K. Fröhlich, R. Luptak, E. Dobrocka, K. Husekova, K. Cico, A. Rosova, M. Lukosius, A. Abrutis, P. Pisecny, J.P. Espinós
Materials Science in Semiconductor Processing, 9 (2006) 1065-1072
doi: 10.1016/j.mssp.2006.10.025

We have prepared rare earth oxides based MOSFET gate stacks using metal-organic chemical vapour deposition, MOCVD. Gd2O3, La2O3, Nd2O3 and Pr6O11 films with thickness 3–20 nm were deposited on silicon substrate at 500 °C. The films were characterized by X-ray diffraction, X-ray reflectivity, transmission electron microscopy and X-ray photoelectron spectroscopy. As a next step, Ru films were grown on the dielectric films at 300 °C as a gate electrode. Electrical characterization of the MOS structures was performed by capacitance–voltage measurements. The structures annealed at 430 °C in forming gas (90% N2+10% H2) exhibited dielectric constant ranging from 12 to 14. Typically, the films showed high values of fixed oxide charge density, View the MathML source. Fixed oxide charges can be decreased by post-deposition annealing in forming gas and in oxygen.

Characterization of rare earth oxides based MOSFET gate stacks prepared by metal-organic chemical vapour deposition