Robert P Chichester

US Patent:

6830942, Dec 14, 2004

Filed:

Apr 6, 1999

Appl. No.:

09/286929

Inventors:

Glenn B. Alers - Chatham NJ
Robert J. Chichester - Somerville NJ
Don X. Sun - Warren NJ
Gordon Albert Thomas - Princeton NJ

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

G01R 3126

US Classification:

438 16, 374121

Abstract:

A method is disclosed for processing a silicon workpiece including a hybrid thermometer system for measuring and controlling the processing temperature where fabrication materials have been or are being applied to the workpiece. The hybrid thermometer system uses optical reflectance and another thermometer technique, such as a thermocouple and/or a pyrometer. Real-time spectral data are compared to values in a spectrum library to determine the âsurface conditionsâ. A decision is then made based on the surface conditions as to how the temperature is measured, e. g. , with optical reflectance, a pyrometer, or a thermocouple, and the temperature is measured using the appropriately selected technique. Utilizing the hybrid thermometer system, the temperature of a silicon workpiece may be accurately measured at low temperatures while accounting for the presence of fabrication materials.