Acceleration of organic contaminant adsorption onto silicon surfaces in the presence of residual fluorine

The influence of fluorine atoms remaining after HF treatment on the adsorption of organic contaminants onto the surface of silicon wafers was investigated by analyzing the organic contaminants with gas chromatography-mass spectrometry following thermodesorption (TD-GC/MS), and the surface composition with x-ray photoelectron spectroscopy (XPS). It has been found that residual fluorine on silicon surfaces after cleaning of the silicon wafers with either aqueous HF or anhydrous HF accelerates the adsorption of organic contamination onto the silicon surfaces. This would be due to the electrostatic force of attraction between the polar groups of organic compounds and the residual fluorine on the silicon surface.