Consumption optimization by Run to Run control with zone control

In conventional Run to Run (RtR) control, the recipe can be adjusted every run by using information of previous runs to maintain the process outputs on the desired target. However, in some semiconductor manufacturing processes, the aim of the RtR control is not to guide the controlled variables to set points or desired target, but only to maintain to them inside appropriate ranges or zones. On the other hand, the run-wise adjusting scheme is likely to generate the situation of “over control” and increase the cost of production. In order to overcome the problems, an exponentially weighed moving average (EWMA) with zone control strategy is presented in this work. The controller is started to regulate the recipe when proposed adjusting index exceeds the threshold. Then, the adjusted numbers can be decreased indeed. As a result of control, the consumption of manufacturing process will be reduced. The advantages of proposed control scheme are demonstrated by benchmark simulation and reversed engineered industrial applications.