Raman spectroscopy was used to study the evolution of host lattice recrystallization in high-fluence W-implanted GaAs. A high-fluence of N+ ions (> 10(15) cm(-2)) was introduced into semi-insulating GaAs by the combinatorial implantation method. Subsequent thermal annealing at 800 degrees C 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 10(16) cm(-2) implantation, the recrystallized layer consists of nano-meter-sized crystallites (similar to 30 nm). The dimension of the recrystallized crystallites decreases with increasing N+ fluences, in good agreement with the model. (c) 2005 Elsevier B.V. All rights reserved.