Electron Irradiation Induced Vacancy Defects Detected by Positron Annihilation in 6H-SiC
This paper presents positron lifetime results which give information on the nature of vacancy defects induced by electron irradiation in bulk nitrogen doped (nD-nA= 2.3x1017 cm-3) Cree 6H-SiC. The electron irradiations have been performed at different energies and with different fluences from 51017 e-cm-2 to 31018 e-cm-2. Positron lifetime have been measured with a 22NaCl source as a function of temperature between 15 and 300 K. The lifetime spectra were analyzed as sums of two exponential lifetime components i weighted by the intensities Ii, convoluted with the resolution function. From the temperature dependence of the lifetime spectra we can infer that several vacancy defects exist in the electron irradiated n-type 6H-SiC. The nature of detected vacancy defects depends on the electron energy.
Dr. Roberta Nipoti, Antonella Poggi and Andrea Scorzoni
M. F. Barthe et al., "Electron Irradiation Induced Vacancy Defects Detected by Positron Annihilation in 6H-SiC", Materials Science Forum, Vols. 483-485, pp. 473-476, 2005