Browsing by Author "Kuo, Tzu-Wei"

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Combined Product and Tool Disturbance Estimator for the Mix-Product Process and Its Application to the Removal Rate Estimation in CMP Process
(2012-04-01)
Lee, An-Chen
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Kuo, Tzu-Wei
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Ma, Chung-Ting
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機械工程學系
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Department of Mechanical Engineering
In this paper, we proposed a control strategy: Combined Product and Tool Disturbance Estimator (CPTDE) which combines threaded double EWMA with the drift compensation scheme, to adaptively estimate the disturbance for a mix-product situation in semiconductor processes. This approach considers the disturbances are related to the combination of the specific product and the tool, and further separates the error into an intercept term and a drift term, where the former is related to the variation of products, whereas the latter is related to the interaction between the tools and the products. The proposed method continuously updates the intercept and drift terms to obtain the recipe for the next run. The simulation case studies, i.e., the fixed schedule process, the random schedule process, and the periodical schedule process, are conducted and the results show that CPTDE control scheme has best control performance when compared with three recently published control schemes. The method is also applied to the estimation of removal rate in mix-product CMP process. The results show that the proposed method has improvements over product-based EWMA control, CF-EWMA control and threaded PCC control by 9.52%, 2523.43% and 11.71% on average, respectively, for estimating removal rate of historical data in mix-product CMP process.
Modified Double EWMA Approach for Mixed Product Run-to-Run CMP Process Control
(2011)
Lee, An-Chen
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Kuo, Tzu-Wei
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Lee, Zeng-Lien
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機械工程學系
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Department of Mechanical Engineering
Advanced process control (APC) has been recognized as a proper tool for maximizing profitability of semiconductor manufacturing facilities by improving efficiency and product quality. Run-to-run (RtR) process control with good quality and reliable performance for APC applications are most applicable. Chemical mechanical planarization (CMP) is part of critical processing module in semiconductor manufacturing. This paper proposes a new RtR control scheme, modified double EWMA controller (m-dEWMA), which is adaptive to the mixed product CMP processes. The m-dEWMA controller combined thread dEWMA with the drift compensation scheme to deal with the drift and shift disturbances caused by tool and products, respectively. Comparing recently mixed product control schemes: threaded EWMA controller, JADE control and threaded prediction correction controller (threaded PCC), the simulation results show that the m-dEWMA has better control performance than other controllers. The experiment results revealed that the m-dEWMA controller improves the wafer uniformity significantly in mixed product CMP process.
Robustness Analysis of Mixed Product Run-to-Run Control for Semiconductor Process Based on ODOB Control Structure
(2014-05-01)
Lee, An-Chen
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Horng, Jeng-Haur
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Kuo, Tzu-Wei
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Chou, Nan-Hung
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機械工程學系
In this paper, we propose a unified framework for the mixed-product run-to-run (RtR) controller, which is called the output disturbance observer (ODOB) structure. Many mixed-product RtR controllers, such as product-based exponentially weighted moving average (PB-EWMA) threaded predictor corrector controller (t-PCC), cycle forecasting EWMA (CF-EWMA), and combined product and tool disturbance estimator (CPTDE), can fit in this framework. The relations of the above-mentioned controllers and the ODOB controller are discussed. Furthermore, based on the ODOB structure, we analyze the robust stable conditions and provide a systematic method for obtaining the optimal parameters that guarantee the optimal nominal performance under the robust stability. The simulation cases show that the output performances of PB-EWMA, t-PCC, CF-EWMA, and CPTDE controllers are improved by using the optimal weights obtained from the proposed approach.
Run-by-run process control of metal sputter deposition: Combining time series and extended kalman filter
(2007-08-01)
Chen, Juhn-Horng
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Kuo, Tzu-Wei
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Lee, An-Chen
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機械工程學系
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Department of Mechanical Engineering