Thin MnO and NiO films grown using atomic layer deposition from ethylcyclopentadienyl type of precursors

We report on the atomic layer deposition (ALD) of MnO and NiO thin films on Si(1 0 0) using Mn(EtCp)2 [EtCp=ethylcyclopentadienyl, (C2H5)C5H4] and Ni(EtCp)2 in the temperature range of 150–300 °C. H2O or O3 is selected as oxygen source for the depositions. The growth temperature (Tg) and oxygen source impact on the structure, electronic density, and impurity concentration for the as-grown MnO and NiO films have been studied using X-ray reflectivity (XRR), grazing incidence X-ray diffraction (GIXRD), and Fourier transform infrared (FTIR) spectroscopy. A steady growth rate of 0.024–0.025 nm/cycle for the films grown using Mn(EtCp)2 and H2O was observed in the Tg range of 250–300 °C. FTIR does not show any carbon impurities in the MnO films grown with H2O. The films grown using Mn(EtCp)2 and O3 at 300 °C exhibit poor adhesion on Si(1 0 0). NiO films with low amounts of contaminants are achieved using O3 and at a Tg of 250 °C or above. The growth rate, however, is very high for films deposited at Tg=150 °C and decreases significantly in films deposited at higher temperatures. In addition, no film growth was observed for the Ni(EtCp)2/H2O process. The as-grown MnO and NiO films prepared using H2O and O3 as oxidizer, is shown, by GIXRD a polycrystalline cubic structure.