Run to Run Control Methods for Semiconductor Manufacturing Processes Subject to Random Shifts and Drifts.
| Autor: | Jin-Jung Chen, 陳進忠 |
|---|---|
| Rok vydání: | 2000 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 88 Semiconductor manufacturing processes are subject to small and large special disturbances such as process drifts or shifts. In many cases the causes of disturbances are known, but it is either impossible or too expensive to remove them. In cases such as these and the output deviations are controllable (without removing the root causes), run-to-run feedback adjustment schemes will be useful. In this thesis, for controlling process shifts, we present a self-tuning control module in which the control parameter is re-tuned sequentially to compensate for the deviation of process output''s from the target. For controlling process drifts, the control methods have been designed based on the formulation of Double Exponentially Weighted Moving Average (D-EWMA). The optimal determination the parameters of the DEWMA and PCC control methods depends on a trade-off between steady-state and transient performance. By adding the self-tuning (ST) feature into the DEWMA and PCC control methods, the resulting ST-DEWMA and ST-PCC control methods are able to control processes subject to random shifts and drifts more effectively. Monte Carlo simulations and the CMP process validation results show that the ST-DEWMA and ST-PCC control methods have better overall performance for processes subject to both random shifts and drifts. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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