Recrystallization behavior of high-dose Mn⁺-implanted GaAs

Raman spectroscopy was used to study the evolution of host lattice recrystallization in Mn⁺-implanted GaAs. A high dose of Mn⁺-ions (> 10¹⁵ cm^-2) was introduced into semi-insulating GaAs by the combinatorial implantation method. Subsequent thermal annealing at 920 °C was carried out to re-grow the implantation-induced amorphous layers. The dependence of the recrystallization behavior on the Mn content was systematically observed. The lattice orientation of recrystallized layers in the surface changed after high-dose implantation ( > 1.6 × 10¹⁵ cm^-2) and annealing. The size of the recrystallized crystallites decreased with increasing Mn⁺ dose, as indicated by images from atomic force microscopy. The decrease in the phonon frequency of the Raman lines with the size reduction of microcrystals was in good agreement with the spatial correlation model. However, at higher doses ( > 7 × 10¹⁶ cm^-2), a blue shift of the frequency was observed due to the compressive stress exerted on the microcrystals.