Study of point- and cluster-defects in radiation-damaged silicon

For the VOi (vacancy-oxygen interstitial) defect ΔEa=0 is found, which confirms that it is a point defect, and validates the method for point defects. For clusters made of deep acceptors the ΔEa values for different defects are determined after annealing at 80∘C as a function of electron energy, and for the irradiation with 15  MeV electrons as a function of annealing temperature. For the irradiation with 3.5  MeV electrons the value ΔEa=0 is found, whereas for the electron energies of 6-27  MeV ΔEa>0. This agrees with the expected threshold of about 5  MeV for cluster formation by electrons. The ΔEa values determined as a function of annealing temperature show that the annealing rate is different for different defects. A naive diffusion model is used to estimate the temperature dependencies of the diffusion of the defects in the clusters.