Modeling and real-time control of plasma-based wafer etching

In this paper, modeling and control issues involved with the use of plasmas in wafer etching processes is analyzed. Controlling plasmas is a key aspect of semiconductor wafer manufacturing due to the increased performance expectations of plasma etching. These expectations are a reduction in feature size and production with larger wafers. Innovations in plasma etching processes that can enable these performance expectations are the use of multiple-strap antenna systems to provide active uniformity control and stabilization of certain types of electronegative plasma instabilities. The implementation of these innovations requires the use of a model-based control system that will in itself lead to improved performance. This application of control theory to plasmas will also benefit thin film processing in general including flat panel displays and various types of coatings