Hot electrons in silicon oxide

One particular application of amorphous silicon oxide ${\rm SiO_2}$, a material crucial for silicon device technology and design, is as a flash memory tunnel dielectric. The breakdown field of ${\rm SiO}_2$ exceeds $10^7$ V $\rm cm^{-1}$. Strong electric fields in ${\rm SiO}_2$ give rise to phenomena that do not occur in crystalline semiconductors. In relatively weak electric fields ($10^4 - 10^6$ V $\rm cm^{-1}$) the electron distribution function is determined by the scattering of electrons on longitudinal optical phonons. In high fields (in excess of $10^6$ V $\rm cm^{-1}$), the distribution function is determined by electron–acoustic phonon scattering.