It was pointed out that H could migrate as a negatively charged species, H-. The evidence for this was the combined observation of a strong electric-field dependence of the removal rate of PH complexes during bias-temperature stressing of Schottky barrier diodes, and the resultant redistribution of neutralized donors. The detection of H- established that, as well as a previously identified deep-donor level, there also existed an acceptor level for H in the Si band gap. The dissociation kinetics of PH yielded an activation energy of 1.18eV; from which a binding energy of between 0.35 and 0.65eV was deduced.

J.Zhu, N.M.Johnson, C.Herring: Physical Review B, 1990, 41[17], 12354-7