A multiple model approach to process control in electronics manufacturing

Abstract

In the first part of the paper, simulations are given of process control methods based on EWMA and single Kalman filter techniques which have already been applied to microelectronics manufacturing. Then a new approach to process control is proposed which is based on interactive multiple model (IMM) Kalman filtering. The application of this new approach to polymer deposition is discussed and simulations are given based on an approximation of process behavior. The results indicate that basing process control on multiple-model estimation can reduce the output variance when the process parameters are varying within the realm of a small number of known modes.