Atomic layer deposition of indium oxide thin film from a liquid indium complex containing 1-dimethylamino-2-methyl-2-propoxy ligands

Abstract

In2O3 thin films were grown from a newly developed, liquid, homoleptic, In-based complex, tris(1-dimethylamino-2-methyl-2-propoxy) indium [In(dmamp)(3)], and O-3 by atomic layer deposition (ALD) at growth temperatures of 150-200 degrees C. In(dmamp)(3) exhibited single-step evaporation with negligible residue and excellent thermal stability between 30 and 250 degrees C. The self-limiting surface reaction of In2O3 during ALD was demonstrated by varying the In(dmamp)(3) and O-3 pulse lengths, with a growth rate of 0.027 nm/cycle achieved at 200 degrees C. The In2O3 films grown at temperatures over 175 degrees C exhibited negligible concentrations of impurities, whereas that grown below 175 degrees C had concentrations of residual C of 6-8 at.%. Glancing angle X-ray diffraction revealed that the In2O3 films were polycrystalline in nature when the deposition temperature was greater than 200 degrees C. The In2O3 films grown at 150-200 degrees C exhibited carrier concentrations of 1.5 x 10(18)-6.6 x 10(19) cm(-3), resistivities of 15.1-2 x 10(-3) Omega cm, and Hall mobilities of 0.8-42 cm(2)/(V s).