应变Si/Si1-xGex n型金属氧化物半导体场效应晶体管反型层中的电子迁移率模型

Model of electron mobility in inversion layer of strained Si/Si_(1-x)Ge_x n type metal-oxide-semiconductor field-effect transistors

为了描述生长在弛豫Si1-xGex层上应变Sin型金属氧化物半导体场效应晶体管(nMOSFETs)反型层中电子迁移率的增强机理,提出了一种新型的、基于物理的电子迁移率模型.该模型不仅能够反映声学声子散射迁移率、表面粗糙度散射迁移率与垂直于半导体-绝缘体界面的电场强度之间的依赖关系,而且也能解释不同的锗组分对两种散射机理的抑制情况从而引起电子迁移率增强的机理.该模型数学表达式简单,可以模拟任意锗组分下的迁移率.通过数值分析验证得出,该模型与已报道的实验数据结果相符合.同时该模型能够被嵌入到ISE模拟器中,获得与原模拟器内置模型相一致的结果.

In order to describe the electron mobility enhancement in inversion layer in strained-Si on Si1-x Gex n type metal-oxide-semiconductor field-effect transistors （nMOSFETs）,a new physically-based electron mobility model is presented in the paper. This model can not only show the dependence of acoustic phonon-limited mobility and surface roughness-limited mobility on transverse electrical field normal to the semiconductor-insulator interface,but also explains the electron mobility enhancement mechanism due to scattering suppression caused by germanium （Ge） content. The expression of the new model is simple and can simulate the mobility for any Ge content. Numerical analysis results show that this model fits the reported experimental data very well. In addition,this model can be easily included in the device simulator ISE and gives good agreement with simulated results of device simulator with built-in model.