Ionization Rates for Electrons and Holes in Silicon

The ionization rates for holes and electrons in silicon have been determined over the following ranges of field: for holes, (2.5-6.0)×${10}^5$ volts ${\mathrm{cm}}^{-1\mathrm{}}$; for electrons, (2.0-5.0)×${10}^5$ volts ${\mathrm{cm}}^{-1\mathrm{}}$. The ionization rate for electrons is higher than that for holes. The results suggest that the field dependence of the ionization rate for holes and, probably, for electrons also, can be expressed by $a\exp (-\frac{b}{E})$, where $E$ is the field. The constants $a$ and $b$ are different for electrons and holes.