High resolution transmission electron microscopy study of Se+-implanted and annealed GaAs: Mechanisms of amorphization and recrystallization

High resolution transmission electron microscopy (HRTEM) has been applied to the study of amorphization and recrystallization mechanisms in Se+-implanted (100) GaAs. Selenium dose of 1×1014 cm−2 at 450 keV (projected range 1550 Å) produced an amorphous band in the depth range 250–2150 Å below the surface. Annealing at 400 °C resulted in the epitaxial regrowth of the upper and lower transition region (0–250 Å and 2150–2500 Å, respectively). Regrowth of the amorphous layer was found to proceed by the nucleation and propagation of the dense network of stacking fault bundles. Amorphization and recrystallization mechanisms in Se+-implanted GaAs are discussed in light of these HRTEM results.