7th International Symposium on Cleaning Technology in Semiconductor Device Manufacturing location:San Francisco, CA, USA date:September 2001
Theoretical and experimental investigations have demonstrated the ability of a single wafer megasonic cleaning system to remove particles less than 100nm in size from a wafer surface. The acoustic streaming forces created at the particle-wafer interface are the primary forces considered for particle removal. These forces are large enough to overcome the Van der Waals adhesion force for particle sizes less than 100nm. Experimentally, the Verteq Goldfinger single wafer megasonic cleaning system removed particles from 03 last wafer surface using only room temperature deionized water and a megasonic frequency of similar to835kHz. The particle sizes removed with this cleaning system include 80+/-9nm SiO2, 60+/-3nm PSL and 36+/-10nm SiO2. Cleaning efficiencies ranged from a low of 97+/-1% for the 36+/-10nm SiO2 and a high of 99.994+/-0.002% 80+/-9nm SiO2 for a sixty-second megasonic cleaning time.