AN ADAPTIVE RUN-TO-RUN OPTIMIZING CONTROLLER FOR LINEAR AND NONLINEARSEMICONDUCTOR PROCESSES

This paper presents a new run-to-run (R2R) multiple-input-multiple-out put controller for semiconductor manufacturing processes. The controll er, termed optimizing adaptive quality controller (OAQC), can act both as an optimizer-in case equipment models are not available-or as a co ntroller for given models. The main components of the OAQC are shown a nd a study of its performance is presented. The controller allows to s pecify input and output constraints and weights, and input resolutions . A multivariate control chart can he applied either as a deadband on the controller or simply to provide out of control alarms. Experimenta l designs can be utilized for on-line (recursive) model identification in the optimization phase. For testing purposes, two chemical mechani cal planarization processes were simulated based on real equipment mod els. It is shown that the OAQC allows to keep adequate control even if the input-output transfer function is severely nonlinear. Software im plementation including the integration of the OAQC with the University of Michigan's Generic Cell Controller (GCC) is briefly discussed.