Atomic and carrier concentration profiles in C-implanted material were measured. The 300keV C-ion implantation was carried out to a dose of 1.0 x 1014/cm2. The C concentration profiles which were revealed by secondary ion mass spectrometric measurements were found to be in good agreement with profiles which were predicted by Monte Carlo simulations. The implanted C did not diffuse greatly during annealing at 900C because the diffusion coefficient was less than 4 x 10-16cm2/s for ion-implanted C. Therefore, a shallow carrier concentration profile was found after annealing. The activation efficiency was equal to 17% at the surface (with a depth of less than 0.47). However, the efficiency was as low as 4% in deeper regions. This was attributed to the suppression of activation by the precipitation of C after annealing.

Carbon Ion Implantation in GaAs. T.Hara, S.Takeda, A.Mochizuki, H.Oikawa, A.Higashisaka, H.Kohzu: Japanese Journal of Applied Physics, 1995, 34[2-8B], L1020-3

Figure 3

Diffusion of Cd in GaAs