Patents by Inventor Sreekrishnan Sankaranarayan

Sreekrishnan Sankaranarayan 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).

  • Mechanism for varying the spacing between sputter magnetron and target
    Patent number: 7674360
    Abstract: A lift mechanism for and a corresponding use of a magnetron in a plasma sputter reactor. A magnetron rotating about the target axis is controllably lifted away from the back of the target to compensate for sputter erosion, thereby maintaining a constant magnetic field and resultant plasma density at the sputtered surface, which is particularly important for stable operation with a small magnetron, for example, one executing circular or planetary motion about the target axis. The lift mechanism can include a lead screw axially fixed to the magnetron support shaft and a lead nut engaged therewith to raise the magnetron as the lead nut is turned. Alternatively, the support shaft is axially fixed to a vertically moving slider. The amount of lift may be controlled according a recipe based on accumulated power applied to the target or by monitoring electrical characteristics of the target.
    Type: Grant
    Filed: September 16, 2004
    Date of Patent: March 9, 2010
    Assignee: Applied Materials, Inc.
    Inventors: Ilyoung Richard Hong, Donny Young, Michael Rosenstein, Robert B. Lowrance, Daniel C. Lubben, Michael Andrew Miller, Peijun Ding, Sreekrishnan Sankaranarayan, Goichi Yoshidome
  • Mechanism for varying the spacing between sputter magnetron and target
    Publication number: 20050133365
    Abstract: A lift mechanism for and a corresponding use of a magnetron in a plasma sputter reactor. A magnetron rotating about the target axis is controllably lifted away from the back of the target to compensate for sputter erosion, thereby maintaining a constant magnetic field and resultant plasma density at the sputtered surface, which is particularly important for stable operation with a small magnetron, for example, one executing circular or planetary motion about the target axis. The lift mechanism can include a lead screw axially fixed to the magnetron support shaft and a lead nut engaged therewith to raise the magnetron as the lead nut is turned. Alternatively, the support shaft is axially fixed to a vertically moving slider. The amount of lift may be controlled according a recipe based on accumulated power applied to the target or by monitoring electrical characteristics of the target.
    Type: Application
    Filed: September 16, 2004
    Publication date: June 23, 2005
    Inventors: Ilyoung Hong, Donny Young, Michael Rosenstein, Robert Lowrance, Daniel Lubben, Michael Miller, Peijun Ding, Sreekrishnan Sankaranarayan, Goichi Yoshidome