AN EXPERIMENTAL-STUDY OF MEGASONIC CLEANING OF SILICON-WAFERS

The use of sonic energy in the 0.8 to 1.0 MHz range, commonly known as megasonic cleaning, has been shown to be effective in the removal of particles from silicon wafers in aqueous baths. Megasonic cleaning at a nominal frequency of 862 kHz is investigated experimentally. The eff ects of particle size, power, and sonication time on the particle remo val efficiency are evaluated for submicron PSL, SiO2, and Si3N4 partic les on silicon wafers using both DI water and SCl (NH4OH/H2O2/H2O, fir st used at RCA) chemistry. The removal efficiency is known to be highe r in SCl than in DI water, and in both cases it is a function of irrad iation time and particle size. increased power is also shown to increa se removal efficiency.