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

Abstract

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 0.083nm/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 3.7eV 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 ∼1.2–7mΩcm, Hall mobility ∼28–66cm2/Vs) of the In2O3 films make them a viable option for optoelectronic applications.