Nonlinear Model Identification for Temperature Control in Single Wafer Rapid Thermal Processing

Abstract

Single wafer rapid thermal processing (RTP) has become one of the key technologies in semiconductor manufacturing due to its faster wafer processing with reduced thermal budget and precise control of processing conditions. As the standard size of the silicon wafer grows and integration of integrated circuits increases, better control to improve the processing time, uniformity, and repeatability of processing is required. In RTP, identification and control are complicated because of high nonlinearity, drift, and time varying nature of the wafer dynamics. Physical models for the wafer dynamics have been available, but they are not utilized fully for identification and control. Here, based on a physical model of wafer, a practical identification method and an analytic linearizing control method are proposed.