Boron, aluminum, nitrogen, oxygen impurities in silicon carbide

Abstract

Diffusion of boron, aluminum, and oxygen was conducted at temperatures 1600 – 1700°C. Very pure original n-SiC crystal (6H-SiC) specially grown by the Lely method annealed in oxygen during 2 h at 1700 °C, in argon during 2 h at 1700 °C, with aluminum and silicon oxide powder during 2 h, and with boron oxide and aluminum during 0.5 h. Electrical characterization of the silicon carbide samples was done by the Hall effect measurements using the square van der Pauw method to determine the sheet resistance, mobility, and free carrier concentration. The model of deep donor level as a complex of nitrogen atom replacing carbon with adjacent silicon vacancy is suggested.