异质多晶SiGe栅应变Si NMOSFET物理模型研究

结合了“栅极工程”和“应变工程”二者的优点, 异质多晶SiGe栅应变Si MOSFET, 通过沿沟道方向使用不同功函数的多晶SiGe材料, 在应变的基础上进一步提高了MOSFET的性能. 本文结合其结构模型, 以应变Si NMOSFET为例, 建立了强反型时的准二维表面势模型, 并进一步获得了其阈值电压模型以及沟道电流的物理模型. 应用MATLAB对该器件模型进行了分析, 讨论了异质多晶SiGe栅功函数及栅长度、衬底SiGe中Ge组分等参数对器件阈值电压、沟道电流的影响, 获得了最优化的异质栅结构. 模型所得结果与仿真结果及相关文献给出的结论一致, 证明了该模型的正确性. 该研究为异质多晶SiGe栅应变Si MOSFET的设计制造提供了有价值的参考. 关键词： 异质多晶SiGe栅 应变Si NMOSFET 表面势 沟道电流

Study on physical model for strained Si MOSFET with hetero-polycrystalline SiGe gate

A new strained Si MOSFET structure with hetero-polycrystalline SiGe gate was studied, which combines the advantages of “gate engineering” and “strain engineering”. The new structure improved the carrier transport efficiency, suppressed the short-channel effects (SCE), and enhanced the performance on the basis of strain. Then a physically modeling strategy such as quasi-2D surface potential of strong inversion, threshold voltage, and channel current was presented for the strained Si NMOSFET. Finally, the above model was computed and the results were analyzed.
Keywords： hetero-polycrystalline SiGe gate strained Si NMOSFET surface potential channel current