Plasma-enhanced atomic layer deposited indium oxide film using a novel dimethylbutylamino-trimethylindium precursor for thin film transistors

In this study, plasma-enhanced atomic layer deposited indium oxide (InO_x) films were analyzed using a new [dimethylbutylamino]trimethylindium (DATI) liquid precursor and Ar/O₂ plasma. The growth property using the DATI precursor, such as growth per cycle, is relatively higher (≥1.0 Å/cycle) than other precursors even in low deposition temperatures (100–250 °C). In addition, impurities (C and N) in the thin films were below the XPS detection limit. Because the number of oxygen vacancies that generate carriers in the InO_x thin films increased with the deposition temperature, the carrier concentration (2.7 × 10¹⁸–1.4 × 10¹⁹ cm⁻³) and Hall mobility (0.3–1.1 cm²/V s) of the InO_x thin film were increased. InO_x channel based staggered bottom gate structure thin film transistors (TFTs) were fabricated, and their switching performance were studied. Because the InO_x films were deposited with high purity, the electrical properties of TFTs show superior switching performance in terms of saturation mobility (17.5 cm²/V s) and I_on/I_off ratio (2.9 × 10⁹). Consequently, InO_x films deposited with DATI have the potential to be widely used in indium oxide semiconductors, especially backplane TFTs.