Patents by Inventor Varatharajan Nagabushnam

Varatharajan Nagabushnam 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: 6433430
    Abstract: Disclosed is a novel contact structure comprising an underlying layer of titanium silicide, an intermediate layer of titanium boride, and an overlying layer of polysilicon. Also disclosed is a method for forming the contact structure which comprises depositing a titanium layer in the bottom of a contact opening having oxide insulation sidewalls, forming an overlying layer of polysilicon above the titanium layer, and annealing the two layers together. The resulting contact structure is formed with fewer steps than contact structures of the prior art and without the need for additional steps to achieve uniform sidewall coverage, due to high adhesion of the overlying layer of polysilicon with oxide insulation sidewalls of the contact opening. The contact structure has low contact resistance, and provides a suitable diffusion barrier due to a high melting point.
    Type: Grant
    Filed: July 30, 2001
    Date of Patent: August 13, 2002
    Assignee: Micron Technology, Inc.
    Inventors: Sujit Sharan, Varatharajan Nagabushnam
  • Publication number: 20020000660
    Abstract: Disclosed is a novel contact structure comprising an underlying layer of titanium silicide, an intermediate layer of titanium boride, and an overlying layer of polysilicon. Also disclosed is a method for forming the contact structure which comprises depositing a titanium layer in the bottom of a contact opening having oxide insulation sidewalls, forming an overlying layer of polysilicon above the titanium layer, and annealing the two layers together. The resulting contact structure is formed with fewer steps than contact structures of the prior art and without the need for additional steps to achieve uniform sidewall coverage, due to high adhesion of the overlying layer of polysilicon with oxide insulation sidewalls of the contact opening. The contact structure has low contact resistance, and provides a suitable diffusion barrier due to a high melting point.
    Type: Application
    Filed: July 30, 2001
    Publication date: January 3, 2002
    Inventors: Sujit Sharan, Varatharajan Nagabushnam
  • Patent number: 6284651
    Abstract: Disclosed is a novel contact structure comprising an underlying layer of titanium silicide, an intermediate layer of titanium boride, and an overlying layer of polysilicon. Also disclosed is a method for forming the contact structure which comprises depositing a titanium layer in the bottom of a contact opening having oxide insulation sidewalls, forming an overlying layer of polysilicon above the titanium layer, and annealing the two layers together. The resulting contact structure is formed with fewer steps than contact structures of the prior art and without the need for additional steps to achieve uniform sidewall coverage, due to high adhesion of the overlying layer of polysilicon with oxide insulation sidewalls of the contact opening. The contact structure has low contact resistance, and provides a suitable diffusion barrier due to a high melting point.
    Type: Grant
    Filed: March 19, 1999
    Date of Patent: September 4, 2001
    Assignee: Micron Technology, Inc.
    Inventors: Sujit Sharan, Varatharajan Nagabushnam
  • Patent number: 5700716
    Abstract: Disclosed is a novel contact structure comprising an underlying layer of titanium silicide, an intermediate layer of titanium boride, and an overlying layer of polysilicon. Also disclosed is a method for forming the contact structure which comprises depositing a titanium layer in the bottom of a contact opening having oxide insulation sidewalls, forming an overlying layer of polysilicon above the titanium layer, and annealing the two layers together. The resulting contact structure is formed with fewer steps than contact structures of the prior art and without the need for additional steps to achieve uniform sidewall coverage, due to high adhesion of the overlying layer of polysilicon with oxide insulation sidewalls of the contact opening. The contact structure has low contact resistance, and provides a suitable diffusion barrier due to a high melting point.
    Type: Grant
    Filed: February 23, 1996
    Date of Patent: December 23, 1997
    Assignee: Micron Technology, Inc.
    Inventors: Sujit Sharan, Varatharajan Nagabushnam