The interaction between substitutional Cu, and one to four H interstitials, was studied by using first-principles molecular dynamics simulations. It was noted that up to three H atoms could bind covalently to one Cus. Such complexes had been observed using deep-level transient spectroscopy. It was found that, although {Cus,H4} had a small binding energy relative to {Cus,H3} + HBC, constant-temperature dynamics showed that this complex was not stable. It could, for instance, dissociate into Cus + 2H2 molecules. The interactions between interstitial Cu and interstitial O showed that Cui+ preferred to be located in the slightly larger void adjacent to Oi. However, the binding energy was quite small (0.31eV) and no covalent Cu-O overlap occurred. The interaction of Cui with an O-vacancy complex involved a kick-out, Cui + {O,V} → {Cus,Oi} + 1.7eV; with Oi bridging a Si-Si bond immediately adjacent to Cu (which was, in turn, at a slightly perturbed substitutional site). No covalent Cu-O bonding occurred. Finally, Cui interacted with the self-interstitial by pushing it, and one host atom, away from a perfect substitutional site and moving itself towards it with an energy gain of 1.6eV.

Copper Interactions with H, O, and the Self-Interstitial in Silicon. D.West, S.K.Estreicher, S.Knack, J.Weber: Physical Review B, 2003, 68[3], 035210