To Compound Semiconductor Patents (Class 257/472)
  • Publication number: 20100207166
    Abstract: A gallium nitride based semiconductor diode includes a substrate, a GaN layer formed on the substrate, an AlGaN layer formed on the GaN layer where the GaN layer and the AlGaN layer forms a cathode region of the diode, a metal layer formed on the AlGaN layer forming a Schottky junction therewith where the metal layer forms an anode electrode of the diode, and a high barrier region formed in the top surface of the AlGaN layer and positioned under an edge of the metal layer. The high barrier region has a higher bandgap energy than the AlGaN layer or being more resistive than the AlGaN layer.
    Type: Application
    Filed: February 18, 2009
    Publication date: August 19, 2010
    Applicant: Alpha & Omega Semiconductor, Inc.
    Inventor: TingGang Zhu
  • 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: 7768092
    Abstract: A semiconductor device comprises a first layer (1) of a wide band gap semiconductor material doped according to a first conductivity type and a second layer (3) on top thereof designed to form a junction blocking current in the reverse biased state of the device at the interface to said first layer. The device comprises extension means for extending a termination of the junction laterally with respect to the lateral border (6) of the second layer. This extension means comprises a plurality of rings (16-21) in juxtaposition laterally surrounding said junction (15) and being arranged as seen in the lateral direction away from said junction alternatively a ring (16-18) of a semiconductor material of a second conductivity type opposite to that of said first layer and a ring (19-21) of a semi-insulating material.
    Type: Grant
    Filed: July 20, 2005
    Date of Patent: August 3, 2010
    Assignee: Cree Sweden AB
    Inventors: Christopher Harris, Cem Basceri
  • Publication number: 20100176478
    Abstract: Provided are a novel method and a novel structure for bringing a Ge or SiGe compound and a metal into ohmic contact with each other. A semiconductor device is provided with a portion composed of only i) Ge or SiGe compound, ii) a metal, and iii) an insulator or a semiconductor arranged between the material i) and the metal ii). In the semiconductor device, A) the material i) and the metal ii) have Schottky junction in the case where the holes of the material i) are majority carriers, and/or B) the material i) and the metal ii) are in an ohmic contact when the electrons of the material i) are majority carriers.
    Type: Application
    Filed: September 1, 2008
    Publication date: July 15, 2010
    Applicant: THE UNIVERSITY OF TOKYO
    Inventors: Akira Toriumi, Tomonori Nishimura
  • Patent number: 7737522
    Abstract: A Schottky diode includes at least a trenched opened in a semiconductor substrate doped with a dopant of a first conductivity type wherein the trench is filled with a Schottky junction barrier metal. The Schottky diode further includes one or more dopant region of a second conductivity type surrounding sidewalls of the trench distributed along the depth of the trench for shielding a reverse leakage current through the sidewalls of the trench. The Schottky diode further includes a bottom-doped region of the second conductivity type surrounding a bottom surface of the trench and a top-doped region of the second conductivity type surrounding a top portion of the sidewalls of the trench. In a preferred embodiment, the first conductivity type is a N-type conductivity type and the middle-depth dopant region comprising a P-dopant region.
    Type: Grant
    Filed: September 30, 2006
    Date of Patent: June 15, 2010
    Assignee: Alpha & Omega Semiconductor, Ltd.
    Inventors: Sik K Lui, Anup Bhalla
  • Patent number: 7732887
    Abstract: A Schottky junction diode device having improved performance is fabricated in a conventional CMOS process. A substrate including a material doped to a first conductivity type is formed. A first well is disposed over the substrate. The first well includes a material doped to a second conductivity type opposite that of the first conductivity type. A region of metal-containing material is disposed over the first well to form a Schottky junction at an interface between the region of metal-containing material and the first well. In one embodiment, a first well contact is disposed in a portion of the first well. A second well is disposed over the substrate wherein the second well includes a material doped to the first conductivity type. In one embodiment, the first well and the second well are not in direct contact with one another.
    Type: Grant
    Filed: March 22, 2006
    Date of Patent: June 8, 2010
    Assignee: Virage Logic Corporation
    Inventors: Yanjun Ma, Ronald A. Oliver, Todd E. Humes, Jaideep Mavoori
  • Patent number: 7728403
    Abstract: A semiconductor device of unipolar type has Schottky-contacts (6) laterally separated by regions in the form of additional layers (7, 7?) of semiconductor material on top of a drift layer (3). Said additional layers being doped according to a conductivity type being opposite to the one of the drift layer. At least one (7?) of the additional layers has a substantially larger lateral extension and thereby larger area of the interface to the drift layer than adjacent such layers (7) for facilitating the building-up of a sufficient voltage between that layer and the drift layer for injecting minority charge carriers into the drift layer upon surge for surge protection.
    Type: Grant
    Filed: May 31, 2006
    Date of Patent: June 1, 2010
    Assignee: Cree Sweden AB
    Inventors: Christopher Harris, Cem Basceri, Kent Bertilsson
  • Patent number: 7692222
    Abstract: A semiconductor structure and method wherein a recess is disposed in a surface portion of a semiconductor structure and a dielectric film is disposed on and in contract with the semiconductor. The dielectric film has an aperture therein. Portions of the dielectric film are disposed adjacent to the aperture and overhang underlying portions of the recess. An electric contact has first portions thereof disposed on said adjacent portions of the dielectric film, second portions disposed on said underlying portions of the recess, with portions of the dielectric film being disposed between said first portion of the electric contact and the second portions of the electric contact, and third portions of the electric contact being disposed on and in contact with a bottom portion of the recess in the semiconductor structure. The electric contact is formed by atomic layer deposition of an electrically conductive material over the dielectric film and through the aperture in such dielectric film.
    Type: Grant
    Filed: November 7, 2006
    Date of Patent: April 6, 2010
    Assignee: Raytheon Company
    Inventors: Kamal Tabatabaie, Robert B. Hallock
  • Patent number: 7679104
    Abstract: A vertical semiconductor element comprises: an electro-conductive substrate; a GaN layer, as a nitride compound semiconductor layer, which is selectively grown as a convex shape on one surface of the electro-conductive substrate through a buffer layer; a source electrode as a first electrode formed on the GaN layer; and a drain electrode as a second electrode formed on another surface of the electro-conductive substrate.
    Type: Grant
    Filed: November 8, 2007
    Date of Patent: March 16, 2010
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Yoshihiro Sato, Sadahiro Kato, Masayuki Iwami, Hitoshi Sasaki, Shinya Ootomo, Yuki Niiyama
  • Publication number: 20100059761
    Abstract: A Schottky barrier diode includes a GaN freestanding substrate having a front surface, a GaN epitaxial layer deposited on the front surface, and an insulation layer deposited on the GaN epitaxial layer at a front surface and having an opening. Furthermore, the Schottky barrier diode also includes an electrode. The electrode is configured by a Schottky electrode provided in the opening in contact with the GaN epitaxial layer, and a field plate electrode connected to the Schottky electrode and also overlapping the insulation layer. The GaN freestanding substrate has a dislocation density of at most 1×108 cm?2.
    Type: Application
    Filed: August 22, 2008
    Publication date: March 11, 2010
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Taku Horii, Tomihito Miyazaki, Makoto Kiyama
  • Patent number: 7622080
    Abstract: A hydrogen gas sensitive semiconductor sensor including a catalytic metal layer, a semiconductor layer and an insulator layer arranged between the catalytic metal layer and the semiconductor layer. The catalytic metal layer includes an outer surface and an inner surface including at least one hydrogen atom adsorption surface portion. Each hydrogen atom adsorption surface portion is arranged adjacent to the insulator layer. The surface area of the outer surface is at least 100% larger than the total surface area of all of the at least one hydrogen atom adsorption surface portion. A probe includes the sensor, A hydrogen gas detection system includes the sensor. Use of the sensor for detection of presence of and/or measurement of concentration of hydrogen gas in a gas sample.
    Type: Grant
    Filed: September 21, 2006
    Date of Patent: November 24, 2009
    Assignee: Adixen Sensistor AB
    Inventor: Fredrik Enquist
  • Patent number: 7612426
    Abstract: A Schottky barrier diode includes a first semiconductor layer and a second semiconductor layer successively formed above a semiconductor substrate with a buffer layer formed between the first and second semiconductor layers and the semiconductor substrate. A Schottky electrode and an ohmic electrode spaced from each other are formed on the second semiconductor layer, and a back face electrode is formed on the back face of the semiconductor substrate. The Schottky electrode or the ohmic electrode is electrically connected to the back face electrode through a via penetrating through at least the buffer layer.
    Type: Grant
    Filed: November 15, 2005
    Date of Patent: November 3, 2009
    Assignee: Panasonic Corporation
    Inventors: Manabu Yanagihara, Yasuhiro Uemoto, Tsuyoshi Tanaka, Daisuke Ueda
  • Publication number: 20090267082
    Abstract: A semiconductor device includes: a semiconductor element having a first surface and a second surface; a first electrode disposed on the first surface of the element; a second electrode disposed on the second surface of the element; and an insulation film covers a part of the first electrode, the first surface of the element and a part of a sidewall of the element. The above semiconductor device has small dimensions and a high breakdown voltage.
    Type: Application
    Filed: April 14, 2009
    Publication date: October 29, 2009
    Applicant: DENSO CORPORATION
    Inventors: Takeo Yamamoto, Takeshi Endo, Eiichi Okuno, Masaki Konishi, Hirokazu Fujiwara
  • Patent number: 7605441
    Abstract: A semiconductor device includes: a semiconductor layer made of a group-III nitride semiconductor and having a first surface and a second surface opposed to the first surface; a Schottky electrode formed on the first surface of the semiconductor layer; and an ohmic electrode electrically connected to the second surface of the semiconductor layer. The semiconductor layer has, in at least the upper portion thereof, highly-resistive regions selectively formed to have a high resistance.
    Type: Grant
    Filed: April 2, 2007
    Date of Patent: October 20, 2009
    Assignee: Panasonic Corporation
    Inventors: Kazushi Nakazawa, Hiroaki Ueno, Manabu Yanagihara, Yasuhiro Uemoto, Tsuyoshi Tanaka
  • Patent number: 7531889
    Abstract: In a Schottky diode 11, a gallium nitride support base 13 includes a first surface 13a and a second surface 13b opposite from the first surface and has a carrier concentration exceeding 1×1018 cm?3. A gallium nitride epitaxial layer 15 is disposed on the first surface 13a. An Ohmic electrode 17 is disposed on the second surface 13b. The Schottky electrode 19 is disposed on the gallium nitride epitaxial layer 15. A thickness D1 of the gallium nitride epitaxial layer 15 is at least 5 microns and no more than 1000 microns. Also, the carrier density of the gallium nitride epitaxial layer 15 is at least 1×1014 cm?3 and no more than 1×1017 cm?3.
    Type: Grant
    Filed: September 1, 2005
    Date of Patent: May 12, 2009
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Makoto Kiyama, Takuji Okahisa, Takashi Sakurada
  • Patent number: 7525186
    Abstract: A stack package comprises a substrate having a circuit pattern; at least two semiconductor chips stacked on the substrate, having a plurality of through-via interconnection plugs and a plurality of guard rings which surround the respective through-via interconnection plugs, and connected with each other by the medium of the through-via interconnection plugs; a molding material for molding an upper surface of the substrate including the stacked semiconductor chips; and solder balls mounted to a lower surface of the substrate.
    Type: Grant
    Filed: December 29, 2006
    Date of Patent: April 28, 2009
    Assignee: Hynix Semiconductor Inc.
    Inventors: Sung Min Kim, Min Suk Suh
  • Publication number: 20090039456
    Abstract: This invention discloses bottom-anode Schottky (BAS) device supported on a semiconductor substrate having a bottom surface functioning as an anode electrode with an epitaxial layer has a same doped conductivity as said anode electrode overlying the anode electrode. The BAS device further includes an Schottky contact metal disposed in a plurality of trenches and covering a top surface of the semiconductor substrate between the trenches. The BAS device further includes a plurality of doped JBS regions disposed on sidewalls and below a bottom surface of the trenches doped with an opposite conductivity type from the anode electrode constituting a junction barrier Schottky (JBS) with the epitaxial layer disposed between the plurality of doped JBS regions. The BAS device further includes an ultra-shallow Shannon implant layer disposed immediate below the Schottky contact metal in the epitaxial layer between the plurality of doped JBS regions.
    Type: Application
    Filed: August 8, 2007
    Publication date: February 12, 2009
    Inventors: Anup Bhalla, Sik K. Lui, Yi Su
  • Patent number: 7485512
    Abstract: A method of compensating resistivity of a near-surface region of a substrate includes epitaxially growing a buffer layer on the substrate, wherein the buffer is grown as having a dopant concentration as dependent on resistivity and conductivity of the substrate, so as to deplete residual or excess charge within the near-surface region of the substrate. The dopant profile of the buffer layer be smoothly graded, or may consist of sub-layers of different dopant concentration, to also provide a highly resistive upper portion of the buffer layer ideal for subsequent device growth. Also, the buffer layer may be doped with carbon, and aluminum may be used to getter the carbon during epitaxial growth.
    Type: Grant
    Filed: June 26, 2006
    Date of Patent: February 3, 2009
    Assignee: Cree, Inc.
    Inventors: Christopher Harris, Thomas Gehrke, T. Warren Weeks, Jr., Cem Basceri, Elif Berkman
  • Patent number: 7476956
    Abstract: New Group III based diodes are disclosed having a low on state voltage (Vf) and structures to keep reverse current (Irev) relatively low. One embodiment of the invention is Schottky barrier diode made from the GaN material system in which the Fermi level (or surface potential) of is not pinned. The barrier potential at the metal-to-semiconductor junction varies depending on the type of metal used and using particular metals lowers the diode's Schottky barrier potential and results in a Vf in the range of 0.1-0.3V. In another embodiment a trench structure is formed on the Schottky diodes semiconductor material to reduce reverse leakage current. and comprises a number of parallel, equally spaced trenches with mesa regions between adjacent trenches. A third embodiment of the invention provides a GaN tunnel diode with a low Vf resulting from the tunneling of electrons through the barrier potential, instead of over it. This embodiment can also have a trench structure to reduce reverse leakage current.
    Type: Grant
    Filed: May 20, 2003
    Date of Patent: January 13, 2009
    Assignee: Cree, Inc.
    Inventors: Primit Parikh, Umesh Mishra
  • Patent number: 7473929
    Abstract: Ion implantation is carried out to form a p-well region and a source region in parts of a high resistance SiC layer on a SiC substrate, and a carbon film is deposited over the substrate. With the carbon film deposited over the substrate, annealing for activating the implanted dopant ions is performed, and then the carbon film is removed. Thus, a smooth surface having hardly any surface roughness caused by the annealing is obtained. Furthermore, if a channel layer is epitaxially grown, the surface roughness of the channel layer is smaller than that of the underlying layer. Since the channel layer having a smooth surface is provided, it is possible to obtain a MISFET with a high current drive capability.
    Type: Grant
    Filed: July 1, 2004
    Date of Patent: January 6, 2009
    Assignee: Panasonic Corporation
    Inventors: Osamu Kusumoto, Makoto Kitabatake, Masao Uchida, Kunimasa Takahashi, Kenya Yamashita, Masahiro Hagio, Kazuyuki Sawada
  • Patent number: 7470940
    Abstract: An UV detector, comprising: a sapphire substrate; a high temperature AlN buffer layer grown on the sapphire substrate; an intermediate temperature GaN buffer layer grown on the high temperature AlN buffer layer; a GaN epitaxial layer deposited on the intermediate temperature GaN buffer layer; a Schottky junction formed on top of the GaN epitaxial layer; and a plurality of ohmic contacts also formed on top of the GaN epitaxial layer, wherein, the high temperature AlN buffer layer and the intermediate temperature GaN buffer layer together form a double buffer layer structure so as to improve the reliability and radiation hardness of the UV detector; and wherein the high temperature AlN buffer layer and the intermediate temperature GaN buffer layer are formed by RF-plasma enhanced MBE growth technology.
    Type: Grant
    Filed: April 14, 2006
    Date of Patent: December 30, 2008
    Assignee: The Hong Kong Polytechnic University
    Inventors: Charles Surya, Patrick Wai-Keung Fong
  • Patent number: 7453133
    Abstract: A preferred embodiment of the present invention comprises a dielectric/metal/2nd energy bandgap (Eg) semiconductor/1st Eg substrate structure. In order to reduce the contact resistance, a semiconductor with a lower energy bandgap (2nd Eg) is put in contact with metal. The energy bandgap of the 2nd Eg semiconductor is lower than the energy bandgap of the 1st Eg semiconductor and preferably lower than 1.1eV. In addition, a layer of dielectric may be deposited on the metal. The dielectric layer has built-in stress to compensate for the stress in the metal, 2nd Eg semiconductor and 1st Eg substrate. A process of making the structure is also disclosed.
    Type: Grant
    Filed: June 30, 2004
    Date of Patent: November 18, 2008
    Assignee: Taiwan Semiconductor Manufacturing Company, Ltd.
    Inventors: Wen-Chin Lee, Chung-Hu Ge, Chenming Hu
  • Publication number: 20080251801
    Abstract: There are provided a method of producing a group III-V compound semiconductor, a Schottky barrier diode, a light emitting diode, a laser diode and methods of fabricating the diodes, that can achieve a reduced n type carrier density. The method of producing a group III-V compound semiconductor is a method of producing the compound semiconductor by metal organic chemical vapor deposition employing a material containing a group III element. Initially the step of preparing a seed substrate is performed. Then the step of growing a group III-V compound semiconductor on the seed substrate is performed by employing as a group III element-containing material an organic metal containing at most 0.01 ppm of silicon, at most 10 ppm of oxygen and less than 0.04 ppm of germanium.
    Type: Application
    Filed: March 12, 2008
    Publication date: October 16, 2008
    Applicant: Sumitomo Electric Industries, Ltd.
    Inventors: Masaki UENO, Yu Saitoh
  • Publication number: 20080251793
    Abstract: A junction barrier Schottky (JBS) rectifier device and a method of making the device are described. The device comprises an epitaxially grown first n-type drift layer and p-type regions forming p+-n junctions and self-planarizing epitaxially over-grown second n-type drift regions between and, optionally, on top of the p-type regions. The device may include an edge termination structure such as an exposed or buried P+ guard ring, a regrown or implanted junction termination extension (JTE) region, or a “deep” mesa etched down to the substrate. The Schottky contact to the second n-type drift region and the ohmic contact to the p-type region together serve as an anode. The cathode can be formed by ohmic contact to the n-type region on the backside of the wafer. The devices can be used in monolithic digital, analog, and microwave integrated circuits.
    Type: Application
    Filed: June 26, 2008
    Publication date: October 16, 2008
    Applicant: SemiSouth Laboratories, Inc.
    Inventors: Michael S. MAZZOLA, Lin CHENG
  • Patent number: 7436039
    Abstract: A gallium nitride based semiconductor Schottky diode fabricated from a n+ doped GaN layer having a thickness between one and six microns disposed on a sapphire substrate; an n? doped GaN layer having a thickness greater than one micron disposed on said n+ GaN layer patterned into a plurality of elongated fingers and a metal layer disposed on the n? doped GaN layer and forming a Schottky junction therewith. The layer thicknesses and the length and width of the elongated fingers are optimized to achieve a device with breakdown voltage of greater than 500 volts, current capacity in excess of one ampere, and a forward voltage of less than three volts.
    Type: Grant
    Filed: January 6, 2005
    Date of Patent: October 14, 2008
    Assignee: Velox Semiconductor Corporation
    Inventors: TingGang Zhu, Bryan S. Shelton, Marek K. Pabisz, Mark Gottfried, Linlin Liu, Milan Pophristic, Michael Murphy, Richard A. Stall
  • Publication number: 20080179703
    Abstract: The structure for millimeter-wave frequency applications, includes a Schottky barrier diode (SBD) with a cutoff frequency (FC) above 1.0 THz formed on a SiGe BiCMOS wafer. A method is also contemplated for forming a Schottky barrier diode on a SiGe BiCMOS wafer, including forming a structure which provides a cutoff frequency (Fc) above about 1.0 THz. In embodiments, the structure which provides a cutoff frequency (Fc) above about 1.0 THz may include an anode having an anode area which provides a cutoff frequency (FC) above about 1.0 THz, an n-epitaxial layer having a thickness which provides a cutoff frequency (FC) above about 1.0 THz, a p-type guardring at an energy and dosage which provides a cutoff frequency (FC) above about 1.0 THz, the p-type guardring having a dimension which provides a cutoff frequency (FC) above about 1.0 THz, and a well tailor with an n-type dopant which provides a cutoff frequency (FC) above about 1.0 THz.
    Type: Application
    Filed: September 12, 2007
    Publication date: July 31, 2008
    Inventors: Jeffrey B. Johnson, Xuefeng Liu, Bradley A. Orner, Robert M. Rassel
  • Patent number: 7391058
    Abstract: A composite structure having a silicon carbide epitaxial layer is provided. The epitaxial layer includes at least four regions arranged vertically and defining respective interfaces, where each of the regions is characterized by a respective impurity concentration, where the impurity concentrations vary across each of the interfaces, and where each of the impurity concentrations exceeds 1×1017 cm?3 for at least one single impurity in all of the regions.
    Type: Grant
    Filed: June 27, 2005
    Date of Patent: June 24, 2008
    Assignee: General Electric Company
    Inventors: Larry Burton Rowland, Ahmed Elasser
  • Patent number: 7375407
    Abstract: A Schottky barrier diode includes a first semiconductor layer and a second semiconductor layer successively formed above a substrate; and a high-resistance region formed in the first semiconductor layer and the second semiconductor layer and having higher resistance than the first semiconductor layer and the second semiconductor layer. A Schottky electrode and an ohmic electrode spaced from each other are formed on the second semiconductor layer in a portion surrounded with the high-resistance region.
    Type: Grant
    Filed: November 14, 2005
    Date of Patent: May 20, 2008
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Manabu Yanagihara, Yasuhiro Uemoto, Tsuyoshi Tanaka, Daisuke Ueda
  • Patent number: 7304330
    Abstract: A nitride semiconductor device, which includes a III-V Group nitride semiconductor layer being composed of a III Group element consisting of at least one of a group containing of gallium, aluminum, boron and indium and V Group element consisting of at least nitrogen among a group consisting of nitrogen, phosphorus and arsenic, including a first nitride semiconductor layer including the III-V Group nitride semiconductor layer being deposited on a substrate, a second nitride semiconductor layer including the III-V Group nitride semiconductor layer being deposited on the first nitride semiconductor and not containing aluminum and a control electrode making Schottky contact with the second nitride semiconductor layer wherein the second nitride semiconductor layer includes a film whose film forming temperature is lower than the first nitride semiconductor layer.
    Type: Grant
    Filed: November 26, 2004
    Date of Patent: December 4, 2007
    Assignee: New Japan Radio Co., Ltd.
    Inventor: Atsushi Nakagawa
  • Patent number: 7294900
    Abstract: A pad electrode of a field effect transistor is formed solely of a pad metal layer without providing a gate metal layer. A high concentration impurity region is provided below the pad electrode, and the pad electrode is directly contacted to a substrate. Predetermined isolation is ensured by the high concentration impurity region. Accordingly, in a structure not requiring a nitride film as similar to the related art, it is possible to avoid defects upon wire boding attributing to hardening of the gate metal layer. Therefore, in the case of a buried gate electrode structure for enhancing characteristics of the field effect transistor, it is possible to enhance reliability and yields.
    Type: Grant
    Filed: June 13, 2005
    Date of Patent: November 13, 2007
    Assignee: Sanyo Electric Co., Ltd.
    Inventor: Tetsuro Asano
  • Patent number: 7274082
    Abstract: Electron-hole production at a Schottky barrier has recently been observed experimentally as a result of chemical processes. This conversion of chemical energy to electronic energy may serve as a basic link between chemistry and electronics and offers the potential for generation of unique electronic signatures for chemical reactions and the creation of a new class of solid state chemical sensors. Detention of the following chemical species was established: hydrogen, deuterium, carbon monoxide, and molecular oxygen. The detector (1b) consists of a Schottky diode between an Si layer and an ultrathin metal layer with zero force electrical contacts.
    Type: Grant
    Filed: April 29, 2005
    Date of Patent: September 25, 2007
    Assignee: Adrena, Inc.
    Inventors: Eric W. McFarland, W. Henry Weinberg, Hermann Nienhaus, Howard S. Bergh, Brian Gergen, Arunava Mujumdar
  • Patent number: 7268407
    Abstract: Provided are a Schottky barrier tunnel single electron transistor and a method of manufacturing the same that use a Schottky barrier formed between metal and semiconductor by replacing a source and a drain with silicide as a reactant of silicon and metal, instead of a conventional method of manufacturing a single electron transistor (SET) that includes source and drain regions by implanting dopants such that an artificial quantum dot is formed in a channel region. As a result, it does not require a conventional PADOX process to form a quantum dot for a single electron transistor (SET), height and width of a tunneling barrier can be artificially adjusted by using silicide materials that have various Schottky junction barriers, and it is possible to improve current driving capability of the single electron transistor (SET).
    Type: Grant
    Filed: August 3, 2005
    Date of Patent: September 11, 2007
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Moon Gyu Jang, Yark Yeon Kim, Jae Heon Shin, Seong Jae Lee
  • Patent number: 7193291
    Abstract: An organic Schottky diode includes a polycrystalline organic semiconductor layer with a rectifying contact on one side of the layer. An amorphous doped semiconductor layer is placed on the other side of the polycrystalline organic semiconductor layer, and it acts as a buffer between the semiconductor layer and an ohmic contact layer.
    Type: Grant
    Filed: March 25, 2004
    Date of Patent: March 20, 2007
    Assignee: 3M Innovative Properties Company
    Inventors: Tzu-Chen Lee, Michael A. Haase, Paul F. Baude
  • Patent number: 7141464
    Abstract: Provided is a method of fabricating a T-type gate including the steps of: forming a first photoresist layer, a blocking layer and a second photoresist layer to a predetermined thickness on a substrate, respectively; forming a body pattern of a T-type gate on the second photoresist layer and the blocking layer; exposing a predetermined portion of the second photoresist layer to form a head pattern of the T-type gate, and performing a heat treatment process to generate cross linking at a predetermined region of the second photoresist layer except for the head pattern of the T-type gate; performing an exposure process on an entire surface of the resultant structure, and then removing the exposed portion; and forming a metal layer of a predetermined thickness on an entire surface of the resultant structure, and then removing the first photoresist layer, the blocking layer, the predetermined region of the second photoresist layer in which the cross linking are generated, and the metal layer, whereby it is possible
    Type: Grant
    Filed: July 12, 2005
    Date of Patent: November 28, 2006
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Jong Moon Park, Kun Sik Park, Seong Wook Yoo, Yong Sun Yoon, Sang Gi Kim, Yoon Kyu Bae, Byung Won Lim, Jin Gun Koo, Bo Woo Kim
  • Patent number: 7105907
    Abstract: A buffer layer, an undoped gallium nitride layer, and an n-type gallium nitride active layer are formed on a sapphire substrate. Ohmic contacts and a Schottky contact are then formed on the n-type gallium nitride active layer as a source contact, a drain contact and a gate contact, respectively. The Schottky contact is a copper alloy, such as palladium copper, in which the content by weight of copper is 5%.
    Type: Grant
    Filed: June 3, 2003
    Date of Patent: September 12, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yoshito Ikeda, Kaoru Inoue, Yutaka Hirose, Katsunori Nishii
  • Patent number: 7078781
    Abstract: A high-breakdown-voltage semiconductor device includes a high-resistance semiconductor layer, first trenches formed on the surface thereof in a longitudinal plane shape and in parallel, a Schottky electrode formed thereon and sandwiched between adjacent first trenches, a first region having an opposite conductivity type to the semiconductor layer continuously disposed in a sidewall and a bottom of each of the first trenches, a sidewall insulating film disposed on the sidewall, a second region of the opposite conductivity type disposed in the bottom of each of the first trenches, a third region disposed on the opposite surface of the semiconductor layer, a control electrode filling each of the first trenches in contact with the second region and connected to the Schottky electrode, a backside electrode formed on the third region, wherein second trenches communicate with the first trenches at both ends of longitudinal sides thereof, and the Schottky electrode is surrounded by the first and second trenches.
    Type: Grant
    Filed: September 16, 2004
    Date of Patent: July 18, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tetsuo Hatakeyama, Takashi Shinohe
  • Patent number: 7071525
    Abstract: A Merged P-i-N Schottky device in which the oppositely doped diffusions extend to a depth and have been spaced apart such that the device is capable of absorbing a reverse avalanche energy comparable to a Fast Recovery Epitaxial Diode having a comparatively deeper oppositely doped diffusion region.
    Type: Grant
    Filed: January 27, 2004
    Date of Patent: July 4, 2006
    Assignee: International Rectifier Corporation
    Inventors: Davide Chiola, Kohji Andoh, Silvestro Fimiani
  • Patent number: 6995396
    Abstract: A SiC bulk substrate whose top face has been flattened is placed in a vertical thin film growth system to be annealed in an inert gas atmosphere. A material gas of Si is then supplied at a flow rate of 1 mL/min. at a substrate temperature of 1200° C. through 1600° C. Subsequently, the diluent gas is changed to a hydrogen gas at a temperature of 1600° C., and material gases of Si and carbon are supplied with nitrogen intermittently supplied, so as to deposit SiC thin films on the SiC bulk substrate. In a flat ?-doped multilayered structure thus formed, an average height of macro steps formed on the top face and on interfaces therein is 30 nm or less. When the resultant substrate is used, a semiconductor device with a high breakdown voltage and high mobility can be realized.
    Type: Grant
    Filed: October 24, 2002
    Date of Patent: February 7, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kunimasa Takahashi, Masao Uchida, Makoto Kitabatake, Toshiya Yokogawa, Osamu Kusumoto, Kenya Yamashita, Ryoko Miyanaga
  • Patent number: 6979863
    Abstract: Silicon carbide semiconductor devices and methods of fabricating silicon carbide semiconductor devices have a silicon carbide DMOSFET and an integral silicon carbide Schottky diode configured to at least partially bypass a built in diode of the DMOSFET. The Schottky diode may be a junction barrier Schottky diode and may have a turn-on voltage lower than a turn-on voltage of a built-in body diode of the DMOSFET. The Schottky diode may have an active area less than an active area of the DMOSFET.
    Type: Grant
    Filed: April 24, 2003
    Date of Patent: December 27, 2005
    Assignee: Cree, Inc.
    Inventor: Sei-Hyung Ryu
  • Patent number: 6969900
    Abstract: A semiconductor diode with hydrogen detection capability includes a semiconductor substrate, a doped semiconductor active layer formed on the substrate and made from a compound having the formula XYZ, in which X is a Group III element, Y is another Group III element different from X, and Z is a Group V element, a semiconductor contact-enhancing layer formed on the active layer and made from a compound having the formula MN, in which M is a Group III element, and N is a Group V element, an ohmic contact layer formed on the semiconductor contact-enhancing layer, and a Schottky barrier contact layer formed on the active layer. The Schottky barrier contact layer is made from a metal that is capable of dissociating a hydrogen molecule into hydrogen atoms.
    Type: Grant
    Filed: March 10, 2004
    Date of Patent: November 29, 2005
    Assignee: National Cheng Kung University
    Inventors: Wen-Chau Liu, Huey-Ing Chen, Kun-Wei Lin, Chun-Tsen Lu
  • Patent number: 6963121
    Abstract: A three-terminal semiconductor transistor device comprises a base region formed by a semiconductor material of a first conductivity type at a first concentration, the base region being in contact with a first electrical terminal via a semiconductor material of the second conductivity type at a second concentration, wherein the second concentration is lower than the first concentration. The three-terminal semiconductor transistor device also includes a conductive emitter region in contact with the semiconductor base region, forming a first Schottky barrier junction at the interface of the conductive emitter region and the semiconductor base region. The conductive emitter region is in contact with a second electrical terminal. The three-terminal semiconductor transistor device further includes a conductive collector region in contact with the semiconductor base region, which forms a second Schottky barrier junction at the interface of the conductive collector region and the semiconductor base region.
    Type: Grant
    Filed: February 18, 2004
    Date of Patent: November 8, 2005
    Inventor: Koucheng Wu
  • Patent number: 6956274
    Abstract: A metallization stack is provided for use as a contact structure in an integrated MEMS device. The metallization stack comprises a titanium-tungsten adhesion and barrier layer formed with a platinum layer formed on top. The platinum feature is formed by sputter etching the platinum in argon, followed by a wet etch in aqua regia using an oxide hardmask. Alternatively, the titanium-tungsten and platinum layers are deposited sequentially and patterned by a single plasma etch process with a photoresist mask.
    Type: Grant
    Filed: January 11, 2002
    Date of Patent: October 18, 2005
    Assignee: Analog Devices, Inc.
    Inventors: Susan A. Alie, Bruce K. Wachtmann, David S. Kneedler, Scott Limb, Kieran Nunan
  • Patent number: 6949401
    Abstract: A method for producing a semiconductor component with adjacent Schottky (5) and pn (9) junctions positions in a drift area (2, 10) of a semiconductor material. According to the method, a silicon carbide substrate doped with a first doping material of at least 1018 cm?3 is provided, and a silicon carbide layer with a second doping material of the same charge carrier type in the range of 1014 and 1017 cm?3 is homo-epitaxially deposited on the substrate. A third doping material with a complimentary charge carrier is inserted, and structured with the aid of a diffusion and/or ion implantation, on the silicon carbide layer surface that is arranged far from the substrate to form pn junctions. Subsequently the component is subjected to a first temperature treatment between 1400° C. and 1700° C. Following this temperature treatment, a first metal coating is deposited on the implanted surface in order to form a Schottky contact and then a second metal coating is deposited in order to form an ohmic contact.
    Type: Grant
    Filed: September 9, 2002
    Date of Patent: September 27, 2005
    Assignee: Daimler Chrysler AG
    Inventors: Nando Kaminski, Raban Held
  • Patent number: 6921957
    Abstract: A new low forward voltage drop Schottky barrier diode and its manufacturing method are provided. The method includes steps of providing a substrate, forming plural trenches on the substrate, and forming a metal layer on the substrate having plural trenches thereon to form a barrier metal layer between the substrate and the surface metal layer for forming the Schottky barrier diode.
    Type: Grant
    Filed: December 31, 2002
    Date of Patent: July 26, 2005
    Assignees: Pyramis Corporation, Delta Electronics, Inc.
    Inventors: Jun Zeng, Ming-Jiang Zhou, Tzong-Shiann Wu
  • Patent number: 6906350
    Abstract: The present invention provides a unit cell of a metal-semiconductor field-effect transistor (MESFET). The unit cell of the MESFET includes a delta doped silicon carbide MESFET having a source, a drain and a gate. The gate is situated between the source and the drain and extends into a doped channel layer of a first conductivity type. Regions of silicon carbide adjacent to the source and the drain extend between the source and the gate and the drain and the gate, respectively. The regions of silicon carbide have carrier concentrations that are greater than a carrier concentration of the doped channel layer and are spaced apart from the gate.
    Type: Grant
    Filed: October 24, 2001
    Date of Patent: June 14, 2005
    Assignee: Cree, Inc.
    Inventor: Saptharishi Sriram
  • Patent number: 6861723
    Abstract: The invention relates to a Schottky diode in which p-doped regions (4, 5) are incorporated in the Schottky contact area. At least one (5) of these regions (4, 5) has a greater minimum extent, in order to initiate a starting current.
    Type: Grant
    Filed: December 19, 2003
    Date of Patent: March 1, 2005
    Assignee: Infineon Technologies AG
    Inventor: Armin Willmeroth
  • Patent number: 6838744
    Abstract: A semiconductor device and a manufacturing method therefor are provided, the semiconductor device having a good reverse recovery characteristic, and having no reduction in breakdown voltage because no defect occurs in the upper main surface of a Si substrate even when wires are bonded onto an anode electrode. A semiconductor device includes a Si substrate including an N+ cathode layer and an N? layer. An impurity such as platinum whose barrier height is less than that of silicon is introduced into upper regions of the N? layer where P anode layers are not formed, thereby forming Schottky junction regions. A barrier metal is formed between the Si substrate and an anode electrode.
    Type: Grant
    Filed: October 18, 2002
    Date of Patent: January 4, 2005
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Hideki Takahashi, Shinji Aono
  • Patent number: 6831345
    Abstract: A high withstand voltage semicnductor device does not show any significant fall of its withstand voltage if the impurity concentration of the RESURF layer of a low impurity concentration semiconductor region thereof varies from the optimal level and/or influenced by the fixed electric charge.
    Type: Grant
    Filed: July 17, 2002
    Date of Patent: December 14, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kozo Kinoshita, Tetsuo Hatakeyama, Takashi Shinohe
  • Patent number: 6822307
    Abstract: A semiconductor triode comprises a gate electrode provided on a channel layer, wherein there is interposed an insulating metal oxide layer between a top surface of the channel layer and the gate electrode.
    Type: Grant
    Filed: December 26, 2000
    Date of Patent: November 23, 2004
    Assignee: Fujitsu Limited
    Inventors: Mizuhisa Nihei, Yuu Watanabe
  • Patent number: 6809352
    Abstract: The semiconductor device of the present invention includes: a gallium nitride (GaN) compound semiconductor layer; and a Schottky electrode formed on the GaN compound semiconductor layer, wherein the Schottky electrode contains silicon.
    Type: Grant
    Filed: December 27, 2002
    Date of Patent: October 26, 2004
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Katsunori Nishii, Yoshito Ikeda, Hiroyuki Masato, Kaoru Inoue