High flux Ar+ sputtering induced structural disorder and amorphization in Si (111)

Abstract

The structural disorder in Si(111) matrix induced by high flux oblique Ar ion sputtering has been investigated extensively. The formation of amorphous phase reflecting accumulation of disorder in the irradiated samples has been revealed by Raman spectroscopy. Interestingly, the stress produced in the irradiated specimens as a function of oblique incidence leads to smoothening of the surfaces via decreased strain. Atomic Force Microscopy confirms the presence of amorphous zones in the irradiated Si(111) specimens. In fact, within this range of oblique incidences, a sharp decrease in surface roughness follows after initial roughing of the surfaces. Our results demonstrate that complex interplay between defect generation (interstitial, substitutional and vacancies) and damage induced amorphization due to high flux Ar+ sputtering leads to angle dependent structural disorder. This dependence of structural disorder on oblique incidence reveals qualitative correlation with the amorphization of the Si(111) matrix. Explicitly, this correlation reveals opportunities of creating angle dependent amorphized layers by high flux ion beam sputtering which can be better exploited in Si based electronic devices.