Strategies for Tetramethylammonium Hydroxide (TMAH) Recovery and Recycling
Allen, Dr. Craig
(SACHEM)
Safe and environmentally responsible handling of tetramethylammonium hydroxide in semiconductor manufacturing is critical at all stages of Fab operations. Expanded use of TMAH in front end of line etching and back end of line wafer thinning can lead to significant volumes of TMAH waste that are added to the already large volumes of wastes from developer and rinses that are generated by photolithographic processes. At the same time, demands for waste reduction, improved chemical efficiency and more stringent discharge limits have challenged traditional waste treatment processes and models. SACHEM has pioneered systems for true recycle and reuse of TMAH that is recovered from Fab processes. We will review recovery and recycle options based on our experience in commercial scale operations.