Effect of germanium substrate loss and nitrogen on dopant diffusion in germanium

Recent experimental studies demonstrate a significant germanium (Ge) substrate loss and consequently dopant loss even during low temperature annealing. Additionally, for phosphorous (P) implanted Ge the capping layer material affects P diffusion. Silicon nitride (Si(3)N(4)) capping is more efficient compared to silicon dioxide (SiO(2)) capping, but an accumulation of P is observed at the Ge/Si(3)N(4) interface. In the present study, the recent experimental evidence is evaluated and with the use of electronic structure simulations the formation of relevant defects is investigated. It is predicted that the formation of clusters containing nitrogen (N) and vacancies (V) can be related to the observed accumulation of P atoms near the Ge/Si(3)N(4) interface.