Effects of SiH Groups on ELDRS Quantified by XPS with Combined Use of Gamma-ray and Electron-beam Irradiation

Abstract

There have been no studies to date estimating the quantitative relation between the increase of interface traps and SiH groups in silicon dioxide films for the effects of total ionizing dose including enhanced low-dose-rate sensitivity (ELDRS). In this study, SiH groups densities in silicon dioxide films are measured and compared with interface trap densities developed at different dose rates to evaluate the impacts of direct proton release mechanism on ELDRS by X-ray photoelectron spectroscopy (XPS) analysis with the combined use of gamma-ray and electron-beam irradiation. The measurement results in this study clearly show that ELDRS depends linearly on SiH groups densities. The linear relationship demonstrates ELDRS is caused by the direct proton release mechanism. The order of magnitude of ELDRS we observed is almost the same as the experimental results reported previously. We emphasize that our results provide the first experimental evidence that the direct proton release mechanism is a critical mechanism affecting ELDRS in addition to the space charge model and H2 cracking.