A Controlled Deposition of Organic Contamination and the Removal with Ozone Based Cleanings

摘要

The efficiency of ozone based cleaning processes for the removal of typical organic contamination such as phthalates, fatty acids, siloxanes and surfactants, originating from clean room air, wafer boxes and wafer handling, is evaluated. Different cleans are effective in removing monolayers of typical clean room contaminants on silicon wafers. Prerequisite for measuring the removal efficiency of ozonated cleans for sub-monolayer organic contamination has been the development of a controlled, reproducible and quantitative deposition method for those species. It is found that deposition (contamination) of rather volatile compounds via a sealed gas phase ambient (e.g. wafer box) is less likely and thus less effective for a controlled contamination. However, via wet chemical exposure, organic compounds could be deposited onto silicon wafers in a reproducible and quantitative way.