应变Si沟道NMOSFET阈值电压特性研究

Study on Threshold Voltage Model of Strained Si Channel NMOSFET

在研究分析弛豫SiGe衬底上的应变Si沟道NMOSFET纵向电势分布的基础上,建立了应变Si NMOSFET阈值电压模型,并利用该模型对不同的器件结构参数进行仿真,获得了阈值电压、阈值电压偏移量与Si Ge层中Ge组分的关系。分析结果表明,阈值电压随SiGe层中Ge组分的提高而降低。该模型为应变Si器件阈值电压设计提供了重要参考。

The model of NMOSFET threshold voltage was established based on study of voltage distribution in strained Si film,which is grown on relaxed SiGe virtual substrate.Then the model was analyzed with reasonable parameters,and the connections of threshold voltage and Ge fraction were gained.The relation between threshold voltage shift and Ge fraction was also gained.The analysis results indicate that the threshold voltage decreases with the increasing Ge fraction of relaxed SiGe layer.This threshold voltage model supplies valuable references to the strained-Si devices design.