It was recalled that experimental studies had demonstrated significant germanium substrate loss, and thus dopant loss, during even low-temperature annealing. In the case of phosphorous-implanted Ge, the capping-layer material affected P diffusion. Silicon nitride capping was more efficient when compared with silicon dioxide capping, but an accumulation of P was observed at the Ge/Si3N4 interface. Here, this experimental evidence was evaluated and, with the use of electronic structure simulations, the formation of relevant defects was investigated. It was predicted that the formation of clusters containing nitrogen and vacancies could be related to the observed accumulation of P atoms near to the Ge/Si3N4 interface.

Effect of Germanium Substrate Loss and Nitrogen on Dopant Diffusion in Germanium. A.Chroneos: Journal of Applied Physics, 2009, 105[5], 056101