Assessing RF/AC Performance and Linearity Analysis of NCFET in CMOS-Compatible Thin-Body FDSOI

The ever-growing exploration of negative capacitance field effect transistors (NCFETs) for low-power digital application and recent integration in the advanced technology node calls for an investigation of NCFET technology in radio-frequency (RF) applications featuring metal ferroelectric insulator semiconductor (MFIS) configuration. In this article, through TCAD simulation study, we investigate the RF/ac performance of NCFETs by well-known performance metrics such as short-circuit unity current gain frequency or cutoff frequency $ f_T $ , transconductance generation factor $g_m/I_d$ , and transconductance frequency product $g_m f_T/I_d$ , a measure of RF performance per dc power consumption, where $g_m$ and $I_d$ are transconductance and drive current, respectively. It is found that MFIS NCFET fares better when compared to the 14-nm fully-depleted silicon-on-insulator (FDSOI) field effect transistor (FET) as a baseline device, in terms of improved performance in $g_m/I_d$ and $g_m f_T/I_d$ . A performance parity in cutoff frequency $f_T$ is observed. Additionally, the intermodulation distortion $IMD_3$ and transistor-level linearity are studied. When a qualitative analysis of the behavior of the key linearity metrics such as higher-order harmonics ( $ g_{m2}, g_{m3} $ ), second- and third-order voltage intercept points ( $ VIP_2, VIP_3 $ ), third-order power-intercept point ( $ IIP_3 $ ) is carried out, NCFETs fared comparatively better in linearity. Our conclusions would provide a better insight into adopting NCFET technology for RF applications.