High epitaxial quality Y2O3 high-κ dielectric on vicinal Si(001) surfaces

Abstract

Thin films of ${\mathrm{Y}}_2{\mathrm{O}}_3$ were grown by molecular-beam epitaxy on silicon aiming at material with adequate crystal quality for use as high-κ gate replacements in future transistors. It was found that ${\mathrm{Y}}_2{\mathrm{O}}_3$ grows in single-crystalline form on $\text{4°}$ misoriented Si(001), due to an in-plane alignment of ${\text{〈110〉}}_{{\mathrm{Y}}_2{\mathrm{O}}_2}$ to the silicon dimer direction. The ${\mathrm{Y}}_2{\mathrm{O}}_3$ layers exhibit a low degree of mosaicity, a small proportion of twinning and sharp interfaces. This represents a significant improvement compared to material grown on exact silicon surfaces.