氢化非晶硅薄膜晶体管的低频噪声特性

发布时间：2018-11-22 10:09

【摘要】：针对氢化非晶硅薄膜晶体管(hydrogenated amorphous silicon thin film transistor,a-Si:H TFT)的低频噪声特性展开实验研究.由测量结果可知,a-Si:H TFT的低频噪声特性遵循1/f~γ(f为频率,γ≈0.92)的变化规律,主要受迁移率随机涨落效应的影响.基于与迁移率涨落相关的载流子数随机涨落模型(?N-?μ模型),在考虑源漏接触电阻、局域态俘获及释放载流子效应等情况时,对器件低频噪声特性随沟道电流的变化进行分析与拟合.基于a-Si:H TFT的亚阈区电流-电压特性提取器件表面能带弯曲量与栅源电压之间的关系,通过沟道电流噪声功率谱密度提取a-Si:H TFT有源层内局域态密度及其分布.实验结果表明:局域态在禁带内随能量呈e指数变化,两种缺陷态在导带底密度分别约为6.31×10~(18)和1.26×10~(18)cm~(-3)·eV~(-1),特征温度分别约为192和290 K,这符合非晶硅层内带尾态密度及其分布特征.最后提取器件的平均Hooge因子,为评价非晶硅材料及其稳定性提供参考.
[Abstract]:The low frequency noise characteristics of hydrogenated amorphous silicon thin film transistor (hydrogenated amorphous silicon thin film transistor,a-Si:H TFT) are investigated experimentally. The measured results show that the low frequency noise characteristics of a-Si:H TFT follow the variation rule of 1 / f ~ 纬 (f = 0.92), which is mainly affected by the random fluctuation effect of mobility. Based on the random fluctuation model of carrier number (? N-渭 model) associated with mobility fluctuations, the source and drain contact resistance, local state capture and release carrier effect are considered. The variation of low frequency noise characteristics with channel current is analyzed and fitted. Based on the subthreshold current-voltage characteristic of a-Si:H TFT, the relationship between the surface energy band bending and the gate voltage is extracted. The local density of states and its distribution in the active layer of a-Si:H TFT are extracted by the channel current noise power spectral density. The experimental results show that the local states change exponentially with the energy in the gap, the bottom densities of the two defect states are about 6.31 脳 10 ~ (18) and 1.26 脳 10 ~ (18) cm~ (-3) eV~ (-1), and the characteristic temperatures are about 192K and 290K, respectively. This accords with the density and distribution of the band tail state in the amorphous silicon layer. Finally, the average Hooge factor of the device is extracted to provide a reference for the evaluation of amorphous silicon material and its stability.
【作者单位】：工业和信息化部电子第五研究所电子元器件可靠性物理及其应用技术国家重点实验室;华南理工大学微电子学院;北京大学深圳研究生院信息工程学院;南华大学电气工程学院;
【基金】：国家自然科学基金(批准号:61574048) 广东省科技重大专项(批准号:2015B090912002) 广州市珠江科技新星专项(批准号:201710010172)资助的课题~~
【分类号】：TN321.5

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