High-temperature effects on the velocity overshoot of hot electrons in 6H-and 3C-SiC

Lattice temperature effects on the high-held transport transient of electro ns in 6H- and 3C-SiC during the subpicosecond regime are studied. The calcu lations are performed considering a nonparabolic band structure, and the re sults are obtained through the numerical solution of Boltzmann-like transpo rt equations for the electron drift velocity v and energy epsilon within th e momentum and relaxation time approximations, tau(p) and tau(epsilon), res pectively. It is shown that an increase of the lattice temperature reduces both the electron drift velocity and energy, being even able to preclude a drift velocity overshoot in 6H- and 3C-SiC. For a given electric field, the growth rate of the electron energy decreases strongly when the 6H-and 3C-S iC lattice temperatures are raised.