Spreading resistance and C-DLTS spectra of proton-irradiated mesa diodes made on thick epitaxial Si layers

High-resistivity, thick silicon epitaxial layers, deposited on Czochralski silicon (CZ Si) substrate were used as a material for test diodes. Resistivity profile as a function of depth and deep-level spectra were measured by spreading resistance method and deep-level transient spectroscopy (C-DLTS) on non-irradiated and proton irradiated mesa diodes. A deep level with activation energy Ec−0.52 eV, attributed to V2O defect, dominates in the non-irradiated diodes. After irradiation two levels, Ec−0.38 and Ec−0.45 eV, related to divacancies and the level Ec−0.17 eV corresponding to VO complex are distinguished.