An Extended State Observer-Based Run to Run Control for Semiconductor Manufacturing Processes

In this paper, an extended state observer (ESO)-based run to run (RtR) controller is presented to suppress various stochastic disturbances emerging in the semiconductor manufacturing process. Using the internal model control theory, the relationship between the ESO-RtR controller and the exponentially weighted moving average (EWMA) controller, and the relationship between the ESO-RtR controller and double EWMA controller are discussed. The stable region of the proposed ESO-RtR controller is calculated and discussed by using the Jury's test. Furthermore, the ESO-RtR controller is extended to a nonlinear form (i.e., nonlinear ESO-RtR controller) to improve its disturbance compensation capability. Finally, numerical simulations and an industrial example are provided to demonstrate the effectiveness of the proposed algorithm.