Novel Complementary Field-Effect Transistors With Tree-Type Channel for 3-nm Technology Node

This article proposes a novel tree-type channel complementary field-effect transistor (Tree-CFET) featuring a channel composed of vertically stacked Si nanosheets (NSs) interconnected by SiGe fin-like interbridges (IBs). Under a unified off-state leakage current benchmark ( ${I} _{\text {off}} =5$ nA), the proposed Tree-CFET provides a significantly higher effective channel width ( ${W}_{\text {eff}}$ ) compared to the NS CFET (NS-CFET), resulting in a substantial increase in on-state current ( ${I} _{\text {on}}$ ) for both NFET and PFET by 24.20% and 42.99%, along with enhancements in transconductance (gm) by 41.14% and 61.76%, respectively. As an inverter, the Tree-CFET demonstrates significant improvements in propagation delay time ( ${t} _{\text {p}}$ ) compared to the NS-CFET. Specifically, the high-to-low ${t} _{\text {p}}$ ( ${t} _{\text {pHL}}$ ) and low-to-high ${t} _{\text {p}}$ ( ${t} _{\text {pLH}}$ ) are reduced by 2.41% and 23.71%, respectively, while exhibiting more symmetrical propagation delays. This article further investigates the effects of different IB heights ( ${H} _{\text {IB}}$ ), IB widths ( ${W}_{\text {IB}}$ ), and Ge concentrations in the SiGe IBs on Tree-CFET performance. These results demonstrate the potential of the Tree-CFET for enhanced performance in advanced technology nodes.