Hot-Electron Transport and Microwave Noise in 4H-SiC

Hot-electron transport and microwave noise are investigated for n-type 4H-SiC (n=2×10$\text{}^{17}$ cm$\text{}^{-3}$) subjected to a pulsed electric field applied parallel to the basal plane. At room temperature, the negative differential conductance, masked by field ionization at the highest fields, is observed in the field range between 280 and 350 kV/cm. The threshold fields for the negative differential conductance and field ionization increase with lattice temperature. The results on microwave noise are used to evaluate the effective hot-electron temperature and the hot-electron energy relaxation time.