Effects of band non-parabolicity on electron drift velocity in silicon above room temperature

Electron drift velocity in silicon is studied at and above room temperature (300, 370 and 430 K) as function of field strength (up to 60 kV cm ) and orientation (〈111〉 and 〈100〉). Experimental data show a small anisotropy even at the highest considered temperature, while saturation is well evidenced only at 300 K with the field oriented along the (111) axis. The data are interpreted with theoretical Monte Carlo calculations. The model includes non-parabolicity of the band, and a non-parabolicity parameter α = 0.5 eV−1 is suggested by the comparison of theoretical and experimental results.