强激光与粒子束, 2014, 26 (8): 084003, 网络出版: 2014-07-30
γ辐照前后多栅NMOS转移特性曲线交叉现象机理分析
Mechanism of crossover of transconductance curves in 0.5 μm multi-finger NMOS FETs before and after γ irradiation
多栅NMOS 转移特性 不均匀辐照 总剂量效应 计算机仿真 multi-finger NMOS transfer characteristics non-uniform irradiation total dose effects computer simulation
摘要
在研究0.5 μm多栅NMOS场效应管γ辐照总剂量效应实验时, 发现部分多栅NMOS器件辐照前后的转移特性曲线出现交叉现象, 相关的解释鲜见报道。经过分析提出假设: 部分多栅NMOS在γ辐照实验过程中各栅极受到剂量不均匀的辐照, 导致辐照前后转移特性曲线出现交叉现象。计算机仿真结果表明: 受到剂量不均匀的辐照后, 多栅NMOS各栅极氧化层陷阱电荷和硅-二氧化硅界面电荷浓度不一致, 使各栅极阈值电压不同步漂移, 导致器件跨导退化和转移特性曲线交叉。通过仿真验证能够说明, 所提出的假设合理地解释了实验中的现象。
Abstract
The crossover phenomenon of transconductance curves was found in part of 0.5 μm multi-finger NMOS FETs after γ irradiation experiments. To give a reasonable explanation, we assumed that the radiation effects on each gate of this part of multi-finger NMOS FETs are non-uniform, and the corresponding computer simulations were performed. The simulation results indicate that after non-uniform irradiation, the difference of oxide trapped charges and interface charges of each gate in multi-finger NMOS FETs will make threshold voltage shift asynchronously, leading to the degeneration of transconductance and the crossover of transconductance curves.
潘立丁, 石瑞英, 龚敏, 刘杰. γ辐照前后多栅NMOS转移特性曲线交叉现象机理分析[J]. 强激光与粒子束, 2014, 26(8): 084003. Pan Liding, Shi Ruiying, Gong Min, Liu Jie. Mechanism of crossover of transconductance curves in 0.5 μm multi-finger NMOS FETs before and after γ irradiation[J]. High Power Laser and Particle Beams, 2014, 26(8): 084003.