Analysis of CMOS Logic Inverter Based on Gate-All-Around Field-Effect Transistors with the Strained-Silicon Layer for Improving the Switching Performances

Abstract

In this paper, we adopt the vertical core–shell nanowire field-effect transistors based on the Silicon-germanium (SiGe)/strained-silicon (strained-Si) layer as a method to improve the performance of the CMOS logic inverter by using technology computer aided design simulation. The lattice constant mismatch between the core region and the shell region causes the global strain of the Si region of the shell, which in turn changes the Si parameters. This phenomenon effects on the improvement the electrical characteristics in the p-type MOSFET (pMOSFET). Through this variation, the asymmetry of the electrical characteristics between n-type MOSFET (nMOSFET) and pMOSFET nanowire is considerably compensated. The inverter using the proposed core–shell structure shows the improved CMOS logic inverter characteristics. For example, the core–shell CMOS logic inverter shows performances such as NML = 0.315 V, NMH = 0.312 V, τPHL of 8.7 ps, and τPHL of 21 ps at an operating voltage of VDD = 0.7 V.