Patents Assigned to Karta Technologies, Inc.
  • System and method for controlling process temperatures for a semi-conductor wafer
    Patent number: 6188050
    Abstract: A system for controlling process temperatures for semi-conductor wafers comprises a heater to heat the wafer, an element to generate a plurality of ultrasonic vibrations in the wafer, a Sagnac interferometer adapted to sense the ultrasonic vibrations and generate a wafer temperature signal responsive thereto, a system to calculate the wafer temperature on the basis of the generated wafer temperature signal, and a control element the wafer heater on the basis of the calculated wafer temperature.
    Type: Grant
    Filed: December 8, 1999
    Date of Patent: February 13, 2001
    Assignee: Karta Technologies, Inc.
    Inventors: Charles E. Duffer, Jorge J. Alcoz