Vanadium doping in 4H-SiC epitaxial growth for carrier lifetime control

We demonstrate controlled vanadium doping in 4H-SiC epitaxial growth, aimed at reducing the carrier lifetime in the epitaxial layers (epilayers), toward quenching the injection of minority carriers from the drift layer into the substrate in the forward operation of bipolar devices. The doping efficiency of vanadium and the quality of the epilayers were investigated for different gas systems and growth conditions. The photoluminescence spectra and decay curves of band-edge luminescence were evaluated for nitrogen-and vanadium-doped epilayers. The epilayers doped with nitrogen and vanadium demonstrated much shorter minority carrier lifetimes (<20 ns) compared with the epilayer doped with nitrogen only. (C) 2016 The Japan Society of Applied Physics