POST-CMP CLEANING USING ACOUSTIC STREAMING

Noncontact surface cleaning is a desirable process in post-chemical me chanical polishing cleaning. High-frequency megasonic cleaning utilize s acoustic streaming as the dominant particle removal mechanism. It is widely used in the semiconductor industry for the removal of particul ate contamination. This paper introduces recent results that involve t he removal of silica slurry using megasonic cleaning. A noncontact (me gasonic) cleaning process for the removal of slurry residues from dipp ed and polished wafers is presented. Complete particle removal (100%) was achieved using megasonics with deionized water with 1% NH4OH using wafers dipped in silica slurry. The optimum conditions for megasonic cleaning (power, temperature, and time) were determined for the remova l of the silica slurry. Up to 99% particle removal from polished wafer s was accomplished using noncontact megasonic cleaning with 1% ammonia for 15 min.