Velocity Overshoot in Silicon Inversion Layers by Broad Band Sub-Millimeter Wave Spectroscopy

Abstract

Small signal velocity overshoot is observed in a Si inversion layer by measuring the dynamical conductivity at d.c. and from 2.5 to 30 cm”1 (75-900 GHz) in the presence of a heating electric field. An overshoot of 30% is directly observed in the frequency domain. By Fourier transform the hot electron dynamics are displayed on a time scale from .5 to 6.5 psec.