Multiple-input dual-output adjustment scheme for semiconductor manufacturing processes using a dynamic dual-response approach

Abstract

This paper presents an optimization-based, multiple-input dual-output (MIDO) run-to-run (R2R) controller for general semiconductor manufacturing processes. This controller, termed ‘adaptive dual-response optimizing controller’ (ADROC), can serve as a recipe regulator between consecutive runs of wafer fabrication. In ADROC, an on-line estimation technique is implemented in a self-tuning (ST) control manner for the adaptation purpose. Subsequently, an ad hoc global optimization algorithm based on the dual-response approach is used to seek the optimum recipe within the acceptability region for the execution of next run. In addition, a ‘responsive-type’ adjustment method is devised, serving as a post hoc filter to alleviate the over-control problem and maintain a better trade-off between two potentially conflicting process responses in MIDO R2R situations. Typical applications of R2R control to chemical mechanical planarization (CMP) in semiconductor manufacturing are demonstrated through simulated processes to illustrate ADROC. The procedure is compared to three benchmark methods (OAQC, single- and double-EWMA controllers) in a simulation experiment.