  This communication presents a comparative study on the charge transport (in
transient and steady state) in bulk n-type doped SiC-polytypes: 3C-SiC, 4H-SiC
and 6H-SiC. The time evolution of the basic macrovariables: the electron drift
velocity and the non-equilibrium temperature are obtained theoretically by
using a Non-Equilibrium Quantum Kinetic Theory, derived from the method of
Nonequilibrium Statistical Operator (NSO). The dependence on the intensity and
orientation of the applied electric field of this macrovariables and mobility
are derived and analyzed. From the results obtained in this paper, the most
attractive of these semiconductors for applications requiring greater
electronic mobility is the polytype 4H-SiC with the electric field applied
perpendicular to the c-axis.
