Schottky Electrode (epo) Patents (Class 257/E21.064)
  • Patent number: 9018638
    Abstract: A MOSFET device is provided. An N-type epitaxial layer is disposed on an N-type substrate. An insulating trench is disposed in the epitaxial layer. A P-type well region is disposed in the epitaxial layer at one side of the insulating trench. An N-type heavily doped region is disposed in the well region. A gate structure is disposed on the epitaxial layer and partially overlaps with the heavily doped region. At least two P-type first doped regions are disposed in the epitaxial layer below the well region. At least one P-type second doped region is disposed in the epitaxial layer and located between the first doped regions. Besides, the first and second doped regions are separated from each other. The first doped regions extend along a first direction, and the second doped region extends along a second direction different from the first direction.
    Type: Grant
    Filed: June 11, 2013
    Date of Patent: April 28, 2015
    Assignee: Industrial Technology Research Institute
    Inventors: Chee-Wee Liu, Hui-Hsuan Wang
  • Patent number: 8987124
    Abstract: A silicon carbide substrate having a main face is prepared. By applying thermal oxidation to the main face of the silicon carbide substrate at a first temperature, an oxide film is formed on the main face. After the oxide film is formed, heat treatment is applied to the silicon carbide substrate at a second temperature higher than the first temperature. An opening exposing a portion of the main face is formed at the oxide film. A Schottky electrode is formed on the main face exposed by the opening.
    Type: Grant
    Filed: October 11, 2012
    Date of Patent: March 24, 2015
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Tomihito Miyazaki, Toru Hiyoshi
  • Patent number: 8685848
    Abstract: A silicon oxide film is formed on an epitaxial layer by dry thermal oxidation, an ohmic electrode is formed on a back surface of a SiC substrate, an ohmic junction is formed between the ohmic electrode and the back surface of the SiC substrate by annealing the SiC substrate, the silicon oxide film is removed, and a Schottky electrode is formed on the epitaxial layer. Then, a sintering treatment is performed to form a Schottky junction between the Schottky electrode and the epitaxial layer.
    Type: Grant
    Filed: January 23, 2012
    Date of Patent: April 1, 2014
    Assignee: Mitsubishi Electric Corporation
    Inventors: Yoshinori Matsuno, Yoichiro Tarui
  • Patent number: 8513122
    Abstract: A method forms an integrated circuit structure. The method patterns a protective layer over a first-type field effect transistor and removes a stress liner from above a second-type field effect transistors. Then, the method removes a first-type silicide layer from source and drain regions of the second-type field effect transistor, but leaves at least a portion of the first-type silicide layer on the gate conductor of the second-type field effect transistor. The method forms a second-type silicide layer on the gate conductor and the source and drain regions of the second-type field effect transistor. The second-type silicide layer that is formed is different than the first-type silicide layer. For example, the first-type silicide layer and the second-type silicide layer can comprise different materials, different thicknesses, different crystal orientations, and/or different chemical phases, etc.
    Type: Grant
    Filed: February 5, 2013
    Date of Patent: August 20, 2013
    Assignee: International Business Machines Corporation
    Inventors: Christian Lavoie, Viorel C. Ontalus, Ahmet S. Ozcan
  • Patent number: 8476154
    Abstract: The present invention provides a charge trapping non-volatile semiconductor memory device and a method of making the device. The charge trapping non-volatile semiconductor memory device comprises a semiconductor substrate, a source region, a drain region, and, consecutively formed over the semiconductor substrate, a channel insulation layer, a charge trapping layer, a blocking insulation layer, and a gate electrode. The drain region includes a P-N junction, and the source region includes a metal-semiconductor junction formed between the semiconductor substrate and a metal including titanium, cobalt, nickel, platinum or one of their various combinations. The charge trapping non-volatile semiconductor memory device according to the present disclosure has low programming voltage, fast programming speed, low energy consumption, and relatively high device reliability.
    Type: Grant
    Filed: January 4, 2011
    Date of Patent: July 2, 2013
    Assignee: Fudan University
    Inventors: Dongping Wu, Shi-Li Zhang
  • Patent number: 8450196
    Abstract: Production of an integrated circuit including an electrical contact on SiC is disclosed. One embodiment provides for production of an electrical contact on an SiC substrate, in which a conductive contact is produced on a boundary surface of the SiC substrate by irradiation and absorption of a laser pulse on an SiC substrate.
    Type: Grant
    Filed: October 25, 2007
    Date of Patent: May 28, 2013
    Assignee: Infineon Technologies Austria AG
    Inventors: Roland Rupp, Thomas Gutt, Michael Treu
  • Patent number: 8404525
    Abstract: The present invention provides a semiconductor device which is formed at low cost and has a great versatility, a manufacturing method thereof, and further a semiconductor device with an improved yield, and a manufacturing method thereof. A structure, which has a base including a plurality of depressions having different shapes or sizes, and a plurality of IC chips which are disposed in the depressions and which fit the depressions, is formed. A semiconductor device which selectively includes a function in accordance with an application, by using the base including the plurality of depressions and the IC chips which fit the depressions, can be manufactured at low cost.
    Type: Grant
    Filed: May 25, 2011
    Date of Patent: March 26, 2013
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Kunio Hosoya, Saishi Fujikawa, Satohiro Okamoto
  • Patent number: 8377811
    Abstract: An object of the invention is to provide a method for manufacturing a silicon carbide semiconductor device having constant characteristics with reduced variations in forward characteristics. The method for manufacturing the silicon carbide semiconductor device according to the invention includes the steps of: (a) preparing a silicon carbide substrate; (b) forming an epitaxial layer on a first main surface of the silicon carbide substrate; (c) forming a protective film on the epitaxial layer; (d) forming a first metal layer on a second main surface of the silicon carbide substrate; (e) applying heat treatment to the silicon carbide substrate at a predetermined temperature to form an ohmic junction between the first metal layer and the second main surface of the silicon carbide substrate; (f) removing the protective film; (g) forming a second metal layer on the epitaxial layer; and (h) applying heat treatment to the silicon carbide substrate at a temperature from 400° C. to 600° C.
    Type: Grant
    Filed: August 8, 2008
    Date of Patent: February 19, 2013
    Assignee: Mitsubishi Electric Corporation
    Inventors: Yoshinori Matsuno, Kenichi Ohtsuka, Kenichi Kuroda, Shozo Shikama, Naoki Yutani
  • Patent number: 8324704
    Abstract: A silicon carbide semiconductor device with a Schottky barrier diode includes a first conductivity type silicon carbide substrate, a first conductivity type silicon carbide drift layer on a first surface of the substrate, a Schottky electrode forming a Schottky contact with the drift layer, and an ohmic electrode on a second surface of the substrate. The Schottky electrode includes an oxide layer in direct contact with the drift layer. The oxide layer is made of an oxide of molybdenum, titanium, nickel, or an alloy of at least two of these elements.
    Type: Grant
    Filed: March 23, 2010
    Date of Patent: December 4, 2012
    Assignees: DENSO CORPORATION, Toyota Jidosha Kabushiki Kaisha
    Inventors: Takeo Yamamoto, Takeshi Endo, Eiichi Okuno, Hirokazu Fujiwara, Masaki Konishi, Takashi Katsuno, Yukihiko Watanabe
  • Patent number: 8188520
    Abstract: A method for fabricating a field effect transistor includes: forming an insulating film provided on a semiconductor layer, the insulating film having an opening via which a surface of the semiconductor layer is exposed and including silicon oxide; forming a Schottky electrode on the insulating film and in the opening, the Schottky electrode having an overhang portion and having a first contact layer that is provided in a region contacting the insulating film and contains oxygen, and a second contact layer that is provided on the first contact layer and contains a smaller content of oxygen than that of the first contact layer; and removing the insulating film by a solution including hydrofluoric acid.
    Type: Grant
    Filed: May 10, 2011
    Date of Patent: May 29, 2012
    Assignee: Eudyna Devices Inc.
    Inventors: Tadashi Watanabe, Hajime Matsuda
  • Patent number: 7977210
    Abstract: A semiconductor substrate includes a silicon carbide substrate having a first impurity concentration, a first silicon carbide layer formed on the silicon carbide substrate and having a second impurity concentration, and a second silicon carbide layer of a first conductivity type formed on the first silicon carbide layer and having a third impurity concentration, wherein the second impurity concentration is higher the an either the first impurity concentration or the third impurity concentration.
    Type: Grant
    Filed: November 25, 2008
    Date of Patent: July 12, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Chiharu Ota, Johji Nishio, Takashi Shinohe
  • Patent number: 7964486
    Abstract: A method for fabricating a field effect transistor includes: forming an insulating film provided on a semiconductor layer, the insulating film having an opening via which a surface of the semiconductor layer is exposed and including silicon oxide; forming a Schottky electrode on the insulating film and in the opening, the Schottky electrode having an overhang portion and having a first contact layer that is provided in a region contacting the insulating film and contains oxygen, and a second contact layer that is provided on the first contact layer and contains a smaller content of oxygen than that of the first contact layer; and removing the insulating film by a solution including hydrofluoric acid.
    Type: Grant
    Filed: February 7, 2008
    Date of Patent: June 21, 2011
    Assignee: Eudyna Devices Inc.
    Inventors: Tadashi Watanabe, Hajime Matsuda
  • Publication number: 20100244049
    Abstract: A silicon carbide semiconductor device with a Schottky barrier diode includes a first conductivity type silicon carbide substrate, a first conductivity type silicon carbide drift layer on a first surface of the substrate, a Schottky electrode forming a Schottky contact with the drift layer, and an ohmic electrode on a second surface of the substrate. The Schottky electrode includes an oxide layer in direct contact with the drift layer. The oxide layer is made of an oxide of molybdenum, titanium, nickel, or an alloy of at least two of these elements.
    Type: Application
    Filed: March 23, 2010
    Publication date: September 30, 2010
    Applicants: DENSO CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Takeo Yamamoto, Takeshi Endo, Eiichi Okuno, Hirokazu Fujiwara, Masaki Konishi, Takashi Katsuno, Yukihiko Watanabe
  • Publication number: 20100224886
    Abstract: A second trench in each source electrode portion (Schottky diode portion) is formed to have a depth equal to or larger than the depth of a first trench in each gate electrode portion. The distance between the first and second trenches is set to be not longer than 10 ?m. A source electrode is formed in the second trench and a Schottky junction is formed in the bottom portion of the second trench. In this manner, it is possible to provide a wide band gap semiconductor device which is small-sized, which has low on-resistance and low loss characteristic, in which electric field concentration into a gate insulating film is relaxed to suppress reduction of a withstand voltage, and which has high avalanche breakdown tolerance at turn-off time.
    Type: Application
    Filed: March 4, 2010
    Publication date: September 9, 2010
    Applicant: FUJI ELECTRIC SYSTEMS CO. LTD.
    Inventor: Noriyuki IWAMURO
  • Patent number: 7777292
    Abstract: A semiconductor device includes a semiconductor substrate of a first conductivity type having a top surface and a bottom surface, a semiconductor layer of a first conductivity type formed on the top surface of the semiconductor substrate, and having an active region and an edge termination region surrounding the active region, a first semiconductor region of a second conductivity type formed in the edge termination region adjacent to an edge of the active region, a second semiconductor region of a second conductivity type buried in the edge termination region in a sheet shape or a mesh shape substantially in parallel with a surface of the semiconductor layer, a first electrode formed on the active region of the semiconductor layer and a part of the first semiconductor region, and a second electrode formed on the bottom surface of the semiconductor substrate.
    Type: Grant
    Filed: June 25, 2007
    Date of Patent: August 17, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Chiharu Ota, Johji Nishio, Tetsuo Hatakeyama, Takashi Shinohe
  • Patent number: 7667273
    Abstract: A semiconductor device includes a p-channel MIS transistor. A p-channel MIS transistor includes; an n-type semiconductor layer formed on the substrate; first source/drain regions being formed in the n-type semiconductor layer and being separated from each other; a first gate insulating film being formed on the n-type semiconductor layer between the first source/drain regions, and containing silicon, oxygen, and nitrogen, or containing silicon and nitrogen; a first gate electrode formed above the first gate insulating film; and a first interfacial layer being formed at an interface between the first gate insulating film and the first gate electrode, and containing a 13-group element. The total number of metallic bonds in the 13-group element in the interfacial layer being larger than the total number of each of oxidized, nitrided, or oxynitrided bonds in the 13-group element in the interfacial layer.
    Type: Grant
    Filed: February 27, 2007
    Date of Patent: February 23, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masato Koyama, Yoshinori Tsuchiya
  • Patent number: 7645691
    Abstract: A method for forming an ohmic contact and a zener zap diode in an integrated circuit includes forming a first contact opening in the insulating layer over a first diffusion region to expose the semiconductor substrate; forming a barrier metal layer on the insulating layer and in the first contact opening; forming a second contact opening in the barrier metal layer over a second diffusion region and the insulating layer to expose the semiconductor substrate; forming a third contact opening in the barrier metal layer and the insulating layer over a third diffusion region to expose the semiconductor substrate; forming an aluminum layer on the barrier metal layer and the insulating layer and in the first, second and third contact openings; and patterning the aluminum layer to form the ohmic contact over the first diffusion region and the zener zap diode over the second and third diffusion regions.
    Type: Grant
    Filed: December 11, 2008
    Date of Patent: January 12, 2010
    Assignee: Micrel, Inc.
    Inventor: Schyi-yi Wu
  • Patent number: 7622752
    Abstract: A Schottky diode with a vertical barrier extending perpendicularly to the surface of a semiconductor chip having a vertical central metal conductor in contact on the one hand with the substrate of the semiconductor chip with an interposed interface forming a Schottky barrier, and on the other hand with radially-extending conductive fingers.
    Type: Grant
    Filed: December 23, 2005
    Date of Patent: November 24, 2009
    Assignees: STMicroelectronics S.A., STMicroelectronics Maroc
    Inventors: Frédéric Lanois, Sylvain Nizou
  • Publication number: 20090096053
    Abstract: A silicon carbide Schottky barrier semiconductor device provided with a Ta electrode as a Schottky electrode, in which the Schottky barrier height is controlled to a desired value in a range where power loss is minimized without increasing the n factor. The method for manufacturing the silicon carbide Schottky barrier semiconductor device includes the steps of depositing Ta on a crystal face of an n-type silicon carbide epitaxial film, the crystal face having an inclined angle in the range of 0° to 10° from a (000-1) C face, and carrying out a thermal treatment at a temperature range of 300 to 1200° C. to form the Schottky electrode.
    Type: Application
    Filed: February 15, 2007
    Publication date: April 16, 2009
    Applicant: CENTRAL RESEARCH INSTITUTE OF ELECTRIC POWER INDUSTRY
    Inventors: Hidekazu Tsuchida, Tomonori Nakamura, Toshiyuki Miyanagi
  • Publication number: 20090098719
    Abstract: An object of the invention is to provide a method for manufacturing a silicon carbide semiconductor device having constant characteristics with reduced variations in forward characteristics. The method for manufacturing the silicon carbide semiconductor device according to the invention includes the steps of: (a) preparing a silicon carbide substrate; (b) forming an epitaxial layer on a first main surface of the silicon carbide substrate; (c) forming a protective film on the epitaxial layer; (d) forming a first metal layer on a second main surface of the silicon carbide substrate; (e) applying heat treatment to the silicon carbide substrate at a predetermined temperature to form an ohmic junction between the first metal layer and the second main surface of the silicon carbide substrate; (f) removing the protective film; (g) forming a second metal layer on the epitaxial layer; and (h) applying heat treatment to the silicon carbide substrate at a temperature from 400° C. to 600° C.
    Type: Application
    Filed: August 8, 2008
    Publication date: April 16, 2009
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Yoshinori MATSUNO, Kenichi Ohtsuka, Kenichi Kuroda, Shozo Shikama, Naoki Yutani
  • Patent number: 7488673
    Abstract: A trench MOS Schottky barrier device has a metal oxide gate dielectric such as TiSi lining the trench wall to increase the efficiency of the elemental cell and to improve depletion in the mesa during reverse bias. A reduced mask process is used in which a single layer of titanium or other metal is deposited on an underlying gate oxide layer on the trench walls and directly atop the mesa between adjacent trenches. A common thermal treatment causes the Ti to diffuse into the SiO2 gate oxide to form the TiO2 gate and to form the TiSi Schottky barrier on the top surface of the mesa.
    Type: Grant
    Filed: February 23, 2007
    Date of Patent: February 10, 2009
    Assignee: International Rectifier Corporation
    Inventors: Carmelo Sanfilippo, Rossano Carta, Giovanni Richieri, Paolo Mercaldi
  • Publication number: 20080237608
    Abstract: A method for fabricating a diode is disclosed. In one embodiment, the method includes forming a Schottky contact on an epitaxial layer of silicon carbide (SiC) and annealing the Schottky contact at a temperature in the range of 300° C. to 700° C. The Schottky contact is formed of a layer of molybdenum.
    Type: Application
    Filed: July 31, 2007
    Publication date: October 2, 2008
    Inventor: Giovanni Richieri
  • Publication number: 20080099769
    Abstract: Production of an integrated circuit including an electrical contact on SiC is disclosed. One embodiment provides for production of an electrical contact on an SiC substrate, in which a conductive contact is produced on a boundary surface of the SiC substrate by irradiation and absorption of a laser pulse on an SiC substrate.
    Type: Application
    Filed: October 25, 2007
    Publication date: May 1, 2008
    Applicant: INFINEON TECHNOLOGIES AUSTRIA AG
    Inventors: Roland Rupp, Thomas Gutt, Michael Treu
  • Patent number: 7326974
    Abstract: A field-effect transistor used as a sensor for measuring a gas or ion concentration utilizes a surface structure such as rings along with surface profiling, for example elevations of the rings and depressions therebetween, to decrease the surface conductivity between a guard ring and the FET, to thereby increase the concentration rise per unit time of a gas signal and increase the time for a potential on a channel region of the FET to approximate the potential on a guard ring. The rings, which may be arranged around the FET structure, may be defined by a surface material different from the remaining surface material and thus having different surface conductivities. The surface profiling, together with the rings, can be utilized to increase an amount of time that may describe the equalization of the channel region potential to the guard ring potential. The elevations may have a surface conductivity different from, for example smaller than, that of the depressions.
    Type: Grant
    Filed: November 21, 2003
    Date of Patent: February 5, 2008
    Assignee: Micronas GmbH
    Inventor: Heinz-Peter Frerichs
  • Publication number: 20080003731
    Abstract: A switching element combining a self-aligned, vertical junction field effect transistor with etched-implanted gate and an integrated antiparallel Schottky barrier diode is described. The anode of the diode is connected to the source of the transistor at the device level in order to reduce losses due to stray inductances. The SiC surface in the SBD anode region is conditioned through dry etching to achieve a low Schottky barrier height so as to reduce power losses associated with the turn on voltage of the SBD.
    Type: Application
    Filed: June 12, 2007
    Publication date: January 3, 2008
    Inventors: Michael Mazzola, Joseph Merrett
  • Patent number: 7268027
    Abstract: Disclosed is a method of manufacturing a photoreceiver, including sequentially laminating a buffer layer, a channel layer, a barrier layer, and a cap layer on a substrate; forming a mesa for HEMT and MSM PD by removing the buffer layer, the channel layer, the barrier layer, and the cap layer with the exception of a region corresponding to HEMT and MSM PD; forming a source electrode and a drain electrode of HEMT; removing the cap layer from a region corresponding to a gate electrode of HEMT and a Schottky electrode of MSM PD; forming the gate electrode of HEMT and the Schottky electrode of HEMT on the cap layer-removed region; and removing the cap layer, the barrier layer and the channel layer from a region corresponding to an optical waveguide, to expose the optical waveguide.
    Type: Grant
    Filed: September 15, 2005
    Date of Patent: September 11, 2007
    Assignee: Korea Advanced Institute of Science and Technology
    Inventors: Young Se Kwon, Jung Ho Cha
  • Patent number: 7135420
    Abstract: Single crystal silicon is grown in a [100] direction to make a bulk. Next, a silicon substrate with a normal of a surface extending in an inclined direction from a [100] direction is cut from the bulk. At this time, when an angle (off-angle) of inclination of the normal is decomposed into a component in a [001] direction and a component in a [010] direction, the component in the [001] direction is made within ±0.2 degrees (excluding 0 degree). An MOS transistor with a moving direction of carriers being the [001] direction is formed on the surface of the silicon substrate. At this time, after steps existing on the surface of the silicon substrate are reconstituted by thermal treatment in a hydrogen atmosphere, a gate insulation film, a gate electrode and the like are formed.
    Type: Grant
    Filed: February 23, 2004
    Date of Patent: November 14, 2006
    Assignee: Fujitsu Limited
    Inventor: Hiroe Kawamura