Patents by Inventor Bertram Schwartz

Bertram Schwartz has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4738934
    Abstract: Epitaxial layers of semi-insulating InP grown by MOCVD on conducting InP wafers make excellent substrates for III-V semiconductor devices. Particularly appealing is the low defect density obtained because of the conducting InP wafers and excellent insulating characteristics of the semi-insulating InP layer. The invention is a procedure for doping the insulating layer by ion implantation. Such a procedure is unusually advantageous for fabricating a variety of devices including MISFETs, MESFETs and JFETs.
    Type: Grant
    Filed: May 16, 1986
    Date of Patent: April 19, 1988
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Wilbur D. Johnston, Jr., Judith A. Long, Albert T. Macrander, Bertram Schwartz, Shobha Singh
  • Patent number: 4731293
    Abstract: A fabrication technique is described for making various devices in which a type of glass is used as a surface protection layer. The glass layers are put down by particle bombardment (generally sputtering or e-beam bombardment) of a phosphorus-containing silicate glass target. Devices with such layers are also described. Such glass layers are highly advantageous as encapsulating material, diffusion barrier layers, etc., particularly for optical type devices and certain semiconductor devices. Particularly important is the preparation procedure for the glass target used in the bombardment process. The glass layers are moisture stable, act as excellent barriers against diffusion, and are usable up to quite high temperatures without cracking or peeling. The glass layers also provide long-term protection against atmosphere components including water vapor, oxygen, atmosphere pollution contaminants, etc.
    Type: Grant
    Filed: June 20, 1986
    Date of Patent: March 15, 1988
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: David T. Ekholm, William H. Grodkiewicz, Bertram Schwartz, Shobha Singh, LeGrand G. Van Uitert, George J. Zydzik
  • Patent number: 4645116
    Abstract: Indium is used to bond semiconductor lasers to their heat-sinks without the presence of a corrosive liquid flux. Fluxless bonding is achieved in a vacuum chamber in reducing ambients of CO or H.sub.2. Low strain bonds are achieved at bonding temperatures of approximately 180.degree.-240.degree. C. in CO and 220.degree.-230.degree. C. in H.sub.2. Void-free bonds are achieved in CO at temperatures as low as about 205.degree. C. The technique is applicable to other microelectronic chips such as LEDs, for example.
    Type: Grant
    Filed: September 5, 1984
    Date of Patent: February 24, 1987
    Assignee: AT&T Bell Laboratories
    Inventors: Gerard E. Henein, Ralph T. Hepplewhite, Bertram Schwartz
  • Patent number: 4599791
    Abstract: The property of materials in the GaAs/AlGaAs system, whereby at certain doses proton bombarded n-type material becomes highly resistive but p-type material remains highly conductive, is utilized to fabrication of integrated circuits which include buried semiconductor interconnections or bus bars between devices.
    Type: Grant
    Filed: November 28, 1983
    Date of Patent: July 15, 1986
    Assignee: AT&T Bell Laboratories
    Inventors: Marlin W. Focht, Louis A. Koszi, Bertram Schwartz
  • Patent number: 4597165
    Abstract: The property of materials in the InP system, whereby helium ion or deuteron bombarded p-type material becomes highly resistive but n-type material remains relatively conductive, is utilized to fabricate integrated circuits which include buried semiconductor interconnections or bus bars between devices.
    Type: Grant
    Filed: November 28, 1983
    Date of Patent: July 1, 1986
    Assignee: AT&T Bell Laboratories
    Inventors: Federico Capasso, Marlin W. Focht, Albert T. Macrander, Bertram Schwartz
  • Patent number: 4539743
    Abstract: The property of Group III-V compound materials, whereby ion bombarded material becomes highly resistive but recovers its original low resistivity by annealing at a temperature which is dopant and material dependant, is utilized to fabricate integrated circuits which include buried semiconductor interconnections or bus bars between devices.
    Type: Grant
    Filed: November 28, 1983
    Date of Patent: September 10, 1985
    Assignee: AT&T Bell Laboratories
    Inventors: Philip J. Anthony, Robert L. Hartman, Louis A. Koszi, Bertram Schwartz
  • Patent number: 4514896
    Abstract: Semiconductor light emitting devices, lasers and LEDs, are described in which the current flow channel is narrower near the top surface of the device and wider at its bottom near the active region. Also, described are several attenuation masks for fabricating the channels of these devices by particle bombardment.
    Type: Grant
    Filed: January 17, 1984
    Date of Patent: May 7, 1985
    Assignee: AT&T Bell Laboratories
    Inventors: Richard W. Dixon, William B. Joyce, Louis A. Koszi, Richard C. Miller, Bertram Schwartz
  • Patent number: 4504952
    Abstract: A TJS light emitting diode (laser or LED) comprises an isotype double heterostructure (DH) and a V-groove which penetrates the intermediate layer of the DH. The groove is filled with a region of semiconductor material which enables carrier injection to occur from the region into the intermediate layer, or conversely, depending on the relative bandgaps of the layer and region. Real-refractive index guiding by the groove is described.
    Type: Grant
    Filed: June 1, 1982
    Date of Patent: March 12, 1985
    Assignee: AT&T Bell Laboratories
    Inventors: Robert L. Hartman, Louis A. Koszi, Bertram Schwartz
  • Patent number: 4447905
    Abstract: Semiconductor light emitting devices, lasers and LEDs, are described in which the current flow channel is narrower near the top surface of the device and wider at its bottom near the active region. Also, described are several attenuation masks for fabricating the channels of these devices by particle bombardment.
    Type: Grant
    Filed: March 25, 1981
    Date of Patent: May 8, 1984
    Assignee: Bell Telephone Laboratories, Incorporated
    Inventors: Richard W. Dixon, Louis A. Koszi, Richard C. Miller, Bertram Schwartz
  • Patent number: 4429231
    Abstract: A system (FIG. 1) for interrogating the ON-OFF status of an electrical switch (31) comprises a semiconductor body (4) containing a PN junction and means (5) for electrically connecting an auxiliary switch (32) coupled to the interrogated switch, or alternately (FIG. 2) the interrogated switch (32), across the PN junction. Light (7) of a first wavelength incident on the semiconductor body causes light of a second wavelength (11) to be emitted from the body when the switch is open (OFF), whereas no light is emitted from the body when the switch is closed (ON). Therefore, photoelectric detection of the emission vs. non-emission of light of the second wavelength from the semiconductor body indicates the OFF vs. ON status of the switch.
    Type: Grant
    Filed: November 25, 1981
    Date of Patent: January 31, 1984
    Assignee: Bell Telephone Laboratories, Incorporated
    Inventors: Bernard C. De Loach, Jr., Richard C. Miller, Bertram Schwartz
  • Patent number: 4408331
    Abstract: Semiconductor lasers and LEDs are described in which the pumping current is constrained to flow from a relatively narrow upper channel formed by a V-groove, which extends to a depth short of the active region, through a relatively wider lower channel bounded by high resistivity regions, which extend from at least that depth into or through the active region. Also described are devices in which the V-groove is refilled with semiconductor material.
    Type: Grant
    Filed: March 25, 1981
    Date of Patent: October 4, 1983
    Assignee: Bell Telephone Laboratories, Incorporated
    Inventors: Robert L. Hartman, Louis A. Koszi, Bertram Schwartz
  • Patent number: 4340967
    Abstract: This invention is a semiconductor junction laser which operates in a transverse mode, other than the fundamental mode, parallel to the p-n junction. An undesired transverse mode parallel to the p-n junction may be suppressed by introducing a lossy region within the laser where this mode has at least one of its maxima. The zero order transverse mode parallel to the p-n junction may be suppressed in a double heterostructure stripe geometry laser by introducing an optically or electrically lossy region in the current flow path of the laser where the zero order mode has its maximum. This double heterostructure stripe geometry laser operates linearly with respect to current in the first order transverse mode parallel to the p-n junction.
    Type: Grant
    Filed: June 2, 1980
    Date of Patent: July 20, 1982
    Assignee: Bell Telephone Laboratories, Incorporated
    Inventors: Richard W. Dixon, Bertram Schwartz
  • Patent number: 4292512
    Abstract: The tracking problems of prior art optical monitoring (e.g., feedback stabilization) schemes are substantially alleviated by positioning a photodiode (PD 130) directly in the light path of the optical source (100) to be stabilized. The active (light-absorbing) layer (104) of the PD samples (absorbs) only a small portion of the light beam (140) emanating from the source and converts that portion to a photocurrent used in a feedback loop (120, 101) to control the excitation supplied to the source. The remaining, major portion (140') of the beam is transmitted unabsorbed through the PD active layer to utilization means (e.g., through an optical fiber 108 to a remote receiver). Advantageously, in one embodiment the PD is a double heterostructure (DH) in which the photocurrent is linearly related to the beam intensity. The use of discrete or integrated lens means (110, 110', 164, 166) to enhance coupling from the source to PD is described.
    Type: Grant
    Filed: June 19, 1978
    Date of Patent: September 29, 1981
    Assignee: Bell Telephone Laboratories, Incorporated
    Inventors: Richard C. Miller, Bertram Schwartz
  • Patent number: 4227975
    Abstract: Plasma etching is described as a selective etch for dielectric masks such as SiO.sub.2, Si.sub.3 N.sub.4 and certain photoresists in the presence of native oxides of Group III-V compound semiconductors. This process can be used in the fabrication of mesa junction lasers and Burrus light emitting diodes.
    Type: Grant
    Filed: January 29, 1979
    Date of Patent: October 14, 1980
    Assignee: Bell Telephone Laboratories, Incorporated
    Inventors: Robert L. Hartman, Louis A. Koszi, Cyril J. Mogab, Bertram Schwartz
  • Patent number: 4127862
    Abstract: A plurality n of double heterostructure photodiodes are coupled together by (n-1) interleaved n.sup.+ -p.sup.+ tunnel junctions to form a multi-layered integrated structure which has an open circuit photovoltage approaching the sum of the open circuit photovoltages of the individual photodiodes. In one embodiment, in which radiation to be detected is made incident normal to the layers, the absorbing layers of the photodiodes get progressively thicker away from the substrate. In a second embodiment, in which the radiation is made incident parallel to the layers, all of the absorbing layers have essentially the same thickness. In a third embodiment, in which radiation is made incident normal to the layers, the structure has a stepped configuration and all of the absorbing layers have essentially the same thickness.
    Type: Grant
    Filed: September 6, 1977
    Date of Patent: November 28, 1978
    Assignee: Bell Telephone Laboratories, Incorporated
    Inventors: Marc Ilegems, Louis A. Koszi, Bertram Schwartz
  • Patent number: 4026741
    Abstract: A technique for preparing stoichiometric group III-V compound semiconductor surfaces involves a repetitive anodizing and etching sequence in an aqueous solution of appropriate pH and a basic solution, respectively. Surfaces treated in the described manner evidence a correct surface stoichiometry and minimum carbon contamination.
    Type: Grant
    Filed: June 16, 1976
    Date of Patent: May 31, 1977
    Assignee: Bell Telephone Laboratories, Incorporated
    Inventors: Chuan Chung Chang, Paul H. Citrin, Bertram Schwartz
  • Patent number: 3959098
    Abstract: An electrolytic process for etching Group III - Group V semiconductive compounds, especially gallium-containing compound semiconductors. The sample to be etched is made the anode in an electrolytic cell wherein the electrolyte includes nitrate or chloride ions. Etching rates may be easily controlled according to the current supplied to the system.
    Type: Grant
    Filed: March 12, 1973
    Date of Patent: May 25, 1976
    Assignee: Bell Telephone Laboratories, Incorporated
    Inventor: Bertram Schwartz
  • Patent number: H147
    Abstract: Helium-3 and helium-4 bombardment of InP over a fluence range of 10.sup.11 to 10.sup.16 ions/cm.sup.2 reproducibly forms highly resistive regions in both p-type and n-type single crystal material. Average peak resistivities are about 10.sup.9 ohm-cm for p-type InP and are about 10.sup.3 ohm-cm for n-type InP. High resistivity has also been produced in GaP, GaSb, GaAs, and InGaAs by helium bombardment. Stripe geometry lasers and planar photodiodes which incorporate helium-bombarded zones are described.
    Type: Grant
    Filed: May 31, 1983
    Date of Patent: November 4, 1986
    Assignee: AT&T Bell Laboratories
    Inventors: Leonard C. Feldman, Marlin W. Focht, Albert T. Macrander, Bertram Schwartz