High Field-Effect Mobility and On/Off Current Ratio of p-Type ALD SnO Thin-Film Transistor
Myeong Gil Chae, Jina Kim, Hee Won Jang, Bo Keun Park, Taek‐Mo Chung, Seong Keun Kim, Jeong Hwan Han
Abstract
High-performance p-type thin-film transistors (TFTs) with high field-effect mobility and high on/off current ratios ( I on / I off ) were fabricated by engineering the microstructure and surface morphology of the atomic layer-deposited (ALD) SnO channel layer. ALD SnO films grown at a deposition temperature of 225 °C showed excellent crystallinity and dense, smooth surfaces, which resulted in superior field-effect mobility of 6.13–7.24 cm 2 /V·s without using a high-temperature postannealing process. Optimization of the SnO channel thickness suppressed the off-state leakage current, which consequently yielded excellent TFT switching performance, with an I on / I off value of 10 4 –10 5 . Additionally, backchannel passivation by the ALD Al 2 O 3 film improved the subthreshold swing characteristics by reducing surface defect states. These results suggest that synergistic control of the microstructure, surface morphology, and thickness of ALD SnO channels is crucial for achieving high-performance p-type SnO TFTs.