Patents by Inventor Subramanian Venkatkrishnan

Subramanian Venkatkrishnan 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: 6403385
    Abstract: A method of decorating a semiconductor substrate with an etchant solution is provided for revealing defects, such as microscratches, resulting from an oxide chemical-mechanical planarization (CMP) polishing. An oxide layer is provided over the substrate made from, for example, tetraethylorthosilicate (TEOS). The oxide layer is polished by a CMP process which tends to leave behind microscratches and other defects that can cause conductivity problems on the wafer. To reveal the microscratches, the wafer is decorated or submerged in an etchant, such as an HF etchant, for a period of time. Following the decorating, the wafer is rinsed, dried and inspected. The method improves the ability to identify and optimize steps in a semiconductor fabrication process that cause semiconductor defects.
    Type: Grant
    Filed: January 27, 1998
    Date of Patent: June 11, 2002
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Subramanian Venkatkrishnan, Tho L. La, Pei-Yuan Gao, Richard Lamm
  • Patent number: 6153933
    Abstract: A multiple-layer interconnect structure in an integrated circuit, is formed using damascene techniques. A first layer interconnect has a first dielectric layer through which at least one first layer conductor extends. A second layer interconnect is then formed on the first layer interconnect. The second layer interconnect also includes a second layer dielectric through which at least one second layer conductor extends. However, the second layer interconnect is created by first forming a thick second later dielectric layer and then reducing the thickness of the second layer dielectric prior to a patterning step. As a result topographical irregularities that may have carried over to the second layer interconnect from the first layer interconnect are removed by providing a substantially planar surface on the second layer dielectric.
    Type: Grant
    Filed: September 5, 1997
    Date of Patent: November 28, 2000
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Darin A. Chan, Steven C. Avanzino, Subramanian Venkatkrishnan, Minh Van Ngo, Christy Mei-Chu Woo de la Girond'arc, Diana M. Schonauer
  • Patent number: 5780204
    Abstract: The accuracy of photolithographic processing, particularly in forming small diameter through holes and/or trenches in a dielectric layer, is improved by polishing the wafer backside prior to photolithography. It was found that particles adhering to and/or scratches on the wafer backside resulting from prior processing steps cause inaccurate photolithographic processing, particularly at a submicron level. Backside polishing, as by chemical-/mechanical polishing, removes such adhering particles and/or scratches, thereby improving photolithographic accuracy.
    Type: Grant
    Filed: February 3, 1997
    Date of Patent: July 14, 1998
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Tho Le La, Subramanian Venkatkrishnan, Mark T. Ramsbey, Jack F. Thomas, Kathleen Early
  • Patent number: 5769696
    Abstract: Planarization of a patterned semiconductor wafer is effected by chemical-mechanical polishing using a carrier assembly comprising a carrier film adhesively bonded to a base plate, preferably by a pressure sensitive adhesive. Chemical-mechanical polishing is preferably conducted employing three phases of different pressures to prevent wafer slippage.
    Type: Grant
    Filed: February 10, 1995
    Date of Patent: June 23, 1998
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Dawn M. Lee, Subramanian Venkatkrishnan
  • Patent number: 5766058
    Abstract: Uniform planarization of a patterned semiconductor wafer is effected with a chemical-mechanical polishing apparatus containing a base plate comprising a convex surface portion.
    Type: Grant
    Filed: January 21, 1997
    Date of Patent: June 16, 1998
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Dawn M. Lee, Subramanian Venkatkrishnan