Characterization of ALCVD-Al2O3 and ZrO2 layer using X-ray photoelectron spectroscopy

The atomic layer chemical vapor deposition (ALCVD) deposited Al2O3 and ZrO2 films were investigated by ex situ X-ray photoelectron spectroscopy. The thickness dependence of band gap and valence band alignment was determined for these two dielectric layers. For layers thicker than 0.9 nm (Al2O3) or 0.6 nm (ZrO2), the band gaps of the Al2O3 and ZrO2 films deposited by ALCVD are 6.7±0.2 and 5.6±0.2 eV, respectively. The valence band offsets at the Al2O3/Si and ZrO2/Si interface are determined to be 2.9±0.2 and 2.5±0.2 eV, respectively. Finally, the escape depths of Al 2p in Al2O3 and Zr 3p3 in ZrO2 are 2.7 and 2.0 nm, respectively.