Scrap Rules Determination for Small Lots in Wafer Fabrication

• Main Authors: Chie-Wun Chiou, 邱志文
• Other Authors: Muh-Cherng Wu
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/54520390516234126454

碩士 === 國立交通大學 === 工業工程與管理學程碩士班 === 90 === In semiconductor manufacturing, a typical wafer lot is composed of 25 wafers. Due to the yield problems, wafers in a lot may decrease in number during manufacturing. Such a lot is called a small wafer lot. The unit cost of manufacturing the wafers in a small lot is more expensive than a normal lot. Yet, completing the manufacture of a small lot would create revenue. Semiconductor fab. therefore always have to make the decision─under what conditions should a small wafer lot be scraped. According to our survey, no literature has been published on this research problem. And the decision made in industry is often by the intuition of shop managers. The main objective of this paper aims to develop the decision-making methods for scrapping small lots in semiconductor fab. in order to maximize the profit. We intend to develop genetic algorithm methods under a simplified production scenario. One main assumption is that the bottleneck machine is a particular type.