Patents by Inventor Sharad Saxena

Sharad Saxena 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).

  • Controlling process modules using site models and monitor wafer control
    Patent number: 5751582
    Abstract: A method is described for controlling a plurality of nonuniformity parameters in processing discrete products such as semiconductor wafers through a module consisting of several individual processes using site models. The method uses a controlled process to compensate for a subsequent uncontrolled process, which allows process goals of one process to be optimized to enhance the output of a subsequent process of the same module.
    Type: Grant
    Filed: September 24, 1996
    Date of Patent: May 12, 1998
    Assignee: Texas Instruments Incorporated
    Inventors: Sharad Saxena, Purnendu K. Mozumder, Gregory B. Shinn, Kelly J. Taylor
  • Method of diagnosing malfunctions in semiconductor manufacturing equipment
    Patent number: 5642296
    Abstract: Manufacturing modern day integrated circuits requires that each of a long sequence of steps perform to a tight set of specifications. Since equipment malfunctions are inevitable, profitable manufacturing of integrated circuits requires that such malfunctions be rapidly isolated and corrected. This invention describes the use of process models for diagnosing semiconductor manufacturing equipment malfunctions. One method makes use of multiple models and the second method makes use of a single model at multiple operating points. The fault isolation approaches described herein are based on the analysis of the discrepancy between model predictions and the observed outputs. The approaches have been evaluated on a process for plasma enhanced chemical-vapor deposition of silicon nitride, and the plasma enhanced etching of silicon nitride.
    Type: Grant
    Filed: July 29, 1993
    Date of Patent: June 24, 1997
    Assignee: Texas Instruments Incorporated
    Inventor: Sharad Saxena
  • Use of spatial models for simultaneous control of various non-uniformity metrics
    Patent number: 5546312
    Abstract: A method and system have been described for simultaneously controlling one or multiple metrics of non-uniformity using a model form independent multi-variable controller.
    Type: Grant
    Filed: February 24, 1994
    Date of Patent: August 13, 1996
    Assignee: Texas Instruments Incorporated
    Inventors: Purnendu K. Mozumder, Sharad Saxena
  • Automated diagnosis using wafer tracking databases
    Patent number: 5483636
    Abstract: A system and method for isolating one or more causes of wafer misprocessing. A list of interesting queries (10) is generated. During wafer processing (15), processing parameters are measured (20) and a wafer tracking database (25) is created. The list of queries (10) may be filtered (30) before the queries are tested for interestingness. Interestingness is determined by outlier calculation (35) and trend analysis (40) on data stored in the wafer tracking database (25). Queries found to be interesting are displayed (50).
    Type: Grant
    Filed: March 29, 1995
    Date of Patent: January 9, 1996
    Assignee: Texas Instruments Incorporated
    Inventor: Sharad Saxena
  • Multi-variable statistical process controller for discrete manufacturing
    Patent number: 5408405
    Abstract: A method and system for controlling a plurality of process control variables for processing discrete products is described.
    Type: Grant
    Filed: September 20, 1993
    Date of Patent: April 18, 1995
    Assignee: Texas Instruments Incorporated
    Inventors: Purnendu K. Mozumder, Sharad Saxena, William W. Pu