Summary: | 碩士 === 國立交通大學 === 工業工程與管理系 === 91 === lection of Alternatives for Improving Recycle Processes of C/D Wafers
Student:Chia-Shien Chien Advisor:Dr. Muh-Cherng Wu
Institute of Industrial Engineering
National Chiao Tung University
ABSTRACT
Control/dummy (C/D) wafers are used to measure the process quality in semiconductor manufacturing. C/D wafers are reusable by recycle cleaning and can be downgraded to the downstream processes. Previous studies on C/D wafers aimed to reduce the use of C/D wafers by making appropriate downgrade decisions. Yet, the yield improvement in the recycle process C/D wafers is seldom explored.
This research formulates a decision problem and proposes solution methods for the selecting the yield improvement alternatives in the C/D recycle processes. The decision problem is to determine the yield improvement targets for each recycle process in order to minimize the use of C/D wafers, under a given budget for yield improvement. The two solution methods involve a genetic algorithm and a marginal allocation algorithm. The two methods yield same solutions but the marginal allocation method is good in requiring much less computation.
key word:control wafer, dummy wafer, recycle cleaning, genetic algorithm,
marginal allocation
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