Junction Field Effect Transistor (unipolar Transistor) Patents (Class 257/256)
  • Patent number: 7323386
    Abstract: A semiconductor device includes a field shield region that is doped opposite to the conductivity of the substrate and is bounded laterally by dielectric sidewall spacers and from below by a PN junction. For example, in a trench-gated MOSFET the field shield region may be located beneath the trench and may be electrically connected to the source region. When the MOSFET is reverse-biased, depletion regions extend from the dielectric sidewall spacers into the “drift” region, shielding the gate oxide from high electric fields and increasing the avalanche breakdown voltage of the device. This permits the drift region to be more heavily doped and reduces the on-resistance of the device. It also allows the use of a thin, 20 ? gate oxide for a power MOSFET that is to be switched with a 1V signal applied to its gate while being able to block over 30V applied across its drain and source electrodes, for example.
    Type: Grant
    Filed: March 14, 2006
    Date of Patent: January 29, 2008
    Inventor: Hamza Yilmaz
  • Patent number: 7321142
    Abstract: On an SiC single crystal substrate, an electric field relaxation layer and a p? type buffer layer are formed. The electric field relaxation layer is formed between the p? type buffer layer and the SiC single crystal substrate to contact SiC single crystal substrate. On the p? type buffer layer, an n type semiconductor layer is formed. On the n type semiconductor layer, a p type semiconductor layer is formed. In the p type semiconductor layer, an n+ type source region layer and an n+ type drain region layer are formed separated by a prescribed distance from each other. At a part of the region of p type semiconductor layer between the n+ type source region layer and the n+ type drain region layer, a p+ type gate region layer is formed.
    Type: Grant
    Filed: May 21, 2004
    Date of Patent: January 22, 2008
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Kazuhiro Fujikawa, Shin Harada, Hiroyuki Matsunami, Tsunenobu Kimoto
  • Publication number: 20080001184
    Abstract: Example embodiments are directed to a junction field effect thin film transistor (JFETFT) including a first electrode formed on a substrate, a first conductive first gate semiconductor pattern formed on the first gate electrode, a second conductive semiconductor channel layer formed on the substrate and the first conductive first gate semiconductor pattern, and source and drain electrodes formed on the second conductive semiconductor pattern and located at both sides of the first conductive gate semiconductor pattern. The JFETFT may further include a first conductive second gate semiconductor pattern formed on a portion of the second conductive semiconductor channel layer between the source electrode and the drain electrode, and a second gate electrode formed on the first conductive second gate semiconductor pattern.
    Type: Application
    Filed: February 12, 2007
    Publication date: January 3, 2008
    Inventors: Stefanovich Genrikh, Choong-Rae Cho, Eun-Hong Lee
  • Publication number: 20080001183
    Abstract: A semiconductor device including complementary junction field effect transistors (JFETS) manufactured on a silicon on insulator (SOI) wafer is disclosed. A p-type JFET includes a control gate formed from n-type polysilicon and an n-type JFET includes a control gate formed from p-type polysilicon. The complementary JFETs may include four terminal JFETs having a back gate formed below a channel region. The back gate may be electrically connected to a control gate formed above a channel region via a cut region in an isolation structure. Furthermore, the complementary JFETs may be formed on strained silicon formed on a silicon germanium (SiGe) or silicon germanium carbon (SiGeC) layer, or the like.
    Type: Application
    Filed: August 22, 2006
    Publication date: January 3, 2008
    Inventor: Ashok Kumar Kapoor
  • Patent number: 7312481
    Abstract: The present invention provides a high-voltage junction field effect transistor (JFET), a method of manufacture and an integrated circuit including the same. One embodiment of the high-voltage junction field effect transistor (JFET) (300) includes a well region (320) of a first conductive type located within a substrate (318) and a gate region (410) of a second conductive type located within the well region (320), the gate region (410) having a length and a width. This embodiment further includes a source region (710) and a drain region (715) of the first conductive type located within the substrate (318) in a spaced apart relation to the gate region (410) and a doped region (810) of the second conductive type located in the gate region (410) and extending along the width of the gate region (410).
    Type: Grant
    Filed: October 1, 2004
    Date of Patent: December 25, 2007
    Assignee: Texas Instruments Incorporated
    Inventors: Kaiyuan Chen, Joe Trogolo, Tathagata Chatterjee, Steve Merchant
  • Publication number: 20070284626
    Abstract: A scalable device structure and process for forming a normally off JFET with 45 NM linewidths or less. The contacts to the source, drain and gate areas are formed by forming a layer of oxide of a thickness of less than 1000 angstroms, and, preferably 500 angstroms or less on top of the substrate. A nitride layer is formed on top of the oxide layer and holes are etched for the source, drain and gate contacts. A layer of polysilicon is then deposited so as to fill the holes and the polysilicon is polished back to planarize it flush with the nitride layer. The polysilicon contacts are then implanted with the types of impurities necessary for the channel type of the desired transistor and the impurities are driven into the semiconductor substrate below to form source, drain and gate regions.
    Type: Application
    Filed: June 12, 2006
    Publication date: December 13, 2007
    Inventors: Madhukar B. Vora, Ashok Kumar Kapoor
  • Publication number: 20070278539
    Abstract: A semiconductor device is described that operates as an improved junction field effect transistor (JFET). A bipolar transistor with a collector region, a base region, an emitter region, a first base contact, and a second base contact insulated from the first base contact, has the base region lightly doped to about a 1E16 to 5E17 atoms/cm3 doping level. A connection is provided between the emitter region and the collector region to act as a JFET gate contact for the bipolar transistor. The semiconductor device operates as an improved JFET with the first base contact being a drain contact and the second base contact being a source contact. A method for manufacture of an improved JFET on a chip containing conventional bipolar devices is also described. The improved JFET is shown being used with a write head in a disk drive system for providing electrostatic discharge protection.
    Type: Application
    Filed: June 2, 2006
    Publication date: December 6, 2007
    Applicant: Agere Systems Inc.
    Inventors: Mark Victor Dyson, Nace Rossi, Ranbir Singh
  • Patent number: 7304335
    Abstract: A vertical-conduction and planar-structure MOS device having a double thickness gate oxide includes a semiconductor substrate including spaced apart active areas in the semiconductor substrate and defining a JFET area therebetween. The JFET area also forms a channel between the spaced apart active areas. A gate oxide is on the semiconductor substrate and includes a first portion having a first thickness on the active areas and at a periphery of the JFET area, and a second portion having a second thickness on a central area of the JFET area. The second thickness is greater than the first thickness. The JFET area also includes an enrichment region under the second portion of the gate oxide.
    Type: Grant
    Filed: April 17, 2006
    Date of Patent: December 4, 2007
    Assignee: STMicroelectronics S.r.l.
    Inventors: Angelo Magri', Ferruccio Frisina, Giuseppe Ferla, Marco Camalleri
  • Patent number: 7301185
    Abstract: A high-voltage transistor device with an interlayer dielectric (ILD) etch stop layer for use in a subsequent contact hole process is provided. The etch stop layer is a high-resistivity film having a resistivity greater than 10 ohm-cm, thus leakage is prevented and breakdown voltage is improved when driving a high voltage greater than 5V at the gate site. A method for fabricating the high-voltage device is compatible with current low-voltage device processes and middle-voltage device processes.
    Type: Grant
    Filed: November 29, 2004
    Date of Patent: November 27, 2007
    Assignee: Taiwan Semiconductor Manufacturing Company, Ltd.
    Inventors: Chung-I Chen, Hsin Kuan, Zhi-Cheng Chen, Rann-Shyan Yeh, Chi-Hsuen Chang, Jun Xiu Liu, Tzu-Chiang Sung, Chia-Wei Liu, Jieh-Ting Cheng
  • Publication number: 20070235774
    Abstract: A semiconductor package with contacts on both sides of the dice on a wafer scale. The back side of the wafer is attached to a metal plate. The scribe lines separating the dice expose the metal plate without extending through the metal plate. A metal layer may be formed on the front side of the dice, covering the exposed portions of the metal plate and extending to side edges of the dice. The metal layer may cover connection pads on the front side of the dice. A second set of scribe lines are made coincident with the first set. Therefore, the metal layer remains on the side edges of the dice coupling the front and the back. As a result, the package is rugged and provides a low-resistance electrical connection between the back and front sides of the dice.
    Type: Application
    Filed: April 11, 2007
    Publication date: October 11, 2007
    Inventors: Felix Zandman, Y. Mohammed Kasem, Yueh-Se Ho
  • Publication number: 20070228424
    Abstract: A semiconductor device includes: a first FET that is formed with first unit FETs each having a first finger electrode and a second finger electrode provided on either side of a gate finger electrode, the first unit FETs being connected in parallel; and a second FET that is formed with second unit FETs each having a first finger electrode and a second finger electrode provided on either side of a gate finger electrode, the second unit FETs being connected in parallel. In this semiconductor device, the second finger electrode of each of the first unit FETs and the first finger electrode of each corresponding one of the second unit FETs form a common finger electrode, and the first finger electrodes of the first unit FETs, the second finger electrodes of the second unit FETs, and the common finger electrodes are arranged in the gate length direction of the first FET and the second FET.
    Type: Application
    Filed: March 29, 2007
    Publication date: October 4, 2007
    Applicant: EUDYNA DEVICES INC.
    Inventor: Takeshi Igarashi
  • Publication number: 20070221963
    Abstract: A switching power supply has a start-up circuit that includes a field effect transistor (JFET), which has a gate region (a p-type well region) formed in a surface layer of a p-type substrate and a drift region (a first n-type well region). A plurality of source regions (second n-type well regions) are formed circumferentially around the drift region. A drain region (a third n-type well region) is formed centrally of the source region. The drain region and the source regions can be formed at the same time. A metal wiring of the source electrode wiring connected to source regions is divided into at least two groups to form at least two junction field effect transistors.
    Type: Application
    Filed: March 24, 2007
    Publication date: September 27, 2007
    Applicant: C/O FUJI ELECTRIC DEVICE TECHNOLOGY CO., LTD.
    Inventors: Masaru SAITO, Koji SONOBE
  • Patent number: 7268378
    Abstract: A junction field effect transistor (JFET) with a reduced gate capacitance. A gate definition spacer is formed on the wall of an etched trench to establish the lateral extent of an implanted gate region for a JFET. After implant, the gate is annealed. In addition to controlling the final junction geometry and thereby reducing the junction capacitance by establishing the lateral extent of the implanted gate region, the gate definition spacer also limits the available diffusion paths for the implanted dopant species during anneal. Also, the gate definition spacer defines the walls of a second etched trench that is used to remove a portion of the p-n junction, thereby further reducing the junction capacitance.
    Type: Grant
    Filed: May 29, 2002
    Date of Patent: September 11, 2007
    Assignee: Qspeed Semiconductor Inc.
    Inventors: Ho-Yuan Yu, Valentino L. Liva
  • Patent number: 7250643
    Abstract: A semiconductor device includes: a gate electrode that is provided on a semiconductor layer; a source electrode and a drain electrode that are provided on the semiconductor layer so as to interpose the gate electrode; a source wall that extends from the source electrode to a point between the gate electrode and the drain electrode through the region above the gate electrode, the source wall having a joining portion in the extending region; and an electrode portion that is joined to the joining portion and has a region extending closer to the drain electrode than the joining portion.
    Type: Grant
    Filed: March 30, 2006
    Date of Patent: July 31, 2007
    Assignee: Eudyna Devices Inc.
    Inventor: Masahiro Nishi
  • Publication number: 20070164322
    Abstract: Transistors are fabricated by forming a protective layer having a first opening extending therethrough on a substrate, forming a dielectric layer on the protective layer having a second opening extending therethrough that is wider than the first opening, and forming a gate electrode in the first and second openings. A first portion of the gate electrode laterally extends on surface portions of the protective layer outside the first opening, and a second portion of the gate electrode is spaced apart from the protective layer and laterally extends beyond the first portion on portions of the dielectric layer outside the second opening. Related devices and fabrication methods are also discussed.
    Type: Application
    Filed: July 26, 2006
    Publication date: July 19, 2007
    Inventors: Richard Peter Smith, Scott T. Sheppard
  • Patent number: 7235827
    Abstract: A junction field effect transistor (JFET) has a gate region, drain region, and a source region. An epitaxial region having a first conductivity type is disposed over the drain region. The first conductivity type is N-type semiconductor material. The gate region is disposed within a trench which is formed in the epitaxial region. A P+ region is disposed within the epitaxial region and under the gate region. The P+ region has a first doping concentration of a second conductivity type opposite the first conductivity type. A P? region is disposed under the P+ region. The P? region has a second doping concentration of the second conductivity type which is less than the first doping concentration. The P? region may be disposed adjacent to a first portion of the P+ region while another P? region is disposed adjacent to a second portion of the P+ region. The P+ region may be implanted from the gate region deep into the epitaxial region.
    Type: Grant
    Filed: April 20, 2004
    Date of Patent: June 26, 2007
    Assignee: Power-One, Inc.
    Inventors: Badredin Fatemizadeh, Ali Salih
  • Patent number: 7221010
    Abstract: Silicon carbide metal-oxide semiconductor field effect transistors (MOSFETs) may include an n-type silicon carbide drift layer, a first p-type silicon carbide region adjacent the drift layer and having a first n-type silicon carbide region therein, an oxide layer on the drift layer, and an n-type silicon carbide limiting region disposed between the drift layer and a portion of the first p-type region. The limiting region may have a carrier concentration that is greater than the carrier concentration of the drift layer. Methods of fabricating silicon carbide MOSFET devices are also provided.
    Type: Grant
    Filed: October 30, 2003
    Date of Patent: May 22, 2007
    Assignee: Cree, Inc.
    Inventor: Sei-Hyung Ryu
  • Patent number: 7202528
    Abstract: Wide bandgap semiconductor devices including normally-off VJFET integrated power switches are described. The power switches can be implemented monolithically or hybridly, and may be integrated with a control circuit built in a single-or multi-chip wide bandgap power semiconductor module. The devices can be used in high-power, temperature-tolerant and radiation-resistant electronics components. Methods of making the devices are also described.
    Type: Grant
    Filed: December 1, 2004
    Date of Patent: April 10, 2007
    Assignee: Semisouth Laboratories, Inc.
    Inventors: Igor Sankin, Joseph N. Merrett
  • Patent number: 7196321
    Abstract: Disclosed is a fine pattern forming apparatus and a fine pattern inspecting apparatus. In one preferred form, the fine pattern forming apparatus includes a surface irregularity information reading device for detecting a shape signal corresponding to a surface irregularity of a surface of an original, while scanning the surface by use of a first probe, and a surface irregularity information writing device for processing a substrate to be processed, while scanning a surface of the substrate by use of a second probe, wherein an applied electric voltage to the second probe is changed in accordance with the shape signal while a distance between the second probe and the substrate is kept substantially constant, or the distance between the second probe and the substrate is changed in accordance with the shape signal while the applied electric voltage to the second probe is kept substantially constant, such that the substrate is processed in accordance with the surface irregularity of the original.
    Type: Grant
    Filed: June 7, 2005
    Date of Patent: March 27, 2007
    Assignee: Canon Kabushiki Kaisha
    Inventors: Eigo Kawakami, Hirohisa Ota, Takashi Nakamura, Kazuyuki Kasumi, Toshinobu Tokita
  • Patent number: 7180105
    Abstract: A normally off JFET is formed by the implantation of a P base; and a shallower P island atop the P base, forming a narrow lateral conduction channel between the two and a shallow gate implant in the device top surface which forms a second lateral conduction channel with the island. The two channels are each less than 0.5 microns thick and have an impurity concentration such that the channels are depleted at zero gate voltage and are turned on when the gate is forward biased. The gate surrounds a source implant region and a remote drain is provided which is connected to the top surface of the device for a lateral JFET or the bottom of the device for a vertical conduction JFET.
    Type: Grant
    Filed: February 8, 2005
    Date of Patent: February 20, 2007
    Assignee: International Rectifier Corporation
    Inventor: Alan Potts
  • Patent number: 7091533
    Abstract: The invention relates to a semiconductor component, in which regions of the conduction type opposite to the conduction type of the drift zone are incorporated in the drift zone and also in the region of the active zones.
    Type: Grant
    Filed: May 11, 2004
    Date of Patent: August 15, 2006
    Assignee: Infineon Technologies AG
    Inventors: Jenö Tihanyi, Gerald Deboy
  • Patent number: 7075132
    Abstract: A programmable junction field effect transistor (JFET) with multiple independent gate inputs. A drain, source and a plurality of gate regions for controlling a conductive channel between the source and drain are fabricated in a semiconductor substrate. A first portion the gate regions are coupled to a first gate input and a second portion of the gate regions are coupled to a second gate input. The first and second gate inputs are electrically isolated from each other. The JFET may be programmed by applying a programming voltage to the first gate input and operated by applying a signal to the second gate input.
    Type: Grant
    Filed: December 30, 2002
    Date of Patent: July 11, 2006
    Assignee: Lovoltech, Inc.
    Inventors: Chong Ming Lin, Ho Yuan Yu
  • Patent number: 7071503
    Abstract: A semi-conductor structure for controlling and switching a current has a switch element and an edge element. The switch element contains a first semi-conductor area of a first conductivity type contacted by way of an anode electrode and a cathode electrode, a depletion area that is arranged inside the first semi-conductor area and that can be influenced by a control voltage applied to the control electrode for the purpose of current control, and an island area of a second conductivity type that is buried inside the first semi-conductor area. The edge element contains an edge area of the second conductivity type that is buried inside the first semi-conductive area and that is formed on a common level with the buried island area, in addition to an edge terminating area of a second conductivity type adjacent the edge area.
    Type: Grant
    Filed: September 24, 2004
    Date of Patent: July 4, 2006
    Assignee: SiCED Electronics Development GmbH & Co. KG
    Inventors: Karl Dohnke, Rudolf Elpelt, Peter Friedrichs, Heinz Mitlehner, Reinhold Schörner
  • Patent number: 7038272
    Abstract: In a method for forming a channel zone in field-effect transistors, a polysilicon layer is patterned above the channel zone to be formed. The polysilicon layer serves as a mask substrate for the subsequent doping of the channel zone. The expedient patterning of the polysilicon layer with holes in a gate region and pillars in a source region enables the channel zone to be doped more lightly. In another embodiment, the novel method is used for a channel width shading of a PMOS transistor cell.
    Type: Grant
    Filed: July 31, 2003
    Date of Patent: May 2, 2006
    Assignee: Infineon Technologies AG
    Inventors: Hans Weber, Dirk Ahlers, Uwe Wahl, Jenö Tihanyi, Armin Willmeroth
  • Patent number: 7009228
    Abstract: A method for fabricating a guard ring structure for JFETs and MESFETs. Trenches are etched in a semiconductor substrate for fabrication of a gate structure for a JFET or MESFET. At time the gate trenches are etched, concentric guard ring trenches are also etched. The process used to fabricate the gate p-h junction or Schottky barrier at the bottom of the gate trenches is also used to fabricate the guard ring at bottom of the guard ring trenches. The separation between the guard ring trenches is 1.0 to 3.0 times greater than the separation between the gate trenches.
    Type: Grant
    Filed: March 4, 2003
    Date of Patent: March 7, 2006
    Assignee: Lovoltech, Incorporated
    Inventor: Ho-Yuan Yu
  • Patent number: 7009209
    Abstract: A silicon carbide semi-insulating epitaxy layer is used to create power devices and integrated circuits having significant performance advantages over conventional devices. A silicon carbide semi-insulating layer is formed on a substrate, such as a conducting substrate, and one or more semiconducting devices are formed on the silicon carbide semi-insulating layer. The silicon carbide semi-insulating layer, which includes, for example, 4H or 6H silicon carbide, is formed using a compensating material, the compensating material being selected depending on preferred characteristics for the semi-insulating layer. The compensating material includes, for example, boron, vanadium, chromium, or germanium. Use of a silicon carbide semi-insulating layer provides insulating advantages and improved thermal performance for high power and high frequency semiconductor applications.
    Type: Grant
    Filed: January 3, 2002
    Date of Patent: March 7, 2006
    Assignee: Mississippi State University Research and Technology Corporation (RTC)
    Inventors: Jeffrey B. Casady, Michael Mazzola
  • Patent number: 7005688
    Abstract: A semiconductor switching device includes a plurality of metal layers. At least one of the metal layers forming a Schottky junction with a semi-insulating substrate or an insulating layer on a substrate. The device also includes an impurity diffusion region, and a high-concentration impurity region formed between two of the metal layers or between one of the metal layers and the impurity diffusion region so as to suppress expansion of a depletion layer from the corresponding metal layer.
    Type: Grant
    Filed: October 14, 2003
    Date of Patent: February 28, 2006
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Tetsuro Asano, Mikito Sakakibara, Yoshibumi Nakajima, Hidetoshi Ishihara
  • Patent number: 6924516
    Abstract: A semiconductor device includes: a substrate; a buffer layer including GaN formed on the substrate, wherein: surfaces of the buffer layer are c facets of Ga atoms; a channel layer including GaN or InGaN formed on the buffer layer,wherein: surfaces of the channel layer are c facets of Ga or In atoms; an electron donor layer including AlGaN formed on the channel layer, wherein: surfaces of the electron donor layer are c facets of Al or Ga atoms; a source electrode and a drain electrode formed on the electron donor layer; a cap layer including GaN or InGaAlN formed between the source electrode and the drain electrode, wherein: surfaces of the cap layer are c facets of Ga or In atoms and at least a portion of the cap layer is in contact with the electron donor layer; and a gate electrode formed at least a portion of which is in contact with the cap layer.
    Type: Grant
    Filed: August 26, 2004
    Date of Patent: August 2, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kaoru Inoue, Katsunori Nishii, Hiroyuki Masato
  • Patent number: 6921932
    Abstract: JFET and MESFET structures, and processes of making same, for low voltage, high current and high frequency applications. The structures may be used in normally-on (e.g., depletion mode) or normally-off modes. The structures include an oxide layer positioned under the gate region which effectively reduces the junction capacitance (gate to drain) of the structure. For normally off modes, the structures reduce gate current at Vg in forward bias. In one embodiment, a silicide is positioned in part of the gate to reduce gate resistance. The structures are also characterized in that they have a thin gate due to the dipping of the spacer oxide, which can be below 1000 angstroms and this results in fast switching speeds for high frequency applications.
    Type: Grant
    Filed: May 20, 2002
    Date of Patent: July 26, 2005
    Assignee: Lovoltech, Inc.
    Inventors: Ho-Yuan Yu, Valentino L. Liva
  • Patent number: 6900482
    Abstract: A high-frequency semiconductor device for power amplification has a comb-teeth electrode on each of active regions formed on the front surface of the semiconductor substrate. One aspect of the present invention, there is provided a monolithic microwave integrated circuit (MMIC) having a plurality of rectangular-shaped active regions arranged side by side on the front surface of the semiconductor substrate, each of the active regions having interdigited gate, drain and source electrodes thereon which are connected to the respective pads by multilayer interconnection technique. Additionally, the source potential is fed from the back surface of the substrate through a metal plugged via-hole.
    Type: Grant
    Filed: March 14, 2002
    Date of Patent: May 31, 2005
    Assignee: Fujitsu Quantum Devices Limited
    Inventors: Yoshio Aoki, Yutaka Mimino, Osamu Baba, Muneharu Gotoh
  • Patent number: 6894346
    Abstract: A structure is provided that ensures a low on-resistance and a better blocking effect. In a lateral type SIT (Static Induction Transistor) in which a first region is used as a p+ gate and a gate electrode is formed on the bottom of the first region, the structure is built such that the p+ gate and an n+ source are contiguous. An insulating film is formed on the surface of an n? channel, and an auxiliary gate electrode is formed on the insulating film. In addition, the auxiliary gate electrode and the source electrode are shorted.
    Type: Grant
    Filed: August 13, 2003
    Date of Patent: May 17, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Hidekatsu Onose, Atsuo Watanabe
  • Patent number: 6885078
    Abstract: A circuit isolation technique that uses implanted ions in embedded portions of a wafer substrate to lower the resistance of the substrate under circuits formed on the wafer or portions of circuits formed on the wafer to prevent the flow of injected currents across the substrate. The embedded ions provide low resistance regions that allow injected currents from a circuit to flow directly to a ground potential in the same circuit rather than flowing across the substrate to other circuits. High energy implantation processes on the order of 1 MeV to 3 MeVs can be used to implant the ions in embedded regions. Multiple energy levels can be used to provide thick embedded layers either prior to or after application of an epitaxial layer. Various masking materials can be used to mask the isolation regions during the implantation process, including hard masking materials such as silicon dioxide or silicon nitride, poly-silicon or an amorphous silicon layer, and a photoresist layer.
    Type: Grant
    Filed: November 9, 2001
    Date of Patent: April 26, 2005
    Assignee: LSI Logic Corporation
    Inventors: Donald M. Bartlett, Gayle W. Miller, Randall J. Mason
  • Patent number: 6852578
    Abstract: A high speed, low power Static Random Access Memory (SRAM) Array, which includes a 4T cell with two integrated Schottky Barrier Diodes (SBD) is provided. In a preferred embodiment, the cell bulk area and speed advantage is 30%, and AC power saving is 75% compared with the 6T CFET cell. The physical construct of the 4T cell saves capacitance in all critical nodes intra or inter cell wise, eliminates pass transistors, reduces the well noises. Typical embodiment uses a 0.15-um-rule based layout, and 1.5V supports operation at 5 ns cycles. SBD are used extensively with CFET to form a CMOS version of the Diode Transistor Logic circuitry. Generic control functions can be implemented including NAND/NOR gates, level shifting, decoding, voltage generator, ESD and latch-up protection, leakage control, and dynamic VT setting while in operation. Product applications include DRAM, SRAM, PLD, DRAM, CAM, Flash, Computing, Networking, and Communication devices as standalone system component or embedded into any ASIC.
    Type: Grant
    Filed: January 15, 2003
    Date of Patent: February 8, 2005
    Inventor: Augustine Wei-Chun Chang
  • Patent number: 6841812
    Abstract: The present invention is a power semiconductor switch having a monolithically integrated low-voltage lateral junction field effect transistor (LJFET) controlling a high-voltage vertical junction field effect transistor (VJFET). The low-voltage LJFET conducting channel is double-gated by p+n junctions at opposite sides of the lateral channel. A buried p-type epitaxial layer forms one of the two p+n junction gates. A p+ region created by ion implantation serves as the p+ region for the second p+n junction gate. Both gates are electrically connected by a p+ tub implantation. The vertical channel of the vertical JFET is formed by converting part of the buried p-type epitaxial layer into n+ channel via n-type ion implantation.
    Type: Grant
    Filed: November 7, 2002
    Date of Patent: January 11, 2005
    Assignee: United Silicon Carbide, Inc.
    Inventor: Jian Hui Zhao
  • Patent number: 6833567
    Abstract: The present invention provide a vertical nano-sized transistor using carbon nanotubes capable of achieving high-density integration, that is, tera-bit scale integration, and a manufacturing method thereof, wherein in the vertical nano-sized transistor using carbon nanotubes, holes having diameters of several nanometers are formed in an insulating layer and are spaced at intervals of several nanometers. Carbon nanotubes are vertically aligned in the nano-sized holes by chemical vapor deposition, electrophoresis or mechanical compression to be used as channels. A gate is formed in the vicinity of the carbon nanotubes using an ordinary semiconductor manufacturing method, and then a source and a drain are formed at lower and upper parts of each of the carbon nanotubes thereby fabricating the vertical nano-sized transistor having an electrically switching characteristic.
    Type: Grant
    Filed: March 13, 2003
    Date of Patent: December 21, 2004
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Won-bong Choi, Jo-won Lee, Young-hee Lee
  • Patent number: 6833571
    Abstract: A transistor device includes a gate region disposed adjacent to a semiconductor substrate such that a low impedance channel is formed between a source region and drain region of a transistor device when a voltage is applied to its gate. The drain region of the device can be disposed aside the gate region on a common surface of the semiconductor substrate. The source region of the device also can be disposed adjacent to the substrate but on a side of the semiconductor substrate opposing the drain and/or gate regions. Based on this topology, a transistor device can be fabricated with a buried source to enhance its operating characteristics such as switching speed.
    Type: Grant
    Filed: July 2, 2002
    Date of Patent: December 21, 2004
    Assignee: University of Massachusetts Lowell
    Inventors: Samson Mil'shtein, Carlos A. Gil
  • Patent number: 6828580
    Abstract: A vertical field effect transistor includes a microelectronic substrate having a trench, the trench defining a sidewall. A conformal monocrystalline silicon layer is provided on the sidewall, including a drain region adjacent the substrate, a source region remote from the substrate, and a channel region between the source and drain regions. A plug is provided in the trench. A gate insulating layer is provided adjacent the channel and a gate electrode is provided on the gate insulating layer.
    Type: Grant
    Filed: October 2, 2003
    Date of Patent: December 7, 2004
    Assignee: North Carolina State University
    Inventor: Zhibo Zhang
  • Patent number: 6822275
    Abstract: A transverse JFET of SiC, employing an n-type SiC substrate and comprising a channel region having carriers of high mobility, bringing a high yield is obtained. This transverse JFET comprises an n-type SiC substrate (1n), a p-type SiC film (2) formed on the right face of the n-type SiC substrate, an n-type SiC film (3), including a channel region (11), formed on the p-type SiC film, source and drain regions (22, 23) formed on the n-type SiC film separately on both sides of the channel region respectively, and a gate electrode (14) provided in contact with the n-type SiC substrate (1n).
    Type: Grant
    Filed: June 19, 2002
    Date of Patent: November 23, 2004
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Shin Harada, Kenichi Hirotsu
  • Patent number: 6815738
    Abstract: A method is disclosed for fabricating multifaceted, tensilely strained Si MOSFET (FinFET) devices. The method comprises the growing by selective epitaxy of a monocrystalline Si strip onto a monocrystalline SiGe layer sidewall surface, where the SiGe layer is bonded to a support platform, typically an insulator on a Si substrate, and where the Si strip also bonds to the support platform. The SiGe sidewall surface has a lattice constant which is larger than the relaxed lattice constant of Si, whereby the Si strip is in a tensilely strained state. Upon removing the SiGe monocrystalline layer the monocrystalline strained Si strip is turned into a multifaceted Si strip on the support platform, suitable for fabricating multifaceted gate FinFETs. Fabrication of processors with such FinFet devices is also disclosed.
    Type: Grant
    Filed: February 28, 2003
    Date of Patent: November 9, 2004
    Assignee: International Business Machines Corporation
    Inventor: Kern Rim
  • Patent number: 6800909
    Abstract: There are provided a gate electrode formed on a semiconductor substrate of one conductivity type via a gate insulating film, ion-implantation controlling films formed on both side surfaces of the gate electrode and having a space between the gate electrode and an upper surface of the semiconductor substrate, first and second impurity diffusion regions of opposite conductivity type formed in the semiconductor substrate on both sides of the gate electrode and serving as source/drain, a channel region of one conductivity type formed below the gate electrode between the first and second impurity diffusion regions of opposite conductivity type, and pocket regions of one conductivity type connected to end portions of the impurity diffusion regions of opposite conductivity type in the semiconductor substrate below the gate electrode and having an impurity concentration of one conductivity type higher than the channel region.
    Type: Grant
    Filed: October 2, 2002
    Date of Patent: October 5, 2004
    Assignee: Fujitsu Limited
    Inventors: Koichi Sugiyama, Yoshihiro Takao, Shinji Sugatani, Daisuke Matsunaga, Takayuki Wada, Tohru Fujita, Hikaru Kokura
  • Patent number: 6784470
    Abstract: An integrated circuit includes an output buffer operable to drive an output node. The output buffer may comprise a MOSFET having a JFET integrated within a portion of a drain region of the MOSFET. The JFET may comprise a gate of second conductivity formed in semiconductor material of first conductivity type, which is contiguous with the drain region for the MOSFET. A voltage shaping circuit may control a bias of the JFET gate in accordance with the voltage levels of an output node and a predetermined output impedance.
    Type: Grant
    Filed: March 6, 2003
    Date of Patent: August 31, 2004
    Assignee: Intel Corporation
    Inventor: Jeffrey B. Davis
  • Patent number: 6777722
    Abstract: A method for fabricating a junction field effect transistor (JFET) with a double dose gate structure. A trench is etched in the surface of a semiconductor substrate, followed by a low dose implant to form a first gate region. An anneal may or may not be performed after the low dose implant. A gate definition spacer is then formed on the wall the trench to establish the lateral extent of a second, high dose implant gate region. After the second implant, the gate is annealed. The double dose gate structure produced by the superposition of two different and overlapping regions provides an additional degree of flexibility in determining the ultimate gate region doping profile. A further step comprises using the gate definition spacer to define the walls of a second etched trench that is used to remove a portion of the p-n junction, thereby further reducing the junction capacitance.
    Type: Grant
    Filed: July 2, 2002
    Date of Patent: August 17, 2004
    Assignee: Lovoltech, Inc.
    Inventors: Ho-Yuan Yu, Valentino L. Liva, Pete Pegler
  • Patent number: 6693314
    Abstract: A junction field-effect transistor containing a semiconductor region with an inner region is described. In addition, a first and a second connecting region, respectively, are disposed within the semiconductor region. The first connecting region has the same conductivity type as the inner region, but in a higher doping concentration. The second connecting region has the opposite conductivity type to that of the inner region. This reduces the forward resistance while at the same time maintaining a high reverse voltage strength.
    Type: Grant
    Filed: June 22, 2001
    Date of Patent: February 17, 2004
    Assignee: SiCed Electronics Development GmbH & Co. KG
    Inventors: Heinz Mitlehner, Dietrich Stephani, Jenoe Tihanyi
  • Patent number: 6690040
    Abstract: A vertical JFET architecture. Generally, an integrated circuit structure includes a semiconductor area with a major surface formed along a plane and a first source/drain doped region formed in the surface. A second doped region forming a channel of different conductivity type than the first region is disposed over the first region. A third doped region is formed over the second doped region having an opposite conductivity type with respect to the second doped region, and forming a source/drain region. A gate is formed over the channel to form a vertical JFET.
    Type: Grant
    Filed: September 10, 2001
    Date of Patent: February 10, 2004
    Assignee: Agere Systems Inc.
    Inventors: Samir Chaudhry, Paul Arthur Layman, John Russell McMacken, Ross Thomson, Jack Qingsheng Zhao
  • Publication number: 20030227034
    Abstract: An integrated circuit includes an output buffer operable to drive an output node. The output buffer may comprise a MOSFET having a JFET integrated within a portion of a drain region of the MOSFET. The JFET may comprise a gate of second conductivity formed in semiconductor material of first conductivity type, which is contiguous with the drain region for the MOSFET. A voltage shaping circuit may control a bias of the JFET gate in accordance with the voltage levels of an output node and a predetermined output impedance.
    Type: Application
    Filed: March 6, 2003
    Publication date: December 11, 2003
    Inventor: Jeffrey B. Davis
  • Patent number: 6593201
    Abstract: Monolithic inductance-enhancing integrated circuits, complementary metal oxide semiconductor (CMOS) inductance-enhancing integrated circuits, inductor assemblies, and inductance-multiplying methods are described. In one embodiment, a monolithic inductance-enhancing integrated circuit comprises a transistor supported by a bulk monocrystalline silicon substrate. An inductor assembly is supported by the substrate and operably connected with the transistor in an inductance-enhancing circuit configuration having a quality factor (Q) greater than 10. In another embodiment, a complementary metal oxide semiconductor (CMOS), inductance-enhancing integrated circuit includes a field effect transistor supported over a silicon-containing substrate and having a gate, a source, and a drain. A first inductor is received within an insulative material layer over the substrate, and is connected to the gate. A second inductor is received within the insulative material layer and is connected to the source.
    Type: Grant
    Filed: April 18, 2000
    Date of Patent: July 15, 2003
    Assignee: Micron Technology, Inc.
    Inventor: Leonard Forbes
  • Patent number: 6590240
    Abstract: A method of manufacturing a unipolar component of vertical type in a substrate of a first conductivity type, including the steps of: forming trenches in a silicon layer of the first conductivity type; coating the lateral walls of the trenches with a silicon oxide layer; filling the trenches with polysilicon of the second conductivity type; and annealing to adjust the doping level of the polysilicon, the excess dopants being absorbed by the silicon oxide layer.
    Type: Grant
    Filed: July 28, 2000
    Date of Patent: July 8, 2003
    Assignee: STMicroelectronics S.A.
    Inventor: Frédéric Lanois
  • Patent number: 6566692
    Abstract: An n-GaN layer is provided as an emitter layer for supplying electrons. A non-doped (intrinsic) AlxGa1−xN layer (0≦x≦1) having a compositionally graded Al content ratio x is provided as an electron transfer layer for transferring electrons toward the surface. A non-doped AlN layer having a negative electron affinity (NEA) is provided as a surface layer. Above the AlN layer, a control electrode and a collecting electrode are provided. An insulating layer formed of a material having a larger electron affinity than that of the AlN layer is interposed between the control electrode and the collecting electrode. This provides a junction transistor which allows electrons injected from the AlN layer to conduct through the conduction band of the insulating layer and then reach the collecting electrode.
    Type: Grant
    Filed: August 8, 2001
    Date of Patent: May 20, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Takeshi Uenoyama, Masahiro Deguchi
  • Publication number: 20030089930
    Abstract: The present invention is a power semiconductor switch having a monolithically integrated low-voltage lateral junction field effect transistor (LJFET) controlling a high-voltage vertical junction field effect transistor (VJFET). The low-voltage LJFET conducting channel is double-gated by p+n junctions at opposite sides of the lateral channel. A buried p-type epitaxial layer forms one of the two p+n junction gates. A p+ region created by ion implantation serves as the p+ region for the second p+n junction gate. Both gates are electrically connected by a p+ tub implantation. The vertical channel of the vertical JFET is formed by converting part of the buried p-type epitaxial layer into n+ channel via n-type ion implantation.
    Type: Application
    Filed: November 7, 2002
    Publication date: May 15, 2003
    Inventor: Jian Hui Zhao
  • Patent number: 6563150
    Abstract: A traveling wave FET in which increasing distances between electrodes and the design of semiconductor regions associated with the various electrodes act to increase maximum gain parameters of the device. The relationship of the electrode series resistance is also considered in the design as it affects these gain parameters.
    Type: Grant
    Filed: July 25, 2000
    Date of Patent: May 13, 2003
    Inventor: Alison Schary