Depth Profiling of Chemical and Electronic Structures and Defects of

We present in-depth profiling of chemical bonding features and defect state density in ultrathin HfSiOxNy (Hf/(Hf+Si)=~43%) films with average nitrogen contents up to ~18at. % by using x-ray photoelectron spectroscopy (XPS) and total photoelectron yield spectroscopy (PYS) in combination with oxide thinning in a dilute HF solution. The films were prepared on pre-cleaned Si(100) by an atomic layer chemical vapor deposition (ALCVD) method and followed by plasma nitridation. By annealing at 1050°C in N2 ambience, Si-N bonding units in the films are increased as a result of thermal decomposition of Hf-Nx(x=2 and 3) units and the interfacial oxidation accompanied with nitrogen incorporation is caused. For the annealed samples, Hf ions coordinated with two N atoms are distributed with a profile peaked around 1nm from the top surface. Also, from the depth profiles of chemical compositions, which were determined from the change in th