Development of clean technology in wafer drying processes

In the aqueous processing of silicon wafers, drying of wafers must take place after each processing step. However, the drying processes currently used are not environmentally sound, i.e., great amounts of solvents and energy are consumed. To fulfill environmental and economic requirements, a new wafer drying system based on concepts of clean technology was investigated. To reduce isopropyl alcohol (IPA) and energy consumption and to improve drying performance, a new dryer consisting of two separate chambers (IPA-chamber and drying-chamber) was developed. On-site operation with this new configuration was performed to compare its characteristics with those of other widely used dryers. It showed that IPA and energy consumption were smaller than those of the conventional dryers. Drying performance of the new dryer was also better than that of the conventional dryer. Consequently, the new dryer provides an environmentally friendly alternative to wafer drying.