Investigation of the interstitial site in As+-ion-implanted GaAs by means of a multidirectional and high-depth resolution RBS/channelling technique

Abstract

The double-yield peak and the site exchange of the responsible interstitial atoms on annealing have been observed for the first time in a low-dose As+-ion-implanted GaAs crystal by means of a high-depth resolution and multidirectional Rutherford back-scattering (RBS)/channelling technique. The newly observed second peak is located deeper than the conventional first peak around the projected range Rp. After annealing at 200-250 degrees C, it is found that the interstitial atoms responsible for both peaks change their sites during aging at a low temperature (RT approximately 40 degrees C) and occupy a more stable bond-centred interstitial site for the first peak and a mixed site of the bond-centred and a split (100) one for the second peak. It is concluded that a split (100) site may be one of the most stable sites in the GaAs even at a higher temperature.