半導体製造プロセスの出力推定値フィードバックによる圧力制御

抄録

In the atomic-level deposition process for semiconductor manufacturing, control of the pressure and gas concentration in the process chamber has become important, and its fast response is required to improve the throughput. At the same time, sensor signals are severely corrupted by noise and there exist constant disturbances which may cause some off-set of the target pressure. Hence this paper proposes a new pressure control system for semiconductor processes, which achieves required fast responses in the presence of heavy sensor noises and constant disturbances. First, a plant model is constructed, and an output estimation mechanism based on the plant model is employed which is effective in the presence of both unknown constant disturbances and heavy measurement noises. Second, we propose a new feedback control system using the output estimation mechanism instead of the output measurement, which can achieve fast response without steady state error and reduce the sensor noise effect. The effectiveness of the proposed control method is demonstrated by some simulations. Finally, experimental validation is performed.