基于自热修正的SOI NMOSFETs热载流子注入效应寿命预测方法

自热效应SHE（self-heating effect）是SOI MOSFETs可靠性研究的关键问题之一.在热载流子注入HCI（hot carrier injection）应力下会导致自热效应加剧,低估器件工作寿命,使得寿命预测不准.本文提出了一种基于直流HCI应力下的0.18μmPD-SOINMOSFETs可靠性寿命预测方法.通过栅电阻法提取沟道中因自热效应产生的温度,采用自热修正后的衬底电流/漏电流比率模型预测PD-SOI NMOSFETs在正常工作电压下的寿命值,预测结果与未消除自热影响预测出的寿命值存在较大差异,说明自热修正在寿命预测中不可忽略,否则会低估器件的工作寿命.

Research on HCI lifetime prediction methodology based on self- heating removal for SOI NMOSFETs

Self-heating effect （SHE） is one of the key concerns for the reliability issues of SOI MOSFETs. The unavoidable SHE during HCI test may underestimate the device＇s performance and lead to the inaccurate lifetime prediction. In this paper, a new method is proposed to accurately predict the lifetime of 0.18 μm PD-SOI NMOS device based on DC HCI stress. The temperature increase （Tsh） caused by SHE is quantitatively extracted by gate resistance measurement. Then, the degradation part due to SHE is removed to accurately extrapolate lifetime of PD-SOI NMOSFET device using substrate/drain current ratio model. As a result, the extrapolated lifetime of 0.18 μm SOI NMOS illustrates a significant difference by 63.5% whether considering removal of SHE or not, indicating that the impact of SHE on the reliability issue of SOI device can not be ignored, otherwise leading to the inaccurate lifetime prediction.