Recovery in crystals which had been implanted with Ga ions, and then subjected to rapid thermal annealing or furnace annealing, was studied by using Raman scattering techniques. The intensity of the LO phonon mode decreased with increasing ion implantation fluence. It was found that the threshold fluence for the amorphization of Ga-implanted GaSb was 5 x 1013/cm2. This value was much lower than that for InP (1014/cm2). In the case of furnace annealing, the recovery processes in Ga-implanted material were very different above and below a fluence of 5 x 1014/cm2. No recovery was observed at this critical fluence. At lower fluences, the LO mode intensity increased with increasing annealing temperatures and times of up to 400C and of up to 0.25h. However, the damage recovery was very poor when compared with that of GaAs, InP, or GaP. In the case of Si3N4-capped rapid thermal annealing, recovery was observed even for a fluence of 5 x 1014/cm2. New modes were observed, at about 114 and 150/cm, in implanted and annealed samples. These 2 modes were related to the Eg and Alg modes of Sb-Sb bond vibrations, respectively, and were attributed to the out-diffusion of Sb atoms. It was found that furnace annealing enhanced Sb out-diffusion, and that the capped rapid thermal annealing process was superior to the furnace annealing process for the healing of damaged layers. These anomalous behaviors were thought to be closely related to the weak bond-strength of Sb-containing materials. The degree of recovery, as a function of annealing temperature, annealing time, and fluence was also investigated.

S.G.Kim, H.Asahi, M.Seta, J.Takizawa, S.Emura, R.K.Soni, S.Gonda, H.Tanoue: Journal of Applied Physics, 1993, 74[1], 579-85