Electrical Properties of Atomic-Layer-Deposited Thin Gadolinium Oxide High-kGate Dielectrics

Amorphous or cubic Gd2O3thin films were grown from tris(2,3-dimethyl-2-butoxy)gadolinium(III), Gd[OC(CH3)2CH(CH3)2]3, and H2Oprecursors at 350°C. As-deposited Gd2O3films grown on etched (H-terminated) Si(100) exhibited better leakage current-voltage characteristics as well as lower flatband voltage shift than films grown on SiO2∕Sisubstrates. Interface trap densities were lower in Al∕Gd2O3/hydrofluoric acid (HF)-etched Si samples annealed at rather high temperatures.