High field high temperature performance of semi-insulating silicon carbide

The influence of ambient temperature (295-730 K) and pulsed electric fields (0.5-80 kV/cm) on the electrical properties of high resistivity single-crystal 6H-SiC is reported. It is shown that the resistivity of the undoped 6H-SiC varies strongly, with the ambient temperature following a temperature/field function dominated by an exponential factor containing the activation (ionization) energy of residual boron of 0.35 eV. The dominant activation energy of semi-insulating Vanadium-compensated material (6H-SiC:V) varies with the ambient temperature, increasing from approx. 0 eV at 295-320 K to approx. 0.8 eV at T > 600 K. This result can explain the viability of insulating 6H-SiC as a substrate for next-generation high temperature power microwave integrated circuits based on large bandgap semiconductors. (C) 1997 Elsevier Science S.A.