Rapid themal processing using in-situ wafer thermal expansion measurement for temperature control

摘要

Abstract: An emissivity independent method of temperature control for rapid thermal processing of silicon wafers is demonstrated. In-situ wafer temperature is determined by measurement of wafer thermal expansion via a laser autofocus mechanism. A closed loop temperature control system based on this technique is integrated into a commercial rapid thermal processor with fully automatic wafer handling capability. A preliminary test using a titanium silicidation process were performed using wafer expansion thermometry. The results of this test demonstrate that this technique can provide improved wafer to wafer process repeatability.!10