A study of the evolution of carrier and vacancy depth profiles with annealing temperature of Si-implanted GaAs

The activation of Si implanted into GaAs as a function of temperature and depth has been studied together with the distribution of implantation-induced vacancy defects by automated differential Hall measurement and positron annihilation spectroscopy respectively. A strong influence of implantation damage on the activation of the carriers has been observed, suggesting that two independent activation mechanisms are present dependent on the concentration of defects. An activation energy for the total sheet n-type carrier concentration of is measured while for the carriers in the first the activation energy is . The vacancy defects observed by positron annihilation measurements begin to anneal at temperatures below C; however, residual defects remain even after annealing at C. This study highlights the necessity to measure depth-resolved as opposed to depth-averaged data for the purposes of carrier activation modelling.