Zhu Zheng, Cao Wei, Huang Xiaoming, Shi Zheng, Zhou Dong, Xu Weizong
College of Integrated Circuit Science and Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210023, China.
School of Communications and Information Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210023, China.
Micromachines (Basel). 2022 Apr 14;13(4):617. doi: 10.3390/mi13040617.
In this work, the impact of nitrogen doping (N-doping) on the distribution of sub-gap states in amorphous InGaZnO (a-IGZO) thin-film transistors (TFTs) is qualitatively analyzed by technology computer-aided design (TCAD) simulation. According to the experimental characteristics, the numerical simulation results reveal that the interface trap states, bulk tail states, and deep-level sub-gap defect states originating from oxygen-vacancy- (V) related defects can be suppressed by an appropriate amount of N dopant. Correspondingly, the electrical properties and reliability of the a-IGZO TFTs are dramatically enhanced. In contrast, it is observed that the interfacial and deep-level sub-gap defects are increased when the a-IGZO TFT is doped with excess nitrogen, which results in the degeneration of the device's performance and reliability. Moreover, it is found that tail-distributed acceptor-like N-related defects have been induced by excess N-doping, which is supported by the additional subthreshold slope degradation in the a-IGZO TFT.
在本工作中，通过技术计算机辅助设计（TCAD）模拟定性分析了氮掺杂（N掺杂）对非晶铟镓锌氧化物（a-IGZO）薄膜晶体管（TFT）中亚带隙态分布的影响。根据实验特性，数值模拟结果表明，适量的N掺杂剂可以抑制源于氧空位（V）相关缺陷的界面陷阱态、体尾态和深能级亚带隙缺陷态。相应地，a-IGZO TFT的电学性能和可靠性得到显著提高。相反，观察到当a-IGZO TFT掺杂过量氮时，界面和深能级亚带隙缺陷增加，这导致器件性能和可靠性退化。此外，发现过量N掺杂诱导了尾部分布的类受主N相关缺陷，这由a-IGZO TFT中额外的亚阈值斜率退化所证实。
