Design and Optimization of FinFETs for Ultra-Low-Voltage Analog Applications

In this paper, we analyze the enormous potential of engineering source/drain extension (SDE) regions in FinFETs for ultra-low-voltage (ULV) analog applications. SDE region design can simultaneously improve two key analog figures of merit (FOM)-intrinsic dc gain (A_VO) and cutoff frequency (f_T) for 60 and 30 nm FinFETs operated at low drive current (J_ds = 5 muA/mum). The improved A_VO and f_T are nearly twice compared to those of devices with abrupt SDE regions. The influence of the SDE region profile and its impact on analog FOM is extensively analyzed. Results show that SDE region optimization provides an additional degree of freedom apart from device parameters (fin width and aspect ratio) to design future nanoscale analog devices. The results are analyzed in terms of spacer-to-straggle ratio-a new design parameter for SDE engineered devices. This paper provides new opportunities for realizing future ULV/low-power analog design with FinFETs.