Patents Examined by J. Carroll
  • Patent number: 5898197
    Abstract: A non-volatile semiconductor memory device accurately stores multivalued data with reduced damage to an insulating layer. The non-volatile semiconductor memory device includes a floating gate electrode configured to be divided into at least two portions. The first portion is employed for accumulating carriers migrating from at least one control gate electrode through a gate insulating layer to the floating gate electrode.
    Type: Grant
    Filed: June 3, 1997
    Date of Patent: April 27, 1999
    Assignee: Sanyo Electric Co., Ltd.
    Inventor: Hideaki Fujiwara
  • Patent number: 5889299
    Abstract: A thin film capacitor including a first electrode having on its surface a (100) face of cubic system or a (001) face of tetragonal system, a dielectric thin film epitaxially grown on the first electrode and exhibiting a crystal structure which inherently belongs to a perovskite structure of cubic system, and a second electrode formed on the dielectric thin film. Further, the dielectric thin film meets the following relationship V/V.sub.0 .gtoreq.1.01 where a unit lattice volume of true perovskite crystal structure belonging to the cubic system (lattice constant a.sub.0) is represented by V.sub.0 =a.sub.0.sup.3, and a unit lattice volume (lattice constant a=b.noteq.c) which is strained toward a tetragonal system after the epitaxial growth is represented by V=a.sup.2 c, and also meets the following relationship c/a.gtoreq.1.01 where c/a represents a ratio between a lattice constant "c" in the direction thicknesswise of the film and a lattice constant "a" in the direction parallel with a plane of the film.
    Type: Grant
    Filed: February 21, 1997
    Date of Patent: March 30, 1999
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kazuhide Abe, Shuichi Komatsu, Mitsuaki Izuha, Noburu Fukushima, Kenya Sano, Takashi Kawakubo
  • Patent number: 5880512
    Abstract: Antifuses and gate arrays with antifuses are disclosed that have high thermal stability, reduced size, reduced leakage current, reduced capacitance in the unprogrammed state, improved manufacturing yield, and more controllable electrical characteristics. Some antifuses include spacers in the antifuse via. In some antifuses, the programmable material is planar, and the top or the bottom electrode is formed in the antifuse via. In some gate arrays, the antifuses are formed above the dielectric separating two levels of routing channels rather than below that dielectric.
    Type: Grant
    Filed: December 18, 1996
    Date of Patent: March 9, 1999
    Assignee: QuickLogic Corporation
    Inventors: Kathryn E. Gordon, Richard J. Wong
  • Patent number: 5872390
    Abstract: A fuse window structure and method for forming the same for a semiconductor device with a fuse and a cutting site on the fuse, the structure having (1) a first oxide region substantially in register with the cutting site, the first oxide region having a first thickness, (2) a second oxide region substantially in register with a first land generally surrounding the cutting site, the first land generally in register with the fuse, the second region having a second thickness, and (3) a third oxide region substantially in register with a second land generally surrounding the fuse, the third region having a third thickness different than the first thickness. Different fuse window structures are formed by using etch stops with different configurations, each configuration differing with regard to coverage of the three oxide regions.
    Type: Grant
    Filed: August 14, 1997
    Date of Patent: February 16, 1999
    Assignee: International Business Machines Corporation
    Inventors: Pei-Ing Paul Lee, William Alan Klaasen, Alexander Mitwalsky
  • Patent number: 5866938
    Abstract: A semi conductor device is provided having the following arrangement. A first electrode is formed on the major surface of a semiconductor substrate and comprises a first Al connection layer formed over the semiconductor substrate and a barrier metal layer provided on, and electrically connected to, the first Al connection layer and serving as a barrier against the Al. An insulating film is formed over the semiconductor substrate so as to cover the first electrode. An opening is formed in the insulating film so as to partially expose the first electrode. An antifuse film is formed in a manner to partially cover the insulating film and contact with the barrier metal layer of the first electrode with the opening therebetween. The antifuse film is formed of silicon nitride whose nitrogen/silicon atomic composition ratio ranges from 0.6 to 1.2. A second electrode is formed over the antifuse film and comprised of a barrier metal layer serving as a barrier against the Al.
    Type: Grant
    Filed: August 15, 1996
    Date of Patent: February 2, 1999
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Mariko Takagi, Ichiro Yoshii, Kaoru Hama, Naoki Ikeda, Hiroaki Yasuda
  • Patent number: 5866937
    Abstract: An antifuse comprises a substantially planar conductive lower electrode covered by a first layer of silicon nitride. A layer of amorphous silicon is disposed over the silicon nitride layer. A first dielectric layer is disposed over the surface of the amorphous silicon layer and has a first aperture therethrough communicating with the amorphous silicon layer. A second layer of silicon nitride is disposed over the first dielectric layer and in the first aperture. A conductive upper electrode, such as a layer of titanium nitride, is disposed over the second layer of silicon nitride. A second dielectric layer is disposed over the surface of the conductive upper electrode and has a second aperture therethrough in alignment with the first aperture communicating with the conductive upper electrode. An overlying metal layer is disposed over the surface of the second dielectric layer and in the second aperture making electrical contact with the conductive upper electrode.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: February 2, 1999
    Assignee: Actel Corporation
    Inventor: John L. McCollum
  • Patent number: 5852323
    Abstract: An antifuse is described that can be formed without masks or mask steps beyond those required for a conventional CMOS process. The antifuse includes adjacent p-type and n-type diffusion regions that together form a P-N junction. The diffusion regions are tapered toward one another such that the P-N junction is located at a necked-down region of the antifuse. The diffusion regions are connected to respective terminals of a programming-voltage source via first and second metal electrical contacts, typically of aluminum metal. Each of the first and second electrical contacts includes a point directed toward the other of the first and second electrical contacts. The antifuse is programmed by providing a reverse-bias programming voltage across the electrical contacts. This programming voltage exceeds the breakdown voltage of the P-N junction so that current flows through the necked-down region of the antifuse between the points on the respective first and second electrical contacts.
    Type: Grant
    Filed: January 16, 1997
    Date of Patent: December 22, 1998
    Assignee: Xilinx, Inc.
    Inventor: Robert O. Conn
  • Patent number: 5825072
    Abstract: A static-charge protection device for an antifuse includes an additional second-sized aperture smaller in area than the antifuse apertures disposed in the same inter-electrode dielectric layer. Antifuse material is disposed in the second-sized aperture, and the upper electrode extends over the second aperture as well as the first aperture. A preferred process for fabricating the protection device utilizes the step of forming the smaller apertures and forming their antifuse material layers simultaneously with forming the antifuse apertures.A static-charge protection device for an antifuse device includes an additional second-sized aperture larger in area than the first-sized antifuse apertures. Metal plug material is deposited and etched back. A layer of amorphous silicon antifuse material is formed and defined over the first and second sized apertures, the portion formed over the larger partially filled antifuse protection device cell being thinner.
    Type: Grant
    Filed: February 14, 1996
    Date of Patent: October 20, 1998
    Assignee: Actel Corporation
    Inventors: Yeochung Yen, Wenn-Jei Chen, Steve S. Chiang, Abdul Rahim Forouhi
  • Patent number: 5818088
    Abstract: An ESD protection network (20) provides energy discharge paths for an ESD event at an external circuit port (42). The paths include one portion (28) into an integrated circuit substrate (72) and other portions (29, 30) from the substrate to external power supply ports (43, 44). In particular, these paths include energy discharge routes around on-circuit voltage sources.
    Type: Grant
    Filed: June 10, 1997
    Date of Patent: October 6, 1998
    Assignee: Analog Devices, Inc.
    Inventor: Denis Ellis
  • Patent number: 5811869
    Abstract: An integrated circuit laser antifuse is described which has two physical states. In the first physical state the laser antifuse has to conductive plates electrically separated by a layer of dielectric material. In the second physical state the two conductive plates are electrically connected through the dielectric in response to an external radiation source, such as a laser.
    Type: Grant
    Filed: January 4, 1996
    Date of Patent: September 22, 1998
    Assignee: Micron Technology, Inc.
    Inventors: Mirmajid Seyyedy, Manny K. F. Ma
  • Patent number: 5798534
    Abstract: In the manufacture of liquid-crystal display devices and other large-area electronics devices, electrostatic discharge damage (ESD) of tracks and other thin-film circuit elements can result during ion implantation and/or during handling. This damage is avoided by connecting the thin-film circuitry in a charge leakage path with gateable TFT links (45). These links (45) are TFTs (45) with a common gate line (7) for applying a gate bias voltage to control current flow through the links, e.g to turn off the TFTs (45) during testing of the device circuit. In accordance with the present invention the gateable links (45) in the leakage path are removed simultaneously by applying a sufficiently high gate bias (Vg2) to the common gate line (7) to break the links (45) by evaporating at least the channel regions (6) of the TFTs. A suitable thin-film structure is chosen for the TFTs (45) to facilitate evaporating their channel regions (6) in this manner.
    Type: Grant
    Filed: August 8, 1995
    Date of Patent: August 25, 1998
    Assignee: U.S. Philips Corporation
    Inventor: Nigel D. Young
  • Patent number: 5793094
    Abstract: A method for substantially reducing variations in a programming voltage of an anti-fuse structure formed on an integrated circuit wafer. The anti-fuse structure has a metal-one layer, an anti-fuse layer disposed above the metal-one layer, a oxide layer disposed above the anti-fuse layer, and a via hole in the oxide layer through to the anti-fuse layer for receiving a deposition of a metal-two material. The method includes the step of rendering a selected anti-fuse area susceptible to fuse link formation by reducing a resistivity of the selected anti-fuse area to diffusion of atoms from one of the metal-one layer and the metal-two layer when a programming voltage is applied between the metal one layer and the metal two layer. The selected anti-fuse area is located in the anti-fuse layer and substantially adjacent to and outside of an anti-fuse area directly below the via hole. The method further includes the step of depositing the metal-two material into the via hole.
    Type: Grant
    Filed: December 28, 1995
    Date of Patent: August 11, 1998
    Assignee: VLSI Technology, Inc.
    Inventors: Ivan Sanchez, Yu-Pin Han, Ying-Tsong Loh, Walter D. Parmantie
  • Patent number: 5789796
    Abstract: The present invention relates to a technology of an electrically programmable anti-fuse device. The anti-fuse device comprises a semiconductor substrate provided with a plurality of functional elements; a field oxide layer formed on said semiconductor substrate, for electrically isolating the functional elements from each other; a predetermined pattern of a first electrode formed on said field oxide layer; a first insulating layer having two contact holes isolated from each other only on said first electrode, deposited on said field oxide layer as well as both end portions and center portion of said first electrode; a second insulating layer formed in said contact holes, to serves as an interlayer; and a second electrode formed on said second insulating layer.
    Type: Grant
    Filed: August 25, 1997
    Date of Patent: August 4, 1998
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Sang-Won Kang, Jong-Tae Baek
  • Patent number: 5789795
    Abstract: An integrated circuit having a semiconductor substrate and an anti-fuse structure formed on the semiconductor substrate. The anti-fuse structure includes a metal-one layer and an anti-fuse layer disposed above the metal-one layer. The anti-fuse layer has a first resistance value when the anti-fuse structure is unprogrammed and a second resistance value lower than the first resistance value when the anti-fuse structure is programmed. There is further provided an etch stop layer disposed above the anti-fuse layer, and an inter-metal oxide layer disposed above the etch stop layer with the inter-metal oxide layer has a via formed therein. Additionally, there is further provided a metal-two layer disposed above the inter-metal oxide layer. In this structure, a portion of the metal-two layer is in electrical contact with the anti-fuse layer through the via in the inter-metal oxide layer.
    Type: Grant
    Filed: December 28, 1995
    Date of Patent: August 4, 1998
    Assignee: VLSI Technology, Inc.
    Inventors: Ivan Sanchez, Yu-Pin Han, Miguel A. Delgado, Ying-Tsong Loh
  • Patent number: 5780919
    Abstract: In one method for forming amorphous silicon antifuses with significantly reduced leakage current, a film of amorphous silicon is formed in a antifuse via between two electrodes. The amorphous silicon film is deposited using plasma enhanced chemical vapor deposition, preferably in an silane-argon environment and at a temperature between 200 and 500 degrees C., or reactively sputtered in a variety of reactive gases. In another method, an oxide layer is placed between two amorphous silicon film layers. In yet another method, one of the amorphous silicon film layers about the oxide layer is doped. In another embodiment, a layer of conductive, highly diffusible material is formed either on or under the amorphous silicon film. The feature size and thickness of the amorphous silicon film are selected to minimize further the leakage current while providing the desired programming voltage. A method also is described for forming a field programmable gate array with antifuses.
    Type: Grant
    Filed: May 21, 1996
    Date of Patent: July 14, 1998
    Assignee: QuickLogic Corporation
    Inventors: Hua-Thye Chua, Andrew K. Chan, John M. Birkner, Ralph G. Whitten, Richard L. Bechtel, Mammen Thomas
  • Patent number: 5780918
    Abstract: An input part of a semiconductor integrated circuit includes a fuse element formed from a metal wiring layer and connected between an input pad and a source line is formed from wiring material. The wiring material is aluminum, possibly doped with silicon. The fuse element is narrowed or thinned at a location remote from an internal circuit. The stability and certainty of the melting properties of the fuse element at the narrowed of thinned location is improved even when the device is sealed with resin, without interfering with the manufacturing process, and at the same time the desired fuse element properties are retained. Consequently, the operating characteristics of the internal circuit can be adjusted highly precisely and with certainty after the assembly of the integrated circuit into a package.
    Type: Grant
    Filed: August 12, 1996
    Date of Patent: July 14, 1998
    Assignee: Seiko Epson Corporation
    Inventor: Kanji Aoki
  • Patent number: 5767553
    Abstract: A method of manufacture for flat-cell Mask ROM devices on a silicon semiconductor substrate covered with a first gate oxide layer comprises, forming a first conductor structure on the first gate oxide layer, forming a buried conductive structure within the substrate by ion implantation with a portion thereof in juxtaposition with the first conductor structure, etching away the exposed surfaces of the first gate oxide layer exposing portions of the semiconductor, forming a second gate oxide layer on the surface of the semiconductor, and forming a second conductor structure on the second gate oxide layer.
    Type: Grant
    Filed: May 15, 1996
    Date of Patent: June 16, 1998
    Assignee: United Microelectronics Corporation
    Inventors: Gary Yeunding Hong, Chen-Chiu Hsue
  • Patent number: 5767578
    Abstract: An integrated circuit chip has full trench dielectric isolation of each portion of the chip. Initially the chip substrate is of conventional thickness and has semiconductor devices formed in it. After etching trenches in the substrate and filling them with dielectric material, a heat sink cap is attached to the passivation layer on the substrate front side surface. The passivation layer is a CVD diamond film which provides both electrical insulation and thermal conductivity. The substrate backside surface is removed (by grinding and/or CMP) to expose the bottom portion of the trenches. This fully isolates each portion of the die and eliminates mechanical stresses at the trench bottoms. Thereafter drain or collector electrical contacts are provided on the substrate backside surface. In a flip chip version, frontside electrical contacts extend through the frontside passivation layer to the heat sink cap.
    Type: Grant
    Filed: April 19, 1996
    Date of Patent: June 16, 1998
    Assignee: Siliconix incorporated
    Inventors: Mike F. Chang, King Owyang, Fwu-Iuan Hshieh, Yueh-Se Ho, Jowei Dun, Hans-Jurgen Fusser, Reinhard Zachai
  • Patent number: 5757081
    Abstract: An integrated circuit chip has full trench dielectric isolation of each portion of the chip. Initially the chip substrate is of conventional thickness and has semiconductor devices formed in it. After etching trenches in the substrate and filling them with dielectric material, a heat sink cap is attached to the passivation layer on the substrate front side surface. The substrate backside surface is removed (by grinding or CMP) to expose the bottom portion of the trenches. This fully isolates each portion of the die and eliminates mechanical stresses at the trench bottoms. Thereafter drain or collector electrical contacts are provided on the substrate backside surface. In a flip chip version, frontside electrical contacts extend through the frontside passivation layer to the heat sink cap.
    Type: Grant
    Filed: February 20, 1996
    Date of Patent: May 26, 1998
    Assignee: Siliconix Incorporated
    Inventors: Mike F. Chang, King Owyang, Fwu-Iuan Hshieh, Yueh-Se Ho, Jowei Dun
  • Patent number: 5747868
    Abstract: An improved laser fusible link structure for semiconductor devices (200) and method of manufacturing thereof (10) is disclosed. A first conductive layer is patterned to create a laser fuse (202) and then covered with a first dielectric layer (212). An etch mask layer, in the preferred embodiment a second layer of polysilicon, is deposited and patterned to form a fuse etch mask (214) directly over the laser fuse (202). The fuse etch mask (214) has a width that is smaller than a minimum laser spot size, but large enough to protect the laser fuse (202) from fuse window over-etch, taking into account any potential misalignment between the laser fuse (202) and the fuse etch mask (214).
    Type: Grant
    Filed: June 26, 1995
    Date of Patent: May 5, 1998
    Assignee: Alliance Semiconductor Corporation
    Inventors: Chitranjan N. Reddy, Ajit K. Medhekar