Monte Carlo simulation of electron transport in 4H–SiC using a two-band model with multiple minima

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Abstract
A Monte Carlo study of the high‐field electron transport in 4H–SiC is presented using a new analytic band model. The band model consists of two analytical bands that include band bending at the Brillouin zone boundaries. The band bending is very important in 4H–SiC and 6H–SiC and has to be taken into account in order to have an accurate model at high electric fields. Numerical calculation of the density of states given by the new model has been used in order to model the energy dependence of the scattering mechanisms accurately. The new model predicts a lower saturation velocity in the c direction (peak velocity 1.8×107 cm/s) than in perpendicular directions (peak velocity 2.1×107 cm/s). This is directly related to the strong band bending in the c direction. This effect is also responsible for a much more pronounced velocity peak in the c direction compared to perpendicular directions. In the low‐field region the mobility is higher in the c direction (mobility ratio near 0.8), which is in agreement with experimental results.