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).