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_off = 5 nA), the proposed Tree-CFET provides a significantly higher effective channel width (W_eff) compared to the NS CFET (NS-CFET), resulting in a substantial increase in on-state current (I_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_p) compared to the NS-CFET. Specifically, the high-to-low t_p (t_pHL) and low-to-high t_p (t_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_IB), IB widths (W_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.