A detailed investigation of the quantum yield experiment

A detailed investigation of the quantum yield (QY) experiment is proposed. Experimental data show that no correlation exists between the QY and the stress-induced leakage current (SILC), and that the QY is determined by high-energy oxide traps. Numerical simulations are then used, based on a detailed calculation of the oxide defect distribution. It is shown that the leakage current and the excess impact ionization component are due to trap-assisted tunneling (TAT) of electrons through different sets of traps: Deep levels are responsible for the SILC, while high-energy states determine the impact ionization current. Simulation results are in good agreement with experiments, showing that the QY results cannot be used to extract the energy loss of the SILC electrons.