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

Abstract

In this study, plasma-enhanced atomic layer deposited indium oxide (InOx) 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 InOx 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 InOx thin film were increased. InOx channel based staggered bottom gate structure thin film transistors (TFTs) were fabricated, and their switching performance were studied. Because the InOx 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 Ion/Ioff ratio (2.9 × 109). Consequently, InOx films deposited with DATI have the potential to be widely used in indium oxide semiconductors, especially backplane TFTs.