Effect of electron irradiation on defect structure of 6H–SiC grown by PVT method

Deep level transient spectroscopy (DLTS) has been applied to study an effect of electron irradiation on the concentrations of deep-level defects in bulk 6H–SiC:N single crystals. Six electron traps labelled as T1A, T1B, T1C, T2, T3 and T4 with activation energies of 0.34, 0.40, 0.50, 0.64, 0.67 and 0.69 eV, respectively, were revealed. It is shown that the irradiation with a dose of ∼2×1017 cm−2 of 300 keV electrons results in the formation of trap T1C (0.50 eV) attributed to carbon vacancies (VC). A significant increase in the concentrations of traps T2 (0.64 eV), T3 (0.67 eV) and T4 (0.69 eV) due to the irradiation has been also found. The results are discussed in terms of generation and annihilation of point defects and give a new insight into microscopic identity of the traps observed.