Analysis of electronic levels in SiC: V, N, Al powders and crystals using thermally stimulated luminescence

The production of semi-insulating SiC depends on two issues: (i) the incorp oration of a transition metal or further defects in the SIC lattice providi ng near midgap electronic levels; and (ii) the control of shallow and middl e deep accepters and donors. In this work a synthesis process for SiC powde rs doped with vanadium (V) as an amphoteric dopant is proposed. The incorpo ration of vanadium as electrically active V,i is monitored via photolumines cence (PL) measurements. Thermally stimulated luminescence (TSL) is used as a characterization technique for shallow levels in the crystals and powder s. Recorded TSL glow curves are compared with numerical solutions of trap e mptying processes revealing quantitative information on the activation ener gy of the ionization of shallow donors and accepters. TSL emission and phot oionization studies give information on existing deep levels. (C) 1999 Else vier Science S.A. All rights reserved.