Run by run process control

Summary form only given. The authors present an approach to process control in VLSI processing where the recipe is modified between every product run, based on measured results, in order to compensate for small drifts and shifts. This approach is implemented in the run-by-run controller, which is part of a process control system being developed at MIT. The run-by-run controller implements a form of adaptive control based on the sequential design of experiments. The algorithmic basis of the run controller is discussed with attention to the implementation of statistical process control (SPC) charting concurrent with run-by-run control. Examples of applications are presented.<<ETX>>