The electrical activity of tetravacancy complexes in high-energy proton-irradiated silicon

Comparative experiments on the formation and annealing of radiation defects in float-zone n-Si irradiated with 8600 MeV protons or 60Co γ-rays were carried out. From the analysis of the temperature dependences of the Hall coefficient the values of the activation energy deltaE of radiation defect ionization are determined. The annealing character and nature of radiation defects with close values of deltaE are found to be dependent on the kind of irradiation. The results obtained are discussed taking into account the radiation defect formation mechanism for the kinds of irradiation used and the influence of the potential barrier of proton-produced defect clusters on the value of deltaE for defects localized in clusters. Proton-irradiation-produced radiation defects with deltaE = Esub(c) -0.12 eV are concluded to represent planar tetravacancies (Si-A3 centres) whose ionization energy is ΔE approx. Esub(c) -0.23 eV, localized in the central region of the defect cluster. (author)