Estimation of defect generation probability in thin Si surface damaged layer during plasma processing

The structural change and defect generation in Si by plasma exposures are investigated by spectroscopic ellipsometry (SE) and photoreflectance spectroscopy (PR). For an Ar-DC plasma exposure with 300 V bias, the SE with an optimized model identifies 1 nm-thick interfacial layer (IL) between the surface layer and the substrate. The PR indicates the mechanical strain change by approximately 0.1%. The PR was applied to an estimation of plasma-induced carrier trap site density on the basis of a model correlating surface potential to the density. Combined with plasma diagnostics, the defect generation probability was estimated for the present condition.