Al_(2)O_(3)钝化层对a-IGZO薄膜晶体管电性能的增强机制研究  

Enhancement Mechanism of Al_(2)O_(3) Passivation Layer on Electrical Properties of a-IGZO Thin Film Transistors

作　　者：王琛 曾超凡 路文墨 宁海玥 马飞[1] Wang Chen;Zeng Chaofan;Lu Wenmo;Ning Haiyue;Ma Fei(State Key Laboratory for Mechanical Behavior of Materials,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]西安交通大学金属材料强度国家重点实验室,陕西西安710049

出　　处：《稀有金属材料与工程》2023年第6期2103-2110,共8页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51771144);陕西省自然科学基金(2019JLM-30,2019TD-020,2021JC-06)。

摘　　要：采用空心阴极增强脉冲激光沉积技术(HC-PLD)在室温制备高质量的Al_(2)O_(3)薄膜,作为非晶铟镓锌氧(a-IGZO)TFT器件的钝化层,显著增强了Al_(2)O_(3)/a-IGZO TFT器件的亚阈值特性,其原因在于空心阴极引入的氧等离子体抑制了Al_(2)O_(3)/a-IGZO界面处氧空位的形成。进一步研究发现,针对a-IGZO薄膜的180℃退火处理有利于消除弱结合氧并抑制深能级缺陷,提高载流子迁移率并降低阈值电压漂移;而针对Al_(2)O_(3)/a-IGZO TFT器件进行100℃退火处理有助于消除其界面附近的氧空位,降低载流子浓度,改善亚阈值特性。结合2步退火工艺所制备的Al_(2)O_(3)/a-IGZO TFT器件迁移率高达22.8 cm^(2)·V^(-1)·s^(-1),亚阈值摆幅为0.6 V·decade-1,综合电性能优异。Al_(2)O_(3) thin films with low oxygen vacancy content were prepared by hollow cathode assistant pulsed laser deposition at room temperature,and they were used as the passivation layer of amorphous In-Ga-Zn-O(a-IGZO)TFT devices.The oxygen plasma introduced by the hollow cathode inhibits the formation of oxygen vacancies at the Al_(2)O_(3)/a-IGZO interface,which significantly improves the subthreshold performance of TFT devices.Annealing at 180℃for a-IGZO films can improve the mobility and reduce the threshold voltage shift,whereas annealing at 100℃ for Al_(2)O_(3)/a-IGZO TFT devices can reduce the carrier concentration and improve the subthreshold characteristics.The mobility of TFT devices processed by the combining annealing process can be as high as 22.8 cm^(2)·V^(-1)·s^(-1),and the subthreshold swing is 0.6 V·decade-1,showing excellent comprehensive electrical properties.

关 键 词：a-IGZO Al_(2)O_(3)钝化层 薄膜晶体管 XPS深度分析 

分 类 号：TN321.5[电子电信—物理电子学]