Iterative identification of temperature dynamics in single wafer rapid thermal processing

Abstract

In the rapid thermal processing (RTP), a control system to improve the processing time, uniformity and repeatability of processing is required. As the standard size of silicon wafer grows and integration of integrated circuits increases, this requirement is increasing. Identification and control are complicated because of highly nonlinearity, drift and time varying nature of the wafer dynamics. Various physical dynamic models for RTP are available and they show diagonal nonlinear first order dynamics with multivariable static gains. Accurate identification of the multivariable static gains is very important for better control. However, these model structures of RTP are not well utilized yet for identification and control. Here, an identification method which refines the multivariable static gains iteratively is proposed. It will simplify the identification procedure and improve the accuracy of identified model.