Structural, chemical, and electrical properties of Y2O3 thin films grown by atomic layer deposition with an (iPrCp)2Y(iPr-amd) precursor

Y2O3 thin films were grown by atomic layer deposition (ALD) through a heteroleptic liquid (iPrCp)2Y(iPr-amd) precursor at 350 °C. The structural and chemical properties of both as-deposited and annealed Y2O3 films at 500 °C and 700 °C are analyzed by atomic force microscopy for variation in surface roughness, X-ray diffraction for crystalline structure, and X-ray photoelectron spectroscopy for chemical states. The as-deposited Y2O3 film shows the same crystalline orientation along the plane (222), a stoichiometric state, and minimal hydroxylate formation up to 700 °C. Being the dielectric layer in the metal-oxide-semiconductor capacitor, the as-deposited ALD-Y2O3 films with liquid (iPrCp)2Y(iPr-amd) precursor without any post-deposition annealing show the much lower leakage density than ALD-Y2O3 with solid Y(MeCp)3.