The purpose of this paper is to report some total-dose radiation response experimental results of Hf-based dielectric films including WON film prepared by ion beam enhanced deposition method (IBAD) and HfO(2) film by ultra high vacuum electron beam evaporation system (UV-EBE). MIS structures with HfON and HfO(2) gate dielectrics were irradiated by 10 keV X-rays with the dose from 0 to 1 x 10(6) rad (Si). Electrical measurement results showed that trap charge density and interface trap charge density of HfON dielectric films are much smaller than HfO(2) dielectric films, and the flatband and midgap voltage shifts in HfON films are also smaller than that in HfO(2) film. AFM and XRD results show that HfON films are smooth and thermal stability even under 800 degrees C high temperature annealing. (C) 2008 Elsevier B.V. All rights reserved.