Recrystallization of Amorphous Layer in Ion Implanted GaAs - Transmission Electron Microscopy Studies

2 MeV arsenic or gallium ions were used to produce nonstoichiometric buried amorphous layers in gallium arsenide. The mechanism of thermally induced regrowth of these layers was investigated using transmission electron microscopy. Low-temperature annealing resulted in nucleation of high densities of stacking faults. This was associated with the local nonstoichiometry of the amorphous layers. After annealing at high temperatures, in arsenic as well as in gallium implanted samples, two layers of voids, formed in result of vacancies clustering, were found in areas adjacent to the initial location of the amorphous-crystalline interfaces. A qualitative model of the formation of such layers was proposed.