Patents Examined by Loc Q. Trinh
  • Patent number: 5272101
    Abstract: A process for fabricating a metal-to-metal antifuse in a process sequence for forming a double layer metal interconnect structure includes the steps of forming and defining a first metal interconnect layer, forming and planarizing an inter-metal dielectric layer, forming an antifuse cell opening in the inter-metal dielectric layer, forming and defining an antifuse layer, forming metal-to-metal via holes in the inter-metal dielectric layer, and forming and defining a second metal interconnect layer.
    Type: Grant
    Filed: August 9, 1991
    Date of Patent: December 21, 1993
    Assignee: Actel Corporation
    Inventors: Abdul R. Forouhi, Esmat Z. Hamdy, Chenming Hu, John L. McCollum
  • Patent number: 5270228
    Abstract: A method of fabricating a field effect transistor in which the gate electrode is formed in a multiple step recess including a first recess located on one level and a second recess located on a lower level. The second, narrower recess is nested in the first, wider recess. The method is initiated by growing a first semiconductor layer of a low etch rate on a semiconductor substrate. Then, a second semiconductor layer of a high etch rate is grown on the first semiconductor layer. A resist film having an opening in a selected location is formed on the second semiconductor layer. Using this resist film as a mask, the semiconductor layers are selectively etched. The gate electrode is formed at the bottom of the multiple step recess created by the etching.
    Type: Grant
    Filed: August 15, 1991
    Date of Patent: December 14, 1993
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Takahide Ishikawa
  • Patent number: 5250465
    Abstract: A semiconductor device having small diameter via-holes, particularly not greater than 0.6 microns, for a multilayer interconnection is produced by a method comprising covering an interlayer film and via-holes with a continuous, first metal film by a CVD process, and heating and melting by an irradiation of an energy beam a second metal film deposited on the first film by a PVD process, together with the first metal film, to fully fill the via-holes with the material from the outside of the holes, to thus form conductive plugs therein. The deposition of the material of the second metal film and the filling of the via-holes may be simultaneously performed by a high temperature sputtering process.
    Type: Grant
    Filed: January 24, 1992
    Date of Patent: October 5, 1993
    Assignee: Fujitsu Limited
    Inventors: Masako Iizuka, Ryoichi Mukai, Motoo Nakano
  • Patent number: 5250456
    Abstract: A method of forming a capacitor in an integrated circuit, such as a dynamic random access memory (DRAM), and a capacitor and DRAM cell formed by such a method, is disclosed. A first capacitor plate is formed of silicon, for example polysilicon, followed by oxidation thereof to form a thin capacitor oxide layer thereover; alternatively, the thin capacitor oxide layer may be deposited. Nitrogen ions are then implanted through the oxide and into the silicon. A high temperature anneal is then performed in a nitrogen atmosphere, which causes the implanted nitrogen to accumulate near the interface between the silicon first plate and the oxide layer, forming a nitride-like region thereat. An optional sealing thermal reaction (oxidation or nitridation) may then be performed, to reduce the effects of pinholes or other defects in the composite film. The second plate may then be formed of polysilicon, metal, or a metal silicide, completing the capacitor.
    Type: Grant
    Filed: September 13, 1991
    Date of Patent: October 5, 1993
    Assignee: SGS-Thomson Microelectronics, Inc.
    Inventor: Frank R. Bryant
  • Patent number: 5250467
    Abstract: An improved process is described for forming planar tungsten-filled contacts to a silicon substrate in contact openings through an insulating layer which provides for the formation of titanium silicide in and on the silicon surface at the bottom of the contact openings to provide low resistance silicide interconnections between the silicon substrate and the tungsten. A titanium nitride layer is formed over the titanium silicide and on the surfaces of the insulation layer, including the top surface of the insulation layer and the sidewall surfaces of the contact openings through the insulating layer. This titanium nitride layer provides a nucleation layer which permits a good bond to form from the tungsten through the titanium nitride and titanium silicide in the contact openings to the silicon substrate; and from the tungsten through the titanium nitride layer to the insulator material such as silicon dioxide (SO.sub.2), resulting in the formation of low resistance and low defect density contacts.
    Type: Grant
    Filed: March 29, 1991
    Date of Patent: October 5, 1993
    Assignee: Applied Materials, Inc.
    Inventors: Sasson Somekh, Jaim Nulman, Mei Chang
  • Patent number: 5250459
    Abstract: The present invention introduces a process to fabricate very low resistive antifuse elements by introducing Antimony (Sb) into one or both of the antifuse element's electrodes and thereby resulting in said very low resistive (programmed) antifuse element. Introducing Sb into the antifuse electrode(s) reduces the depletion width of the dopant impurities thereby causing a large concentration of n+ dopants in the antifuse electrode(s). This allows a reduction in the voltage required across the electrodes to breakdown the inner lying dielectric and thus program or short the electrodes together. In addition, once the two electrodes become shorted together to form a filament, the Sb will flow form one or both electrode(s) and thereby heavily dope the filament itself with n+ atoms. With the presence of the heavy concentration of n+ atoms in the filament, the shorted antifuse element is reduced in resistance by as much as a few hundred ohms or below when compared to antifuse elements fabricated by other methods.
    Type: Grant
    Filed: April 14, 1992
    Date of Patent: October 5, 1993
    Assignee: Micron Technology, Inc.
    Inventor: Roger R. Lee
  • Patent number: 5250448
    Abstract: A heterojunction bipolar transistor of this invention is a miniaturized heterojunction bipolar transistor wherein at least one of an emitter layer and a collector layer is formed of a semiconductor material having a wider band gap than a material of a base layer. A method of fabricating the transistor includes the steps of forming a first semiconductor layer of a first conductivity type on a substrate, which first semiconductor layer serves as a collector layer, etching an unnecessary portion of the first semiconductor layer to form a groove, and burying an insulating layer in the groove, forming a second semiconductor layer serving as a base layer on the first semiconductor layer and that part of the insulating layer surrounding the first semiconductor layer, and forming a third semiconductor layer of the first conductivity type, serving as an emitter layer, on the second semiconductor layer.
    Type: Grant
    Filed: January 31, 1991
    Date of Patent: October 5, 1993
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toshihiko Hamasaki, Hideki Satake
  • Patent number: 5248628
    Abstract: A semiconductor memory device wherein at least one of a storage node contact hole and a bit line contact hole includes a first contact hole made in a first inter-layer insulating film formed over a gate electrode and a second contact hole made in a second inter-layer insulating film formed over an electrically conductive material embedded up to a level higher than the gate electrode in the first contact hole which is contacted with the electrically conductive material, the conductive material being exposed by etching a part of the second inter-layer insulating film, whereby the size of the memory device can be made small and the reliability can be improved. Further, a capacitor is formed in a layer higher than a bit line thereby to facilitate the processing of a storage node electrode to increase the capacitor area and to improve the reliability since it is unnecessary to carry out patterning a plate electrode within a cell array.
    Type: Grant
    Filed: June 9, 1992
    Date of Patent: September 28, 1993
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Naoko Okabe, Satoshi Inoue, Kazumasa Sunouchi, Takashi Yamada, Akihiro Nitayama, Hiroshi Takato
  • Patent number: 5244839
    Abstract: A method of making a hybrid semiconductor device and the device comprising providing a semiconductor substrate having electrical devices therein, providing a first resilient layer of electrically insulating material over the substrate which can be disposed directly onto the substrate with a substantially planar exposed surface, providing a second resilient layer of electrically insulating material over the first resilient layer which can be disposed directly onto the first layer with a substantially planar exposed surface, the second layer having a relatively resilient state and a rigid state, providing resilient standoff from the third resilient layer at spaced locations on the second layer by removing predetermined portions of the third layer, securing a semiconductor superstrate to the semiconductor device, forming electrical devices on the superstrate, and then connecting the electrical devices on the superstrate to the electrical devices on the substrate.
    Type: Grant
    Filed: June 18, 1991
    Date of Patent: September 14, 1993
    Assignee: Texas Instruments Incorporated
    Inventors: James C. Baker, Emily A. Groves, Douglas Paradis, Charles P. Monaghan, Barry Lanier, Thomas D. Bonifield, Julie S. England, Glenn A. Cerny
  • Patent number: 5242851
    Abstract: A programmable interconnect device particularly suitable for field programmable ROM, field programmable gate array and field programmable microprocessor code, includes an intrinsic polycrystalline antifuse dielectric layer.
    Type: Grant
    Filed: July 16, 1991
    Date of Patent: September 7, 1993
    Assignee: Samsung Semiconductor, Inc.
    Inventor: Kyu H. Choi
  • Patent number: 5240871
    Abstract: A dynamic random access memory (DRAM) cell having a corrugated storage contact capacitor for enhancing capacitance. A noncritical alignment is effected between the substrate contact area and the lower capacitor plate by using an etch stop layer to protect wordlines, field-effect transistors (FETs), and field oxide regions during the patterning and etching of storage capacitor regions. The corrugated storage contact capacitor is fabricated by depositing alternating layers of dielectric materials having either substantially different etch rates or wet etch selectivity one toward the other. The layers are isotropically etched and a cavity having corrugated sidewalls is provided. A doped poly layer is deposited to function as the storage-node capacitor plate. The deposition of a dielectric layer is followed by an insitu-doped poly layer deposited to form the upper capacitor plate. The capacitor thus formed is typified as having the storage-node capacitor plate self-aligned to the contact area of the substrate.
    Type: Grant
    Filed: September 6, 1991
    Date of Patent: August 31, 1993
    Assignee: Micron Technology, Inc.
    Inventors: Trung T. Doan, David A. Cathey
  • Patent number: 5238855
    Abstract: A contact-free floating-gate non-volatile memory cell array and process with silicided NSAG bitlines and with source/drain regions buried beneath relatively thick silicon oxide. The bitlines have a relatively small resistance, eliminating the need for parallel metallic conductors with numerous bitline contacts. The array has relatively small bitline capacitance and may be constructed having relatively small dimensions. Bitline isolation is by P/N junction or by oxide-filled trench, permitting relatively small spacing between transistors. Wordlines may be formed from silicided polycrystalline or other material with low resistivity. Coupling of programming and erasing voltages to the floating gate is improved by using an insulator with relatively high dielectric constant between the control gate and the floating gate. The resulting structure is a dense cross-point array of programmable memory cells.
    Type: Grant
    Filed: June 27, 1991
    Date of Patent: August 24, 1993
    Assignee: Texas Instruments Incorporated
    Inventor: Manzur Gill
  • Patent number: 5238860
    Abstract: A semiconductor device comprises an N-type semiconductor substrate, a first P-type well formed in the semiconductor substrate, a second P-type well formed adjacent to the first P-type well in the semiconductor substrate, the surface impurity concentration of the second P-type well being set lower than that of the first P-type well, a DRAM memory cell structure formed in the first P-type well, and an MOS transistor structure formed in the second P-type well to function in combination with the memory cell structure.
    Type: Grant
    Filed: January 3, 1992
    Date of Patent: August 24, 1993
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shizuo Sawada, Syuso Fujii, Masaki Ogihara
  • Patent number: 5236858
    Abstract: The invention relates to a method of manufacturing a DRAM in which a storage capacitor is stacked vertically over a switching junction FET.
    Type: Grant
    Filed: November 25, 1991
    Date of Patent: August 17, 1993
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Kyu H. Lee, Sang H. Chai, Soon I. Yeo, Jin S. Kim, Jin H. Lee
  • Patent number: 5236855
    Abstract: A stacked v-cell (SVC) capacitor using a modified stacked capacitor storage cell fabrication process. The SVC capacitor is made up of polysilicon structure, having a v-shaped cross-section, located at a buried contact and extending to an adjacent storage node overlaid by polysilicon with a dielectric sandwiched in between. The addition of the polysilicon structure increases storage capability 70% without enlarging the surface area defined for a normal stacked capacitor cell.
    Type: Grant
    Filed: November 6, 1990
    Date of Patent: August 17, 1993
    Assignee: Micron Technology, Inc.
    Inventors: Charles H. Dennison, Pierre C. Fazan, Ruojia Lee, Yauh-Ching Liu
  • Patent number: 5236853
    Abstract: A method of forming a closely spaced self-aligned polysilicon pattern of conductive lines is achieved. The method involves forming semiconductor device structures in and on a semiconductor substrate. An insulating layer is formed over the device structures. An insulating layer structure is formed over the semiconductor device structures. A conductive polysilicon layer is formed over the insulating layer. A silicon oxide layer is formed over the polysilicon layer. The oxide layer is now patterned by lithography and etching. The patterning of the oxide layer leaves a first pattern of the oxide over a first designated plurality of polysilicon conductor lines and a second pattern between the oxide which exposes the polysilicon layer over a second designated plurality of polysilicon conductor lines plus the planned spacing between the first and second plurality of polysilicon conductor lines.
    Type: Grant
    Filed: February 21, 1992
    Date of Patent: August 17, 1993
    Assignee: United Microelectronics Corporation
    Inventor: Peter C. C. Hsue
  • Patent number: 5236856
    Abstract: A polysilicon layer is provided with a p-type impurity, and masked with an oxide mask to define a p-type region of the polysilicon layer. A second impurity is then provided into first unmasked regions of the polysilicon layer. A second oxide mask is deposited and anisotropically etched to form spacers adjacent to the first oxide mask. The spacers define two diffusion barrier regions of the polysilicon layer adjacent to the p-type region. An n-type impurity is then provided into second unmasked regions of the polysilicon layer to form two n-type regions adjacent the diffusion barrier regions. The diffusion barrier regions prevent cross diffusion of the p-type and the n-type impurities within the polysilicon layer, while also being of sufficient dimensions to permit normal p/n operations.
    Type: Grant
    Filed: August 30, 1991
    Date of Patent: August 17, 1993
    Assignee: Micron Technology, Inc.
    Inventors: Hiang C. Chan, Pierre C. Fazan, Bohr-Winn Shih
  • Patent number: 5234856
    Abstract: A new stacked-trench DRAM cell has a trench that is self-aligned to an adjacent field oxide region and the dielectric spacer insulated edge of the access transistor gate. The trench is lined with dielectric material and an arsenic-doped polysilicon storage node plate makes contact with the storage node junction on a horizontal surface on the lip of the trench. The horizontal surface is exposed following trench formation by etching away an outer portion of the transistor gate spacer, which is comprised of a material that is selectively etchable with respect to an inner portion of the spacer. Since the contact area between the storage node plate and the storage node junction is limited to this very small area, the potential for leakage of capacitor charge into the substrate is minimized.
    Type: Grant
    Filed: April 15, 1992
    Date of Patent: August 10, 1993
    Assignee: Micron Technology, Inc.
    Inventor: Fernando Gonzalez
  • Patent number: 5234855
    Abstract: A stacked comb spacer capacitor (SCSC) using a modified stacked capacitor storage cell fabrication process. The SCSC is made up of polysilicon structure, having a spiked v-shaped (or comb-shaped) cross-section, located at a buried contact and extending to an adjacent storage node overlaid by polysilicon with a dielectric sandwiched in between. The creation of the spiked polysilicon structure increases storage capability 50% without enlarging the surface area defined for a normal buried digit line stacked capacitor cell. Removing the dielectric residing under the backside of the storage node cell plate and filling that area with polysilicon increases storage capacity by an additional 50% or more.
    Type: Grant
    Filed: December 21, 1990
    Date of Patent: August 10, 1993
    Assignee: Micron Technology, Inc.
    Inventors: Howard E. Rhodes, Hiang C. Chan, Charles H. Dennison, Yauh-Ching Liu, Pierre C. Fazan, Gurtej S. Sandhu
  • Patent number: 5232860
    Abstract: A method of flexible photovoltaic device manufacture in which an inorganic separation layer and inorganic first protective film layer are formed on a supporting substrate. On the inorganic first protective film, a first electrode, an amorphous silicon photovoltaic layer, a second electrode, and a second protective film are formed in that order. Then the supporting substrate and the inorganic separation layer are separated. The inorganic separation layer is a material that bonds weakly with both the supporting substrate and the inorganic first protective film.
    Type: Grant
    Filed: March 16, 1992
    Date of Patent: August 3, 1993
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Yasuyoshi Kawanishi, Osamu Takahashi, Masatoshi Otsuki, Kenzi Sawada