Analysis of anisotropic ionization coefficient in bulk 4H-SiC with full-band Monte Carlo simulation

High-field electron transport characteristics in bulk 4H-SiC are simulated with the full-band Monte Carlo method, and anisotropy of the ionization coefficient α is discussed. The simulation results exhibit larger α along 〈1120〉 direction than 〈0001〉 direction, which is consistent with the experimental observation. Furthermore, the dependence of α on the electric field direction θ is investigated. Compared to the existing analytical model, the present simulation results show a steeper increase when θ is tilted from the c-axis, which is originated from the anisotropic nature of the hot-electron heating.