Influence of preparing process on total-dose radiation response of high-k Hf-based gate dielectrics

The purpose of this paper is to report some total-dose radiation response experimental results of Hf-based dielectric films including HfON film prepared by ion beam enhanced deposition method (IBAD) and HfO2 film by ultra high vacuum electron beam evaporation system (UV-EBE). MIS structures with HfON and HfO2 gate dielectrics were irradiated by10 keV X-rays with the dose from 0 to1 × 106 rad (Si). Electrical measurement results showed that trap charge density and interface trap charge density of HfON dielectric films are much smaller than HfO2 dielectric films, and the flatband and midgap voltage shifts in HfON films are also smaller than that in HfO2 film. AFM and XRD results show that HfON films are smooth and thermal stability even under 800 °C high temperature annealing.