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

In ₂ O ₃ 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 °C. In(dmamp) ₃ exhibited single-step evaporation with negligible residue and excellent thermal stability between 30 and 250 °C. The self-limiting surface reaction of In ₂ O ₃ 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 °C. The In ₂ O ₃ films grown at temperatures over 175 °C exhibited negligible concentrations of impurities, whereas that grown below 175 °C had concentrations of residual C of 6-8 at.%. Glancing angle X-ray diffraction revealed that the In ₂ O ₃ films were polycrystalline in nature when the deposition temperature was greater than 200 °C. The In ₂ O ₃ films grown at 150-200 °C exhibited carrier concentrations of 1.5 × 10 ¹⁸ -6.6 × 10 ¹⁹ cm ^-3 , resistivities of 15.1-2 × 10 ^-3 Ω cm, and Hall mobilities of 0.8-42 cm ² /(V s).