Gadolinium tris(acetylacetonate) phenantroline adduct Gd(acac)3(phen) was synthesized and characterised The complex is volatile (evaporated at 200°C/2.7 mbar in MOCVD conditions).
Gd(acac)3(phen) has been applied for the low-pressure MOCVD growth of Gd2O3 thin films on Si(100) and fused quartz substrates at 450–800 °C temperatures (the
precursor was evaporated at 200°C/2.7 mbar). Gd2O3 films grown on fused quartz (amorphous substrate) and silicon (single-crystal substrate) consisted of cubic Gd2O3 phase with (111) texture , according to XRD, irrespective of the growth temperature. The
presence of the monoclinic phase of Gd2O3 was found in the layers grown on fused quartz at higher temperatures. (minimization of the surface energy was explanation for the growth of strongly oriented films on fused quartz). Gd2O3 layers grown at ≥525°C
were densely packed and grainy, according to SEM and AFM. Optical properties of the films were strongly dependant on the CVD conditions, as detected by UV-visible spectrophotometry and FTIR. Gd2O3 layers grown at ≥500 °C were impurities-free.
(no C, N, and H detected). Gd2O3 films optical band gap was in the range of 5.0–5.4 eV. C–V and I-V analyses were used for the electrical characterization of Al∕Gd2O3∕Si metal-insulator-semiconductor structures. Layer relative effective dielectric constant was 7–23. Presence of slow interface traps as found to be a cause of the bidirectional C–V characteristics showing a counterclockwise hysteresis.
A minimum leakage current of 4.6×10–5 A∕cm2 at the 1-MV∕cm field was demonstrated.[[i]]
[i] M. P. Singh, C. S. Thakur, K. Shalini, S. Banerjee, N. Bhat, S. A. Shivashankar, J. Appl. Phys. (2004) 96, 5631; http://dx.doi.org/10.1063/1.1801157 “Structural, optical, and electrical characterization of gadolinium oxide films deposited by low-pressure metalorganic chemical vapor deposition”