在室温环境下采用射频磁控溅射方法制备了氧化铝(Al2O3)薄膜, 通过调节溅射气压实现了对薄膜特性的优化控制。当溅射功率为120 W、Ar气压强为0.13 Pa时, 制备的Al2O3薄膜具有最好的厚度均匀性, 薄膜中Al和O的原子比为1∶1.67, 密度为3.21 g/cm3, 粗糙度为0.62 nm。这种平滑、致密的薄膜结构能够有效地减少缺陷的形成, 获得高击穿电压、高相对介电常数和低漏电等性能。利用优化后的Al2O3薄膜作为栅极绝缘层, 在聚酰亚胺树脂(PI)基板上室温制备了柔性非晶态铟镓锌氧化物-薄膜晶体管(α-IGZO-TFT), 其迁移率为2.19 cm2/(V·s), 开关比达到105, 亚阈值摆幅为0.366 V/decade, 阈值电压为3.01 V。

Aluminum oxide (Al2O3) thin films are prepared by radio frequency magnetron sputtering at room temperature, and the optimal control of the properties of these films is realized by adjusting the sputtering pressure. The prepared films with the best thickness uniformity are obtained under the sputtering power of 120 W and Ar pressure of 0.13 Pa, whose ratio of aluminum atoms to oxygen atoms is 1∶1.67, density is 3.21 g/cm3, and surface roughness is 0.62 nm. This smooth and compact Al2O3 thin film can significantly reduce the defects, and it also possesses the characteristics of high breakdown voltage, high relative dielectric constant and low leakage current. The flexible α-IGZO-TFTs are prepared on a polyimide (PI) substrate at room temperature by utilizing the optimized Al2O3 films as the gate insulation layer, and exhibit electrical performance with a mobility of 2.19 cm2/(V·s), an on/off current ratio of 105, a sub-threshold swing of 0.366 V/decade, and a threshold voltage of 3.01 V.