Run-to-Run Process Control: Literature Review and Extensions

In the last few years, “Run-to-Run” (R2R) control techniques have been developed and used to control various semiconductor manufacturing processes. These techniques combine response surface, statistical process control, and feedback control techniques. This paper provides a literature review of R2R control methods from a statistical and control engineering point of view. It is shown that self-tuning controllers can provide a valuable control strategy for R2R applications. In this paper we address the single-input-single-output (SISO) case. Two proposed self-tuning controllers compensate not only for the standard case of process shifts, but also in the case a deterministic trend and/or autocorrelation is present in the observed response (i.e., in case there exist process dynamics). In order to reduce the input variance, a control chart is added to the output and acts as a deadband.