在考虑应变对SiGe合金能带结构参数影响的基础上,建立了一个半经验的Si1-xGex pMOSFET反型沟道空穴迁移率模型。该模型重点讨论了反型电荷对离化杂质散射的屏蔽作用,由此对等效体晶格散射迁移率进行了修正。并且详细讨论了等效体晶格散射迁移率随掺杂浓度Nd和组分x的变化。利用该模型,对影响空穴迁移率的主要因素进行了分析讨论。通过模拟得出,增加组分x可以显著提高等效体晶格散射迁移率,从而可以提高PMOSFET的空穴迁移率。
Based on the consideration of the strain-effect in Si1-xGexalloy band, a semi-epirical hole mobility model in inversion channel of the Si1-xGex pMOSFET is founded. This model focuses discussion on the shielded effect of inversion charges to ionized inpurity scattering, then modifies the equivalent lattice scattering bobility and explores its variation as a function of doping concentration Nd and content x. By using this model, we analyze some major factors affecting the hole mobility. Simulation work indicates that increasing the Ge content x can obviously improve the equivalent lattice mobility resulting in higher equivalent hole mobility of pMOSFET.