Characterization of crystalline rare-earth oxide high-K dielectrics grown by molecular beam epitaxy on silicon carbide

We have investigated the growth and electrical properties of crystalline Gd2O3 directly grown on 6H-SiC(0001) substrates by molecular beam epitaxy. Initially, Gd2O3 islands with hexagonal structure are formed. Further growth resulted in the formation of flat layers in a mixture of cubic bixbyite in [111] orientation and monoclinic structure. The fabricated capacitors exhibited suitable dielectric properties at room temperature; such as a dielectric constant of epsilon=22, a leakage current of 10(-8) A/cm(2) at 1 V and breakdown fields > 4.3 MV/cm for layers with 14 nm thickness. These properties make Gd2O3 interesting for high-K application on SiC. (c) 2006 American Vacuum Society.