The electronic structures for the optical absorption of Hf-O-N thin films

Abstract

The local structures of Hf-O-N thin films were analyzed using an extended X-ray absorption fine structure (EXAFS) study on Hf L-III-edge and first-principles calculations. Depending on their composition and atomic configurations, Hf4O8 (CN: 7.0), Hf4O5N2 (CN: 6.25) and Hf4O2N4(CN: 5.5) were suggested as the local structures of Hf-O-N thin films. The optical band gaps of Hf-O-N thin films were compared with the calculated band gap. And to investigate the optical absorption, the effects of film compositions on the valence bands of Hf-O-N thin films were analyzed by comparing the experimental valence band with the valence band.