Having Junction Gate (e.g., Jfet, Sit, Etc.) Patents (Class 438/186)
  • Publication number: 20110156052
    Abstract: A semiconductor device having a JFET includes: a substrate made of semi-insulating semiconductor material; a gate region in a surface portion of the substrate; a channel region disposed on and contacting the gate region; a source region and a drain region disposed on both sides of the gate region so as to sandwich the channel region, respectively; a source electrode electrically coupled with the source region; a drain electrode electrically coupled with the drain region; and a gate electrode electrically coupled with the gate region. An impurity concentration of each of the source region and the drain region is higher than an impurity concentration of the channel region.
    Type: Application
    Filed: December 16, 2010
    Publication date: June 30, 2011
    Applicant: DENSO CORPORATION
    Inventors: Rajesh Kumar Malhan, Yuuichi Takeuchi, Naohiro Sugiyama
  • Patent number: 7968393
    Abstract: A semiconductor device can include at least a first diffusion region formed by doping a semiconductor substrate and at least a second diffusion region formed by doping the semiconductor substrate that is separated from the first diffusion region by an isolation region. At least a first conductive line can comprise a semiconductor material formed over and in contact with the first diffusion region and the second diffusion region. A portion of the first conductive line in contact with the first diffusion region is doped to an opposite conductivity type as the first diffusion region. At least a second conductive line comprising a semiconductor material is formed in parallel with the first conductive line and over and in contact with the first diffusion region and the second diffusion region. A portion of the second conductive line can be in contact with the first diffusion region and doped to a same conductivity type as the first diffusion region.
    Type: Grant
    Filed: February 26, 2009
    Date of Patent: June 28, 2011
    Assignee: SuVolta, Inc.
    Inventor: Madhukar B. Vora
  • Publication number: 20110143505
    Abstract: Provided is a method for fabricating a field effect transistor. In the method, an active layer and a capping layer are formed on a substrate. A source electrode and a drain electrode is formed on the capping layer. A dielectric interlayer is formed on the substrate, and resist layers having first and second openings with asymmetrical depths are formed on the dielectric interlayer between the source electrode and the drain electrode. The first opening exposes the dielectric interlayer, and the second opening exposes the lowermost of the resist layers. The dielectric interlayer in the bottom of the first opening and the lowermost resist layer under the second opening are simultaneously removed to expose the capping layer to the first opening and expose the dielectric interlayer to the second opening. The capping layer of the first opening is removed to expose the active layer.
    Type: Application
    Filed: May 4, 2010
    Publication date: June 16, 2011
    Applicant: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Hokyun AHN, Jong-Won Lim, Hyung Sup Yoon, Woojin Chang, Hae Cheon Kim, Eun Soo Nam
  • Patent number: 7944017
    Abstract: An n type impurity region is continuously formed on the bottom portion of a channel region below a source region, a gate region and a drain region. The n type impurity region has an impurity concentration higher than the channel region and a back gate region, and is less influenced by the diffusion of p type impurities from the gate region and the back gate region. Moreover, by continuously forming the impurity region from a portion below the source region to a portion below the drain region, the resistance value of a current path in the impurity region is substantially uniformed. Therefore, the IDSS is stabilized, the forward transfer admittance gm and the voltage gain Gv are improved, and the noise voltage Vno is decreased. Furthermore, the IDSS variation within a single wafer is suppressed.
    Type: Grant
    Filed: August 5, 2008
    Date of Patent: May 17, 2011
    Assignees: Sanyo Electric Co., Ltd., Sanyo Semiconductor Co., Ltd.
    Inventors: Mitsuo Hatamoto, Yoshiaki Matsumiya
  • Patent number: 7939863
    Abstract: Analog ICs frequently include circuits which operate over a wide current range. At low currents, low noise is important, while IC space efficiency is important at high currents. A vertically integrated transistor made of a JFET in parallel with an MOS transistor, sharing source and drain diffused regions, and with independent gate control, is disclosed. N-channel and p-channel versions may be integrated into common analog IC flows with no extra process steps, on either monolithic substrates or SOI wafers. pinchoff voltage in the JFET is controlled by photolithographically defined spacing of the gate well regions, and hence exhibits low variability.
    Type: Grant
    Filed: August 7, 2009
    Date of Patent: May 10, 2011
    Assignee: Texas Instruments Incorporated
    Inventors: Pinghai Hao, Marie Denison
  • Publication number: 20110101424
    Abstract: A junction field effect transistor having a drain and a source, each defined by regions of a first type of semiconductor interconnected by a channel, and in which a dopant profile at a side of the drain facing the channel is modified so as to provide a region of reduced doping compared to a body region of the drain. The region of reduced doping and the body region can be defined by the same mask and doping step, but the mask is shaped to provide a lesser amount and thus less depth of doping for the region of reduced doping.
    Type: Application
    Filed: November 2, 2009
    Publication date: May 5, 2011
    Applicant: ANALOG DEVICES, INC.
    Inventors: Paul Malachy Daly, Andrew David Bain, Derek Frederick Bowers, Anne Maria Deignan, Michael Thomas Dunbar, Patrick Martin McGuinness, Bernard Patrick Stenson, William Allan Lane
  • Publication number: 20110101423
    Abstract: A field effect transistor having a drain, a gate and a source, where the drain and source are formed by semiconductor regions of a first type, and in which a further doped region is provided intermediate the gate and the drain. Field gradients around the drain are thereby reduced.
    Type: Application
    Filed: November 2, 2009
    Publication date: May 5, 2011
    Applicant: ANALOG DEVICES, INC.
    Inventors: Derek Frederick Bowers, Andrew David Bain, Paul Malachy Daly, Anne Maria Deignan, Michael Thomas Dunbar, Patrick Martin McGuinness, Bernard Patrick Stenson, William Allan Lane
  • Patent number: 7935601
    Abstract: A method is disclosed that provides a self-aligned nitrogen-implant particularly suited for a Junction Field Effect Transistor (JFET) semiconductor device preferably comprised of a silicon carbide (SiC). This self-aligned nitrogen-implant allows for the realization of durable and stable electrical functionality of high temperature transistors such as JFETs. The method implements the self-aligned nitrogen-implant having predetermined dimensions, at a particular step in the fabrication process, so that the SiC junction field effect transistors are capable of being electrically operating continuously at 500° C. for over 10,000 hours in an air ambient with less than a 10% change in operational transistor parameters.
    Type: Grant
    Filed: September 4, 2009
    Date of Patent: May 3, 2011
    Assignee: The United States of America as represented by the Administrator of National Aeronautics and Space Administration
    Inventor: Philip G. Neudeck
  • Patent number: 7915107
    Abstract: This invention describes a method of building complementary logic circuits using junction field effect transistors in silicon. This invention is ideally suited for deep submicron dimensions, preferably below 65 nm. The basis of this invention is a complementary Junction Field Effect Transistor which is operated in the enhancement mode. The speed-power performance of the JFETs becomes comparable with the CMOS devices at sub-70 nanometer dimensions. However, the maximum power supply voltage for the JFETs is still limited to below the built-in potential (a diode drop). To satisfy certain applications which require interface to an external circuit driven to higher voltage levels, this invention includes the structures and methods to build CMOS devices on the same substrate as the JFET devices.
    Type: Grant
    Filed: June 26, 2009
    Date of Patent: March 29, 2011
    Assignee: SuVolta, Inc.
    Inventor: Ashok K. Kapoor
  • Patent number: 7910417
    Abstract: A Junction Field Effect Transistor (JFET) can be fabricated with a well region that include a channel region having an average dopant concentration substantially less the average doping concentration of the remaining portions of the well region. The lower average doping concentration of channel region compared to the remaining portions of the well region reduces the pinch-off voltage of the JFET.
    Type: Grant
    Filed: July 21, 2008
    Date of Patent: March 22, 2011
    Assignee: Texas Instruments Incorporated
    Inventors: Philip L. Hower, David A. Walch, John Lin, Steven L. Merchant
  • Patent number: 7892904
    Abstract: A semiconductor device with an amorphous silicon (a-Si) metal-oxide-nitride-oxide-silicon (MONOS) or metal-aluminum oxide-silicon (MAS) memory cell structure with one-time programmable (OTP) function. The device includes a substrate, a first dielectric layer overlying the substrate, and one or more source or drain regions embedded in the first dielectric layer with a co-planar surface of n-type a-Si and the first dielectric layer. Additionally, the device includes a p-i-n a-Si diode junction. The device further includes a second dielectric layer on the a-Si p-i-n diode junction and a metal control gate overlying the second dielectric layer. Optionally the device with OTP function includes a conductive path formed between n-type a-Si layer and the metal control gate. A method of making the same memory cell structure is provided and can be repeated to integrate the structure three-dimensionally.
    Type: Grant
    Filed: October 27, 2008
    Date of Patent: February 22, 2011
    Assignee: Semiconductor Manufacturing International (Shanghai) Corporation
    Inventor: Mieno Fumitake
  • Patent number: 7867862
    Abstract: A high voltage device includes a substrate with a device region defined thereon. A gate stack is disposed on the substrate in the device region. A channel region is located in the substrate beneath the gate stack, while a first diffusion region is located in the substrate on a first side of the gate stack. A first isolation structure in the substrate, located on the first side of the gate stack, separates the channel and the first diffusion region. The high voltage device also includes a first drift region in the substrate coupling the channel to the first diffusion region, wherein the first drift region comprises a non-uniform depth profile conforming to a profile of the first isolation structure.
    Type: Grant
    Filed: September 14, 2007
    Date of Patent: January 11, 2011
    Assignee: Chartered Semiconductor Manufacturing, Ltd
    Inventors: Jeoung Mo Koo, Purakh Raj Verma, Sanford Chu, Chunlin Zhu, Yisuo Li
  • Publication number: 20110001144
    Abstract: A JFET is a semiconductor device allowing more reliable implementation of the characteristics essentially achievable by employing SiC as a material and includes a wafer having at least an upper surface made of silicon carbide, and a gate contact electrode formed on the upper surface. The wafer includes a first p-type region serving as an ion implantation region formed so as to include the upper surface. The first p-type region includes a base region disposed so as to include the upper surface, and a protruding region. The base region has a width (w1) in the direction along the upper surface greater than a width (w2) of the protruding region. The gate contact electrode is disposed in contact with the first p-type region such that the gate contact electrode is entirely located on the first p-type region as seen in plan view.
    Type: Application
    Filed: December 11, 2009
    Publication date: January 6, 2011
    Applicant: Sumitomo Electric Industries, Ltd.
    Inventors: Kuzuhiro Fujikawa, Hideto Tamaso, Shin Harada, Yasuo Namikawa
  • Publication number: 20100302810
    Abstract: Voltage converters with integrated low power leaker device and associated methods are disclosed herein. In one embodiment, a voltage converter includes a switch configured to convert a first electrical signal into a second electrical signal different than the first electrical signal. The voltage converter also includes a controller operatively coupled to the switch and a leaker device electrically coupled to the controller. The controller is configured to control the on and off gates of the switch, and the leaker device is configured to deliver power to the controller. The leaker device and the switch are formed on a first semiconductor substrate, and the controller is formed on second semiconductor substrate separate from the first semiconductor substrate.
    Type: Application
    Filed: May 28, 2009
    Publication date: December 2, 2010
    Inventors: Michael R. Hsing, Ognjen Milic, Tiesheng Li
  • Patent number: 7842549
    Abstract: Edge termination for silicon carbide devices has a plurality of concentric floating guard rings in a silicon carbide layer that are adjacent and spaced apart from a silicon carbide-based semiconductor junction. An insulating layer, such as an oxide, is provided on the floating guard rings and a silicon carbide surface charge compensation region is provided between the floating guard rings and is adjacent the insulating layer. Methods of fabricating such edge termination are also provided.
    Type: Grant
    Filed: August 21, 2008
    Date of Patent: November 30, 2010
    Assignee: Cree, Inc.
    Inventors: Sei-Hyung Ryu, Anant K. Agarwal
  • Publication number: 20100295102
    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: Application
    Filed: June 29, 2010
    Publication date: November 25, 2010
    Applicant: SEMISOUTH LABORATORIES, INC.
    Inventors: Igor SANKIN, Joseph Neil MERRETT
  • Patent number: 7838902
    Abstract: A single-chip common-drain JFET device comprises a drain, two gates and two source arranged such that two common-drain JFETs are formed therewith. Due to the two JFETs merged within a single chip, no wire bonding connection is needed therebetween, thereby without parasitic inductance and resistance caused by bonding wire, and therefore improving the performance and reducing the package cost. The single-chip common-drain JFET device may be applied in buck converter, boost converter, inverting converter, switch, and two-step DC-to-DC converter to improve their performance and efficiency. Alternative single-chip common-drain JFET devices are also provided for current sense or proportional current generation.
    Type: Grant
    Filed: April 17, 2009
    Date of Patent: November 23, 2010
    Assignee: Richtek Technology Corp.
    Inventors: Liang-Pin Tai, Jing-Meng Liu, Hung-Der Su
  • Patent number: 7838900
    Abstract: A single-chip common-drain JFET device comprises a Drain, two gates and two source arranged such that two common-drain JFETs are formed therewith. Due to the two JFETs merged within a single chip, no wire bonding connection is needed therebetween, thereby without parasitic inductance and resistance caused by bonding wire, and therefore improving the performance and reducing the package cost. The single-chip common-drain JFET device may be applied in buck converter, boost converter, inverting converter, switch, and two-step DC-to-DC converter to improve their performance and efficiency. Alternative single-chip common-drain JFET devices are also provided for current sense or proportional current generation.
    Type: Grant
    Filed: April 17, 2009
    Date of Patent: November 23, 2010
    Assignee: Richtek Technology Corp.
    Inventors: Liang-Pin Tai, Jing-Meng Liu, Hung-Der Su
  • Publication number: 20100244104
    Abstract: A compound semiconductor device includes a compound semiconductor laminated structure; a source electrode, a drain electrode, and a gate electrode formed over the compound semiconductor laminated structure; a first protective film formed over the compound semiconductor laminated structure between the source electrode and the gate electrode and including silicon; and a second protective film formed over the compound semiconductor laminated structure between the drain electrode and the gate electrode and including more silicon than the first protective film.
    Type: Application
    Filed: March 10, 2010
    Publication date: September 30, 2010
    Applicant: FUJITSU LIMITED
    Inventors: Kozo Makiyama, Toshihide Kikkawa
  • Patent number: 7795083
    Abstract: The invention provides a method for forming a semiconductor structure. A plurality of first type well regions is formed in the first type substrate. A plurality of second type well regions and a plurality of second type bar doped regions are formed in the first type substrate by a doping process using a mask. The second type bar doped regions are diffused to form a second type continuous region by annealing. The second type continuous region is adjoined with the first type well regions. A second type dopant concentration of the second type continuous region is smaller than a second type dopant concentration of the second type bar doped regions. A second type source/drain region is formed in the second type well region.
    Type: Grant
    Filed: February 16, 2009
    Date of Patent: September 14, 2010
    Assignee: Vanguard International Semiconductor Corporation
    Inventors: Hung-Shern Tsai, Shang-Hui Tu, Shin-Cheng Lin
  • Patent number: 7785973
    Abstract: An electronic device can include a gate electrode having different portions with different conductivity types. In an embodiment, a process of forming the electronic device can include forming a semiconductor layer over a substrate, wherein the semiconductor layer has a particular conductivity type. The process can also include selectively doping a region of the semiconductor layer to form a first doped region having an opposite conductivity type. The process can further include patterning the semiconductor layer to form a gate electrode that includes a first portion and a second portion, wherein the first portion includes a portion of the first doped region, and the second region includes a portion of the semiconductor layer outside of the first doped region. In a particular embodiment, the electronic device can have a gate electrode having edge portions of one conductivity type and a central portion having an opposite conductivity type.
    Type: Grant
    Filed: January 25, 2008
    Date of Patent: August 31, 2010
    Assignee: Spansion LLC
    Inventor: Burchell B. Baptiste
  • Patent number: 7781809
    Abstract: In a high voltage junction field effect transistor, a first well (11) of a first conductivity type is formed in a substrate (10) of a second conductivity type. A source (14) and a drain (15) which are each of the first conductivity type are formed in the first well. A gate (16) of the second conductivity type is arranged in a second well (12) of the second conductivity type, wherein the second well is of the retrograde type. The source, gate and drain are spaced apart from one another by field oxide regions (13a to 13d). Field plates (17a, 17b) extend over the field oxide (13a, 13b) from the gate (16) in the direction of source and drain.
    Type: Grant
    Filed: April 6, 2005
    Date of Patent: August 24, 2010
    Assignee: Austriamicrosystems AG
    Inventor: Martin Knaipp
  • Patent number: 7768033
    Abstract: A single-chip common-drain JFET device comprises a drain, two gates and two source arranged such that two common-drain JFETs are formed therewith. Due to the two JFETs merged within a single chip, no wire bonding connection is needed therebetween, thereby without parasitic inductance and resistance caused by bonding wire, and therefore improving the performance and reducing the package cost. The single-chip common-drain JFET device may be applied in buck converter, boost converter, inverting converter, switch, and two-step DC-to-DC converter to improve their performance and efficiency. Alternative single-chip common-drain JFET devices are also provided for current sense or proportional current generation.
    Type: Grant
    Filed: April 17, 2009
    Date of Patent: August 3, 2010
    Assignee: Richtek Technology Corp.
    Inventors: Liang-Pin Tai, Jing-Meng Liu, Hung-Der Su
  • Patent number: 7763523
    Abstract: A method for forming a device isolation structure of a semiconductor device using at least three annealing steps to anneal a flowable insulation layer is presented. The method includes the steps of forming a hard mask pattern on a semiconductor substrate having active regions exposing a device isolation region of the semiconductor substrate; etching the device isolation region of the semiconductor substrate exposed through the hard mask pattern, and therein forming a trench; forming a flowable insulation layer to fill a trench; first annealing the flowable insulation layer at least three times; second annealing the first annealed flowable insulation layer; removing the second annealed flowable insulation layer until the hard mask pattern is exposed; and removing the exposed hard mask pattern.
    Type: Grant
    Filed: March 10, 2008
    Date of Patent: July 27, 2010
    Assignee: Hynix Semiconductor Inc.
    Inventors: Sang Tae Ahn, Ja Chun Ku, Eun Jeong Kim
  • Patent number: 7759695
    Abstract: A single-chip common-drain JFET device comprises a drain, two gates and two source arranged such that two common-drain JFETs are formed therewith. Due to the two JFETs merged within a single chip, no wire bonding connection is needed therebetween, thereby without parasitic inductance and resistance caused by bonding wire, and therefore improving the performance and reducing the package cost. The single-chip common-drain JFET device may be applied in buck converter, boost converter, inverting converter, switch, and two-step DC-to-DC converter to improve their performance and efficiency. Alternative single-chip common-drain JFET devices are also provided for current sense or proportional current generation.
    Type: Grant
    Filed: April 17, 2009
    Date of Patent: July 20, 2010
    Assignee: Richtek Technology Corp.
    Inventors: Liang-Pin Tai, Jing-Meng Liu, Hung-Der Su
  • Publication number: 20100171118
    Abstract: Junction field-effect transistors (JFETs) having insulator-isolated source/drain regions and fabrication methods therefor are disclosed here. In SOI JFETs and bulk silicon JFETs having junction isolated source and drain regions from the body region, the junction leakage current is one of the leakage components of the off-state leakage current and consequently limits the on-off switching performance. In particular, for short-channel devices (for example, sub-100 nm and/or sub-65 nm devices), the leakage currents are especially pronounced. The techniques herein introduced include JFET with an insulating spacer such that the source and drain regions are insulator isolated from the body region. In one embodiment, the source and drain regions of the transistor are insulator isolated by silicon dioxide thus reducing the source-drain to body junction leakage current and improved on-off performance.
    Type: Application
    Filed: January 8, 2009
    Publication date: July 8, 2010
    Inventors: Samar Kanti Saha, Ashok K. Kapoor
  • Publication number: 20100171155
    Abstract: Silicon-on-insulator JFET having a body bias and a fully depleted body and fabrication methods therefore are disclosed. SOI JFETs offer leakage advantages over bulk silicon JFETs. However, some SOI JFETs have poor switching characteristics (e.g., high switch on time), and have poor leakage performance at high temperatures. The techniques herein introduced include a fully-depleted body SOI-JFET, with a non-zero bias applied to its body. In one example, the body region of the JFET can be fully depleted by tuning the thickness of the silicon containing layer of the SOI substrate. Additionally, the deep depletion can be induced by applying a non-zero bias to the body region, at a range of operating temperatures. Full body depletion and/or the application of body bias offers the benefits of suppressed leakage current at higher operating temperatures (e.g., between or above 25-115 C) and improved AC performance (e.g., faster switching time).
    Type: Application
    Filed: January 8, 2009
    Publication date: July 8, 2010
    Inventor: Samar Kanti Saha
  • Publication number: 20100163934
    Abstract: A method for fabricating a junction field effect transistor includes the steps of the type I semiconductor at the base thereof being doped with the type II semiconductor to form a type II well with a hole; then, a drive-in process of the type II semiconductor is performed to allow the implant dosage of the type II well getting less gradually from the surroundings of the hole toward the center of the hole; and finally, the gate, the source and the drain of the junction field effect transistor being formed successively on the type II well. The implant dosage at the hole, which is acted as a channel, is determined in accordance with the preset size of the hole during the type II well being formed such that it is capable being compatible with the output voltages of different junction field effect transistors to achieve the purpose of the adjustment of the pinch-off voltage of the junction field effect transistor without the need of the mask and the manufacturing process.
    Type: Application
    Filed: April 3, 2009
    Publication date: July 1, 2010
    Applicant: Richtek Technology Corp.
    Inventor: Chih-Feng Huang
  • Patent number: 7745274
    Abstract: The disclosure herein pertains to fashioning a low noise junction field effect transistor (JFET) where transistor gate materials are utilized in forming and electrically isolating active areas of a the JFET. More particularly, active regions are self aligned with patterned gate electrode material and sidewall spacers which facilitate desirably locating the active regions in a semiconductor substrate. This mitigates the need for additional materials in the substrate to isolate the active regions from one another, where such additional materials can introduce noise into the JFET. This also allows a layer of gate dielectric material to remain over the surface of the substrate, where the layer of gate dielectric material provides a substantially uniform interface at the surface of the substrate that facilitates uninhibited current flow between the active regions, and thus promotes desired device operation.
    Type: Grant
    Filed: March 8, 2007
    Date of Patent: June 29, 2010
    Assignee: Texas Instruments Incorporated
    Inventors: Xiaoju Wu, Fan-Chi Frank Hou, Pinghai Hao
  • Patent number: 7745273
    Abstract: A method for manufacturing a semiconductor device. The method includes providing a semiconductor body of a conductivity type, wherein the semiconductor body comprises a first surface. At least one buried region of a second conductivity type is formed in the semiconductor body and at least a surface region of the second conductivity type is formed at the first surface of the semiconductor body, wherein the buried region and the surface region are formed such that they are spaced apart from each other. The buried region is formed by deep implantation of a first dopant of the second conductivity type.
    Type: Grant
    Filed: July 30, 2007
    Date of Patent: June 29, 2010
    Assignee: Infineon Technologies Austria AG
    Inventors: Michael Treu, Roland Rupp, Michael Rueb, Rudolf Elpelt
  • Publication number: 20100155743
    Abstract: One aspect includes a semiconductor device with self-aligned contacts, integrated circuit and manufacturing method. One embodiment provides gate control structures. Each of the gate control structures is configured to control the conductivity of a channel region within a silicon carbide substrate by field effect. A contact hole is self-aligned to opposing sidewalls of adjacent gate control structures by intermediate spacers.
    Type: Application
    Filed: December 22, 2008
    Publication date: June 24, 2010
    Applicant: INFINEON TECHNOLOGIES AUSTRIA AG
    Inventors: Michael Treu, Kathrin Rueschenschmidt, Oliver Haeberlen, Franz Auerbach
  • Patent number: 7736962
    Abstract: A junction field effect transistor comprises an insulating layer formed in a substrate. A source region of a first conductivity type is formed on the insulating layer, and a drain region of the first conductivity type is formed on the insulating layer and spaced apart from the drain region. A channel region of the first conductivity type is located between the source region and the drain region and formed on the insulating layer. A gate region of the second conductivity type surrounds all surfaces of a length of the channel region such that the channel region is embedded within the gate region.
    Type: Grant
    Filed: January 7, 2009
    Date of Patent: June 15, 2010
    Assignee: SuVolta, Inc.
    Inventor: Kiyoshi Mori
  • Patent number: 7736961
    Abstract: A high voltage field effect transistor device is fabricated. A substrate is provided. Isolation structures and well regions are formed therein. Drain well regions are formed within the well regions. An n-type channel stop resist mask is formed. N-type channel stop regions and n-type surface channel regions are formed. A p-type channel stop resist mask is formed. P-type channel stop regions and p-type surface channel regions are then formed. A dielectric layer is formed over the surface channel regions. Source regions are formed within the well regions. Drain regions are formed within the drain well regions. Back gate regions are formed within the well regions. Top gates are formed on the dielectric layer overlying the surface channel regions.
    Type: Grant
    Filed: June 28, 2005
    Date of Patent: June 15, 2010
    Assignee: Texas Instruments Incorporated
    Inventors: Steven L. Merchant, Philip L. Hower, Scott Paiva
  • Patent number: 7709311
    Abstract: A junction field effect transistor comprises a semiconductor substrate. A first impurity region of a first conductivity type is formed in the substrate. A second impurity region of the first conductivity type is formed in the substrate and spaced apart from the first impurity region. A channel region of the first conductivity type is formed between the first and second impurity regions. A gate region of a second conductivity type is formed in the substrate between the first and second impurity regions. A gap region is formed in the substrate between the gate region and the first impurity region such that the first impurity region is spaced apart from the gate region.
    Type: Grant
    Filed: July 23, 2008
    Date of Patent: May 4, 2010
    Assignee: SuVolta, Inc.
    Inventors: Samar K. Saha, Ashok K. Kapoor
  • Patent number: 7704813
    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: November 1, 2007
    Date of Patent: April 27, 2010
    Assignee: Texas Instruments Incorporated
    Inventors: Kaiyuan Chen, Joe Trogolo, Tathagata Chatterjee, Steve Merchant
  • Publication number: 20100097853
    Abstract: A memory cell (FIG. 6A) compatible with dynamic random access memories (DRAM) and static random access memories (SRAM) is disclosed. The memory cell includes a first junction field effect transistor (600) having a first conductivity type. A second junction field effect transistor (602) having a second conductivity type is coupled to the first junction field effect transistor. An access transistor (610) is coupled to the first and second junction field effect transistors.
    Type: Application
    Filed: October 20, 2008
    Publication date: April 22, 2010
    Inventor: Robert N. Rountree
  • Publication number: 20100090260
    Abstract: A circuit 32 is provided comprising a first diffusion region 34 and a parallel second diffusion region 36. A sequence of N gate layers 40, 42, 46 is provided with a first and an Nth of these gate layers covering different respective ones of the diffusion regions 34, 36 whilst the middle (N-2) gate layers 42 cover both diffusion regions 34, 36. A bridging conductor 64 connects the first gate layer 40 and the Nth gate layer 46. In some embodiments, the second diffusion region is provided as two second diffusion sub-regions 68, 70 having a diffusion region gap 74 therebetween and electrically connected via a jumper connector 42. A first gate layer 76 which forms a gate electrode with a first diffusion region 66 can extend through this diffusion region gap 74 not forming a gate electrode therewith and facilitating use of a collinear bridging conductor 82 to connect to the Nth gate layer 80.
    Type: Application
    Filed: October 14, 2008
    Publication date: April 15, 2010
    Applicant: ARM Limited
    Inventors: Marlin Wayne Frederick, David Paul Clark
  • Patent number: 7692220
    Abstract: The invention can include at least one storage cell having a store gate structure formed from a semiconductor material doped to a first conductivity type and in contact with a channel region comprising a semiconductor material doped to a second conductivity type. A storage cell can also include at least a first source/drain region and a second source/drain region separated from one another by the channel region. A control gate structure, comprising a semiconductor layer doped to the first conductivity type can be formed over a substrate surface. The control gate structure can be in contact with the channel region. Such a storage cell can be more compact and/or provide longer data retention times than conventional storage cells, such as many conventional dynamic random access memory (DRAM) type cells.
    Type: Grant
    Filed: May 1, 2007
    Date of Patent: April 6, 2010
    Assignee: SuVolta, Inc.
    Inventor: Madhu P. Vora
  • Patent number: 7691694
    Abstract: A silicon carbide semiconductor device includes a substrate and a junction field effect transistor. The transistor includes: a first semiconductor layer disposed on the substrate; a first gate layer disposed on a surface of the first semiconductor layer; a first channel layer adjacent to the first gate layer on the substrate; a first source layer connecting to the first channel layer electrically; a second gate layer adjacent to the first channel layer to sandwich the first channel layer; a second channel layer adjacent to the second gate layer to sandwich the second gate layer; a third gate layer adjacent to the second channel layer to sandwich the second channel layer; and a second source layer connecting to the second channel layer electrically.
    Type: Grant
    Filed: April 17, 2007
    Date of Patent: April 6, 2010
    Assignee: DENSO CORPORATION
    Inventors: Rajesh Kumar, Andrei Mihaila, Florin Udrea
  • Patent number: 7687336
    Abstract: A method of forming a MOSFET is provided. The method comprises forming a relatively thin layer of dielectric on a substrate. Depositing a gate material layer on the relatively thin layer of dielectric. Removing portions of the gate material layer to form a first and second gate material regions of predetermined lateral lengths. Introducing a first conductivity type dopant in the substrate to form a top gate using first edges of the first and second gate material regions as masks, Introducing a second conductivity dopant of high dopant density in the substrate to form a drain region adjacent the surface of the substrate using a second edge of the second gate material region as a mask to form a first edge of the drain region, wherein a spaced distance between the top gate and the drain region is determined by the lateral length of the second gate material region.
    Type: Grant
    Filed: March 28, 2008
    Date of Patent: March 30, 2010
    Assignee: Intersil Americas Inc.
    Inventor: James D. Beasom
  • Patent number: 7687335
    Abstract: A JFET integrated onto a substrate having a semiconductor layer at least and having source and drain contacts over an active area and made of first polysilicon (or other conductors such as refractive metal or silicide) and a self-aligned gate contact made of second polysilicon which has been polished back to be flush with a top surface of a dielectric layer covering the tops of the source and drain contacts. The dielectric layer preferably has a nitride cap to act as a polish stop. In some embodiments, nitride covers the entire dielectric layer covering the source and drain contacts as well as the field oxide region defining an active area for said JFET. An embodiment with an epitaxially grown channel region formed on the surface of the substrate is also disclosed.
    Type: Grant
    Filed: September 22, 2008
    Date of Patent: March 30, 2010
    Assignee: SuVolta, Inc.
    Inventor: Ashok Kumar Kapoor
  • Patent number: 7687834
    Abstract: This invention describes a method of building complementary logic circuits using junction field effect transistors in silicon. This invention is ideally suited for deep submicron dimensions, preferably below 65 nm. The basis of this invention is a complementary Junction Field Effect Transistor which is operated in the enhancement mode. The speed-power performance of the JFETs becomes comparable with the CMOS devices at sub-70 nanometer dimensions. However, the maximum power supply voltage for the JFETs is still limited to below the built-in potential (a diode drop). To satisfy certain applications which require interface to an external circuit driven to higher voltage levels, this invention includes the structures and methods to build CMOS devices on the same substrate as the JFET devices.
    Type: Grant
    Filed: November 3, 2008
    Date of Patent: March 30, 2010
    Assignee: SuVolta, Inc.
    Inventor: Ashok K. Kapoor
  • Patent number: 7687825
    Abstract: Insulated gate bipolar conduction transistors (IBCTs) are provided. The IBCT includes a drift layer having a first conductivity type. An emitter well region is provided in the drift layer and has a second conductivity type opposite the first conductivity type. A well region is provided in the drift layer and has the second conductivity type. The well region is spaced apart from the emitter well region. A space between the emitter well region and the well region defines a JFET region of the IBCT. An emitter region is provided in the well region and has the first conductivity type and a buried channel layer is provided on the emitter well region, the well region and the JFET region and has the first conductivity type. Related methods of fabrication are also provided.
    Type: Grant
    Filed: September 18, 2007
    Date of Patent: March 30, 2010
    Assignee: Cree, Inc.
    Inventor: Qingchun Zhang
  • Publication number: 20100059798
    Abstract: There is provided a semiconductor device including: a SiC substrate; an AlGaN layer formed on the SiC substrate; a source electrode and a drain electrode formed on the AlGaN layer so as to be spaced from each other; a first insulation film formed between the source electrode and the drain electrode and having a band-like opening parallel to the drain electrode and the source electrode; a gate electrode formed at the opening in the first insulation film; a second insulation film formed on the first insulation film in such a manner as to cover a surface of the gate electrode; and a source field plate electrode which is formed on the second insulation film and the source electrode and an end portion of which on the drain electrode side is spaced from the second insulation film, thereby suppressing degradation in device performance.
    Type: Application
    Filed: September 4, 2009
    Publication date: March 11, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Hisao KAWASAKI
  • Patent number: 7670890
    Abstract: An junction field effect transistor (JFET) is fashioned with a patterned layer of silicide block (SBLK) material utilized in forming gate, source and drain regions. Utilizing the silicide block in this manner helps to reduce low-frequency (flicker) noise associated with the JFET by suppressing the impact of surface states, among other things.
    Type: Grant
    Filed: July 26, 2006
    Date of Patent: March 2, 2010
    Assignees: Texas Instruments Deutschland GmbH, Texas Instruments Incorporated
    Inventors: Badih El-Kareh, Hiroshi Yasuda, Scott Gerard Balster, Philipp Steinmann, Joe R. Trogolo
  • Patent number: 7670888
    Abstract: Fashioning a low noise (1/f) junction field effect transistor (JFET) is disclosed, where multiple implants are performed to push a conduction path of the transistor away from the surface of a layer upon which the transistor is formed. In this manner, current flow in the conduction path is less likely to be disturbed by defects that may exist at the surface of the layer, thereby mitigating (1/f) noise.
    Type: Grant
    Filed: April 11, 2007
    Date of Patent: March 2, 2010
    Assignee: Texas Instruments Incorporated
    Inventors: Pinghai Hao, Imran Khan, Joe Trogolo
  • Patent number: 7670889
    Abstract: A design structure, and more particularly, to a design structure for manufacturing a JFET in SOI, a JFET and methods of manufacturing the JFET are provided. The JFET includes a gate poly formed directly on an SOI layer and a gate oxide layer interposed between outer edges of the gate poly and the SOI layer.
    Type: Grant
    Filed: June 4, 2008
    Date of Patent: March 2, 2010
    Assignee: International Business Machines Corporation
    Inventors: John J. Pekarik, Richard A. Phelps, Robert M. Rassel, Yun Shi
  • Publication number: 20100019291
    Abstract: Devices and methods for providing JFET transistors with improved operating characteristics are provided. Specifically, one or more embodiments of the present invention relate to JFET transistors with a higher diode turn-on voltage. For example, one or more embodiments include a JFET with a PIN gate stack. One or more embodiments also relate to systems and devices in which the improved JFET may be employed, as well as methods of manufacturing the improved JFET.
    Type: Application
    Filed: July 24, 2008
    Publication date: January 28, 2010
    Applicant: MICRON TECHNOLOGY, INC.
    Inventor: Chandra Mouli
  • Publication number: 20100019289
    Abstract: A junction field effect transistor comprises a semiconductor substrate and a well region formed in the substrate. A source region of a first conductivity type is formed in the well region. A drain region of the first conductivity type is formed in the well region and spaced apart from the source region. A channel region of the first conductivity type is located between the source region and the drain region and formed in the well region. A gate region of a second conductivity type is formed in the well region. The transistor further includes first, second, and third connection regions. The first connection region is in ohmic contact with the source region and formed of silicide. The second connection region is in ohmic contact with the drain region and formed of silicide. The third connection region in ohmic contact with the gate region.
    Type: Application
    Filed: July 25, 2008
    Publication date: January 28, 2010
    Applicant: DSM Solutions, Inc.
    Inventors: Ashok K. Kapoor, Madhukar B Vora
  • Publication number: 20100019249
    Abstract: Devices and methods for providing JFET transistors with improved operating characteristics are provided. Specifically, one or more embodiments of the present invention relate to JFET transistors with a higher diode turn-on voltage. For example, one or more embodiments include a JFET with a doped silicon-carbide gate, while other embodiments include a JFET with a metal gate. One or more embodiments also relate to systems and devices in which the improved JFET may be employed, as well as methods of manufacturing the improved JFET.
    Type: Application
    Filed: July 24, 2008
    Publication date: January 28, 2010
    Applicant: MICRON TECHNOLOGY, INC.
    Inventor: Chandra Mouli