharge (ESD) protection device comprising: a n-doped region and a p-doped region in a p-well in a semiconductor structure. The n-doped region and the p-doped region are spaced. A n-well and a deep n-well surrounding the p-well on the sides and bottom. A first I/O pad connected to the n-doped region. A trigger circuit connected the first I/O pad and the p-doped region. A second I/O pad connected to the n-well. A parasitic bipolar transistor is comprised of the n-doped region that functions as a collector terminal, the P-well that functions as a base terminal, and the deep N-well that functions as the emitter terminal. Whereby under an ESD condition, the p-well is charged positive using the trigger circuit and the parasitic bipolar transistor can be turned on.
    Type: Grant
    Filed: December 22, 2003
    Date of Patent: June 20, 2006
    Assignee: Chartered SemiConductor Manufacturing, LTD
    Inventors: Indrajlt Manna, Keng Foo Lo, Pee Ya Tan, Raymond Filippi
  • Patent number: 7060538
    Abstract: The present invention provides a system for electrostatic discharge protection in a semiconductor device, utilizing a silicon-controlled rectifier (502). The system includes the silicon controlled rectifier, which has a first p-type region (508) coupled to a voltage node (504), a first n-type region (512) having a first side adjoining the first p-type region, a second p-type region (510) having a first side adjoining a second side of the first n-type region, and a second n-type region (514) having a first side adjoining a second side of the second p-type region. A clamping structure (506) is intercoupled between the second n-type region and ground, to prevent the junction between the second p-type region and the second n-type region from retaining a forward bias. A switching structure (518) is intercoupled between the second p-type region and ground to ground the second p-type region during normal operation of the semiconductor device.
    Type: Grant
    Filed: September 28, 2004
    Date of Patent: June 13, 2006
    Assignee: Texas Instruments Incorporated
    Inventor: Robert M. Steinhoff
  • Patent number: 7049181
    Abstract: A heterojunction P-I-N diode switch comprises a first layer of doped semiconductor material of a first doping type, a second layer of doped semiconductor material of a second doping type and a substrate on which is disposed the first and second layers. An intrinsic layer of semiconductor material is disposed between the first layer and second layer. The semiconductor material composition of at least one of the first layer and second layer is sufficiently different from that of the intrinsic layer so as to form a heterojunction therebetween, creating an energy barrier in which injected carriers from the junction are confined by the barrier, effectively reducing the series resistance within the I region of the P-I-N diode and the insertion loss relative to that of homojunction P-I-N diodes.
    Type: Grant
    Filed: August 10, 2004
    Date of Patent: May 23, 2006
    Assignee: M/A-Com
    Inventors: David Russell Hoag, Timothy Edward Boles, James Joseph Brogle
  • Patent number: 7037763
    Abstract: In an example gated-thyristor circuit, formation of thyristor body regions involves an angled implant of a thyristor body region, such as a base region, to mitigate capacitive coupling of a gated voltage pulse from the thyristor gate to a body region that is not underlying the thyristor gate. According to a more particular example embodiment, such a thyristor switches between a current-passing mode and a current blocking mode in response to at least one voltage pulse coupling to an underlying thyristor base region. Using a first ion type to provide one polarity, an immediately-adjacent thyristor base region is angle implanted through an emitter body region that is located to other side of the adjacent thyristor base region. The emitter body region is then implanted using ions of another ion type to provide the opposite polarity. This angle implantation permits definition of the adjacent thyristor base region sufficiently distant from (e.g.
    Type: Grant
    Filed: December 18, 2003
    Date of Patent: May 2, 2006
    Assignee: T-RAM Semiconductor, Inc.
    Inventors: Farid Nemati, Scott Robins, Andrew E. Horch
  • Patent number: 7015120
    Abstract: A method of fabricating a semiconductor device includes the steps of forming (or providing) a series of layers formed on a substrate, the layers including a first plurality of layers including an n-type ohmic contact layer, a p-type modulation doped quantum well structure, an n-type modulation doped quantum well structure, and a fourth plurality of layers including a p-type ohmic contact layer. Etch stop layers are used during etching operations when forming contacts to the n-type ohmic contact layer and contacts to the n-type modulation doped quantum well. Preferably, each such etch stop layer is made sufficiently thin to permit current tunneling therethrough during operation of optoelectronic/electronic devices realized from this structure (including heterojunction thyristor devices, n-channel HFET devices, p-channel HFET devices, p-type quantum-well-base bipolar transistor devices, and n-type quantum-well-base bipolar transistor devices).
    Type: Grant
    Filed: January 13, 2003
    Date of Patent: March 21, 2006
    Assignees: The University of Connecticut, Opel, Inc.
    Inventors: Geoff W. Taylor, Scott W. Duncan
  • Patent number: 7005678
    Abstract: A silicon carbide semiconductor device includes: a semiconductor substrate including a base substrate, a first semiconductor layer, a second semiconductor layer and a third semiconductor layer, which are laminated in this order; a cell portion disposed in the semiconductor substrate and providing an electric part forming portion; and a periphery portion surrounding the cell portion. The periphery portion includes a trench, which penetrates the second and the third semiconductor layers, reaches the first semiconductor layer, and surrounds the cell portion so that the second and the third semiconductor layers are divided by the trench substantially. The periphery portion further includes a fourth semiconductor layer disposed on an inner wall of the trench.
    Type: Grant
    Filed: November 10, 2004
    Date of Patent: February 28, 2006
    Assignee: Denso Corporation
    Inventors: Rajesh Kumar, Andrei Mihaila, Florin Udrea
  • Patent number: 7005686
    Abstract: Disclosed is a method for increasing substrate resistance in a silicon controlled rectifier in order to decrease turn on time so that the silicon controlled rectifier may be used as an effective electrostatic discharge protection device to protect against HBM, MM and CDM discharge events. Additionally, disclosed is an improved SCR structure that is adapted for use as an electrostatic discharge device to protect against human body model events by delivering an electrostatic discharge current directly to a ground rail. The improved SCR structure incorporates various features for increasing substrate resistance and, thereby, for decreasing turn on time. These features include a second n-well that functions as an obstacle to current flow, a narrow current flow channel between co-planar buried n-bands connected to a lower portion of the second n-well, a zero threshold voltage area, and an external resistor electrically connected between the SCR and the ground rail.
    Type: Grant
    Filed: July 26, 2005
    Date of Patent: February 28, 2006
    Assignee: International Business Machines Corporation
    Inventors: Kiran V. Chatty, Robert J. Gauthier, Jr., Mujahid Muhammad, Andreas D. Stricker, Min Woo
  • Patent number: 6998298
    Abstract: A thyristor memory device may comprise a capacitor electrode formed over a base region of the thyristor using a replacement gate process. During formation of the thyristor, a base-emitter boundary may be aligned relative to a shoulder of the capacitor electrode. In a particular embodiment, the replacement gate process may comprise defining a trench in a layer of dielectric over semiconductor material. Conductive material for the electrode may be formed over the dielectric and in the trench. It may further be patterned to form a shoulder for the electrode that extends over regions of the dielectric over a base region for the thyristor. The extent of the shoulder may be used to pattern the dielectric and/or to assist alignment of implants for the base and emitter regions of the thyristor.
    Type: Grant
    Filed: August 11, 2003
    Date of Patent: February 14, 2006
    Assignee: T-Ram Semiconductor, Inc.
    Inventor: Andrew E. Horch
  • Patent number: 6958263
    Abstract: The invention includes SOI constructions containing one or more memory cells which include a transistor and a thyristor. In one aspect, a scalable GLTRAM cell provides DRAM-like density and SRAM-like performance. The memory cell includes an access transistor and a gated-lateral thyristor integrally formed above the access transistor. The cathode region (n+) of the stacked lateral thyristor device (p+/n/p/n+) is physically and electrically connected to one of the source/drain regions of the FET to act as the storage node for the memory cell. The FET transistor can include an active region which extends into a Si/Ge material. The material comprising Si/Ge can have a relaxed crystalline lattice, and a layer having a strained crystalline lattice can be between the material having the relaxed crystalline lattice and the transistor gate. The device construction can be formed over a versatile substrate base.
    Type: Grant
    Filed: September 28, 2004
    Date of Patent: October 25, 2005
    Assignee: Micron Technology, Inc.
    Inventor: Arup Bhattacharyya
  • Patent number: 6927422
    Abstract: A direct-wafer-bonded, double heterojunction, light emitting semiconductor device includes an ordered array of quantum dots made of one or more indirect band gap materials selected from a group consisting of Si, Ge, SiGe, SiGeC, 3C—SiC, and hexagonal SiC, wherein the quantum dots are sandwiched between an n-type semiconductor cladding layer selected from a group consisting of SiC, 3C—SiC, 4H—SiC, 6H—SiC and diamond, and a p-type semiconductor cladding layer selected from a group consisting of SiC, 3C—SiC, 4H—SiC, 6H—SiC and diamond. A Ni contact is provided for the n-type cladding layer. An Al, a Ti or an Al/Ti alloy contact is provided for the p-type cladding layer. The quantum dots have a thickness that is no greater than about 250 Angstroms, a width that is no greater than about 200 Angstroms, and a center-to-center spacing that is in the range of from about 10 Angstroms to about 1000 Angstroms.
    Type: Grant
    Filed: May 6, 2003
    Date of Patent: August 9, 2005
    Assignee: Astralux, Inc.
    Inventor: John Tarje Torvik
  • Patent number: 6924177
    Abstract: A thyristor having a first zone, a second zone, a third zone, and a fourth zone. At least one control electrode is connected to the second and/or third zone. In order to reduce the static and dynamic power loss in a symmetrical thyristor, it is proposed that a field stop zone of the second conductivity type be disposed approximately in the center of the second zone, with the result that it subdivides the second zone into two sections of essentially the same size. To that end, the field stop layer is produced on an inner surface of a first wafer or of a second wafer, and the first wafer is connected to the second wafer, such that the two inner surfaces of the two wafers lie one on top of the other.
    Type: Grant
    Filed: December 22, 2003
    Date of Patent: August 2, 2005
    Assignee: Infineon Technologies AG
    Inventors: Hans-Joachim Schulze, Daniel Reznik
  • Patent number: 6913955
    Abstract: A thyristor-based semiconductor device has a control port formed in a trench having a height-to-width aspect ratio that can be prohibitive to filling a bottom portion of the trench with an insulative material. According to an example embodiment of the present invention, a trench is formed in the substrate adjacent to a thyristor region, and a control port is formed near a bottom of the trench. An upper portion of the trench is then filled, thereby covering the control port. The control port is adapted to reduce the aspect ratio of a remaining portion of the trench over the control port, making it possible to fill trenches having a high height-to-width aspect ratio (e.g., at least 2:1). The thyristor control port is capacitively coupled to the thyristor region via a dielectric on a sidewall of the trench, and is configured and arranged to control current in the thyristor body via the capacitive coupling.
    Type: Grant
    Filed: October 1, 2002
    Date of Patent: July 5, 2005
    Assignee: T-RAM, Inc.
    Inventors: Andrew Horch, Scott Robins
  • Patent number: 6909107
    Abstract: A method for manufacturing sidewall contacts for a chalcogenide memory device is disclosed. A first conductive layer is initially deposited on top of a first oxide layer. The first conductive layer is then patterned and etched using well-known processes. Next, a second oxide layer is deposited on top of the first conductive layer and the first oxide layer. An opening is then etched into at least the first oxide layer such that a portion of the first conductive layer is exposed within the opening. The exposed portion of the first conductive layer is then removed from the opening such that the first conductive layer is flush with an inner surface or sidewall of the opening. After depositing a chalcogenide layer on top of the second oxide layer, filling the opening with chalcogenide, a second conductive layer is deposited on top of the chalcogenide layer.
    Type: Grant
    Filed: April 26, 2004
    Date of Patent: June 21, 2005
    Assignee: BAE Systems, Information and Electronic Systems Integration, Inc.
    Inventors: John C. Rodgers, Jon D. Maimon
  • Patent number: 6905916
    Abstract: A method for treating a surface on an SiC semiconductor body produced by epitaxy. According to the method, the parts of the epitactic layer that are deposited in the final phase of the epitaxy are removed by etching and a wet chemical treatment is then carried out in order to remove a thin natural oxide on the surface. Alternatively, a metal layer configured as a Schottky contact and/or as an ohmic contact can also be applied to the surface immediately after the removal process.
    Type: Grant
    Filed: May 15, 2002
    Date of Patent: June 14, 2005
    Assignee: Infineon Technologies AG
    Inventors: Wolfgang Bartsch, Michael Treu, Roland Rupp
  • Patent number: 6870199
    Abstract: A semiconductor device that helps to prevent the occurrence of current localization in the vicinity of an electrode edge and improves the reverse-recovery withstanding capability. The semiconductor device according to the invention includes a first carrier lifetime region, in which the carrier lifetime is short, formed in such a configuration that the first carrier lifetime region extends across the edge area of an anode electrode projection, which projects the anode electrode vertically into a semiconductor substrate. The first carrier lifetime region also includes a vertical boundary area spreading nearly vertically between a heavily doped p-type anode layer and a lightly doped semiconductor layer. The first carrier lifetime region of the invention is formed by irradiating with a particle beam, such as a He2+ ion beam or a proton beam.
    Type: Grant
    Filed: November 3, 2000
    Date of Patent: March 22, 2005
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Ko Yoshikawa, Michio Nemoto, Takeshi Fujii
  • Patent number: 6858885
    Abstract: A protection circuit for use in a semiconductor apparatus includes a first conductivity type semiconductor substrate, a second conductivity type first diffusion region formed on the semiconductor substrate, and a second conductivity type second diffusion region formed on the semiconductor substrate. The second diffusion region is distanced at a prescribed interval from the first diffusion region. The first diffusion region is electrically connected to a pad for electrically connecting the semiconductor apparatus to an outside region. The second diffusion region is electrically connected to a power supply voltage. At least a portion of each of the first and second diffusion regions is entirely formed right under a pad area having the pad.
    Type: Grant
    Filed: March 28, 2003
    Date of Patent: February 22, 2005
    Assignee: Ricoh Company, Ltd.
    Inventor: Atsushi Ebara
  • Patent number: 6849481
    Abstract: A method for manufacturing an integrated circuit structure includes providing a semiconductor substrate and forming a thyristor thereon. The thyristor has at least four layers, with three P-N junctions therebetween. At least two of the layers are formed horizontally and at least two of the layers are formed vertically. A gate is formed adjacent at least one of the vertically formed layers. An access transistor is formed on the semiconductor substrate, and an interconnect is formed between the thyristor and the access transistor.
    Type: Grant
    Filed: July 28, 2003
    Date of Patent: February 1, 2005
    Assignee: Chartered Semiconductor Manufacturing Ltd.
    Inventors: Elgin Quek, Pradeep Ramachandramurthy Yelehanka, Jia Zhen Zheng, Tommy Lai, Weining Li
  • Patent number: 6838321
    Abstract: An N?-type silicon substrate (1) has a bottom surface and an upper surface which are opposed to each other. In the bottom surface of the N?-type silicon substrate (1), a P-type impurity diffusion layer (3) of high concentration is entirely formed by diffusing a P-type impurity. In the upper surface of the N?-type silicon substrate (1), a P-type isolation region (2) is partially formed by diffusing a P-type impurity. The P-type isolation region (2) has a bottom surface reaching an upper surface of the P-type impurity diffusion layer (3). As viewed from the upper surface side of the N?-type silicon substrate (1), the P-type isolation region (2) is formed, surrounding an N? region (1a) which is part of the N?-type silicon substrate (1). The N? region (1a) surrounded by the P-type isolation region (2) is defined as an element formation region of the N?-type silicon substrate (1).
    Type: Grant
    Filed: September 26, 2003
    Date of Patent: January 4, 2005
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Mitsuru Kaneda, Hideki Takahashi
  • Patent number: 6828176
    Abstract: A thyristor-based semiconductor device exhibits a relatively increased base-emitter capacitance. According to an example embodiment of the present invention, a base region and an adjacent emitter region of a thyristor are doped such that the emitter region has a lightly-doped portion having a light dopant concentration, relative to the base region. In one embodiment, the thyristor is implemented in a memory circuit, wherein the emitter region is coupled to a reference voltage line and a control port is arranged for capacitively coupling to the thyristor for controlling current flow therein. In another implementation, the thyristor is formed on a buried insulator layer of a silicon-on-insulator (SOI) structure. With these approaches, current flow in the thyristor, e.g., for data storage therein, can be tightly controlled.
    Type: Grant
    Filed: August 28, 2003
    Date of Patent: December 7, 2004
    Assignee: T-Ram, Inc.
    Inventors: Farid Nemati, Scott Robins, Andrew Horch
  • Patent number: 6815266
    Abstract: A method for manufacturing sidewall contacts for a chalcogenide memory device is disclosed. A first conductive layer is initially deposited on top of a first oxide layer. The first conductive layer is then patterned and etched using well-known processes. Next, a second oxide layer is deposited on top of the first conductive layer and the first oxide layer. An opening is then etched into at least the first oxide layer such that a portion of the first conductive layer is exposed within the opening. The exposed portion of the first conductive layer is then removed from the opening such that the first conductive layer is flush with an inner surface or sidewall of the opening. After depositing a chalcogenide layer on top of the second oxide layer, filling the opening with chalcogenide, a second conductive layer is deposited on top of the chalcogenide layer.
    Type: Grant
    Filed: December 30, 2002
    Date of Patent: November 9, 2004
    Assignees: BAE Systems Information and Electronic Systems Integration, Inc., Ovonyx, Inc.
    Inventors: John C. Rodgers, Jon D. Maimon
  • Patent number: 6812070
    Abstract: A method of epitaxially growing backward diodes and diodes grown by the method are presented herein. More specifically, the invention utilizes epitaxial-growth techniques such as molecular beam epitaxy in order to produce a thin, highly doped layer at the p-n junction in order to steepen the voltage drop at the junction, and thereby increase the electric field. By tailoring the p and n doping levels as well as adjusting the thin, highly doped layer, backward diodes may be consistently produced and may be tailored in a relatively easy and controllable fashion for a variety of applications. The use of the thin, highly doped layer provided by the present invention is discussed particularly in the context of InGaAs backward diode structures, but may be tailored to many diode types.
    Type: Grant
    Filed: January 8, 2003
    Date of Patent: November 2, 2004
    Assignee: HRL Laboratories, LLC
    Inventors: Joel N. Schulman, David H. Chow
  • Patent number: 6803259
    Abstract: A silicon controlled rectifier for SiGe process. The silicon controlled rectifier comprises a substrate, a buried layer of a first conductivity type in the substrate, a well of the first conductivity type in the substrate and above the buried layer, a doped region of a second conductivity type in the well, a first conducting layer of the second conductivity type on the substrate, and a second conducting layer of the first conductivity type on the first conducting layer.
    Type: Grant
    Filed: March 31, 2003
    Date of Patent: October 12, 2004
    Assignee: Taiwan Semiconductor Manufacturing Co., Ltd.
    Inventor: Jian-Hsing Lee
  • Patent number: 6790713
    Abstract: A semiconductor device having a thyristor is manufactured and arranged in a manner that reduces or eliminates difficulties commonly experienced in the formation and implementation of such devices. According to an example embodiment of the present invention, a thyristor (e.g., a thin capacitively-coupled thyristor) is formed having some or all of the body of the thyristor formed inlayed in a semiconductor device substrate. A trench is provided in the substrate, and a semiconductor material is formed in the trench. One or more layers of material are formed in the trench and used to form a portion of a body of the thyristor. The thyristor is formed having adjacent regions of different polarity, wherein at least one of the adjacent regions includes a portion of the semiconductor material and at least one of the adjacent regions includes a portion of the substrate.
    Type: Grant
    Filed: September 9, 2002
    Date of Patent: September 14, 2004
    Assignee: T-Ram, Inc.
    Inventor: Andrew Horch
  • Patent number: 6787400
    Abstract: An electrostatic discharge protection device is formed in a substrate and contains a drain area of a first dopant concentration abutting an extended drain area having a dopant concentration lower than the first dopant concentration. Similarly, a highly doped source area abuts a lower doped source extension area. The source and drain are laterally bounded by oxide regions and covered by an insulation layer. The areas of lower doping prevent charge crowding during an electrostatic discharge event by resistively forcing current though the nearly planer bottom surface of the drain, rather than the curved drain extension. In addition, a highly doped buried layer can abut an area of a graded doping level. By adjusting the doping levels of the graded areas and the buried layers, the substrate breakdown voltage is pre-selected.
    Type: Grant
    Filed: January 16, 2003
    Date of Patent: September 7, 2004
    Assignee: Micron Technology, Inc.
    Inventors: Stephen R. Porter, Manny K. Ma, Stephen Casper, Kevin Duesman
  • Patent number: 6787816
    Abstract: A method is provided for forming one or more doped layers using ion-implantation in the fabrication of thyristor devices. For example, these thyristors may be made from single crystalline silicon carbide. According to one aspect of the invention, one of the required layers is formed by introducing dopants after crystal growth as opposed to conventional methods which involve doping during crystal growth. Specifically, impurities may be introduced by using the technique of ion implantation.
    Type: Grant
    Filed: August 31, 2001
    Date of Patent: September 7, 2004
    Assignee: Rensselaer Polytechnic Institute
    Inventors: Tatsing P. Chow, Jeffrey B. Fedison
  • Patent number: 6781161
    Abstract: A semiconductor device with two epitaxial layers formed on a substrate. The middle layer of epitaxial material can be formed thin and with an appropriate doping concentration to provide a low avalanche breakdown voltage with a negative resistance characteristic. The top layer of epitaxial material is doped with the same concentration as the substrate to provide a two-terminal thyristor device with symmetrical bidirectional operating characteristics.
    Type: Grant
    Filed: April 9, 2003
    Date of Patent: August 24, 2004
    Assignee: Teccor Electronics, LP
    Inventors: Elmer L. Turner, Jr., Yong-Fa Alan Wang
  • Patent number: 6767770
    Abstract: A semiconductor memory device having a thyristor is manufactured in a manner that makes possible self-alignment of one or more portions of the thyristor. According to an example embodiment of the present invention, a gate is formed over a first portion of doped substrate. The gate is used to mask a portion of the doped substrate and a second portion of the substrate is doped before or after a spacer is formed. After the second portion of the substrate is doped, the spacer is then formed adjacent to the gate and used to mask the second portion of the substrate while a third portion of the substrate is doped. The gate and spacer are thus used to form self-aligned doped portions of the substrate, wherein the first and second portions form base regions and the third portion form an emitter region of a thyristor.
    Type: Grant
    Filed: October 1, 2002
    Date of Patent: July 27, 2004
    Assignee: T-Ram, Inc.
    Inventors: Andrew Horch, Scott Robins, Farid Nemati
  • Publication number: 20040137666
    Abstract: A power semiconductor switching device such as a power MOSFET that includes breakdown voltage enhancement regions formed by self-alignment.
    Type: Application
    Filed: December 23, 2003
    Publication date: July 15, 2004
    Applicant: International Rectifier Corporation
    Inventors: Timothy Henson, Jianjun Cao
  • Publication number: 20040137665
    Abstract: A thyristor having a first zone, a second zone, a third zone, and a fourth zone. At least one control electrode is connected to the second and/or third zone. In order to reduce the static and dynamic power loss in a symmetrical thyristor, it is proposed that a field stop zone of the second conductivity type be disposed approximately in the center of the second zone, with the result that it subdivides the second zone into two sections of essentially the same size. To that end, the field stop layer is produced on an inner surface of a first wafer or of a second wafer, and the first wafer is connected to the second wafer, such that the two inner surfaces of the two wafers lie one on top of the other.
    Type: Application
    Filed: December 22, 2003
    Publication date: July 15, 2004
    Applicant: Infineon Technologies AG
    Inventors: Hans-Joachim Schulze, Daniel Reznik
  • Patent number: 6762080
    Abstract: In a method of manufacturing a semiconductor element (6) having a cathode (3) and an anode (5), the starting material used is a relatively thick wafer (1) to which, as a first step, a barrier region (21) is added on the anode side. It is then treated on the cathode side, and the thickness of the wafer (1) is then reduced on the side opposite to the cathode (3), and an anode (5) is produced on this side in a further step. The result is a relatively thin semiconductor element which can be produced economically and without epitaxial layers.
    Type: Grant
    Filed: August 21, 2002
    Date of Patent: July 13, 2004
    Assignee: ABB Schweiz Holding AG
    Inventor: Stefan Linder
  • Publication number: 20040124445
    Abstract: A semiconductor substrate is disclosed, which comprises a lightly doped substrate that contains impurities at a low concentration, a heavily doped diffusion layer which is formed over a top of the lightly doped substrate and is higher in impurity concentration than the lightly doped substrate, and an epitaxial layer which is formed over a top of the heavily doped diffusion layer and contains impurities at a lower concentration than the heavily doped diffusion layer.
    Type: Application
    Filed: November 17, 2003
    Publication date: July 1, 2004
    Inventors: Masanobu Ogino, Yoshikatsu Suto, Yoshiro Baba
  • Patent number: 6750085
    Abstract: A method for manufacturing sidewall contacts for a chalcogenide memory device is disclosed. A first conductive layer is initially deposited on top of a first oxide layer. The first conductive layer is then patterned and etched using well-known processes. Next, a second oxide layer is deposited on top of the first conductive layer and the first oxide layer. An opening is then etched into at least the first oxide layer such that a portion of the first conductive layer is exposed within the opening. The exposed portion of the first conductive layer is then removed from the opening such that the first conductive layer is flush with an inner surface or sidewall of the opening. After depositing a chalcogenide layer on top of the second oxide layer, filling the opening with chalcogenide, a second conductive layer is deposited on top of the chalcogenide layer.
    Type: Grant
    Filed: December 30, 2002
    Date of Patent: June 15, 2004
    Inventors: John C. Rodgers, Jon D. Maimon
  • Patent number: 6734462
    Abstract: A structure and method for a voltage blocking device comprises a cathode region, a drift region positioned on the cathode region, a gate region positioned on the drift region, an anode region positioned on the gate region and a plurality of contacts positioned on each of the cathode region, the gate region, and the anode region, wherein the drift region comprises multiple epilayers having first doped type layers surrounding second doped type layers, wherein dopant concentrations of the first doped type layers are lower than dopant concentrations of the second doped type layers. The epilayers comprise at least one i-n-i layer and/or at least one i-p-i layer. Moreover, the multiple epilayers are operable to block voltages in the device.
    Type: Grant
    Filed: December 6, 2002
    Date of Patent: May 11, 2004
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventor: Pankaj B. Shah
  • Patent number: 6734054
    Abstract: A structure of an ESD protection circuit device located under a pad, protecting an internal circuit and a method of manufacturing the same are disclosed. The ESD protection circuit device having a pad window, located under a pad, includes a semiconductor substrate having a P-well and an N-well. The P-well and the N-well have an interface. A predetermined area, pad window is selected in the substrate. A first STI structure, a second STI structure and a third STI structure are formed in the substrate within the pad window. N-type doped regions are formed P-well and in the N-well. First p-type doped regions are formed in the P-well and in the N-well and second p-type doped regions are formed in the P-well and in the N-well. A first zener diode is formed in the N-well and a second zener diode is formed in the P-well.
    Type: Grant
    Filed: June 27, 2002
    Date of Patent: May 11, 2004
    Assignee: United Microelectronics Corp.
    Inventors: Tien-Hao Tang, Shiao-Shien Chen
  • Patent number: 6723586
    Abstract: A thyristor includes a semiconductor body having an anode-side base zone of a first conductance type, and having a cathode-side base zone of the second, opposite conductance type, and has cathode-side and anode-side emitter zones. An anode-side defect zone is included within the anode-side base zone, in which the free charge carriers have a reduced life, with a predetermined thickness of at least 20 &mgr;m. The defect zone may be produced by anode-side irradiation of predetermined regions of the semiconductor body with charged particles, and with heat treatment of the semiconductor body in order to stabilize the defect zone.
    Type: Grant
    Filed: April 1, 2002
    Date of Patent: April 20, 2004
    Assignee: Siemens Aktiengesellschaft
    Inventors: Franz Josef Niedernostheide, Hans-Joachim Schulze
  • Publication number: 20040067609
    Abstract: A silicon controlled rectifier for SiGe process. The silicon controlled rectifier comprises a substrate, a buried layer of a first conductivity type in the substrate, a well of the first conductivity type in the substrate and above the buried layer, a doped region of a second conductivity type in the well, a first conducting layer of the second conductivity type on the substrate, and a second conducting layer of the first conductivity type on the first conducting layer.
    Type: Application
    Filed: March 31, 2003
    Publication date: April 8, 2004
    Inventor: Jian-Hsing Lee
  • Publication number: 20040033645
    Abstract: A method to form a SCR device in the manufacture of an integrated circuit device is achieved. The method comprises providing a SOI substrate comprising a silicon layer overlying a buried oxide layer. The silicon layer further comprises a first well of a first type and a second well of a second type. A first heavily doped region of the first type is formed in the second well to form an anode terminal. A second heavily doped region of the second type is formed in the first well to form a cathode terminal and to complete the SCR device. A gate isolation method is described. A salicide method is described. LVT-SCR methods, including a floating-well, LVT-SCR method, are described.
    Type: Application
    Filed: August 13, 2003
    Publication date: February 19, 2004
    Applicant: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY
    Inventor: Ta Lee Yu
  • Patent number: 6683328
    Abstract: A power semiconductor containing an anode disposed on either a top side or a bottom side is described. A cathode is disposed on the side that is unoccupied by the anode, and edge terminations are provided on the top side. The power semiconductor is characterized in that at least one region extends from an edge termination on the top side to a semiconductor region on the bottom side in order to form an ohmic connection, and is characterized in that this at least one region is doped with sulfur.
    Type: Grant
    Filed: April 23, 2001
    Date of Patent: January 27, 2004
    Assignee: Infineon Technologies AG
    Inventor: Hans-Joachim Schulze
  • Patent number: 6660570
    Abstract: A high voltage semiconductor device including a semiconductor substrate on which a semi-insulating polycrystalline silicon layer is formed to alleviate electric field concentration in a field region, is disclosed. A thermal oxide layer is formed on the semi-insulating polycrystalline silicon layer to serve as a protective layer. The thermal oxide layer forms a good interface with the semi-insulating polycrystalline silicon layer compared to a wet etched oxide layer or a chemical vapor deposition (CVD) oxide layer, thereby decreasing the amount of leakage current. In addition, compared to a dual semi-insulating polycrystalline silicon layer, the thermal oxide layer exhibits a high surface protection effect and a high resistance against dielectric breakdown. It also allows a great reduction in fabrication time.
    Type: Grant
    Filed: May 8, 2002
    Date of Patent: December 9, 2003
    Assignee: Fairchild Korea Semiconductor, Ltd.
    Inventors: Jin-kyeong Kim, Jong-min Kim, Kyung-wook Kim, Tae-hoon Kim, Cheol Choi, Chang-wook Kim