Effects of Random Nanosized TiN Grain on Characteristic of Gate-All-Around FinFETs with Ferroelectric HZO Layer

In this paper, we computationally study electrical characteristics for gate-all-around fin field effect transistors (GAA FinFETs) and negative capacitance GAA FinFETs (NC-GAA FinFETs) for sub-3-nm technological nodes. For the devices with the fin height of 55 nm, the on-state current increases (about 33% improvement) and the off-state current decreases (about 73% suppression) due to the NC effect. NC-GAA FinFETs have larger standard deviation of threshold voltage induced by the workfunction fluctuation (WKF) for both N-/P-type devices than those of GAA FinFETs. It is attributed to the variation of polarization in the different position of the ferroelectric layer. Notably, the inverter of NC-GAA FinFETs has larger noise margin and shorter delay time, compared with the inverter of GAA FinFETs; however, the characteristics of inverter of NC-GAA FinFETs suffer larger variability induced by the WKF.