基板温度对氧化锌薄膜晶体管性能的影响

以ITO玻璃为衬底，利用射频磁控溅射制备了以氧化硅为绝缘层的氧化锌薄膜晶体管。研究了氧化锌薄膜制备过程中不同的衬底温度（衬底温度分别为室温、100℃ 和200℃）对于器件性能的影响。和室温下制备的氧化锌薄膜晶体管相比，衬底温度200℃条件下制备的器件的场效应迁移率提高了94% （从1.6cm2/Vs 提高至3.11cm2/Vs），亚阈值摆幅 从2.5V/dec 降低至1.9 V/dec 而且阈值电压漂移也从18V 减小至3V （老化电压为25V的正栅压，老化时间为1小时）。实验结果表明，衬底加热对于氧化锌薄膜晶体管的迁移率、亚阈值摆幅和偏压稳定性有明显的影响。利用原子力显微镜AFM对氧化锌薄膜的特性就行了研究，器件性能提高的原因也在文中进行了阐述。

Influence of substrate temperature on the performance of zinc oxide thin film transistor

Top-contact thin film transistors (TFTs) using radio frequency (RF) magnetron sputtering zinc oxide (ZnO) and silicon dioxide (SiO₂/ films as the active channel layer and gate insulator layer, respectively, were fabricated. The performances of ZnO TFTs with different ZnO film deposition temperatures (room temperature, 100oC and 200oC) were investigated. Compared with the transistor with room-temperature deposited ZnO films, the mobility of the device fabricated at 200oC is improved by 94% and the threshold voltage shift is reduced from 18 to 3 V (after 1 h positive gate voltage stress). Experimental results indicate that substrate temperature plays an important role in enhancing the field effect mobility, sharping the subthreshold swing and improving the bias stability of the devices. Atomic force microscopy was used to investigate the ZnO film properties. The reasons for the device performance improvement are discussed.