Published online by Cambridge University Press: 01 February 2011
We investigated the influence of additional oxygen supply and temperature during the growth of thin Gd2O3 layers on Si(001) with molecular beam epitaxy. Additional oxygen supply during growth improves the dielectric properties significantly; however too high oxygen partial pressures lead to an increase in the lower permittivity interfacial layer thickness. The growth temperature mainly influences the dielectric gate stack properties due to changes of the Gd2O3/Si interface structure. Optimized conditions (600 °C, pO2 = 5·10-7 mbar) were found to achieve equivalent oxide thickness values below 1 nm accompanied by leakage current densities below 1 mA/cm2 at 1 V.