Electron-trap generation by recombination of electrons and holes in SiO₂

It is shown that after holes are injected and trapped in silicon dioxide (SiO₂), subsequent electron injection will generate neutral electron traps. The density of electron traps generated is about 30% of the density of trapped holes. It is proposed that electron traps are created by the energy released through the recombination of electrons and holes, and that this is the mechanism of electron-trap generation during high-field oxide stressing. Similar oxide field and thickness dependencies of the rate of electron-trap generation and hole generation further support this model. This model can reconcile the main evidence for the electron-trapping oxide breakdown model with the hole-trapping breakdown model. It is consistent with the higher trap generation rate in irradiated SiO₂. An analytical trapping model is derived and the electron capture cross sections of trapped holes and the generated neutral traps are found to be 10^-14 cm² and 5×10^-16 cm², respectively.