Epitaxial growth of HfO2 doped CeO2 thin films on Si(001) substrates for high-κ application

The authors report on the growth and characterization of CeO2 epitaxial films doped with 18at.% HfO2 (HDC) as gate dielectrics for Si technology prepared by ultrahigh vacuum pulsed laser deposition. In situ reflection high-energy electron diffraction and cross-sectional high-resolution transmission electron microscopy reveal the formation of an epitaxial HDC/Si structure with (111)HDC‖(001)Si and [110]HDC‖[110]Si orientation relationship. C-V and I-V measurements indicate a dielectric constant κ∼19.5 for HDC film and the leakage current density at 1V gate bias is about four orders of magnitude lower than that of the CeO2 in both 25nm thickness.