Laser pulse annealing of ion-implanted GaAs

Abstract
GaAs single‐crystals wafers are implanted at room temperature with 400‐keV Te+ ions to a dose of 1×1015 cm−2 to form an amorphous surface layer. The recrystallization of this layer is investigated by backscattering spectrometry and transmission electron microscopy after transient annealing by Q‐switched ruby laser irradiation. An energy density threshold of about 1.0 J/cm2 exists above which the layer regrows epitaxially. Below the threshold the layer is polycrystalline; the grain size increases as the energy density approaches threshold. The results are analogous to those reported for the elemental semiconductors, Si and Ge. The threshold value observed is in good agreement with that predicted by the simple model successfully applied previously to Si and Ge.