Ion-implanted Zn diffusion and impurity-induced disordering of an AlGaAs superlattice

Abstract
The diffusion coefficient of ion‐implanted Zn and the Al‐Ga interdiffusion coefficient in an Al0.5Ga0.5As/GaAs superlattice (SL) are extracted from secondary‐ion mass spectroscopy profiles for four diffusion times at 750 °C. The zinc diffusion coefficient goes as the square of the zinc concentration, implying local thermal equilibrium, and is over 200 times smaller than reported values for gaseous‐source Zn diffusions at 650 °C in GaAs. The SL disordering rate increases with increasing zinc concentration and is attributed to the diffusion of positively charged column III interstitials (Ga+mI or Al+mI) with m between 2 and 3.