Division of Materials Science and Engineering, Hanyang University, 222, Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea.
Department of Materials Science and Engineering, Chungnam National University, 99, Daehak-ro, Yuseong-gu, Daejeon 34134, Republic of Korea.
ACS Appl Mater Interfaces. 2023 Jul 5;15(26):31652-31663. doi: 10.1021/acsami.3c05678. Epub 2023 Jun 22.
Achieving high mobility and reliability in atomic layer deposition (ALD)-based IGZO thin-film transistors (TFTs) with an amorphous phase is vital for practical applications in relevant fields. Here, we suggest a method to effectively increase stability while maintaining high mobility by employing the selective application of nitrous oxide plasma reactant during plasma-enhanced ALD (PEALD) at 200 °C process temperature. The nitrogen-doping mechanism is highly dependent on the intrinsic carbon impurities or nature of each cation, as demonstrated by a combination of theoretical and experimental research. The GaO subgap states are especially dependent on plasma reactants. Based on these insights, we can obtain high-performance indium-rich PEALD-IGZO TFTs (threshold voltage: -0.47 V; field-effect mobility: 106.5 cm/(V s); subthreshold swing: 113.5 mV/decade; hysteresis: 0.05 V). In addition, the device shows minimal threshold voltage shifts of +0.45 and -0.10 V under harsh positive/negative bias temperature stress environments (field stress: ±2 MV/cm; temperature stress: 95 °C) after 10000 s.
在原子层沉积（ALD）基非晶相 IGZO 薄膜晶体管（TFT）中实现高迁移率和可靠性对于相关领域的实际应用至关重要。在这里，我们建议了一种在 200°C 工艺温度下通过选择性应用一氧化二氮等离子体反应物来有效提高稳定性同时保持高迁移率的方法。氮掺杂机制高度依赖于内在的碳杂质或每个阳离子的性质，这可以通过理论和实验研究的结合来证明。GaO 带隙态特别依赖于等离子体反应物。基于这些见解，我们可以获得高性能富铟的 PEALD-IGZO TFT（阈值电压：-0.47V；场效应迁移率：106.5cm/（V s）；亚阈值摆幅：113.5mV/decade；滞后：0.05V）。此外，该器件在经过 10000 秒的苛刻正/负偏置温度应力环境（场应力：±2MV/cm；温度应力：95°C）后，其阈值电压偏移仅为+0.45V 和-0.10V。
