Abstract :
Raman spectroscopy was used to study the evolution of host lattice recrystallization in high-fluence N+-implanted GaAs. A
high-fluence of N+ ions (>1015 cm 2) was introduced into semi-insulating GaAs by the combinatorial implantation method.
Subsequent thermal annealing at 800 8C was carried out to re-grow the implantation-induced amorphous layers. The dependence
of Raman parameters on N contents was systematically observed for each recrystallized cell. The volume of the newly formed
crystallites with original orientation decreases with increasing fluences, whereas that of crystallites of other orientations
increases after high-fluence implantation and annealing. The correlation length L, representing the size of crystalline regions
with preserved translational symmetry, was determined by fitting the LO phonon signal with spatial correlation model. For
1016 cm 2 implantation, the recrystallized layer consists of nano-meter-sized crystallites ( 30 nm). The dimension of the
recrystallized crystallites decreases with increasing N+ fluences, in good agreement with the model.
