Patents Examined by S. Mulpuri
  • Patent number: 5482899
    Abstract: An apparatus and method are disclosed that prevent the breakage of semiconductor wafers that have not been entirely sawed, during the process of removing dicing tape from the back of the wafer. In addition, an improved semiconductor demounter is disclosed that allows optimum positioning of the semiconductor wafer for removal of the dicing tape. The apparatus for preventing breakage of semiconductor wafers consists of a leveling block 32 for use with a semiconductor demounter 16 having an incline 18 leading up to a tape removal apparatus 20. The leveling block 32 comprises an declined plane 34 with an angle of declination 36 approximately equal to the angle of inclination 26 of the incline leading up to the tape removal apparatus 20.
    Type: Grant
    Filed: March 21, 1994
    Date of Patent: January 9, 1996
    Assignee: Texas Instruments Incorporated
    Inventors: Robert G. McKenna, Michael G. Baxter
  • Patent number: 5482869
    Abstract: After a trench is formed in a semiconductor substrate, a semiconductor film is formed on the inner wall of the trench. Annealing is performed in a predetermined condition to subject an unwanted metal impurity to gettering into the semiconductor film. The semiconductor film is then oxidized.
    Type: Grant
    Filed: March 1, 1994
    Date of Patent: January 9, 1996
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Yusuke Kohyama
  • Patent number: 5482887
    Abstract: A method of manufacturing semiconductor devices with a passivated semiconductor body (1) provided with an electrode (2) and fastened on an electrically conducting support body (3), in which method a slice of semiconductor material (5) is fastened on a surface (6) of an electrically conducting auxiliary slice (7), and mesa structures (8) are formed in the slice of semiconductor material (5) by the application of grooves (9) in the slice of semiconductor material (5) subsequently, a layer of insulating material (10) is provided on the walls of the grooves (9), electrodes (2) are provided on upper sides (11) of the mesa structures (8), and the auxiliary slice (7) with the mesa structures (8) is split up at the areas of the grooves (9) into individual semiconductor bodies (1) each fastened on its own support body (3).
    Type: Grant
    Filed: December 22, 1993
    Date of Patent: January 9, 1996
    Assignee: U.S. Philips Corporation
    Inventors: Geert J. Duinkerken, Roelvinus M. M. Fonville
  • Patent number: 5478782
    Abstract: A wafer bonding method for forming a SOI structure comprising the steps of bringing wafers into proximity in a state with one wafer a slight, substantially uniform clearance away from the other wafer and pressing one point of at least one wafer of the two wafers against the other wafer. In another aspect of the invention, there is provided a method of positioning for photolithography using an alignment mark portions and/or a vernier portions formed on a SOI substrate, which comprises the step of removing semiconductor layer portions corresponding to the alignment mark portions and/or the vernier portions. In further another aspect of the invention, there is provided a new DRAM semiconductor device formed by using SOI structure, which comprises a new pattern of a strage node formed longitudinally along a word line. Further, there is provided a new DRAM semiconductor device formed by using SOI structure, which comprises a unique strage node having a conductive side wall.
    Type: Grant
    Filed: May 20, 1993
    Date of Patent: December 26, 1995
    Assignee: Sony Corporation
    Inventors: Hiroshi Satoh, Yasunori Ohokubo, Takeshi Matsushita, Toshiyuki Nishihara, Makoto Hashimoto
  • Patent number: 5478776
    Abstract: The invention is directed to a process for fabricating a device with a junction thereon with a depth of 0.06 microns or less. The substrate also has a silicon dioxide material thereon. A dopant source is applied over a junction on the substrate. The substrate is then rapid thermal annealed to drive the dopant source into the substrate. The dopant source is then removed from the substrate using an etchant that does not contain a significant amount of HF.
    Type: Grant
    Filed: December 27, 1993
    Date of Patent: December 26, 1995
    Assignee: AT&T Corp.
    Inventors: Henry S. Luftman, Roderick K. Watts
  • Patent number: 5476800
    Abstract: The present invention provides a buried layer fabrication sequence suitable for bipolar and BiCMOS applications. The buried layer fabrication sequence for forming a buried layer having a first conductivity type includes the steps of: forming a first dielectric layer on a semiconductor substrate, the semiconductor substrate having a second conductivity type; forming a first mask layer having openings on top of the first dielectric layer, wherein the openings in the first mask layer are positioned over the regions where the first buried layer is formed; exposing the semiconductor substrate in the regions where openings in the first mask layer are formed; forming a second dielectric layer; removing the second dielectric layer; and forming a semiconductor layer.
    Type: Grant
    Filed: January 31, 1994
    Date of Patent: December 19, 1995
    Inventors: Gregory N. Burton, Chen-Hsi Lin, Chi-Kwan Lau
  • Patent number: 5474944
    Abstract: A manufacturing process for an integrated circuit which includes at least one vertical-current-flow MOS transistor. The patterned photoresist which screens the body implant is also used to mask the etching of a nitride layer over a pad oxide. After the photoresist is cleared, the nitride pattern is transferred into the oxide, and the resulting oxide/nitride stack is used to mask the source implant. The nitride/oxide stack is then removed, the gate oxide is grown, and the gate layer is then deposited.
    Type: Grant
    Filed: December 7, 1992
    Date of Patent: December 12, 1995
    Assignees: SGS-Thomson Microelectronics, S.r.l., Consorzio per la Ricerca sulla Microelettronica nel Mezzogiorno
    Inventor: Raffaele Zambrano
  • Patent number: 5472909
    Abstract: An efficient method is proposed for the preparation of a silicon single crystal wafer for discrete semiconductor devices, such as transistors, deeply doped with a dopant on one surface, the other surface being mirror-polished.
    Type: Grant
    Filed: November 15, 1994
    Date of Patent: December 5, 1995
    Assignee: Naoetsu Electronics Company
    Inventors: Takeshi Akatsuka, Tsutomu Sato
  • Patent number: 5472906
    Abstract: A first underlaid oxide layer, a polysilicon layer, and a first silicon nitride layer are formed on a silicon substrate in this order. Using a photoresist as a mask, a portion of the first silicon nitride layer, the polysilicon layer, the first underlaid oxide layer and the silicon substrate which is to be an isolation region is etched by a depth which regulates a length of bird's beak and a threshold voltage drop of a FET adequately. After forming a second underlaid oxide layer and a second silicon nitride layer, silicon nitride side walls of more than 25 nm in thickness are formed. An isolation oxide layer is formed by selective oxidation, using the silicon nitride layer as a mask. Favorable etched depth in the step of removing the silicon substrate is one third of the thickness of the isolation oxide layer. Favorable etched depth in case of a normal FET is 20-100 nm.
    Type: Grant
    Filed: August 18, 1994
    Date of Patent: December 5, 1995
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Norisato Shimizu, Yasushi Naito, Yuichi Hirofuji
  • Patent number: 5470781
    Abstract: In an isolation trench in a silicon-on-insulator wafer, the sidewalls of the trench curve outwardly at the bottom of the trench where the top silicon layer meets the underlying oxide insulating layer. This sidewall geometry eliminates the sharp corner at the bottom of the trench. Preferably, the top edge of the trench wall is also curved.
    Type: Grant
    Filed: December 14, 1993
    Date of Patent: November 28, 1995
    Assignee: International Business Machines Corporation
    Inventors: Dureseti Chidambarrao, Louis L. Hsu, J. Daniel Mis, James P. Peng
  • Patent number: 5470801
    Abstract: A low dielectric insulation layer for an integrated circuit structure material, and a method of making same, are disclosed. The low dielectric constant insulation layer comprises a porous insulation layer, preferably sandwiched between non-porous upper and lower insulation layers. The presence of some gases such as air or an inert gas, or a vacuum, in the porous insulation material reduces the overall dielectric constant of the insulation material, thereby effectively reducing the capacitance of the structure. The porous insulation layer is formed by a chemical vapor deposition of a mixture of the insulation material and a second extractable material; and then subsequently selectively removing the second extractable material, thereby leaving behind a porous matrix of the insulation material, comprising the low dielectric constant insulation layer.
    Type: Grant
    Filed: June 28, 1993
    Date of Patent: November 28, 1995
    Assignee: LSI Logic Corporation
    Inventors: Ashok K. Kapoor, Nicholas F. Pasch
  • Patent number: 5468687
    Abstract: A method for low temperature annealing (oxidation) of high dielectric constant Ta.sub.2 O.sub.5 thin films uses an ozone enhanced plasma. The films produced are especially applicable to 64 and 256 Mbit DRAM applications. The ozone enhanced plasma annealing process for thin film Ta.sub.2 O.sub.5 reduces the processing temperature to 400.degree. C. and achieves comparable film quality, making the Ta.sub.2 O.sub.5 films more suitable for Ultra-Large Scale Integration (ULSI) applications (storage dielectric for 64 and 256 Megabit DRAMs with stack capacitor structures, etc.) or others that require low temperature processing. This low temperature process is extendable to other high dc and piezoelectric thin films which may have many other applications.
    Type: Grant
    Filed: July 27, 1994
    Date of Patent: November 21, 1995
    Assignee: International Business Machines Corporation
    Inventors: Dan Carl, David M. Dobuzinsky, Son V. Nguyen, Tue Nguyen
  • Patent number: 5468672
    Abstract: A method of fabricating a thin film resistor includes a step of sputter depositing a thin film of resistive material such as a chromium diboride compound on an insulative substrate using an argon sputter gas having a percentage of dopant such as nitrogen selected to optimize a trade off between desirably increasing the thickness of the film and undesirably increasing the temperature coefficient of resistance. A cap layer having a solid diffusant such as free chromium is deposited over the thin film of resistive material. The cap layer serves to protect the thin film of resistive material during subsequent patterning of conductors using wet etching, and also the solid diffusant diffuses into the resistive material during subsequent thermal treatment to drive the temperature coefficient of resistance back down.
    Type: Grant
    Filed: June 29, 1993
    Date of Patent: November 21, 1995
    Assignee: Raytheon Company
    Inventor: Warren C. Rosvold
  • Patent number: 5464795
    Abstract: A semiconductor thin film is formed by depositing an amorphous silicon thin film and heat-treating the deposited amorphous silicon thin film. The amorphous silicon thin film is formed by a chemical vapor deposition (CVD) process while a dopant impurity is introduced, the film being not thicker than 50 nanometers. In the reaction gases used, the ratio (D/S) between the numbers S and D of atoms of silicon and dopant impurity in reaction gases is as large as 0.05.about.0.2. The polycrystalline silicon thin film thus formed is with reduced electrical resistivities.
    Type: Grant
    Filed: March 1, 1994
    Date of Patent: November 7, 1995
    Assignee: NEC Corporation
    Inventor: Shizuo Oguro
  • Patent number: 5464779
    Abstract: The method and apparatus of this invention for evaluation of a semiconductor production process effect the determination of the shallow pit density of a silicon wafer by predetermining the correlation between the average shallow pit density on a wafer surface obtained by microscopic observation and the average magnitude of a scattered light on the wafer surface obtained by the determination with the wafer surface inspection system operated in the haze mode, determining the average magnitude on the wafer surface of a scattered light for a silicon wafer treated by a semiconductor production process under evaluation, and analyzing the data found by the determination in combination with the correlation mentioned above.
    Type: Grant
    Filed: April 5, 1994
    Date of Patent: November 7, 1995
    Assignee: Shin-Etsu Handotai Co., Ltd.
    Inventor: Nobuyoshi Fujimaki
  • Patent number: 5459086
    Abstract: A new method of forming the dielectric layer of an integrated circuit is described. A thick insulating layer is formed over semiconductor device structures in and on a semiconductor substrate. A first metal layer is deposited over the thick insulating layer. The first metal layer is etched using conventional photolithography and etching techniques to form the desired metal pattern on the surface of the thick insulating layer. The intermetal dielectric layer is formed by first covering the patterned first metal layer with a layer of silicon oxide. The silicon oxide layer is covered with a layer of spin-on-glass material which is baked and cured. A second layer of silicon oxide completes the intermetal dielectric layer. Via openings are formed through the intermetal dielectric layer to the underlying patterned first metal layer.
    Type: Grant
    Filed: November 7, 1994
    Date of Patent: October 17, 1995
    Assignee: United Microelectronics Corporation
    Inventor: Ming-Tzong Yang
  • Patent number: 5459108
    Abstract: There is provided a semiconductor device manufacturing process which enables film deposition at low temperatures and can produce an interlayer insulating film of good quality which exhibits good surface smoothing effect. In the TEOS-O.sub.3 system normal pressure CVD process, film growth is carried out by adding to TEOS source a source containing nitrogen in its composition. For the source is used heptamethyl disilazane (chemical formula (CH.sub.3).sub.3 SiN(CH.sub.3)Si(CH.sub.3).sub.3), N, O-bis-trimethylsilyl acetamide (chemical formula (CH.sub.3)C(OSi(CH.sub.3).sub.3)(NSi(CH.sub.3).sub.3)) or tridimethylamino silane (chemical formula (CH.sub.3).sub.2 N).sub.3 SiN). Also, there is provided a semiconductor device manufacturing method which enables film deposition at a uniform growth rate irrespective of the substrate material and can produce a silicon oxide film of good quality which exhibits good surface smoothing effect. An organic source having an Si--N bond in its composition and O.sub.
    Type: Grant
    Filed: July 29, 1993
    Date of Patent: October 17, 1995
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Tsukasa Doi, Yukiko Mori
  • Patent number: 5456765
    Abstract: A mixed crystal ratio difference is introduced in a gallium arsenide phosphide mixed crystal layer having a desired constant mixed crystal ratio, thereby reducing the amount of stress remaining within the resulting epitaxial wafer. This is less likely or unlikely to crack, and so can be well used for LED fabrication.
    Type: Grant
    Filed: June 7, 1993
    Date of Patent: October 10, 1995
    Assignee: Mitsubishi Kasei Corporation
    Inventors: Tadashige Sato, Hisanori Fujita
  • Patent number: 5453386
    Abstract: A method of fabricating an LED array including epitaxially and sequentially growing a conductive layer on a substrate, a first carrier confinement layer, an active layer, a second carrier confinement layer and a conductive cap. Selectively etching the cap to provide exposed surface areas defining row and column areas with a matrix of diodes positioned in rows and columns therebetween. Implanting a first impurity in the row areas to form vertical conductors extending through the second confinement, active and first confinement layers to provide surface contacts to each diode. Implanting a second impurity in the row and column areas through the second confinement and active layers to form an isolating resistive volume around each diode. Implanting a third impurity in the row areas through the second confinement, active, and first confinement layers and into the substrate to form an isolating resistive volume between each row of diodes.
    Type: Grant
    Filed: May 9, 1994
    Date of Patent: September 26, 1995
    Assignee: Motorola, Inc.
    Inventors: Paige Holm, Benjamin W. Gable
  • Patent number: 5447889
    Abstract: Disclosed herein is a method of preparing a polycrystalline silicon film comprising a step of forming an amorphous silicon film containing hydrogen and having an intensity ratio TA/TO of at least 0.5 of TA peak intensity to TO peak intensity in a Raman spectrum, and a step of heat treating the amorphous silicon film for converting the same to a polycrystalline silicon film.
    Type: Grant
    Filed: September 8, 1993
    Date of Patent: September 5, 1995
    Assignee: Sanyo Electric Co., Ltd.
    Inventor: Keiichi Sano