Schottky Diode (epo) Patents (Class 257/E29.338)
  • Publication number: 20110278589
    Abstract: A gallium nitride based semiconductor diode includes a substrate, a semiconductor body including a first heavily doped GaN layer and a second lightly doped GaN layer. The semiconductor body includes mesas projecting upwardly from a lower surface where each of the mesas includes the second GaN layer and a portion of the first GaN layer. Schottky contacts are formed on the upper surface of the mesas and ohmic contacts are formed on the lower surface of the semiconductor body. An insulating layer is formed over the Schottky and ohmic contacts. Vias are formed in the insulating layer to the Schottky contacts and vias are formed in the semiconductor body to the Ohmic contacts. An anode electrode is formed in a first metal pad in electrical contact with the Schottky contacts. A cathode electrode is formed in a second metal pad in electrical contact with the ohmic contacts.
    Type: Application
    Filed: July 26, 2011
    Publication date: November 17, 2011
    Applicant: ALPHA & OMEGA SEMICONDUCTOR, INC.
    Inventor: TingGang Zhu
  • Patent number: 8044485
    Abstract: A semiconductor device made of a group-III nitride semiconductor having excellent properties is provided. The semiconductor device has a horizontal diode structure of Schottky type or P-N junction type, or combined type thereof having a main conduction pathway in the horizontal direction in a conductive layer with unit anode portions and unit cathode electrodes being integrated adjacently to each other in the horizontal direction. The conductive layer is preferably formed by depositing a group-III nitride layer and generating a two-dimensional electron gas layer on the interface. Forming the conductive layer of the group-III nitride having high breakdown field allows the breakdown voltage to be kept high while the gap between electrodes is narrow, which achieves a semiconductor device having high output current per chip area.
    Type: Grant
    Filed: March 28, 2007
    Date of Patent: October 25, 2011
    Assignee: NGK Insulators, Ltd.
    Inventors: Makoto Miyoshi, Yoshitaka Kuraoka
  • Patent number: 8044486
    Abstract: This invention discloses a bottom-anode Schottky (BAS) diode that includes an anode electrode disposed on a bottom surface of a semiconductor substrate. The bottom-anode Schottky diode further includes a sinker dopant region disposed at a depth in the semiconductor substrate extending substantially to the anode electrode disposed on the bottom surface of the semiconductor and the sinker dopant region covered by a buried Schottky barrier metal functioning as a Schottky anode.
    Type: Grant
    Filed: December 11, 2009
    Date of Patent: October 25, 2011
    Assignee: Alpha & Omega Semiconductor, Inc.
    Inventor: François Hébert
  • Publication number: 20110254118
    Abstract: A Schottky diode optimizes the on state resistance, the reverse leakage current, and the reverse breakdown voltage of the Schottky diode by forming an insulated control gate over a region that lies between the metal-silicon junction of the Schottky diode and the n+ cathode contact of the Schottky diode.
    Type: Application
    Filed: April 20, 2010
    Publication date: October 20, 2011
    Inventors: Zia Alan Shafi, Jeffrey A. Babcock
  • Publication number: 20110248284
    Abstract: An SiC Schottky diode die or a Si Schottky diode die is mounted with its epitaxial anode surface connected to the best heat sink surface in the device package. This produces a substantial increase in the surge current capability of the device.
    Type: Application
    Filed: October 12, 2010
    Publication date: October 13, 2011
    Applicant: INTERNATIONAL RECTIFIER CORP.
    Inventors: Rossano Carta, Luigi Merlin, Laura Bellemo
  • Patent number: 8030155
    Abstract: A method of forming a rectifying diode. The method comprises providing a first semiconductor region of a first conductivity type and having a first dopant concentration and forming a second semiconductor region in the first semiconductor region. The second semiconductor region has the first conductivity type and having a second dopant concentration greater than the first dopant concentration. The method also comprises forming a conductive contact to the first semiconductor region and forming a conductive contact to the second semiconductor region. The rectifying diode comprises a current path, and the path comprises: (i) the conductive contact to the first semiconductor region; (ii) the first semiconductor region; (iii) the second semiconductor region; and (iv) the conductive contact to the second semiconductor region. The second semiconductor region does not extend to a layer buried relative to the first semiconductor region.
    Type: Grant
    Filed: May 12, 2008
    Date of Patent: October 4, 2011
    Assignee: Texas Instruments Incorporated
    Inventors: Vladimir F. Drobny, Derek W. Robinson
  • Publication number: 20110233713
    Abstract: A Schottky diode includes a deep well formed in a substrate, an isolation layer formed in the substrate, a first conductive type guard ring formed in the deep well along an outer sidewall of the isolation layer and located at a left side of the isolation layer, a second conductive type well formed in the deep well along the outer sidewall of the isolation layer and located at a right side of the isolation layer, an anode electrode formed over the substrate and coupled to the deep well and the guard ring, and a cathode electrode formed over the substrate and coupled to the well. A part of the guard ring overlaps the isolation layer.
    Type: Application
    Filed: October 4, 2010
    Publication date: September 29, 2011
    Inventor: Jin-Yeong Son
  • Publication number: 20110227135
    Abstract: Improved Schottky diodes with reduced leakage current and improved breakdown voltage are provided by building a JFET with its current path of a first conductivity type serially located between a first terminal comprising a Schottky contact and a second terminal. The current path lies (i) between multiple substantially parallel finger regions of a second, opposite, conductivity type substantially laterally outboard of the Schottky contact, and (ii) partly above a buried region of the second conductivity type that underlies a portion of the current path, which regions are electrically coupled to the first terminal and the Schottky contact and which portion is electrically coupled to the second terminal. When reverse bias is applied to the first terminal and Schottky contact, the current path is substantially pinched off in vertical or horizontal directions or both, thereby reducing the leakage current and improving the breakdown voltage of the device.
    Type: Application
    Filed: June 1, 2011
    Publication date: September 22, 2011
    Applicant: FREESCALE SEMICONDUCTOR, INC.
    Inventors: Xin Lin, Daniel J. Blomberg, Jiang-Kai Zuo
  • Publication number: 20110227187
    Abstract: The present invention provides a Schottky barrier semiconductor device having a semiconductor substrate 101, a low-concentration semiconductor layer 102, trenches 103 formed in the low-concentration semiconductor layer 102 and extending to the semiconductor substrate 101, and a mesa portion 102a formed between the trenches 103. This provides a high durability against a surge or transient voltage.
    Type: Application
    Filed: May 24, 2011
    Publication date: September 22, 2011
    Applicant: Panasonic Corporation
    Inventor: Kazuhiro Oonishi
  • Publication number: 20110220918
    Abstract: A high-performance semiconductor device capable of suppressing a leak current with little electric field concentration, reducing an invalid region in a PN junction region, securing a sufficient area for a Schottky junction region, and achieving efficient and easy manufacturing, in which, in one surface of a semiconductor substrate (1) having a first conduction type made of SiC, a PN junction region (7a) and a Schottky junction region (7b) are provided, in the PN junction region (7a), a convex portion (2a) which has a trapezoidal shape in sectional view and includes a second conduction type layer (2) provided on the semiconductor substrate (1) and a contact layer (3) which is in ohmic contact with the second conduction type layer (2) of the convex portion (2a) are provided, and Schottky electrode (4) covers the side surface of the convex portion (2a) and the contact layer (3), and is provided continuously over the PN junction region (7a) and the Schottky junction region (7b).
    Type: Application
    Filed: October 23, 2009
    Publication date: September 15, 2011
    Applicant: SHOWA DENKO K.K.
    Inventor: Akihiko Sugai
  • Patent number: 8018020
    Abstract: The invention provides a Schottky barrier diode in which a forward voltage is low, a backward leakage current is small, and a withstanding voltage of an element is high, by improving both the forward voltage VF and the backward leakage current IR. A Schottky barrier diode of the invention includes a semiconductor substrate whose surface is provided with a semiconductor layer of first conduction type, a plurality of semiconductor layers of second conduction type provided as junction barriers at a predetermined depth from the surface of the semiconductor layer of first conduction type, an annular shape guard ring comprised of a semiconductor layer of second conduction type to surround the semiconductor layer of second conduction type on the surface of the semiconductor layer of first conduction type, and a metal layer disposed so as to contact the semiconductor layer of first conduction type and the semiconductor layer of second conduction type.
    Type: Grant
    Filed: August 29, 2008
    Date of Patent: September 13, 2011
    Assignee: Panasonic Corporation
    Inventor: Kazuhiro Oonishi
  • Patent number: 8004058
    Abstract: A semiconductor diode that is disclosed. An exemplary semiconductor diode includes a portion of a semiconductor substrate including a first dopant, a first well with a Schottky region, and a second well with a second dopant; and an isolation region replacement element positioned over the semiconductor substrate and adjacent to the first and second wells.
    Type: Grant
    Filed: December 14, 2009
    Date of Patent: August 23, 2011
    Assignee: Taiwan Semiconductor Manufacturing Company, Ltd.
    Inventor: Shou-Mao Chen
  • Patent number: 7999345
    Abstract: Provided is a technology, in a semiconductor device having a power MISFET and a Schottky barrier diode on one semiconductor substrate, capable of suppressing a drastic increase in the on-resistance of the power MISFET while making the avalanche breakdown voltage of the Schottky barrier diode greater than that of the power MISFET. In the present invention, two epitaxial layers, one having a high doping concentration and the other having a low doping concentration, are formed over a semiconductor substrate and the boundary between these two epitaxial layers is located in a region equal in depth to or shallower than the bottom portion of a trench.
    Type: Grant
    Filed: March 9, 2009
    Date of Patent: August 16, 2011
    Assignee: Renesas Electronics Corporation
    Inventors: Yoshito Nakazawa, Hitoshi Matsuura
  • Publication number: 20110193062
    Abstract: Methods by which the growth of a nanostructure may be precisely controlled by an electrical current are described here. In one embodiment, an interior nanostructure is grown to a predetermined geometry inside another nanostructure, which serves as a reaction chamber. The growth is effected by a catalytic agent loaded with feedstock for the interior nanostructure. Another embodiment allows a preexisting marginal quality nanostructure to be zone refined into a higher-quality nanostructure by driving a catalytic agent down a controlled length of the nanostructure with an electric current. In both embodiments, the speed of nanostructure formation is adjustable, and the growth may be stopped and restarted at will. The catalytic agent may be doped or undoped to produce semiconductor effects, and the bead may be removed via acid etching.
    Type: Application
    Filed: November 23, 2010
    Publication date: August 11, 2011
    Applicant: The Regents of the University of California
    Inventors: Kenneth J. Jensen, William E. Mickelson, Alex K. Zettl
  • Publication number: 20110186933
    Abstract: An integrated circuit includes a Schottky diode having a cathode defined by an n-type semiconductor region, an anode defined by a cobalt silicide region, and a p-type region laterally annularly encircling the cobalt silicide region. The resulting p-n junction forms a depletion region under the Schottky junction that reduces leakage current through the Schottky diodes in reverse bias operation. An n+-type contact region is laterally separated by the p-type region from the first silicide region and a second cobalt silicide region is formed in the n-type contact region. The silicided regions are defined by openings in a silicon blocking dielectric layer. Dielectric material is left over the p-type region. The p-type region may be formed simultaneously with source/drain regions of a PMOS transistor.
    Type: Application
    Filed: April 12, 2011
    Publication date: August 4, 2011
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Sameer Prakash Pendharkar, Eugen Pompiliu Mindricelu
  • Patent number: 7982240
    Abstract: A main semiconductor region grown on a substrate has formed on its surface a pair of main electrodes spaced from each other, a gate electrode between the main electrodes, and a pair of diode-forming electrodes spaced farther away from the gate electrode than are the main electrodes. Making ohmic contact with the main semiconductor region, the pair of main electrodes serve both as drain or source of a HEMT switch and as cathodes of a pair of Schottky diodes integrated with the HEMT switch. Both gate electrode and diode-forming electrodes are in Schottky contact with the main semiconductor region.
    Type: Grant
    Filed: December 16, 2008
    Date of Patent: July 19, 2011
    Assignee: Sanken Electric Co., Ltd.
    Inventor: Osamu Machida
  • Publication number: 20110163408
    Abstract: A Schottky diode structure with low reverse leakage current and low forward voltage drop has a first conductive material semiconductor substrate combined with a metal layer. An oxide layer is formed around the edge of the combined conductive material semiconductor substrate and the metal layer. A plurality of dot-shaped or line-shaped second conductive material regions are formed on the surface of the first conductive material semiconductor substrate connecting to the metal layer. The second conductive material regions form depletion regions in the first conductive material semiconductor substrate. The depletion regions can reduce the leakage current area of the Schottky diode, thereby reducing the reverse leakage current and the forward voltage drop. When the first conductive material is a P-type semiconductor, the second conductive material is an N-type semiconductor. When the first conductive material is an N-type semiconductor, the second conductive material is a P-type semiconductor.
    Type: Application
    Filed: January 6, 2010
    Publication date: July 7, 2011
    Inventors: Chiun-Yen Tung, Kun-Hsien Chen, Kai-Ying Wang, Hung Ta Weng, Yi-Chen Shen
  • Publication number: 20110156199
    Abstract: A Schottky diode and a method of manufacturing the Schottky diode are disclosed. The Schottky diode has an N-well or N-epitaxial layer with a first region, a second region substantially adjacent to an electron doped buried layer that has a donor electron concentration greater than that of the first region, and a third region substantially adjacent to the anode that has a donor electron concentration that is less than that of the first region. The second region may be doped with implanted phosphorus and the third region may be doped with implanted boron.
    Type: Application
    Filed: September 3, 2009
    Publication date: June 30, 2011
    Applicant: Monolithic Power Systems, Incc
    Inventors: Ji-Hyoung Yoo, Martin E. Garnett
  • Patent number: 7964930
    Abstract: A semiconductor device includes a trench MOS barrier Schottky diode having an integrated PN diode and a method is for manufacturing same.
    Type: Grant
    Filed: September 13, 2005
    Date of Patent: June 21, 2011
    Assignee: Robert Bosch GmbH
    Inventors: Alfred Goerlach, Ning Qu
  • Publication number: 20110133251
    Abstract: Some exemplary embodiments of a semiconductor device using a III-nitride heterojunction and a novel Schottky structure and related method resulting in such a semiconductor device, suitable for high voltage circuit designs, have been disclosed. One exemplary structure comprises a first layer comprising a first III-nitride material, a second layer comprising a second III-nitride material forming a heterojunction with said first layer to generate a two dimensional electron gas (2DEG) within said first layer, an anode comprising at least a first metal section forming a Schottky contact on a surface of said second layer, a cathode forming an ohmic contact on said surface of said second layer, a field dielectric layer on said surface of said second layer for isolating said anode and said cathode, and an insulating material on said surface of said second layer and in contact with said anode.
    Type: Application
    Filed: December 7, 2009
    Publication date: June 9, 2011
    Applicant: INTERNATIONAL RECTIFIER CORPORATION
    Inventor: Zhi He
  • Publication number: 20110108941
    Abstract: A fast recovery diode includes a base layer of a first conductivity type. The base layer has a cathode side and an anode side opposite the cathode side. An anode buffer layer of a second conductivity type having a first depth and a first maximum doping concentration is arranged on the anode side. An anode contact layer of the second conductivity type having a second depth, which is lower than the first depth, and a second maximum doping concentration, which is higher than the first maximum doping concentration, is also arranged on the anode side. A space charge region of the anode junction at a breakdown voltage is located in a third depth between the first and second depths. A defect layer with a defect peak is arranged between the second and third depths.
    Type: Application
    Filed: November 9, 2010
    Publication date: May 12, 2011
    Applicant: ABB Technology AG
    Inventors: Jan Vobecky, Arnost Kopta, Marta Cammarata
  • Publication number: 20110101369
    Abstract: This invention discloses a gallium nitride based semiconductor power device disposed in a semiconductor substrate. The power device comprises a termination area disposed at a peripheral area of the semiconductor power device comprises a termination structure having at least a guard ring disposed in a trench filled with doped gallium-based epitaxial layer therein.
    Type: Application
    Filed: October 30, 2009
    Publication date: May 5, 2011
    Inventor: Tinggang Zhu
  • Publication number: 20110101485
    Abstract: An apparatus comprises a substrate having a type of conductivity, an intrinsic region above the substrate, and a metal layer on a portion of the surface of the intrinsic region. The intrinsic region has a surface. The metal layer may have a thickness that is configured to allow a plurality of photons to pass through the metal layer into the intrinsic region and form a rectifying contact with the intrinsic region.
    Type: Application
    Filed: November 5, 2009
    Publication date: May 5, 2011
    Applicant: The Boeing Company
    Inventor: Eric Yuen-Jun Chan
  • Publication number: 20110095361
    Abstract: A semiconductor device formed on a semiconductor substrate may include a component formed in a contact trench located in an active cell region. The component may comprise a barrier metal deposited on a bottom and portions of sidewalls of the contact trench and a tungsten plug deposited in a remaining portion of the contact trench. The barrier metal may comprise first and second metal layers. The first metal layer may be proximate to the sidewall and the bottom of the contact trench. The first metal layer may include a nitride. The second metal layer may be between the first metal layer and the tungsten plug and between the tungsten plug and the sidewall. The second metal layer covers portions of the sidewalls of not covered by the first metal layer.
    Type: Application
    Filed: October 26, 2009
    Publication date: April 28, 2011
    Applicant: ALPHA & OMEGA SEMICONDUCTOR, INC.
    Inventors: Hong Chang, John Chen, Limin Weng, Wenjun Li
  • Publication number: 20110095391
    Abstract: A Schottky diode device is provided, including a p-type semiconductor structure. An n drift region is disposed over the p-type semiconductor structure, wherein the n drift region comprises first and second n-type doping regions having different n-type doping concentrations, and the second n-type doping region is formed with a dopant concentration greater than that in the first n-type doping region. A plurality of isolation structures is disposed in the second n-type doping region of the n drift region, defining an anode region and a cathode region. A third n-type doping region is disposed in the second n-type doping region exposed by the cathode region. An anode electrode is disposed over the first n-type doping region in the anode region. A cathode electrode is disposed over the third n-type doping region in the cathode region.
    Type: Application
    Filed: October 28, 2009
    Publication date: April 28, 2011
    Applicant: VANGUARD INTERNATIONAL SEMICONDUCTOR CORPORATION
    Inventors: Huang-Lang Pai, Hung-Shern Tsai
  • Publication number: 20110089516
    Abstract: Provided is a rectifier such as a detector in which a cutoff frequency may be increased in a view point different from the reduction in size of the structure. The rectifier includes: a Schottky barrier portion including a Schottky electrode; a barrier portion having a rectifying property with respect to a majority carrier in the Schottky barrier portion; and an ohmic electrode in electrical contact with the barrier portion having the rectifying property, in which each of the Schottky barrier portion and the barrier portion having the rectifying property has an asymmetrical band profile whose gradient on one side is larger than a gradient of another side, and the Schottky barrier portion and the barrier portion having the rectifying property are connected to each other so that the steep gradient side of the band profile is located on a side of the Schottky electrode.
    Type: Application
    Filed: July 27, 2009
    Publication date: April 21, 2011
    Applicant: CANON KABUSHIKI KAISHA
    Inventor: Ryota Sekiguchi
  • Patent number: 7915703
    Abstract: Fabrication of a Schottky diodes may include providing a Schottky contact layer containing a low barrier metal layer with spaced apart high barrier metal islands therein on a first surface of a substrate. A diode contact is formed on a second surface of the substrate that is opposite to the first surface. Formation of the Schottky contact layer may include providing a liquid mixture of a high barrier metal and a low barrier metal on the first surface of the substrate. Temperature and/or relative concentrations of the high and low barrier metals in the liquid mixture may be controlled to cause regions of the high barrier metal to solidify within the liquid mixture and agglomerate to form the spaced apart high barrier metal islands while inhibiting solidification of the low barrier metal. The temperature and relative concentrations may then be controlled to cause the low barrier metal to solidify and form the low barrier metal layer containing the high barrier metal islands.
    Type: Grant
    Filed: May 13, 2009
    Date of Patent: March 29, 2011
    Assignee: Cree, Inc.
    Inventors: Jason Patrick Henning, Allan Ward
  • Publication number: 20110057286
    Abstract: The present invention provides a semiconductor device including: a base substrate; a first semiconductor layer which is disposed on the base substrate and has a front surface and a rear surface opposite to the front surface; first ohmic electrodes disposed on the front surface of the first semiconductor layer; a second ohmic electrode disposed on the rear surface of the first semiconductor layer; a second semiconductor layer interposed between the first semiconductor layer and the first ohmic electrodes; and a Schottky electrode part which covers the first ohmic electrodes on the front surface of the first semiconductor layer.
    Type: Application
    Filed: January 8, 2010
    Publication date: March 10, 2011
    Applicant: SAMSUNG ELECTRO-MECHANICS CO., LTD.
    Inventors: Woo Chul Jeon, Jung Hee Lee, Young Hwan Park, Ki Yeol Park
  • Publication number: 20110049572
    Abstract: The present invention provides a semiconductor device including: a base substrate; a semiconductor layer which is disposed on the base substrate and has a 2-Dimensional Electron Gas (2DEG) formed therewithin; a first ohmic electrode disposed on a central region of the semiconductor layer; a second ohmic electrode which is formed on the edge regions of the semiconductor layer in such a manner to be disposed to be spaced apart from the first ohmic electrodes, and have a ring shape surrounding the first ohmic electrode; and a Schottky electrode part which is formed on the central region to cover the first ohmic electrode and is formed to be spaced apart from the second ohmic electrode.
    Type: Application
    Filed: January 8, 2010
    Publication date: March 3, 2011
    Applicant: SAMSUNG ELECTRO-MECHANICS CO., LTD.
    Inventors: Woo Chul Jeon, Jung Hee Lee, Young Hwan Park, Ki Yeol Park
  • Publication number: 20110042775
    Abstract: A method of producing a Schottky diode includes the steps of: forming a resist layer on the semiconductor substrate; performing a first exposure process on the resist layer; performing a first developing process for developing the resist layer to form a first Schottky diode having an excess region; performing a first cleaning process; performing a second exposure process on the first Schottky diode; performing a second developing process on the first Schottky diode to remove the excess region from the first Schottky diode so that a second Schottky diode corresponding to the specific Schottky diode is formed; and performing a second cleaning process.
    Type: Application
    Filed: August 20, 2010
    Publication date: February 24, 2011
    Inventors: Yuuki DOI, Hirokazu Fujimaki
  • Publication number: 20110037139
    Abstract: A merged PN/Schottky diode is provided having a substrate of a first conductivity type and a grid of doped wells of the second conductivity type embedded in the substrate. A Schottky barrier metal layer makes a Schottky barrier contact with the surface of the substrate above the grid. Selected embedded wells in the grid may make electrical contact to the Schottky bather metal layer, while most embedded wells do not. The diode forward voltage drop is reduced for the same diode area with reverse blocking benefits similar to a conventional JBS structure.
    Type: Application
    Filed: October 26, 2010
    Publication date: February 17, 2011
    Applicant: MICROSEMI CORPORATION
    Inventors: Feng Zhao, Bruce Odekirk, Dumitru Sdrulla
  • Publication number: 20110006307
    Abstract: A group III-nitride semiconductor Schottky diode comprises a conducting substrate having a first surface, a stack of multiple layers including a buffer layer and a semiconductor layer sequentially formed on the first surface, wherein the semiconductor layer comprises a group III nitride compound, a first electrode on the semiconductor layer, and a second electrode formed in contact with the first surface at a position adjacent to the stack of multiple layers. In other embodiments, the application also describes a method of fabricating the group III-nitride semiconductor Schottky diode.
    Type: Application
    Filed: July 1, 2010
    Publication date: January 13, 2011
    Applicant: TEKCORE CO., LTD.
    Inventors: Guan-Ting CHEN, Chia-Ming LEE
  • Publication number: 20110007546
    Abstract: An anti-parallel diode structure and method of fabrication is presently disclosed. In some embodiments, an anti-parallel diode structure has a semiconductor region comprising a first insulator layer disposed between a first semiconductor layer and a second semiconductor layer. The semiconductor region can be bound on a first side by a first metal material and bound on a second side by a second metal material so that current below a predetermined value is prevented from passing through the semiconductor region and current above the predetermined value passes through the semiconductor region.
    Type: Application
    Filed: July 13, 2009
    Publication date: January 13, 2011
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Nurul Amin, Insik Jin, Venugopalan Vaithyanathan, Wei Tian, YoungPil Kim
  • Publication number: 20100327288
    Abstract: A trench Schottky diode and its manufacturing method are provided. The trench Schottky diode includes a semiconductor substrate having therein a plurality of trenches, a gate oxide layer, a polysilicon structure, a guard ring and an electrode. At first, the trenches are formed in the semiconductor substrate by an etching step. Then, the gate oxide layer and the polysilicon structure are formed in the trenches and protrude above a surface of the semiconductor substrate. The guard ring is formed to cover a portion of the resultant structure. At last, the electrode is formed above the guard ring and the other portion not covered by the guard ring. The protruding gate oxide layer and the protruding polysilicon structure can avoid cracks occurring in the trench structure.
    Type: Application
    Filed: June 28, 2010
    Publication date: December 30, 2010
    Applicant: PFC DEVICE CORPORATION
    Inventors: Kou-Liang CHAO, Hung-Hsin Kuo, Tse-Chuan Su, Mei-Ling Chen
  • Publication number: 20100320557
    Abstract: Provided is a semiconductor device having an anode of a Si-FRD and a cathode of a Si-SBD which are serially connected. The Si-SBD has a junction capacitance whose amount of accumulable charge is equal to or more than an amount of charge occurring at the time of reverse recovery of the Si-FRD, and has a lower breakdown voltage than the Si-FRD does.
    Type: Application
    Filed: June 16, 2010
    Publication date: December 23, 2010
    Applicants: SANYO Electric Co., Ltd., SANYO Semiconductor Co., Ltd.
    Inventors: Seiji MIYOSHI, Testuya Okada, Shiho Arimoto
  • Publication number: 20100314708
    Abstract: A junction barrier Schottky diode has an N-type well having a surface and a first peak impurity concentration; a P-type anode region in the surface of the well, and having a second peak impurity concentration; an N-type cathode contact region in the surface of the well and laterally spaced from a first wall of the anode region, and having a third peak impurity concentration; and a first N-type region in the surface of the well and laterally spaced from a second wall of the anode region, and having a fourth impurity concentration. The center of the spaced region between the first N-type region and the second wall of the anode region has a fifth peak impurity concentration. An ohmic contact is made to the anode region and cathode contact region, and a Schottky contact is made to the first N-type region. The first and fifth peak impurity concentrations are less than the fourth peak impurity concentration, and the fourth peak impurity concentration is less that the second and third peak impurity concentrations.
    Type: Application
    Filed: August 25, 2010
    Publication date: December 16, 2010
    Applicant: Intersil Americas Inc.
    Inventors: Dev Alok Girdhar, Michael David Church
  • Publication number: 20100314707
    Abstract: Disclosed are semiconductor devices and methods of making semiconductor devices. An exemplary embodiment comprises a semiconductor layer of a first conductivity type having a first surface, a second surface, and a graded net doping concentration of the first conductivity type within a portion of the semiconductor layer. The graded portion is located adjacent to the top surface of the semiconductor layer, and the graded net doping concentration therein decreasing in value with distance from the top surface of the semiconductor layer. The exemplary device also comprises an electrode disposed at the first surface of the semiconductor layer and adjacent to the graded portion.
    Type: Application
    Filed: June 12, 2009
    Publication date: December 16, 2010
    Inventors: Joseph A. Yedinak, Mark L. Rinehimer, Thomas E. Grebs, John L. Benjamin
  • Patent number: 7851882
    Abstract: A silicon carbide semiconductor device includes a drift layer having first conductive type on a substrate, a cell region in the drift layer, a schottky electrode on the drift layer and multiple second conductive type layers in the cell region. The second conductive type layers are separated from each other and contact the schottky electrode. A size and an impurity concentration of the second conductive type layers and a size and an impurity concentration of a portion of the drift layer sandwiched between the second conductive type layers are determined so that a charge quantity of the second conductive type layers is equal to a charge quantity of the portion. Hereby, the pressure-proof JBS and low resistivity second conductive type layers arranged on a surface of the drift layer to provide a PN diode, can be obtained.
    Type: Grant
    Filed: July 1, 2008
    Date of Patent: December 14, 2010
    Assignee: DENSO CORPORATION
    Inventors: Eiichi Okuno, Takeo Yamamoto
  • Publication number: 20100308337
    Abstract: Hybrid semiconductor devices including a PIN diode portion and a Schottky diode portion are provided. The PIN diode portion is provided on a semiconductor substrate and has an anode contact on a first surface of the semiconductor substrate. The Schottky diode portion is also provided on the semiconductor substrate and includes a polysilicon layer on the semiconductor substrate and a ohmic contact on the polysilicon layer. Related Schottky diodes are also provided herein.
    Type: Application
    Filed: June 3, 2009
    Publication date: December 9, 2010
    Applicant: Cree, Inc.
    Inventors: Saptharishi Sriram, Qingchun Zhang
  • Patent number: 7838888
    Abstract: An SiC semiconductor device is provided, which comprises: a substrate made of silicon carbide and having a principal surface; a drift layer made of silicon carbide and disposed on the principal surface; an insulating layer disposed on the drift layer and including an opening; a Schottky electrode contacting with the drift layer through the opening; a termination structure disposed around an outer periphery of the opening; and second conductivity type layers disposed in a surface part of the drift layer, contacting the Schottky electrode, surrounded by the termination structure, and separated from one another. The second conductivity type layers include a center member and ring members. Each ring member surrounds the center member and is arranged substantially in a point symmetric manner with respect to the center member.
    Type: Grant
    Filed: March 25, 2008
    Date of Patent: November 23, 2010
    Assignee: DENSO CORPORATION
    Inventors: Takeo Yamamoto, Naohiro Suzuki, Eiichi Okuno
  • Publication number: 20100289109
    Abstract: Fabrication of a Schottky diodes may include providing a Schottky contact layer containing a low barrier metal layer with spaced apart high barrier metal islands therein on a first surface of a substrate. A diode contact is formed on a second surface of the substrate that is opposite to the first surface. Formation of the Schottky contact layer may include providing a liquid mixture of a high barrier metal and a low barrier metal on the first surface of the substrate. Temperature and/or relative concentrations of the high and low barrier metals in the liquid mixture may be controlled to cause regions of the high barrier metal to solidify within the liquid mixture and agglomerate to form the spaced apart high barrier metal islands while inhibiting solidification of the low barrier metal. The temperature and relative concentrations may then be controlled to cause the low barrier metal to solidify and form the low barrier metal layer containing the high barrier metal islands.
    Type: Application
    Filed: May 13, 2009
    Publication date: November 18, 2010
    Inventors: Jason Patrick Henning, Allan Ward
  • Publication number: 20100283115
    Abstract: In the diffusion region (3) of the second conductivity mode, a more highly doped region of the same conductivity mode (5) is introduced in such a manner that the region of the first conductivity mode (2) which is covered by the metal silicide (9) and of the second conductivity mode (3) are connected in a conductive manner. The region (3) of the second conductivity mode is diffused in such a manner that it reaches the more highly doped region (1) of the first doping type (1), with an outward diffusion of the doping from the more highly doped substrate layer (1) into the more weakly doped layer (2) of the same conductivity mode in the direction of the semiconductor surface taking place at the same time.
    Type: Application
    Filed: April 19, 2010
    Publication date: November 11, 2010
    Applicant: ERIS TECHNOLOGY CORPORATION
    Inventors: Michael Reschke, Hans-Jürgen Hillemann, Klaus Günther
  • Patent number: 7829970
    Abstract: A junction barrier Schottky diode has an N-type well having surface and a first impurity concentration; a p-type anode region in the surface of the well, and having a second impurity concentration; and an N-type cathode region in the surface of the well and horizontally abutting the anode region, and having a third impurity concentration. A first N-type region vertically abuts the anode and cathode regions, and has a fourth impurity concentration. An ohmic contact is made to the anode and a Schottky contact is made to the cathode. The fourth impurity concentration is less than the first, second and third impurity concentrations.
    Type: Grant
    Filed: April 22, 2008
    Date of Patent: November 9, 2010
    Assignee: Intersil Americas Inc.
    Inventors: Dev Alok Girdhar, Michael David Church
  • Publication number: 20100258897
    Abstract: A method for manufacturing a Schottky diode comprising steps of 1) providing a region with a dopant of a second conductivity type opposite to a first conductivity type to form a top doped region in a semiconductor substrate of said first conductivity type; 2) providing a trench through the top doped region to a predetermined depth and providing a dopant of the second conductivity type to form a bottom dopant region of the second conductivity type; and 3) lining a Schottky barrier metal layer on a sidewall of the trench at least extending from a bottom of the top doped region to a top of the bottom doped region.
    Type: Application
    Filed: June 14, 2010
    Publication date: October 14, 2010
    Inventors: Sik K. Lui, Anup Bhalla
  • Publication number: 20100258899
    Abstract: A Schottky diode device includes a silicon substrate, an epitaxial silicon layer on the silicon substrate, an annular trench in a scribe line region that encompasses the epitaxial silicon layer, an insulation layer on interior sidewall of the annular trench, a silicide layer on the epitaxial silicon layer, a conductive layer on the silicide layer, and a guard ring in the epitaxial silicon layer, wherein the guard ring butts the insulation layer.
    Type: Application
    Filed: April 8, 2009
    Publication date: October 14, 2010
    Inventors: Chih-Tsung Huang, Jhih-Siang Huang
  • Patent number: 7808069
    Abstract: A high-voltage Schottky diode including a deep P-well having a first width is formed on the semiconductor substrate. A doped P-well is disposed over the deep P-well and has a second width that is less than the width of the deep P-well. An M-type guard ring is formed around the upper surface of the second doped well, A Schottky metal is disposed on an upper surface of the second doped well and the N-type guard ring.
    Type: Grant
    Filed: December 31, 2008
    Date of Patent: October 5, 2010
    Assignee: Taiwan Semiconductor Manufacturing Co., Ltd.
    Inventors: Dah-Chuen Ho, Chien-Shao Tang, Yu-Chang Jong, Zhe-Yi Wang
  • Publication number: 20100244089
    Abstract: High-side and low-side surface voltage sustaining regions is produced by utilizing optimum surface variation lateral doping. Schottky junctions are formed by depositing metal M on an n-type region having the lowest potential, taking M as the anode AL or AH of the Schottky diode, and ohmic contact is formed at the portion having the highest potential, which is taken as the cathode KL or KH of the Schottky diode. Where said potentials refer to a reverse bias is applied to the Schottky diode. A small isolation region is formed between two surface voltage sustaining regions. Each voltage sustaining region can be divided into several sections. Isolation region are inserted between neighbouring sections. A Schottky diode is formed in each section. Schottky diode of each section is connected to each other in series. A lateral Schottky diode and an n-MOST can be formed within a single voltage sustaining region.
    Type: Application
    Filed: August 6, 2009
    Publication date: September 30, 2010
    Inventor: Xingbi Chen
  • Publication number: 20100230774
    Abstract: A Schottky or PN diode is formed where a first cathode portion is an N epitaxial layer that is relatively lightly doped. An N+ buried layer is formed beneath the cathode for conducting the cathode current to a cathode contact. A more highly doped N-well is formed, as a second cathode portion, in the epitaxial layer so that the complete cathode comprises the N-well surrounded by the more lightly doped first cathode portion. An anode covers the upper areas of the first and second cathode portions so both portions conduct current when the diode is forward biased. When the diode is reverse biased, the depletion region in the central N-well will be relatively shallow but substantially planar so will have a relatively high breakdown voltage. The weak link for breakdown voltage will be the curved edge of the deeper depletion region in the lightly doped first cathode portion under the outer edges of the anode. Therefore, the N-well lowers the on-resistance without lowering the breakdown voltage.
    Type: Application
    Filed: March 10, 2009
    Publication date: September 16, 2010
    Applicant: MICREL, INC.
    Inventor: Martin Alter
  • Publication number: 20100224952
    Abstract: A Schottky barrier diode includes an epitaxial growth layer disposed on a substrate and having a mesa portion, and a Schottky electrode disposed on the mesa portion, wherein a distance between an edge of the Schottky electrode and a top surface edge of the mesa portion is 2 ?m or less. Since the distance x is 2 ?m or less, a leakage current is significantly decreased, a breakdown voltage is improved, and a Schottky barrier diode having excellent reverse breakdown voltage characteristics is provide.
    Type: Application
    Filed: March 19, 2008
    Publication date: September 9, 2010
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Tomihito Miyazaki, Makoto Kiyama
  • Patent number: 7781859
    Abstract: An integrated circuit structure includes a semiconductor substrate; a well region of a first conductivity type over the semiconductor substrate; a metal-containing layer on the well region, wherein the metal-containing layer and the well region form a Schottky barrier; an isolation region encircling the metal-containing layer; and a deep-well region of a second conductivity type opposite the first conductivity type under the metal-containing layer. The deep-well region has at least a portion vertically overlapping a portion of the metal-containing layer. The deep-well region is vertically spaced apart from the isolation region and the metal-containing layer by the well region.
    Type: Grant
    Filed: March 24, 2008
    Date of Patent: August 24, 2010
    Assignee: Taiwan Semiconductor Manufacturing Company, Ltd.
    Inventors: Puo-Yu Chiang, Tsai Chun Lin, Chih-Wen (Albert) Yao, David Ho