Thermal atomic layer deposition of In2O3 thin films using dimethyl(N-ethoxy-2,2-dimethylcarboxylicpropanamide)indium and H2O

Indium oxide (In2O3) thin films were deposited by atomic layer deposition using dimethyl(N-ethoxy-2,2-dimethylcarboxylicpropanamide)indium (Me2In(EDPA)) and H2O as the In-precursor and reactant, respectively. The In2O3 films exhibited a saturated growth rate of 0.083 nm/cycle at a deposition temperature of 300 °C. Porous and amorphous films were grown at 150 °C, whereas dense polycrystalline films were deposited at higher deposition temperatures of 200-300 °C. XPS analysis revealed negligible carbon and nitrogen impurities incorporation within the films. The estimated bandgap of the In2O3 films by spectroscopic ellipsometry and UV-vis spectroscopy was about 3.7 eV and the increase in refractive index with deposition temperature from 150 to 300 °C indicated that dense films were grown at higher temperatures. The high transmittance (>94% in visible light) and good electrical properties (resistivity ∼1.2-7 mΩ cm, Hall mobility ∼28-66 cm2/V s) of the In2O3 films make them a viable option for optoelectronic applications.