Correlation of trap creation with electron heating in silicon dioxide

Abstract

Electron trap creation in thin films of silicon dioxide is shown to follow the electron heating characteristic of this material. No trap creation is observed in the near-thermal transport regime at electric field magnitudes less than 1.5 MV/cm. At these low fields, electrons travel in a streaming fashion close to the bottom of the oxide conduction band at energies less than that of the dominant optical phonon mode at 0.153 eV. At higher electric fields, the rate of bulk trap creation is proportional to the average energy of the hot electrons which move in a dispersive manner and can reach energies as large as 4 eV. Also, interface charge and interface state buildup are observed to be proportional to electron capture into bulk traps in the as-fabricated oxides or into those induced by the passage of hot electrons.