MIGRATION OF THE H-2STAR COMPLEX AND ITS RELATION TO H- IN N-TYPE SILICON

Much, often most, of the hydrogen that is introduced into n-type silicon at moderate temperatures (e.g., 150-degrees-C) forms complexes that have been labeled "H-2*" to distinguish them from the stable and much less mobile complex "H-2" that forms in p-type silicon. This paper reports measurements by secondary-ion mass spectrometry of the thermally induced depth redistribution of deuterium present mostly as H-2(2)*. The activation energy for migration is 0.81 +/- 0.06 eV, but the data do not determine whether the migration involves dissociation. Both migration kinetics and direct measurements on reverse-bias-annealed Schottky diodes show that for annealing times up to 25 h at temperatures near 60-degrees-C there is no detectable redistribution or dissociation of H-2(2)*, contradicting a currently ambiguous claim that such annealing produces a large redistribution due to dissociations yielding H-. The effect of the presence of H-2* on the evolution of the neutralized-donor profiles at such temperatures is negligible.