HYDROGEN INTERACTIONS WITH SELF-INTERSTITIALS IN SILICON

We present a first-principles investigation of complexes between one or two hydrogen atoms and a Si self-interstitial (Si-i). The atomic structure of these complexes is a distortion of the (110) split-interstitial configuration. The (H,Si-i) complex has donor and acceptor levels in the band gap, both about 0.4 eV above the valence band. The (2H,Si-i) complex is electrically inactive, with all Si atoms bonded to four neighbors. The binding energy of H to the self-interstitial is about 2.4 eV (referenced to free atomic H). Consequences of these results for observation of self-interstitials and for processes such as point-defect condensation and dislocation nucleation are discussed.