The annealing of interstitial carbon atoms in high-resistivity n-type silicon after proton irradiation

Abstract

The annealing of interstitial carbon C i after 7– 10 MeV and 23 GeV proton irradiations at room temperature in high-resistivity n-type silicon is investigated. Deep level transient spectroscopy is used to determine the defect parameters. The annealing characteristics of the impurity defects C i, C iC s, C iO i and VO i suggest that the mobile C i atoms are also captured at divacancy VV sites at the cluster peripheries and not only at C s and O i sites in the silicon bulk. The deviation of the electrical filling characteristic of C i from the characteristic of a homogeneously distributed defect can be explained by an aggregation of C i atoms in the environment of the clusters. The capture rate of electrons into defects located in the cluster environment is reduced due to a positive space charge region surrounding the negatively charged cluster core. The optical filling characteristic of C i suggests that the change of the triangle-shaped electric field distribution in a reverse biased p +n junction due to charged clusters is negligible.