Using Auger electron spectroscopy for chemical analysis of plasma damage induced by reactive ion etching of SiO2

Surface damage induced by reactive ion etching (RIE) at the bottom of the p attern was investigated in terms of chemical information by Auger electron spectroscopy (AES). The Si-L23VV line shape was changed during the removal of the damage by chemical dry etching after RIE. The relationship between t he changing of the Si-L23VV line shape and the chemically damaged layer, wh ich contains SiOx and SiC, was investigated by X-ray photoelectron spectros copy (XPS) and AES for nonpattemed wafers. The height of the peaks at 90 eV and 79 eV in the Si-L23VV spectra were correlated with the amounts of chem ical damage in the layer measured by XPS. The thickness of the residual SiO x damage was estimated from the relationship between the Si-L23VV line shap e and the thickness of the SiOx layer. This relationship was applied to the chemical analysis for patterned wafers. The line shape of the Si-L23VV spe ctrum from the bottom of the pattern was also changed as the chemical-dry-e tching time increased.