0.18μm MOSFET器件的总剂量辐照效应

Total ionizing dose effect of 0.18μm nMOSFETs

对0.18μm metal-oxide-semiconductor field-effect-transistor(MOSFET)器件进行γ射线辐照实验,讨论分析器件辐照前后关态漏电流、阈值电压、跨导、栅电流、亚阈值斜率等特性参数的变化,研究深亚微米器件的总剂量效应.通过在隔离氧化物中引入等效陷阱电荷,三维模拟结果与实验结果符合很好.深亚微米器件栅氧化层对总剂量辐照不敏感,浅沟槽隔离氧化物是导致器件性能退化的主要因素.

A 0.18μm MOSFET with shallow trench isolation is exposed to a γ-ray radiation.The parameters such as off-state leakage current,threshold voltage,transconductance,gate leakage current,and subthreshold slope are analyzed for pre- and post-irradiation.By introducing constant sheet charges at the shallow trench isolation oxide sidewall,good agreement between 3D simulation and experiment result is demonstrated.We believe that the thin gate oxide is insensitive to radiation,and the radiation induced charge trapping in the shallow trench isolation still leads to macroscopic effects such as drain-to-source leakage current,ultimately limiting the tolerance of CMOS circuits.