He Gang, Li Wendong, Sun Zhaoqi, Zhang Miao, Chen Xiaoshuang
School of Physics and Materials Science, Radiation Detection Materials & Devices Lab, Anhui University Hefei 230601 P. R. China
Institute of Physical Science and Information Technology, Anhui University Hefei 230601 P. R. China.
RSC Adv. 2018 Oct 30;8(64):36584-36595. doi: 10.1039/c8ra07813k. eCollection 2018 Oct 26.
Recently, much attention has been paid to the investigation of solution-driven oxides for application in thin film transistors (TFTs). In current study, a fully solution-based method, using 2-methoxyethanol as solvent, has been adopted to prepare InZnO thin films and HfAlO gate dielectrics. Amorphous HfAlO thin films annealed at 600 °C have shown a high transparency (>85%), low leakage current density (6.9 × 10 A cm at 2 MV cm), and smooth surface. To verify the potential applications of HfAlO gate dielectrics in oxide-based TFTs, fully solution-induced InZnO/HfAlO TFTs have been integrated. Excellent electrical performance for InZnO/HfAlO TFTs annealed at 450 °C has been observed, including a low operating voltage of 3 V, a saturated mobility of 5.17 cm V s, a high / of ∼10, a small subthreshold swing of 87 mV per decade, and a threshold voltage shift of 0.52 V under positive bias stress (PBS) for 7200 s, respectively. In addition, time dependent threshold voltage shift under PBS could be described by a stretched-exponential model, which can be due to charge trapping in the semiconductor/dielectric interface. Finally, to explore the possible application in logic operation, a resistor-loaded inverter based on InZnO/HfAlO TFTs has been built and excellent swing characteristic and well dynamic behavior have been obtained. Therefore, it can be concluded that fully solution-driven InZnO/HfAlO TFTs have demonstrated potential application in nontoxic, eco-friendly and low-power consumption oxide-based flexible electronics.
最近，溶液驱动氧化物在薄膜晶体管（TFT）中的应用研究受到了广泛关注。在当前的研究中，采用了一种完全基于溶液的方法，以2-甲氧基乙醇为溶剂，制备了InZnO薄膜和HfAlO栅介质。在600°C退火的非晶HfAlO薄膜具有高透明度（>85%）、低漏电流密度（在2 MV/cm时为6.9×10 A/cm²）和光滑的表面。为了验证HfAlO栅介质在氧化物基TFT中的潜在应用，集成了完全由溶液诱导的InZnO/HfAlO TFT。观察到在450°C退火的InZnO/HfAlO TFT具有优异的电学性能，包括3 V的低工作电压、5.17 cm²/V·s的饱和迁移率、约10的高Ion/Ioff、每十倍频程87 mV的小亚阈值摆幅以及在7200 s的正偏压应力（PBS）下0.52 V的阈值电压偏移。此外，PBS下随时间变化的阈值电压偏移可以用拉伸指数模型来描述，这可能是由于电荷俘获在半导体/介质界面中。最后，为了探索在逻辑运算中的可能应用，构建了基于InZnO/HfAlO TFT的电阻负载反相器，并获得了优异的摆幅特性和良好的动态行为。因此，可以得出结论，完全由溶液驱动的InZnO/HfAlO TFT在无毒、环保和低功耗的氧化物基柔性电子学中显示出潜在的应用前景。
