On the Closed-loop Control of an Argon Plasma Process

Closed-loop control of a plasma process for etching applications is discussed in this study. Plasma processes are highly nonlinear systems that typically feature complex chemical and physical reactions. A laboratory-based plasma reactor is presented in this work, and issues concerning its closed-loop control are discussed. A PID controller for the experimental plasma process is developed and its performance is analyzed. The need for a more advance control methodology is studied and some appropriate control structures are proposed. Finally, a description of the practical implementation of real-time multivariable closed-loop control for the studied plasma reactor is presented.