Abstract
In IC foundries, the test wafers, also known as control wafer or dummy wafer, are used for monitoring production process, production equipment, manufacturing environment or optimizing parameters setting etc. Since the semiconductor production is so sophisticated that the stability and consistency of production process are crucial. Through using of test wafers, engineers can acquire real time information about process, equipment or environment, helping them to maintain a high and stable yield rate. Therefore, they can lower the yield loss and smooth the production plan. Consequently, the test wafer is one of the essential materials in IC foundries. Virgin test wafers are supplied by silicon wafer makers while reclaim wafers are provided by reclaim wafer suppliers. After a series of processes, which are mainly grinding, polishing and cleaning process, the used test wafers or scrap pattern wafers can be reclaimed to original condition and ready to be used again. The wafer is now called reclaim wafer after a reclaim process. The qualities of a reclaim wafer are normally the same as a virgin test wafer in terms of cleanness, flatness, except for thickness. Moreover, the price of reclaim wafer is relatively cheap comparing to virgin test wafer. Using reclaim wafers as test wafers or control wafers can reduce consumption of virgin test wafers, and reduce production cost consequently. Before 1997, all IC foundries in Taiwan sent their wafers to reclaim wafer suppliers overseas, mainly to Japanese companies considering higher return rates and lower shipping costs. The majority of wafers is 8 inch at that time. In 1997 Mar. PSI established the first reclaim wafer production line in Taiwan, providing domestic reclaim wafer service. Afterward, KPG, invested by Kinik company, started entering this business area actively through the technical support from ITIS. SCSC also built a reclaim wafer factory in 1998. Nowadays, semiconductor industry has grown up rapidly. The dominant wafer size has become 12 inch, the line width of circuit has evolved into 70nm, even 45nm from 35nm. Accompanying the prosperity of semiconductor industry, the number of reclaim wafer suppliers has reached the highest peak, which were nearly 20 companies throughout the world. However, once the economy is turning down, or the utilization of capacity drops, supply of reclaim wafer will exceeds demand easily. Under these circumstances, reclaim wafer suppliers often struggle to make a profit. By analyzing market information, different strategies and real experiences in reclaim wafer industry, this essay is expected to conclude a winning business strategy and business model.