Patents Examined by Ramamohan Rao Paladugu
  • Patent number: 5484746
    Abstract: A process for forming a semiconductor thin film by forming an amorphous semiconductor film on a substrate having a surface comprising an amorphous insulating material and seed crystals arranged at desired positions, applying heat treatment on the amorphous semiconductor film and growing crystals by solid phase growth with the seed crystals as the origination points is characterized in that high frequency energies with different frequencies are supplied to a susceptor having the substrate mounted thereon and a target holder to irradiate the ions generated between the susceptor and the target holder to the substrate and remove the surface adherents on the substrate, and subsequently an amorphous semiconductor film is formed on the substrate within the same apparatus.
    Type: Grant
    Filed: July 5, 1994
    Date of Patent: January 16, 1996
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takeshi Ichikawa, Takao Yonehara
  • Patent number: 5482892
    Abstract: A phosphorus effusion cell for molecular beam epitaxy is disclosed. It consists of a vessel in which, by sublimation of red phosphorus, the vapor of this element is produced, the vessel being closed by means of a vacuum tight valve which regulates its flow. In the vessel, there are two zones having different temperatures, one of sublimation of red phosphorus and another of condensation and re-evaporation of white phosphorus, both zones being thermally insulated by means of reflecting screens which prevent the temperature of the heating resistance from having to reach temperatures above 350.degree. C. The valve, intermittent closing of which regulates the effusion of phosphorus vapor, is at a temperature slightly above that of the thermostated zone of condensation/re-evaporation of the white phosphorus. It finds applicable in the manufacture of semiconducting structures.
    Type: Grant
    Filed: March 15, 1995
    Date of Patent: January 9, 1996
    Assignee: Riber S.A.
    Inventor: Fernando F. Briones
  • Patent number: 5482890
    Abstract: A method of fabricating quantum dot structures and devices including the steps of: (i) forming a quantum well membrane on a substrate; (ii) on the quantum well membrane forming a masking layer including a plurality of dot-shaped mask regions which protect the underlying quantum well membrane; (iii) using thermal etching to evaporate portions of the quantum well membrane that are not protected by the dotted mask regions of the masking layer so as to form a plurality of quantum dots; and (iv) after thermal etching, covering the plurality of quantum dots with a layer of material having an energy gap that is greater than the energy gap of the quantum well membrane. The quantum dot produced by this invention is found to generate ten times more illumination than the prior art when measured by photoluminescence.
    Type: Grant
    Filed: October 14, 1994
    Date of Patent: January 9, 1996
    Assignee: National Science Council
    Inventors: Der-Cherng Liu, Chien-Ping Lee
  • Patent number: 5478400
    Abstract: A beam generating apparatus disposed in a vacuum processing chamber for processing a substrate for emitting activated beams into the processing chamber comprises a beam generating cell for generating the activated beams, the beam generating cell having a speculum contact surface, a gas introduction member for introducing gas into the beam generating cell, the gas introduction member having a speculum contact surface, a bellows members connected to the gas introduction member, for pressing the contact surface of the gas introduction member against the contact surface of the beam generating cell so as to vacuum-seal a contact between the beam generating cell and the gas introduction member. At this contact both members are pressed against each other by the resiliency of the bellows, and accordingly higher air-tightness can be provided. A method for fabricating a semiconductor device comprises the steps of heating a silicon substrate to a temperature below 700.degree. C.
    Type: Grant
    Filed: December 13, 1994
    Date of Patent: December 26, 1995
    Assignee: Fujitsu Limited
    Inventor: Noriyoshi Shimizu
  • Patent number: 5468678
    Abstract: A method for manufacturing a III-V Group compound or a II-VI Group compound semiconductor element by VPE, comprising the step of annealing a grown compound at 400.degree. C. or higher, or irradiating electron beam the grown compound at 600.degree. C. or higher.
    Type: Grant
    Filed: January 12, 1994
    Date of Patent: November 21, 1995
    Assignee: Nichia Chemical Industries, Ltd.
    Inventors: Shuji Nakamura, Naruhito Iwasa, Masayuki Senoh
  • Patent number: 5462883
    Abstract: A method for fabricating silicon on insulator structures having a dislocation free silicon layer. The method utilizes low temperature UHVCVD to deposit a very heavily doped etch stop layer having a very steep doping profile onto a substrate and a lightly doped active layer onto the etch stop layer. An insulator is formed on the active layer and a carrier wafer is formed on the insulator layer. The original substrate is removed in a first etch and the etch stop layer is removed in a second etch resulting in a thin, uniform active layer. In one embodiment, a small percentage of germanium is added to the etch stop layer to produce a defect free epitaxial active layer.
    Type: Grant
    Filed: April 11, 1994
    Date of Patent: October 31, 1995
    Assignee: International Business Machines Corporation
    Inventors: Robert H. Dennard, Bernard S. Meyerson, Robert Rosenberg
  • Patent number: 5453405
    Abstract: Light emitting diodes (LEDs) and LED bars and LED arrays formed of semiconductive material, such as III-V, and particularly AlGaAs/GaAs material, are formed in very thin structures using organometallic vapor deposition (OMCVD). Semiconductor p-n junctions are formed as deposited using carbon as the p-type impurity dopant. Various lift-off methods are described which permit back side processing when the growth substrate is removed and also enable device registration for LED bars and arrays to be maintained.
    Type: Grant
    Filed: December 9, 1993
    Date of Patent: September 26, 1995
    Assignee: Kopin Corporation
    Inventors: John C. C. Fan, Brenda Dingle, Shambhu Shastry, Mark B. Spitzer, Robert W. McClelland
  • Patent number: 5445992
    Abstract: A semiconductor film having a very high light response of photoconductivity and good electrical characteristics such a wide band gap, for example, a non-monocrystalline silicon carbide film, is formed by decomposition reaction of a silicon-containing raw material gas and a hydrocarbon as a carbon raw material under light irradiation or high frequency, where the carbon raw material gas comprises at least one of tertiary and quaternary carbon atom-containing hydrocarbons of specific chemical formulae, and a semiconductor device using the thus formed semiconductor film is also provided.
    Type: Grant
    Filed: May 5, 1994
    Date of Patent: August 29, 1995
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hiroyuki Tokunaga, Tadashi Atoji
  • Patent number: 5441913
    Abstract: A semiconductor epitaxial substrate and a process for producing the same, the semiconductor epitaxial substrate comprising a GaAs single-crystal substrate having thereon an In.sub.y Ga.sub.(1-y) As (0<y.ltoreq.1) crystal layer as a channel layer, the composition and the thickness of the In.sub.y Ga.sub.(1-y) As layer being in the ranges within the elastic deformation limit of crystals constituting the In.sub.y Ga.sub.(1-y) As layer and the vicinity of the In.sub.y Ga.sub.(1-y) As layer, the semiconductor epitaxial substrate further comprising a semiconductor layer between the channel layer and an electron donating layer for supplying electrons to the channel layer, the semiconductor layer having a thickness of from 0.5 to 5 nm and a bandgap width within the range of from the bandgap width of GaAs to the bandgap width of the electron donating layer.
    Type: Grant
    Filed: June 28, 1994
    Date of Patent: August 15, 1995
    Assignee: Sumitomo Chemical Company, Limited
    Inventors: Masahiko Hata, Noboru Fukuhara, Hiroaki Takata, Katsumi Inui
  • Patent number: 5434044
    Abstract: A process is described for forming, over a silicon surface, a titanium nitride barrier layer having a surface of (111) crystallographic orientation. The process comprises: depositing a first titanium layer over a silicon surface; sputtering a titanium nitride layer over the titanium layer; depositing a second titanium layer over the sputtered titanium nitride layer; and then annealing the structure in the presence of a nitrogen-bearing gas, and in the absence of an oxygen-bearing gas, to form the desired titanium nitride having a surface of (111) crystallographic orientation and a sufficient thickness to provide protection of the underlying silicon against spiking of the aluminum. When an aluminum layer is subsequently formed over the (111) oriented titanium nitride surface, the aluminum will then assume the same (111) crystallographic orientation, resulting in an aluminum layer having enhanced resistance to electromigration.
    Type: Grant
    Filed: June 3, 1994
    Date of Patent: July 18, 1995
    Assignee: Applied Materials, Inc.
    Inventors: Jaim Nulman, Kenny K. Ngan
  • Patent number: 5433170
    Abstract: A metal-organic chemical vapor-phase deposition process for fabricating a layer of a Group II-VI compound semiconductor using an organometallic compound based on bis(cyclopentadienyl)magnesium having a vapor pressure in the range of from 1.3.times.10 Pa to 1.3.times.10.sup.2 Pa at a temperature of 330.degree. K. The present invention also provides a light-emitting device which is fabricated by means of the metal-organic vapor-phase deposition process above. The process according to the present invention provides a magnesium-containing compound semiconductor layer having an accurately controlled composition, and it readily enables the fabrication of a compound semiconductor layer having a grated structure.
    Type: Grant
    Filed: November 4, 1994
    Date of Patent: July 18, 1995
    Assignee: Sony Corporation
    Inventors: Atsushi Toda, Takeharu Asano
  • Patent number: 5433791
    Abstract: Ultraviolet (UV) light from a lamp or UV laser, such as a metal can short arc xenon lamp or excimer laser, respectively, is provided for cracking Group V and Group VI species comprising clusters (dimers and tetramers) or metal-organic molecules to form monomers (atoms). The UV radiation interacts with a molecular beam of Group V and Group VI species subsequent to their generation in a source cell and thermal cracking. The source cell may comprise an effusion source in molecular beam epitaxy (MBE) apparatus, a thermal cracker cell in gas-source MBE apparatus, or a gas injector cell in metal-organic MBE apparatus (MOMBE). Light from the UV lamp or laser is coupled into a vacuum chamber in which the source cell is located, at a point below the source cell and is then directed along a path parallel to the source cell by a first reflector and finally directed onto the thermally-cracked beam of molecules by a second reflector, where the UV radiation photo-cracks the molecular beam.
    Type: Grant
    Filed: May 26, 1994
    Date of Patent: July 18, 1995
    Assignee: Hughes Aircraft Company
    Inventors: Peter D. Brewer, Clifford A. LeBeau
  • Patent number: 5434100
    Abstract: A substrate wafer for epitaxy of a compound semiconductor single crystal and an epitaxy using the substrate wafer are disclosed. Where the orientation off-angle from the <100> plane of an area available for device formation of a surface of the substrate wafer is .theta..degree., and the growth rate on an epitaxial layer on the substrate wafer is V .mu.m/hr, and the growth temperature of the epitaxial layer is T K, the orientation off-angle .theta..degree. is given by the following expression: ##EQU1## where 0.1.ltoreq.V.ltoreq.10 and 853.ltoreq.T.ltoreq.1023. The substrate wafer is capable of significantly reducing the number of teardrop-like hillock defects which appear on the surface of the epitaxial layer and of increasing the smoothness of the surface of the epitaxial layer.
    Type: Grant
    Filed: April 23, 1993
    Date of Patent: July 18, 1995
    Assignee: Japan Energy Corporation
    Inventors: Masashi Nakamura, Shigeo Katsura, Ryuichi Hirano, Nobuhito Makino, Eiji Ikeda
  • Patent number: 5429983
    Abstract: A method of manufacturing a semiconductor device according to the present invention comprises the steps of forming a conductive film on an insulating film, forming growth nucleuses containing any of elements in group IIIb, group IVb, group Vb and group VIIb that does not constitute the conductive film and the insulating film on the surface of the conductive film, and growing a semiconductor selectively on growth nucleuses.
    Type: Grant
    Filed: August 29, 1994
    Date of Patent: July 4, 1995
    Assignee: Fujitsu Limited
    Inventors: Yutaka Takizawa, Ken-ichi Yanai
  • Patent number: 5427977
    Abstract: An Si or SiC semiconductor layer is subjected to anodic oxidation in an HF solution to form a porous semiconductor layer. Without drying, the porous semiconductor layer is then immersed in pure water. Ultrasonic waves applied to the pure water shorten the reaction time and help bubbles separate from the surface of the porous region. The porous semiconductor layer is used for forming a pn junction, and carriers are injected into the pn junction.
    Type: Grant
    Filed: January 6, 1994
    Date of Patent: June 27, 1995
    Assignee: Fujitsu Limited
    Inventors: Masao Yamada, Motoo Nakano, George J. Collins, Tetsuro Tamura, Akira Takazawa
  • Patent number: 5427630
    Abstract: Epitaxial and polycrystalline layers of silicon and silicon-germanium alloys are selectively grown on a semiconductor substrate or wafer by forming over the wafer a thin film masking layer of an oxide of element selected from scandium, yttrium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium and then growing the epitaxial layer over the wafer at temperatures below 650.degree. C. The epitaxial and polycrystalline layers do not grow on the masking layer. The invention overcomes the problem of forming epitaxial layers at temperatures above 650.degree. C. by providing a lower temperature process.
    Type: Grant
    Filed: May 9, 1994
    Date of Patent: June 27, 1995
    Assignee: International Business Machines Corporation
    Inventors: Cyril Cabral, Jr., Kevin K. Chan, Jack O. Chu, James M. E. Harper
  • Patent number: 5427054
    Abstract: A process of forming high quality diamond films, wherein non-diamond components and crystal defects are significantly reduced. Diamond films are formed on a diamond substrate by vapor-phase synthesis using a source gas, wherein the atomic concentrations of oxygen and carbon, [0] and [C], respectively, in the source gas satisfy the condition that 0.01.ltoreq.[C]/([C]+[O]).ltoreq.0.40. Boron (B) doped p-type semiconducting films can also be formed using the same source gas which further includes a B-containing compound.
    Type: Grant
    Filed: June 6, 1994
    Date of Patent: June 27, 1995
    Assignee: Kabushiki Kaisha Kobe Seiko Sho
    Inventors: Kimitsugu Saito, Koichi Miyata
  • Patent number: 5426068
    Abstract: An undoped p-type GaAs epitaxial layer or an n-type GaAs epitaxial layer is grown on the surface of a wafer, and thereafter the wafer is annealed at a temperature which ranges from 800.degree. C. to 1,200.degree. C. and is equal to or higher than a predetermined critical temperature depending on the carrier concentration in the epitaxial layer before it is annealed. The epitaxial layer thus annealed is rendered semi-insulating without addition of any impurity. Accordingly, performances of an electronic device which incorporates such a wafer are improved.
    Type: Grant
    Filed: March 25, 1994
    Date of Patent: June 20, 1995
    Assignee: Japan Energy Corporation
    Inventors: Toyoaki Imaizumi, Osamu Oda
  • Patent number: 5424243
    Abstract: A method of producing a compound semiconductor crystal-on-substrate structure includes forming a first compound semiconductor crystal layer made of a group III-V compound semiconductor on a Si substrate, forming a stacked structure by forming an amorphous compound semiconductor layer made of the group III-V compound semiconductor on the first compound semiconductor crystal layer, subjecting the stacked structure to a thermal process, removing at least the amorphous compound semiconductor layer from the stacked structure that is subjected to the thermal process, and forming a second compound semiconductor crystal layer made of the group III-V compound semiconductor, to thereby form the compound semiconductor crystal-on-substrate structure.
    Type: Grant
    Filed: September 9, 1994
    Date of Patent: June 13, 1995
    Assignee: Fujitsu Limited
    Inventor: Kanetake Takasaki
  • Patent number: 5424103
    Abstract: A method for making a semiconductor, without using a vacuum pump or vacuum chamber, using corona discharge, which comprises the steps or: supplying a reactive gas to, at least, one electrode capable of generating corona discharge above a substrate with an RF power source under the atmosphere; irradiating ions or radicals resulted from the decomposition of said reactive gas by said corona discharge to said substrate; allowing said ions or radicals to be chemically reacted with said substrate or be diffused in said substrate.
    Type: Grant
    Filed: November 3, 1993
    Date of Patent: June 13, 1995
    Assignee: Goldstar Co., Ltd.
    Inventor: Byung C. Ahn