Clustering of Vacancies in Semi-Insulating SiC Observed with Positron Spectroscopy
Positron annihilation radiation Doppler broadening spectroscopy was used to study defects in semi-insulating (SI) silicon carbide (SiC) substrates grown by high-temperature chemical vapour deposition (HTCVD). The Doppler broadening measurements show (i) that the measured samples contain vacancy clusters (ii) that the positron trapping to the clusters is increased in annealing (iii) that the chemical environment of the defects in the un-annealed samples is different from those of the annealed samples.
Robert P. Devaty, David J. Larkin and Stephen E. Saddow
R. Aavikko et al., "Clustering of Vacancies in Semi-Insulating SiC Observed with Positron Spectroscopy", Materials Science Forum, Vols. 527-529, pp. 575-578, 2006