Journal of Micro/Nanolithography, MEMS, and MOEMSBenchmark study of run-to-run controllers for the lithographic control of the critical dimension
|Format||Member Price||Non-Member Price|
We present a systematic robustness analysis for several feedback controllers used in photolithographic critical dimension (CD) control in semiconductor manufacturing. Our study includes several controllers based on either the exponentially weighted moving average (EWMA) estimation or Kalman filters. The robustness is characterized by two features, namely the controller's stability margin in the presence of model mismatch and the controller's sensitivity to unknown noise. Simulations on the closed-loop control system are shown for the performance comparison. Both the analysis and the simulations prove that the multiple-dimensional feedback controller developed in this paper using the average of previous inputs and outputs outperforms the other controllers in the group.