Multivariable Feedback Relevant System Identification of a Wafer Stepper System

This paper discusses the approximate and feedback relevant parametric identification of a positioning mechanism present in a wafer stepper. The positioning mechanism in a wafer stepper is used in chip manufacturing processes for accurate positioning of the silicon wafer on which the chips are to be produced. The accurate positioning requires a robust and high performance feedback controller that enables a fast through put of silicon wafers. A set of multivariable finite dimensional linear time invariant discrete time models will be estimated, that is suitable for model-based robust control design of the positioning mechanism.