HYDROGEN-BERYLLIUM COMPLEXES IN CRYSTALLINE SILICON

Abstract

We present the results of ab initio pseudopotential calculations to study the atomic structure of various forms of hydrogen-beryllium complexes in crystalline Si. For both the monatomic- and diatomic-hydrogen-Be complexes considered, the C site which corresponds to the middle of the rhombus formed by two neighboring Be-Si bonds is found to be energetically most favorable for interstitial H atoms. In a recently proposed [111]-oriented substitutional-interstitial Be pair which was shown to be more stable than a single substitutional Be, H is also positioned at the C site. For monatomic-H-Be complexes, we propose a hydrogen tunneling path going through an M site, which is located midway between two neighboring C sites, with an energy barrier of about 0.4 eV.