A predictive damage accumulation model, which took accounted of various interdependent implant parameters, was developed. The model assumes that the recrystallization rate of damage structures known as amorphous pockets (AP) was a function of its effective size, regardless of their spatial configuration. In the model, APs were three-dimensional agglomerates of interstitials (I) and vacancies (V), whose initial coordinates were generated by a binary collision approximation (BCA) code. The importance of the spatial correlation of I’s and V’s in modelling damage accumulation and amorphization was analysed by comparing simulations in which the initial coordinates of I and V were generated by BCA or randomly generated from the concentration distribution of an input damage profile. Low-temperature implantations were simulated so as to avoid dynamic annealing in order to compare the initial damage morphology. For the same damage level, simulations by BCA resulted in ion mass-dependent AP sizes, with lighter implant ions generating smaller AP sizes, implying a more dilute damage compared with heavier ions. However, the ion mass dependent APs’ size effect was lost by loading the same damage profile and randomly positioning the I’s and V’s. Consequently, the damage morphology, as well as the annealing behaviour obtained by reading I, V damage profiles was substantially different from those obtained using the much more realistic cascades generated by BCA.

Ion-Implant Simulations - the Effect of Defect Spatial Correlation on Damage Accumulation. K.R.C.Mok, M.Jaraiz, I.Martin-Bragado, J.E.Rubio, P.Castrillo, R.Pinacho, M.P.Srinivasan, F.Benistant: Materials Science and Engineering B, 2005, 124-125, 386-8