Effects of Fin shape on sub-10 nm FinFETs

As a successful novel structure, FinFET has been a hot research area, whereas how Fin influences FinFETs' performance on the hypothetical silicon process limitation is still an open issue. In reported works, Fin shape was normally mixed with the change of other parameters, such as the size scaling, and its effect was confused by those. In this paper, we just focus on Fin shape's effect itself. A simple and quantitative two-incline-angle description of Fin shape is proposed. Using this method, four typical (trapezoidal, rectangular, convex and concave) Fins' control abilities upon the hypothetical silicon limitation process node (sub-10 nm) are analyzed, and their impacts on FinFETs' characteristics are discussed systematically. The results show that in this case the rectangle shape Fin is prior on both analog and digital characteristics. The Fin shape's influence on FETs' frequency characteristic is not obvious. As an in-depth exploration, a ratio factor between the effective channel width and the cross-section area of channel is pointed out. The proposed factor can quantitatively evaluate Fin's impact not only for the regular shape Fins but also for the irregular ones. This work gives a guidance of FinFET's design on both nano scale silicon FinFETs and other advanced material FinFETs.