Test Wafer Management and Automated Wafer Sorting

Typical usage of test wafers (TW) in semiconductor manufacturing involves testing and development of new processes, equipment qualification, and process monitoring activities. A 300 mm fab can potentially spend millions of dollars each year purchasing test wafers. Over the years, improvements in TW management systems have led to a reduction in cost by enabling better inventory control. However, even with the increased level of automation of 300 mm fabs, the TW management process still leaves much to be automated. In this paper, we describe an automated TW management system and the performance benefits derived from its usage.