AMORPHIZATION DURING ELEVATED-TEMPERATURE IMPLANTATION

Transition state theory is employed to predict the rates of amorphous zone recrystallisation by direct thermal and radiation mediated therma l annealing processes. These rates are functions of zone radius and ar e employed to describe the competition between amorphous zone generati on and annealing during elevated temperature heavy ion implantation of , particularly, Si and the accumulation of amorphousness with increasi ng ion fluence. This analysis predicts a change from monotonic to sigm oidal to biexponential accumulation functions with increasing annealin g rate or substrate temperature in agreement with experiments. A logar ithmic dependence of ion flux density upon substrate temperature for t he achievement of defined fractional amorphisation is predicted and is in agreement with experiments also.