Effect of substrate doping on the flatband and threshold voltages of strained-Si pMOSFET

The effect of substrate doping on the flatband and threshold voltages of strained-Si/SiGe p metal-oxide semiconductor field-effect transistor (pMOSFET) has been studied. By physically deriving the models of the flatband and threshold voltages, which have been validated by numerical simulation and experimental data, the shift in the plateau from the inversion region to the accumulation region as the substrate doping increases has been explained. The proposed model can provide valuable reference to the designers of strained-Si devices and has been implemented in software for extracting the parameters of strained-Si MOSFET.