ANALYTICAL EXPRESSIONS FOR THE DRIFT VELOCITY OF HOT CHARGE-CARRIERS IN SILICON

Analytical expressions for the drift velocities of electrons and holes in Si have been reviewed. It has been found that these either do not fit with experimental data in an appreciable part of the high-field region with the desired accuracy or involve too many parameters. Simple drift velocity expressions, with only two parameters, which appear to be the best fit in the high-field range of 10(3) - 5 x 10(5)V cm-1, have been presented. The modification of the expression parameters has been discussed to fulfil the need for doped and higher temperature cases which are more common and practical in solid-state devices. These can be utilized for the modelling of Si devices such as the Impatt diode with simplicity and better accuracy.