A move to single-wafer cleaning: liming is the biggest challenge

摘要

One of the biggest trends in wafer cleaning is single-wafer wet cleans at the critical pre-gate level. Strictly speaking, PVA brushes (scrubbers) used in post-CMP cleans can be considered a single-wafer cleaning process, and some fabs use single-wafer etching for backside thinning and layer removal. But for critical cleans, single-wafer cleaning is new. At 180nm and smaller, traditional cleaning technologies can damage device structures, forcing a reduction in applied energy and/or time. Thus, smaller particles require higher energies to free them from the wafer surface. One solution is the application of megasonic technology.