Radiation damage in SiO2/Si induced by low‐energy electrons via plasmon excitation

We have found definite evidence which proves that radiation damage in SiO2/Si induced by low‐energy electrons is caused by plasmon excitation in SiO2. The SiO2/Si sample was irradiated by accelerated thermoelectrons, and the flat‐band voltage shift, ΔVFB, of the sample was measured by the C‐V method. The effective charge generation yield, Rf, in SiO2/Si was evaluated from the ΔVFB and the electron dose. The effective positive charges were measured in p‐type SiO2/Si, and the effective negative charges were measured in n‐type SiO2/Si. This is because interface states behave like positive charges in p‐type SiO2/Si and negative charges in n‐type SiO2/Si. The Rf in p‐type SiO2/Si oscillated as a function of the incident electron energy of 5–150 eV with several clear peaks. These peaks correspond to the quantum energy of a bulk plasmon or a surface plasmon. Both plasmons decay into electron‐hole pairs. The holes that escape from recombination with the electrons are trapped at the SiO2/Si interface and cause eff...