Investigating the formation of time-dependent haze on stored wafers

摘要

Silicon wafer users expect that the surface of the wafers they receive from their suppliers will meet all requirements for light point defects (LPDs), metals, grown-on-film quality, and cleanability. Yet many users have observed a very large number of >0.12-μm LPDs on wafers that have experienced extended storage prior to use. This phenomenon has come to be called time-dependent haze (TDH). Its appearance may or may not trigger wafer rejection at incoming quality assurance or create a performance problem in the device manufacturing line, but it will certainly suggest to the user that something in the supply chain is out of control.