Patents by Inventor Mohan Bhan

Mohan Bhan 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: 6296712
    Abstract: The invention provides a substrate support member and a purge guide for directing purge gas past the edge of a substrate and towards the outer perimeter of the chamber. The purge guide includes a plurality of holes disposed around the inner perimeter thereof to provide a purge gas passage and to prevent purge gas from interfering with the deposition chemistry on the surface of the substrate. A substrate support member is also provided having a vacuum chuck for securing a substrate to the upper surface thereof. The substrate support member preferably includes a shoulder on which the purge guide is supported during processing. The invention also provides a method for shielding an edge of a substrate by flowing a purge gas adjacent the edge of the substrate and then through a plurality of purge holes on a purge guide.
    Type: Grant
    Filed: April 6, 1998
    Date of Patent: October 2, 2001
    Assignee: Applied Materials, Inc.
    Inventors: Xin Sheng Guo, Mohan Bhan, Justin Jones, Lawrence Lei, Russell Ellwanger, Mei Chang, Ashok Sinha, Avi Tepman
  • Patent number: 6223685
    Abstract: An improved method of reducing the level of contaminants (e.g., fluorine) absorbed in films deposited within a substrate processing chamber. A seasoning layer is deposited within the substrate processing chamber to cover contaminants that may be absorbed within walls or insulation areas of the chamber interior. The deposited seasoning layer is more stable than prior art seasoning layers and is thus less likely to release the absorbed contaminants into the substrate processing chamber during the subsequent deposition of films. In a preferred embodiment, the seasoning layer is formed from a mixed frequency PECVD process in which the low frequency RF signal is supplied at a high power level to increase ion bombardment and enhance film stability. The increased bombardment favors the formation of stable SiF bonds between silicon and fluorine atoms in the lattice structure of the film rather than unstable SiF2 or other bonds. When residual fluorine atoms (e.g.
    Type: Grant
    Filed: December 1, 1999
    Date of Patent: May 1, 2001
    Assignee: Applied Materials, Inc.
    Inventors: Anand Gupta, Mohan Bhan, Sudhakar Subrahmanyam
  • Patent number: 6020035
    Abstract: An improved method of reducing the level of contaminants (e.g., fluorine) absorbed in films deposited within a substrate processing chamber. A seasoning layer is deposited within the substrate processing chamber to cover contaminants that may be absorbed within walls or insulation areas of the chamber interior. The deposited seasoning layer is more stable than prior art seasoning layers and is thus less likely to release the absorbed contaminants into the substrate processing chamber during the subsequent deposition of films. In a preferred embodiment, the seasoning layer is formed from a mixed frequency PECVD process in which the low frequency RF signal is supplied at a high power level to increase ion bombardment and enhance film stability. The increased bombardment favors the formation of stable SiF bonds between silicon and fluorine atoms in the lattice structure of the film rather than unstable SiF.sub.2 or other bonds. When residual fluorine atoms (e.g.
    Type: Grant
    Filed: October 29, 1996
    Date of Patent: February 1, 2000
    Assignee: Applied Materials, Inc.
    Inventors: Anand Gupta, Mohan Bhan, Sudhakar Subrahmanyam