总剂量辐照效应对窄沟道SOI NMOSFET器件的影响

Effects of total ionizing dose on narrow-channel SOI NMOSFETs

本文深入研究了130nm Silicon-on-Insulator(SOI)技术下的窄沟道n型metal-oxide-semiconductor-field-effect-transistor(MOSFET)器件的总剂量辐照效应.在总剂量辐照下,相比于宽沟道器件,窄沟道器件的阈值电压漂移更为明显.论文利用电荷守恒定律很好地解释了辐照增强的窄沟道效应.另外,本文首次发现,对于工作在线性区的窄沟道器件,辐照产生的浅沟槽隔离氧化物(STI)陷阱正电荷会增加沟道区载流子之间的碰撞概率和沟道表面粗糙度散射,从而导致主沟道晶体管的载流子迁移率退化以及跨导降低.最后,对辐照增强的窄沟效应以及迁移率退化进行了三维器件仿真模拟,仿真结果与实验结果符合得很好.

The effects of total ionizing dose on narrow-channel N-type metal-oxide-semiconductor field-effect-transistors （NMOSFETs） in a 130 nm partially depleted silicon-on-insulator （SOI） technology are presented. The charge conservation principle is utilized to analyze the radiation-induced narrow-channel effect （RINCE）. In addition, it is found for the first time, as for as we know that for the narrow-channel NMOSFETs operated in the linear region, the radiation-induced positive charges trapped in the shallow trench isolation can increase the probability of electron-electron collisions and surface roughness scattering, resulting in the degradation of the carrier mobility and transconductance of the main transistor. Finally, the RINCE as well as the degradation of the carrier mobility has been verified by our three-dimensional device simulation; and good agreement between the simulation and experimental results is obtained.