High-field carrier drift velocity measurements in silicon by a time-of-flight technique

Experimental apparatus for determining carrier velocities by a time-of-flight technique has been constructed, and data on both holes and electrons in silicon has been obtained for E in the range 4 × 10³< E < 2.5 × 10⁴volt/cm. The experiment employs electron-hole pair generation by energetic electron bombardment to inject a plane of carriers at one edge of a reverse-biased pin junction diode. Observation of the resulting transient diode carrier currents and knowledge of the width of the pin depletion region allows the direct determination of carrier velocity over a wide range of diode reverse bias.