| Summary: | 碩士 === 中原大學 === 工業與系統工程研究所 === 103 === This paper considers wafer manufacturing of semiconductor where wafer cleaning should be taken to avoid pollution. The function of wafer cleaning is to clean up the dirt, i.e., particle, organic, and metal-ions on the surface of wafer. The main materials of wafer cleaning is cleaning agent which can take away the dirt on the wafer surface. The dirt is dissolved in the cleaning agent. Once the accumulation of substantial dirt is over a permitted value, the cleaning agent will damage the wafer surface and it is necessary to be changed. Thus, we deal with the problem of scheduling jobs and dirt clean-up based maintenance to avoid the loss of capacity. The objective is to minimize number of tardy jobs. This problem is strongly NP-hard. Two mixed binary integer programming models are developed to optimally solve this problem. Furthermore, an efficient heuristic algorithm is proposed for solving large-sized problems.
In this study, we have two integer programming models for the following problem: 1|clean﹣up| ∑_(i=1)^N▒〖NT〗_i . Model (1) considers at most (N-1) numbers of clean-up dust activities for the machine in the planning horizon. Model (2) uses binary variables to control whether the maintenance is carried or not. The number numbers of maintenance will affect the solving speed. When the numbers of job more, model (2) is faster than models (1). The large size problem is solved by the heuristic algorithm.
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