Semi-insulating 4H-SiC epitaxial layers were produced by chloro-carbon epitaxial growth at an intermediate growth temperature of 1450 degrees C and at high growth temperatures of 1600 C, enabling growth rates of 6 and in excess of 60 mu m/h, respectively. Vanadium tetrachloride was used as the source of vanadium doping. In epitaxial layers otherwise dominated by nitrogen donors, vanadium-acceptor compensation mechanism was achieved, providing resistivities in excess of 105 SI cm in fully compensated epilayers. Partial compensation enabled control of n-type doping in a wide range, down to around 10(14) cm(-3) in epilayers with N-2 donor concentration of 1 x 10(15) cm(-3). The domination of deep levels of vanadium was confirmed by photoluminescence spectroscopy. The limits for vanadium concentration consistent with degradation-free epilayer morphology were established to be around 1-1.5 x 10(17) and slightly less than 1 x 10(17) cm(-3) for the growth at 1450 and 1600 degrees C, respectively. (C) 2011 Elsevier B.V. All rights reserved.