Empirical equations for drift velocities in silicon

Hardening against the electromagnetic pulse and high power microwave radiation is discussed. Vital to semiconductor modeling of burnout are the transport properties of semiconductors at high fields and high temperatures. At present, there is no single expression valid for this hot electron regime. The results of this study will be used in the thermal modification of the DIODE2D program, now underway. A recent report of the National Reseach Council, Evaluation of Methodologies for Estimating Vulnerability to Electromagnetic Pulse Effects, recommended that there should be a better understanding of the mechanisms of component failure. The theoretical work included in this report provides physical insight into the damage mechanisms and should lead to nondestructive means of characterizing specific devices. Empirical equations for the drift velocities of electron and holes in silicon are given as a function of electric field, temperature, and doping density. A single equation, which is valid above room temperature, results from the inverse dependence of the saturation velocity upon the square root of the temperature.