First-principles study of Si-SiO2 interface and the impact on mobility -: art. no. 082104

For Si devices, the high-field effective mobility is generally reproducible irrespective of SiO2 quality. This suggests that interface scattering is an intrinsic property of the Si-SiO2 interface. We have performed first-principles density functional calculations of several crystalline models of the Si-SiO2 interface. Universal features are found in the local density of states of these model interfaces. Based on these intrinsic interfacial properties, an atomistic model for Si-SiO2 inversion layer mobility is constructed. Quantum transport simulations calibrated with the mobility model show excellent agreement with experimental data. The strain effects on mobility are also studied and show interesting features in strained Si/Si1-xGex devices. (c) 2005 American Institute of Physics.