Studies of boron–interstitial clusters in Si

Abstract

The large number of self-interstitials created during implantation mediate the fast transient diffusion of implanted boron, leading to clustering. Sophisticated annealing strategies based on knowledge of the formation energy of the clusters are required to achieve full activation of the implant. In recent years attempts have been made to determine these data a priori from theoretical calculations. However, energy calculations alone are not sufficient to establish the key players in the clustering process of boron. The present paper describes a systematic first-principles quantum mechanical study of the characteristic vibration frequencies of a large number of boron–interstitial clusters (including possible configurational isomers). Comparison with the first Raman spectra obtained on B-implanted samples after high temperature annealing is presented.