Hydrogen-defect interactions in Si

The interactions between hydrogen and intrinsic defects in silicon are stud ied using ab-initio (tight-binding) molecular-dynamics simulations in super cells and ab-initio Hartree-Fock in clusters. The configurations, electroni c structures, and binding energies of H bound to small vacancy aggregates a re calculated. The vacancy (V) and the self-interstitial (I)-both rapid dif fusers in Si-efficiently dissociate interstitial H, molecules. At low tempe ratures, this results in the formation of {V, H, H} or {I, H, H} complexes. At high temperatures, one or both H's may be released as interstitials. Pr eliminary calculations show that H-2* result from the reaction {I, H, H} V --> H-2*. (C) 1999 Elsevier Science S.A. All rights reserved.