Title :
Run-to-run control of DC-sputtering processes
Author :
Gillet, Denis ; Crisalle, Oscar D. ; Bonvin, Dominique
Author_Institution :
Swiss Fed. Inst. of Technol., Lausanne, Switzerland
Abstract :
A nonlinear model is proposed for describing the relationship between the relevant inputs and outputs of a DC-magnetron sputtering system used in a manufacturing line for digital-compact discs and other optical data-storage devices. It is shown that the process is intrinsically discrete, and that it has an inherent transport delay. A control scheme is proposed consisting of a Smith predictor to address the delayed dynamics, and a globally linearizing operator introduced to address the nonlinear nature of the model. The control structure requires knowledge of two model parameters, namely, the maximum film reflectivity and the characteristic-energy factor of the sputterer and makes use of one tuning variable, namely, the parameter of an integral-only controller. The performance of the control system is illustrated via a simulation study
Keywords :
control system synthesis; delays; feedback; linearisation techniques; predictive control; process control; sputter deposition; DC magnetron sputtering system; DC sputtering processes; Smith predictor; characteristic-energy factor; control scheme; delayed dynamics; digital compact discs; globally linearizing operator; inherent transport delay; integral-only controller; maximum-film reflectivity; nonlinear model; optical data-storage devices; run-to-run control; tuning variable; Added delay; Nonlinear dynamical systems; Nonlinear optical devices; Nonlinear optics; Optical devices; Optical films; Predictive models; Process control; Sputtering; Virtual manufacturing;
Conference_Titel :
American Control Conference, 2001. Proceedings of the 2001
Conference_Location :
Arlington, VA
Print_ISBN :
0-7803-6495-3
DOI :
10.1109/ACC.2001.946035
