单轴应变硅 N沟道金属氧化物半导体场效应晶体管电容特性模型∗

摘要

The capacitance model is fundamental for the transient analysis, AC analysis and noise analysis of uniaxially strained Si MOSFET device and circuit. Firstly, the 16-differential capacitance model for uniaxially strained Si NMOSFET is developed. Secondly, the simulation results from that model match the experimental results well, which validates the accuracy of the model. Meanwhile the simulated relations of key gate capacitance Cgg to stress intensity, bias voltage, channel length and concentration of poly gate are obtained and analyzed, showing that the value of Cgg is a little larger than that of strainless bulk device while the changing tendency keeps the same.%电容特性模型是单轴应变硅金属氧化物半导体场效应晶体管(Si MOSFET)和电路进行瞬态分析、交流小信号分析、噪声分析等的重要基础。本文首先建立了单轴应变Si NMOSFET 的16个微分电容模型，并将微分电容的仿真结果与实验结果进行了比较，验证了所建模型的正确性。同时对其中的关键性栅电容Cgg 与应力强度、偏置电压、沟道长度、栅极掺杂浓度等的关系进行了分析研究。结果表明，与体硅器件相比，应变的引入使得单轴应变Si NMOSFET器件的栅电容增大，随偏置电压、沟道长度、栅极掺杂浓度的变化趋势保持不变。