Electrical breakdown paths in crystals

Offenbacher and Callen (1) have shown that the orientation of electrical breakdown paths may be due to the existence of asymmetrical electron scattering from the borders of the Brillouin zone for lattice vibrations. Observations of the orientation of electrical breakdown paths in the alkali halide crystals indicate that other sources of anisotropic electron scattering are present. This additional anisotropy may be due, for example, to the existence of non-spherical electronic energy surfaces within the Brillouin zone. Further details regarding the nature of anisotropic electron scattering are obtained from breakdown studies in more complex crystal systems. Some of the implications of these studies will be considered.