Parameters of Defect Clusters in Irradiated Silicon and a Method for Their Determining

Abstract

A method for determining the main parameters (potential barrier ψ for charge carriers, size r, and density N* of electrically active defects) of defect clusters in semiconductors is suggested. This method is based on the experimentally observed variation in the occupancy of defect levels during their localization in defect clusters. The method is used for estimating the parameters of the central (the core) and the peripheral regions of defect clusters forming in n‐Si (ϱ0 = 3 to 200 Ωcm) at 660 MeV proton and fast reactor neutron irradiation. Taking into account the results obtained it is concluded that these parameters depend on the irradiation conditions (temperature, energy EAof primarily knocked on atoms) and impurity content. It is shown that the core parameters are determined by EA and those of the periphery are dependent on Eg, irradiation temperature, and impurity content. With EA increase the sizes of defect cluster core and periphery are increased and the defect density within them and the potential barrier height are decreased. On increasing the irradiation temperature and decreasing the impurity concentration in crystals the diffusion length of the mobile primary defects migrating from the primary displacement cascade is increased, on this account the periphery size is increased and ψ and N* are decreased.