非晶铟锌氧化物薄膜晶体管的低频噪声特性与分析

Analysis of low-frequency noise in the amorphous indium zinc oxide thin film transistors

本文针对底栅结构非晶铟锌氧化物薄膜晶体管的低频噪声特性开展实验与理论研究.由实验结果可知:受铟锌氧化物与二氧化硅界面处缺陷态俘获与释放载流子效应的影响,器件沟道电流噪声功率谱密度随频率的变化遵循1/fγ(γ≈0.75)的变化规律;此外,器件沟道电流归一化噪声功率谱密度随沟道长度与沟道宽度的增加而减小,证明器件低频噪声来源于沟道的闪烁噪声,可忽略源漏结接触及寄生电阻对器件低频噪声的影响.最后,基于载流子数涨落及迁移率涨落模型,提取γ因子与平均Hooge因子,为评价材料及器件特性奠定基础.

Properties of low-frequency noise in the amorphous InZnO thin film transistors have been investigated in this paper. Due to the emission and trapping processes of carriers between trapping states located in the interface between the IZO layer and gate insulator, the drain current spectral density shows a 1/f^γ（γ = 0.75） low-frequency noise behavior. In addition, the normalized drain current spectral density is decreased linearly with the increase of gate length and width. This property confirms that the low-frequency noise in the IZO TFTs is due to the flicker noise in the channel, the contribution of source/drain contact and parasitic resistances can be ignored. Finally, based on the number fluctuation theory and the mobility fluctuation theory, the γ and average Hooge’s parameters have been extracted to estimate the quality of devices and materials.