Patents by Inventor Brij Bihari Lal

Brij Bihari Lal 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: 6303217
    Abstract: A magnetic recording medium having a dual underlayer structure is described. The underlayer structure is composed of a first underlayer of chromium and a second underlayer of a chromium alloy.
    Type: Grant
    Filed: October 2, 1998
    Date of Patent: October 16, 2001
    Assignee: HMT Technology, Corporation
    Inventors: Sudhir S. Malhotra, Brij Bihari Lal, Michael A. Russak
  • Patent number: 6210819
    Abstract: A longitudinal magnetic recording medium having a CrTi underlayer deposited under a substrate bias is described. The medium has improved magnetic recording properties.
    Type: Grant
    Filed: July 24, 1998
    Date of Patent: April 3, 2001
    Assignee: HMT Technology Corporation
    Inventors: Brij Bihari Lal, Lan Zhang
  • Patent number: 6146737
    Abstract: A magnetic recording medium having a barrier layer deposited directly on the magnetic recording layer is described. The barrier layer is deposited by sputter deposition under a nitrogen-containing sputtering atmosphere to form a nitrogen-containing chromium or chromium alloy barrier layer. The barrier layer is effective to inhibit migration of cobalt from the underlying magnetic recording layer, reducing corrosion of the medium and improving magnetic recording performance.
    Type: Grant
    Filed: September 18, 1998
    Date of Patent: November 14, 2000
    Assignee: HMT Technology Corporation
    Inventors: Sudhir S. Malhotra, Brij Bihari Lal, James L. Chao, Michael A. Russak
  • Patent number: 6007924
    Abstract: An improvement in a magnetic recording medium having an underlayer and first and second magnetic recording layers is described. The improvement, effective to reduce media noise, includes deposition of an interlayer between the first and second magnetic recording layers. The interlayer is deposited to a thickness of between 5-50 .ANG. and is composed of an CoCr-based alloy having a defined saturation magnetization.
    Type: Grant
    Filed: July 2, 1997
    Date of Patent: December 28, 1999
    Assignee: HMT Technology Corporation
    Inventors: Brij Bihari Lal, Sudhir S. Malhotra, Michael A. Russak
  • Patent number: 5922442
    Abstract: An improvement in a magnetic recording medium having an underlayer and a magnetic layer is described. The improvement, effective to increase the coercivity of the medium, includes deposition of an interlayer between the underlayer and the magnetic recording layer. The interlayer is deposited to a thickness of between 10-60 .ANG. and is composed of an CoCr-based alloy having a defined saturation magnetization.
    Type: Grant
    Filed: March 28, 1997
    Date of Patent: July 13, 1999
    Assignee: HMT Technology Corporation
    Inventors: Brij Bihari Lal, Sudhir S. Malhotra, Michael A. Russak
  • Patent number: 5849386
    Abstract: An improvement in a magnetic recording medium having an underlayer and a magnetic recording layer is described. The improvement, effective to reduce media anisotropy, includes deposition of a prelayer on the substrate, prior to deposition of the underlayer. The prelayer is deposited to a thickness of between 10-60 .ANG. and is composed of an CoCr-based alloy having a defined saturation magnetization.
    Type: Grant
    Filed: August 7, 1997
    Date of Patent: December 15, 1998
    Assignee: HMT Technology Corporation
    Inventors: Brij Bihari Lal, Sudhir S. Malhotra, Michael A. Russak
  • Patent number: 5834111
    Abstract: A bilayer magnetic recording medium having first and second magnetic recording layers separated by a nonmagnetic isolation layer is disclosed. The medium is characterized by a high coercivity, low noise and an improved overwrite. In producing the medium, the second magnetic layer is deposited under sputtering conditions effective to produce a higher coercivity.
    Type: Grant
    Filed: May 31, 1994
    Date of Patent: November 10, 1998
    Assignee: HMT Technology Corporation
    Inventors: Brij Bihari Lal, Tadashi Shinohara
  • Patent number: 5744253
    Abstract: A magnetic thin-film medium characterized by high coercivity, loop squareness, and signal-to-noise ratio characteristics. The medium includes a disc-like substrate, a sputtered Cr underlayer having a thickness between 100-300 .ANG., and a sputtered Co alloy magnetic thin-film layer having a thickness between 250-800 .ANG.. The sputtered Cr and magnetic layers are preferably formed under sputtering conditions in which a negative bias of between -50 to -600 volts is applied to the substrate.
    Type: Grant
    Filed: October 22, 1992
    Date of Patent: April 28, 1998
    Assignee: HMT Technology Corporation
    Inventors: Brij Bihari Lal, Tadashi Shinohara
  • Patent number: 5736020
    Abstract: A target assembly for use in forming a protective overcoat in a magnetic recording medium is described. The assembly includes a centrally positioned target with inner and outer magnetic means adjacent the target. A sputtering shield is positioned between the target and the medium for controlling the amount and angle of material deposition on the medium. The assembly is effective to deposit an overcoat having a greater thickness in the inner landing zone of the medium than in the outer data zone. A method of using the assembly is also disclosed.
    Type: Grant
    Filed: December 19, 1995
    Date of Patent: April 7, 1998
    Assignee: HMT Technology Corporation
    Inventors: Brij Bihari Lal, Allen J. Bourez, Michael A. Russak
  • Patent number: 5714044
    Abstract: A method for forming an overcoat having first and second layers in a magnetic recording medium is described. The first overcoat layer is deposited in a first sputtering chamber where the magnetic means for confining target plasma in the chamber are oriented to retain magnetic-field confinement about the target surface and to produce magnetic field lines between directly confronting portions of the confronting sputtering targets. The second overcoat layer is deposited under a nitrogen-containing atmosphere.
    Type: Grant
    Filed: August 7, 1995
    Date of Patent: February 3, 1998
    Assignee: HMT Technology Corporation
    Inventors: Brij Bihari Lal, Allen J. Bourez, Michael A. Russak
  • Patent number: 5693197
    Abstract: A method of producing a magnetic recording medium by sputtering a layer onto a substrate by DC-magnetron sputtering from a target while exposing the target to an RF signal is described. The RF signal is effective to extend the target utilization without significantly decreasing the sputtering rate. Also disclosed is an apparatus for use forming a medium in accordance with the method of the invention.
    Type: Grant
    Filed: October 6, 1994
    Date of Patent: December 2, 1997
    Assignee: HMT Technology Corporation
    Inventors: Brij Bihari Lal, Allen J. Bourez, Tadashi Shinohara
  • Patent number: 5693199
    Abstract: A sputtering assembly for use in forming sputter deposited layers on a substrate is described. The assembly includes a pair of confronting sputtering targets for depositing sputtered layers onto the substrate and a movably mounted heating means for heating the substrate. A method of using the assembly is also disclosed.
    Type: Grant
    Filed: July 24, 1996
    Date of Patent: December 2, 1997
    Assignee: HMT Technology Corporation
    Inventors: Allen J. Bourez, Brij Bihari Lal, Michael A. Russak
  • Patent number: 5693198
    Abstract: A method for forming a magnetic recording medium having a chromium underlayer and a magnetic recording layer is described. The method includes sputtering the underlayer and the magnetic layer in a single sputtering chamber from a two-region target having an inner chromium region and an outer magnetic region. Each target region is successively energized for sputter deposition of each layer.
    Type: Grant
    Filed: January 13, 1995
    Date of Patent: December 2, 1997
    Assignee: HMT Technology Corporation
    Inventors: Brij Bihari Lal, Tadashi Shinohara
  • Patent number: 5685959
    Abstract: A cathode assembly having a magnetic-field shunt for use in a magnetron sputtering apparatus is described. The magnetic-field shunt disposed between a sputtering target and a source of magnetic flux, and the shunt is moveable between first and second positions to effect preferential target erosion at first and second target regions, respectively. A method of using the assembly for preparation of a magnetic recording medium is also described.
    Type: Grant
    Filed: October 25, 1996
    Date of Patent: November 11, 1997
    Assignee: HMT Technology Corporation
    Inventors: Allen J. Bourez, Brij Bihari Lal, Michael A. Russak