Amorphous lanthanum lutetium oxide thin films as an alternative high-$κ$ gate dielectric

Lanthanum lutetium oxide thin films were grown on (100) Si by pulsed laser deposition. Rutherford backscattering spectrometry, atomic force microscopy, x-ray diffraction, and x-ray reflectometry were employed to investigate the samples. The results indicate the growth of stoichiometric and smooth $LaLuO3$ films that remain amorphous up to $1000°C$⁠. Internal photoemission and photoconductivity measurements show a band gap width of $5.2±0.1eV$ and symmetrical conduction and valence band offsets of $2.1eV$⁠. Capacitance and leakage current measurements reveal $C-V$ curves with a small hysteresis, a dielectric constant of $≈32$⁠, and low leakage current density levels.