0.6V threshold voltage thin film transistors with solution processable indium oxide (In₂O₃) Channel and Anodized High-κ Al₂O₃ Dielectric

Low-voltage operation and low processing temperature of metal oxide transistors remain a challenge. Commonly metal oxide transistors are fabricated at very high processing temperatures (above 500°C) and their operating voltage is quite high (30-50 V). Here, thin-film transistors (TFT) are reported based upon solution processable indium oxide (In₂O₃) and room temperature processed anodized high- κ aluminum oxide (Al₂O₃) for gate dielectrics. The In₂O₃ TFTs operate well below the drain bias (V_ds) of 3.0 V, with on/off ratio 10⁵, subthreshold swing (SS) 160 mV/dec, hysteresis 0.19 V, and low threshold voltage (V_th)~0.6 V. The electron mobility (μ) is as high as 3.53 cm²/V.s in the saturation regime and normalized transconductance (g_m) is 75μS/mm. In addition, the detailed capacitance-voltage (C-V) analysis to determine interface trap states density was also investigated. The interface trap density (D_it) in the oxide/semiconductor interface was quite low, i.e., 0.99 × 10¹¹ - 2.98 × 10¹¹ eV^-1· cm², signifying acceptable compatibility of In₂O₃ with anodic Al₂O₃.