Structural bonding of deep level defects and the nature of amphoteric centres in silicon

Publisher Website
Google Scholar
Abstract
A self-consistent procedure for interpolating defect parameters from perfect lattice tight-binding Slater-Koster parameters is applied to a 17 atom silicon cluster. Deep-level states associated with the neutral lattice vacancy, and charged states of some deep donors in silicon, are studied where meaningful quantitative results are established for both energy levels and particularly the associated lattice relaxation. The model is finally applied to study the amphoteric Au centre, where it is concluded from structural bonding considerations that a lattice reconstruction about the centre is responsible for the acceptor behaviour of the defect. It is then suggested that donor behaviour is associated with a deep level relating to an s orbital of the chemical defect itself.