On the formation of defect clusters in neutron-irradiated Si

The formation of radiation-induced defect clusters in neutron-irradiated silicon have been studied by solving the semilinear parabolic reaction-diffusion coupled equations. It is found that most of primary displacement defects (interstitial and vacancy) would be annihilated by direct I–V recombination in an extremely short time, and a lot of divacancies would be formed meantime. In particular, the production of 4-vacancy defects is independent of the concentration of sinks and impurities in the sample, and of the energy of recoil particles. The threshold energy of vacancy cluster formation has also been investigated. The results are discussed and compared with experiment observations.