高k栅介质SOI nMOSFET正偏压温度不稳定性的实验研究

对高k栅介质SOI nMOSFET器件的PBTI退化和恢复进行实验研究, 并且与pMOSFET器件的NBTI效应进行比较, 分析PBTI效应对阈值电压漂移、线性及饱和漏电流、亚阈摆幅和应力诱导漏电流的影响。结果显示, PBTI的退化和恢复与NBTI效应具有相似的趋势, 但是PBTI具有较高的退化速率和较低的恢复比例, 这会对器件的寿命预测带来影响。 最后给出在PBTI应力条件下, 界面陷阱和体陷阱的产生规律及其对器件退化的影响。

Experimental Study on Positive Bias Temperature Instability of SOI nMOSFETs with High-k Gate Dielectrics

Experimental study on the positive bias temperature instability (PBTI) degradation and recovery of SOI nMOSFET with high-k gate dielectrics was conducted with comparison of negative bias temperature instability (NBTI) in pMOSFETs. A comprehensive analysis was presented on impacts of PBTI in terms of threshold voltage shift(V_th), drain current in linear region (I_dlin) and saturated region (I_dsat), subthreshold swing (S) and stress-induced leakage current (SILC). The results show that the degradation and recovery of PBTI have the similar tendency as NBTI, but the higher degradation rate and lower recovery ratio than NBTI may produce an effect on the lifetime prediction. Interface traps and oxide traps generation under PBTI stress were investigated and their influences to the device degradation were also presented.