Neodymium oxide and neodymium aluminate thin films by atomic layer deposition

Nd2O3 and NdAlO3 thin films were deposited onto Si(100) and soda lime glass by atomic layer deposition using Nd(thd)3, O3, (CH3)3Al and H2O as precursors at 200-450 °C. Films were analyzed by X-ray diffraction, Fourier transform infrared spectroscopy, atomic force microscopy, X-ray fluorescence spectroscopy and time-of-flight elastic recoil detection analysis. Cubic (100) oriented Nd2O3 films with a relative permittivity of 10.5 were obtained at 290-325 °C. The carbon content of the films deposited at low temperatures was high but decreased with increasing temperature and could be further reduced by annealing at 650-700 °C. Nd2O3 films with low carbon content were somewhat unstable and became hydrated upon storage in the ambient. NdAlO3 films deposited at 300 °C were amorphous but crystallized during annealing in nitrogen or oxygen at 850-900 °C.