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

The annealing of interstitial carbon Ci 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 Ci, CiCs, CiOi and VOi suggest that the mobile Ci atoms are also captured at divacancy VV sites at the cluster peripheries and not only at Cs and Oi sites in the silicon bulk. The deviation of the electrical filling characteristic of Ci from the characteristic of a homogeneously distributed defect can be explained by an aggregation of Ci 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 Ci suggests that the change of the triangle-shaped electric field distribution in a reverse biased p+n junction due to charged clusters is negligible.