Reflection electron energy loss spectroscopy for ultrathin gate oxide materials

Abstract

The band alignment of HfZrO 4 gate oxide thin films on Si (100) deposited by the atomic layer deposition method has been investigated using reflection electron energy loss spectroscopy and XPS. The band gap of HfZrO 4 gate oxide thin film is 5.±0.05 eV. The valence band offset (ΔE v) and the conduction band offset (ΔE c) are 2.50±0.05 eV and 1.78±0.05 eV, respectively. These values satisfy the minimum requirement for the hole and electron barrier heights of larger than 1 eV for device applications. We have demonstrated that the quantitative analysis of reflection electron energy loss spectroscopy spectra obtained from HfZrO 4 thin films provides us a straightforward way to determine the optical properties and the inelastic mean free path of ultrathin gate oxide materials. Copyright © 2012 John Wiley & Sons, Ltd. Copyright © 2012 John Wiley & Sons, Ltd.