Atomic layer deposition of Y2O3 thin films from yttrium tris(N,N'-diisopropylacetamidinate) and water

Y2O3 thin film was deposited by atomic layer deposition (ALD) with a new precursor yttriuni tris-(N,N'-diisopropylacetamidinate), Y((i)Pr(2)amd)(3), and water. The precursor was thermally stable and volatile and had high reactivity with water. The growth rate Of Y2O3 films was 0.8 angstrom/cycle over a wide temperature range (150-280 degrees C). The films were very pure (C, N < 0.5 at. %) and had a refractive index of 1.8. The films were smooth and had a cubic polycrystalline structure. High quality films were also deposited in 40:1 aspect ratio profiled substrates. Y2O3 films adsorbed water after air exposure because Rutherford backscattering spectroscopy (RBS) and X-ray photoelectron spectroscopy (XPS) showed, in increased oxygen ratio (O/Y > 1.5) and -OH bonds in air-exposed films. A relatively high permittivity (similar to 12). 1 low leakage current density (< 10(-7) cm(2) at 2 MV/cm) and high electrical breakdown field (similar to 5 MV/cm) were measured for capacitors prepared from Al2O3 (10 angstrom)/Y2O3/n-Si structures. Uncapped Y2O3, films showed flatband voltage shifts of 1 V and increased leakage current prior to annealing. ALD Y2O3; is a promising dielectric for advanced electronic applications in nanoscale devices.