华南理工大学学报(自然科学版) ›› 2010, Vol. 38 ›› Issue (1): 14-17,43.doi: 10.3969/j.issn.1000-565X.2010.01.003

• 电子、通信与自动控制 • 上一篇    下一篇

低掺杂多晶硅TFT阈值电压的确定和提取

姚若河   欧秀平   

  1. 华南理工大学 电子与信息学院, 广东 广州 510640
  • 收稿日期:2009-01-20 修回日期:2009-03-07 出版日期:2010-01-25 发布日期:2010-01-25
  • 通信作者: 姚若河(1961-),男,教授,博士生导师,主要从事集成半导体物理及器件研究. E-mail:phrhyao@seut.edu.cn
  • 作者简介:姚若河(1961-),男,教授,博士生导师,主要从事集成半导体物理及器件研究.
  • 基金资助:

    国家自然科学基金资助项目(60776020)

Modified Model of Threshold Voltage for Thin-Film Transistors with Low-Doped Polysilicon

Yao Ruo-he  Ou Xiu-ping   

  1. School of Electronic and Information Engineering, South China University of Technology, Guangzhou 510640, Guangdong
  • Received:2009-01-20 Revised:2009-03-07 Online:2010-01-25 Published:2010-01-25
  • Contact: 姚若河(1961-),男,教授,博士生导师,主要从事集成半导体物理及器件研究. E-mail:phrhyao@seut.edu.cn
  • About author:姚若河(1961-),男,教授,博士生导师,主要从事集成半导体物理及器件研究.
  • Supported by:

    国家自然科学基金资助项目(60776020)

摘要: 对低掺杂多晶硅薄膜晶体管的表面势进行分析,将表面势开始偏离亚阈值区、沟道电流迅速增加时所对应的栅压作为晶体管的阂值电压.考虑到多晶硅薄膜的陷阱态密度为单指数分布,通过对低掺杂多晶硅薄膜晶体管的表面势进行求解,推导出一个多晶硅薄膜晶体管阈值电压解析模型,并采用数值仿真方法对模型进行了验证.结果表明:新模型所得到的阈值电压与采用二次导数法提取的阈值电压相吻合.

关键词: 多晶硅, 薄膜晶体管, 阈值电压, 表面势

Abstract:

In this paper, first, the surface potential of thin-film transistors with light-doped polysilicon is analyzed. Next, the gate voltage, which corresponds to the channel current that quickly increases when the surface potential deviates from the sub-threshold region, is considered as the threshold voltage. Then, by taking into consideration the single-exponential distribution of trap state density, the surface potential of the transistor is derived, and an ana- lytical model of the threshold voltage is presented. Finally, a numerical simulation is performed to verify the model. The results indicate that the threshold voltage obtained by the proposed model perfectly matches that extracted by the second-derivative method.

Key words: polysilicon, thin-film transistor, threshold voltage, surface potential