晶圓製造廠控擋片供給與需求之研究

The Supply and Demand of Control/Dummy Wafer in a Semiconductor Fab

追求卓越產品及快速滿足市場需求為半導體製造廠致力達成的目標，然為了提升產品良率，穩定製程能力並即時追蹤產品品質是非常重要的。控擋片的應用即是為了穩定機台製程能力、以及快速反應製程是否異常，減少產品晶圓的損失。然而大量的控擋片運用卻會導致成本增加，因此如何在提升產品良率以及減少控擋片使用量兩者間找到平衡點是業界極為重視的議題。控擋片本身是有分級制的，不同機台所需等級皆不同，其在使用後經由回收站清洗，而後根據其潔淨度重新分配等級，本研究主要在針對生產線上各等級需求，透過建構一線性規劃模型，找出最佳化回收站清洗後之等級分配數量，並透過案例驗證此模型可有效最小化新片下線量，降低總成本。

Excellence of products and quickly meet market demand for the semiconductor factory is committed to achieving its goals. In order to enhance the yield of products, keeping process capability stabile and real-time tracing of products qualities is very important. The application of non-product wafers (control wafer and dummy wafer) is to stabilize the machines process capability, and as well as rapid response the process is abnormal or not, then reduce the loss of product wafers. However, the use of a large number of non-production wafers but it will lead to increased costs, so how to find the balance point between enhancing product yield and reducing the amount of control and dummy wafers is the great important issue in semiconductor manufacturing. There are grade distribution of control and dummy wafers, and the different machines and processes need to different wafers to be used. After the wafers have been used by tools, they must enter to reclaim station to clean and re-grade the grading by there own clean degree. The purpose of this research is to develop a Linear Programming Model to optimize the distribution of control and dummy wafers after finishing the clean and regrading of the reclaim station based on the different grade demand of each process. And verifying the model by lingo software can effective minimize the new wafer start quantities and decrease the total cost by case study.