Hydrogenation of amorphous silicon prepared by ion implantation

Abstract

Hydrogenation effects on structural relaxation and crystallization processes of non-hydrogenated amorphous silicon (a-Si) prepared by ion implantation are investigated using Raman scattering and positron lifetime measurements. It has been found that hydrogenation enhances agglomeration of vacancy-type defects which in turn accelerates the crystallization processes. Based on these results, we propose a model in which larger vacancy-type defects, such as microvoids, formed during relaxation processes of a-Si are dissociated into mono- and divacancies at the amorphous/crystalline interface resulting in enhancement of solid phase epitaxial crystallization.