Zinc diffusion in gallium arsenide and the properties of gallium interstitials

摘要: We have performed zinc diffusion experiments in gallium arsenide at temperatures between $620\phantom{\rule{0.2em}{0ex}}\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}$ and $870\phantom{\rule{0.2em}{0ex}}\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}$ with a dilute $\mathrm{Ga}\ensuremath{-}\mathrm{Zn}$ source. The low Zn partial pressure established during annealing realizes surface concentrations of $\ensuremath{\leqslant}2\ifmmode\times\else\texttimes\fi{}{10}^{19}\phantom{\rule{0.3em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}3}$, which lead to the formation characteristic S-shaped profiles. Accurate modeling profiles, were measured by means secondary ion mass spectroscopy, shows that under particular doping conditions is mainly mediated neutral singly positively charged Ga interstitials via kick-out mechanism. determined temperature dependence individual contributions for electronically intrinsic conditions. data are lower than total self-diffusion coefficient hence consistent general interpretation vacancies. Our results disprove accepted GaAs doubly triply solves inconsistency related electrical compensation acceptor dopant multiply interstitials.