Reduction of surface contamination in post-CMP cleaning

摘要

Chemical-mechanical polishing is followed with a scrubbing procedure for the removal of any particulate contaminants. Scrubbing is succeeded by a plasma etching step, using a parallel electrode plasma etcher, a downstream plasma etcher, or similar apparatus. Plasma etching is performed for about 30 seconds using CF4 as the etching gas, so that about 300 Angstroms of the post CMP surface is removed. This results in the almost total elimination of residual mobile ions from the polished surface without the introduction of microgrooves and similar blemishes as is often the case when HF is used for this purpose.