Recombination characteristics in 2–3 MeV protons irradiated FZ Si

Combined analysis of the carrier recombination and generation lifetime as well as reverse recovery durations (τRR), dependent on proton irradiation fluence in the range of 7×1012−7×1014 p/cm2, has been performed in FZ silicon PIN diodes and wafer structures. A δ-layer and triangle profiles of radiation induced defects were formed by varying energy of protons in the range 2–3 MeV. Carrier decay constituents and values of recombination lifetime have been evaluated by employing a microwave probed photoconductivity transient technique, while deep levels spectra ascribed to generation lifetime variations have been examined by exploiting capacitance deep-level transient (DLTS) spectroscopy. Recombination lifetime decreases from several μs to few ns, while DLTS spectra show an increase in the amplitude of a DLTS peak at 170 K with irradiation fluence. Transforms of DLTS spectra and a decrease in density of the majority carrier traps have been revealed after 24 h isochronal anneals in the range of temperatures of 80–420 °C. Inhomogeneous depth distribution of recombination lifetime in proton irradiated samples has been revealed from the cross-sectional scans of the excess carrier lifetime measured by MW-PC technique and compared for δ-layer and triangle profiles of radiation induced defects. After isochronal anneals, the τRR changes its behaviour as a function of irradiation fluence.