Patents Represented by Attorney Richard D. Laumann

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  • Field effect transistor with landing pad
    Patent number: 5407859
    Abstract: A field effect transistor is fabricated with a window pad layer that is patterned using a patterned dielectric with sublithographic spacing as an etch mask. Desirable attributes of the transistor include small junction capacitance.
    Type: Grant
    Filed: December 1, 1993
    Date of Patent: April 18, 1995
    Assignee: AT&T Corp.
    Inventors: Kuo-Hua Lee, Chun-Ting Liu, Ruichen Liu
  • Optical circulator for dispersion compensation
    Patent number: 5404413
    Abstract: Dispersion compensation is achieved in an optical communications system by using an optical circulator with first, second, and third ports. The first and third ports are connected to system optical fibers. The second port is connected to a dispersion compensating fiber and return means. The signal passes through the dispersion compensating fiber twice permitting shorter dispersion compensating fibers to be used than were previously used. A Faraday rotator may be used compensate for the polarization mode dispersion of the fiber.
    Type: Grant
    Filed: December 14, 1993
    Date of Patent: April 4, 1995
    Assignee: AT&T Corp.
    Inventors: Jean-Marc P. Delavaux, Kinichiro Ogawa
  • Method for forming solder bumps on a substrate using an electrodeposition technique
    Patent number: 5396702
    Abstract: Solder bumps are electrodeposited onto a substrate with carefully controlled heights by forming patterned conductors on an substrate, depositing and patterning a layer of material, such as titanium that is easily oxidized, and electrodepositing the solder bumps. The solder does not deposit on the titanium. Solder bumps of uniform height are obtained because the titanium layer acts as part of the electrical circuit during electrodeposition.
    Type: Grant
    Filed: December 15, 1993
    Date of Patent: March 14, 1995
    Assignee: AT&T Corp.
    Inventor: Mindaugas F. Dautartas
  • Integrated circuit with self-aligned isolation
    Patent number: 5395789
    Abstract: Integrated circuits are fabricated on a bonded wafer which has a buried silicide layer.
    Type: Grant
    Filed: August 6, 1993
    Date of Patent: March 7, 1995
    Assignee: AT&T Corp.
    Inventor: Bruce A. Beitman
  • Method of manufacturing shallow junction field effect transistor
    Patent number: 5395787
    Abstract: Shallow junctions n- and p-channel field effect transistors are formed with a single ion implant into a conformal tungsten silicide layer. Although phosphorous and boron are implanted into the same silicide regions, the phosphorous prevents the boron from outdiffusing.
    Type: Grant
    Filed: December 1, 1993
    Date of Patent: March 7, 1995
    Assignee: AT&T Corp.
    Inventors: Kuo-Hua Lee, Chun-Ting Liu, Ruichen Liu
  • Optical amplifier
    Patent number: 5392153
    Abstract: An amplifier is described which has a two stage arrangement in which the second stage is pumped with the pump signal not used in the first stage.
    Type: Grant
    Filed: August 31, 1993
    Date of Patent: February 21, 1995
    Assignee: AT&T Corp.
    Inventor: Jean-Marc P. Delavaux
  • Method for selectively etching AlGaAs
    Patent number: 5380398
    Abstract: A method for semiconductor device fabrication that uses a mixture of SiCl.sub.4, CF.sub.4, O.sub.2, and He to selectively etch GaAs with respect to AlGaAs. Etch selectivities greater than 300:1 are obtained.
    Type: Grant
    Filed: November 25, 1992
    Date of Patent: January 10, 1995
    Assignee: AT&T Bell Laboratories
    Inventor: Lawrence E. Smith
  • Method for laser welding of optical packages
    Patent number: 5367140
    Abstract: A piezoelectric actuator is used to control the relative positions of a laser and optical fiber during laser welding of components to a base.
    Type: Grant
    Filed: December 27, 1993
    Date of Patent: November 22, 1994
    Assignee: AT&T Bell Laboratories
    Inventors: Musa K. Jouaneh, Sabbir S. Rangwala
  • ISDN transmitter
    Patent number: 5353309
    Abstract: A transmitter suitable for ISDN use feeds the 2B1Q transmit signals directly into a sigma-delta modulator. The input word is two or three bits and the datapath within the sigma-delta modulator need be only six bits wide. The sigma-delta modulator has sample-hold means which has some filtering effect. The additional filtering requirements are met with an analog filter. No digital interpolation filter is required.
    Type: Grant
    Filed: May 1, 1992
    Date of Patent: October 4, 1994
    Assignee: AT&T Bell Laboratories
    Inventors: Oscar E. Agazzi, Steven R. Norsworthy
  • Method of integrated circuit manufacturing using deposited oxide
    Patent number: 5328872
    Abstract: Contamination of LPCVDBP TEOS films is reduced by preventing volatile compounds, resulting from reactions of the residue in the outlet of the furnace from reaching the deposition portion of the furnace where they would otherwise react with the deposition gases to produce chemically generated particles which contaminate the dielectric film.
    Type: Grant
    Filed: December 29, 1989
    Date of Patent: July 12, 1994
    Assignee: AT&T Bell Laboratories
    Inventors: Ajit S. Manocha, Virendra V. S. Rana, James F. Roberts, Ankineedu Velaga
  • Method for integrated circuit fabrication including linewidth control during etching
    Patent number: 5326727
    Abstract: Pattern transfer from a resist to an underlying layer is accomplished by etching the underlying layer in a plasma comprising hydrogen bromide and oxygen. Accuracy of pattern transfer is obtained by using first and second materials underneath the resist. The first and second materials may be, e.g., polysilicon and a photoresist. Etching of the resist is performed under conditions designed to minimize changes in the horizontal dimensions.
    Type: Grant
    Filed: December 30, 1992
    Date of Patent: July 5, 1994
    Assignee: AT&T Bell Laboratories
    Inventors: Taeho Kook, Avinoam Kornblit, Kolawole R. Olasupo
  • Method of making thin film transistors including recrystallization and high pressure oxidation
    Patent number: 5322807
    Abstract: A thin film transistor is formed by depositing amorphous silicon and forming a gate structure and then using a high-pressure oxidation to form a high-quality gate oxide that has a layered structure.
    Type: Grant
    Filed: August 19, 1992
    Date of Patent: June 21, 1994
    Assignee: AT&T Bell Laboratories
    Inventors: Min-Liang Chen, Pradip K. Roy
  • Method of integrated circuit fabrication including selective etching of silicon and silicon compounds
    Patent number: 5310457
    Abstract: High etch selectivity of both silicon nitride and silicon with respect to silicon oxide is obtained using an etch bath of phosphoric acid, hydrofluoric acid, and nitric acid. Minimal loading effects are observed and a long bath life is obtained by replenishing the hydroflouric and nitric acids.
    Type: Grant
    Filed: September 30, 1992
    Date of Patent: May 10, 1994
    Assignee: AT&T Bell Laboratories
    Inventor: David H. Ziger
  • Method of etching anti-reflection coating
    Patent number: 5308742
    Abstract: A polyimide layer used in manufacturing semiconductor integrated circuits is etched in a plasma comprising O.sub.2, Ar, and CHF.sub.3. The plasma produces excellent critical dimension control and yields good resist to polyimide etching selectivity.
    Type: Grant
    Filed: June 3, 1992
    Date of Patent: May 3, 1994
    Assignee: AT&T Bell Laboratories
    Inventor: Thuy B. Ta
  • Transistor with inverse silicide T-gate structure
    Patent number: 5290720
    Abstract: A method of making a silicided inverse T-gate with an L-shaped silicon spacer and nitride sidewall spacers is described. The L-shaped spacer is electrically connected to the gate.
    Type: Grant
    Filed: July 26, 1993
    Date of Patent: March 1, 1994
    Assignee: AT&T Bell Laboratories
    Inventor: Min-Liang Chen
  • Manhattan street network with loop architecture
    Patent number: 5289467
    Abstract: A network is described which has a Manhattan Street architecture that is implemented using a token ring system, such as the fiber distributed data interface, with the primary and secondary rings representing vertical and horizontal lines, respectively.
    Type: Grant
    Filed: November 27, 1990
    Date of Patent: February 22, 1994
    Assignee: AT&T Bell Laboratories
    Inventor: Stamatios V. Kartalopoulos
  • Integrated circuit process using a "hard mask"
    Patent number: 5264076
    Abstract: A layer of spin-on-glass is used as a hard mask for patterning an underlying layer of polysilicon. The patterned polysilicon may be used in the gate structures of field effect transistors.
    Type: Grant
    Filed: December 17, 1992
    Date of Patent: November 23, 1993
    Assignee: AT&T Bell Laboratories
    Inventors: John D. Cuthbert, David P. Favreau
  • Matrix addressed S-SEED optical modulator array
    Patent number: 5233184
    Abstract: Monolithic optically bistable modulator arrays, such as an M.times.N array of S-SEEDs, are electrically addressed with a matrix of electrical row and column contacts. Connected to the center node of each S-SEED is an addressing means having elements, such as diodes, transistors, or capacitors, which are electrically enabled and disabled.
    Type: Grant
    Filed: December 27, 1991
    Date of Patent: August 3, 1993
    Assignee: AT&T Bell Laboratories
    Inventors: Leo M. F. Chirovsky, Anthony L. Lentine, David A. B. Miller
  • Method of integrated circuit manufacturing including cell assembly
    Patent number: 5229231
    Abstract: A method is described which reduces the size of the constraint graph used in assembling cells into a tiled module for integrated circuit manufacture. The smaller size significantly reduces the amount of time required to assemble the cells appropriately.
    Type: Grant
    Filed: August 30, 1991
    Date of Patent: July 20, 1993
    Assignee: AT&T Bell Laboratories
    Inventors: Debaprosad Dutt, Chi-Yuan Lo
  • Tungsten metallization
    Patent number: 5227335
    Abstract: The adhesion of tungsten to an underlying dielectric layer is improved by the use of a thin glue layer of either TiN or Al.
    Type: Grant
    Filed: April 30, 1990
    Date of Patent: July 13, 1993
    Assignee: AT&T Bell Laboratories
    Inventors: Lowell H. Holschwandner, Virendra V. S. Rana