SUPERVISORY CONTROL OF A RAPID THERMAL MULTIPROCESSOR

An application of supervisory control theory to a semiconductor manufa cturing piece of equipment is presented. This approach allows the flex ible design and reliable update of processing ''recipes'' to accommoda te frequently changing manufacturing requirements. An input-output int erpretation of supervisory control theory is given. This interpretatio n leads to a generic implementation scheme for manufacturing systems. A synthesis fixpoint algorithm implementation using binary decision di agrams enables the design of supervisors of realistic size. A sample s ynthesis for an oxide growth recipe is performed on a state space of t he order of 10(6) states. The actual implementation of the logic seque ncing control software for the application under investigation is desc ribed.