Importance

Loading Importance Indicators...

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. A method for controlling process temperatures for semi-conductor wafers comprises the steps of heating the wafer, generating a plurality of ultrasonic vibrations in the wafer, sensing the ultrasonic vibrations with a Sagnac interferometer, generating the wafer temperature signal in response to sensing the ultrasonic vibrations with the Sagnac interferometer, calculating the wafer temperature on the basis of the generated wafer temperature signal, and controlling the heat applied to the wafer on the basis of the calculated wafer temperature.

Loading the Abstract Image...

First Claim