Amorphization Processes and Structural Relaxation in Ion Implanted Si

Abstract
Amorphization processes in Si+, P+, Ge+, and As+ ion implanted Si as well as structural relaxation of amorphous Si (a-Si) during low-temperature (200-450°C) annealing have been investigated using Raman spectroscopy and depth-resolved positron annihilation spectroscopy. Based on the analysis of bond angle deviation Δθ derived from the a-Si Raman TO peak width and line-shape parameter, the S prameter, obtained by the positron annihilation measurements, we have proposed that (1) amorphization is controlled by ion-beam-induced divacancy concentration; and (2) there exist microvoids in the a-Si layers and during isothermal annealing, both of Δθ and the S parameter do not decrease monotonically but show an increase after the initial decrease due to dissociation of the microvoids.