Defect generation in crystalline silicon irradiated with high energy particles

Abstract

High resistivity silicon with different concentrations of the impurities oxygen and carbon were irradiated with neutrons and charged particles. The deep level transient spectroscopy (DLTS) method is used to determine the defect parameters. During irradiation of silicon with particles lattice atoms are displaced and the primary defects silicon interstitials and vacancies form the impurity defects C i, C iC s, C iO i and VO i. In the dense displacement regions mainly divacancies VV are formed. The radiation-induced defects change the macroscopic parameters of silicon detectors. During irradiation with neutrons mainly clusters are created. During irradiation with charged particles the generation of single isolated displacements is enhanced due to Coulomb scattering. This is the main difference between irradiation damage after charged particle and neutron irradiation. The higher radiation tolerance of oxygen enriched silicon after charged particle irradiation is related to the higher introduction rates of impurity defects, because only the reaction kinetic of point defects is influenced by the impurity content. The cluster damage is less particle dependent and the threshold energy at which a recoiled silicon atom starts to create a cluster is estimated to be 300 eV.