Asymmetric gate capacitance and dynamic characteristic fluctuations in 16 nm bulk MOSFETs due to random distribution of discrete dopants

Abstract

Characteristic variability of a transistor is a crucial issue for nanoscale metal-oxide-semiconductor field-effect transistors (MOSFETs). In this study, we explore the asymmetric sketch of the random dopant distribution near the source end and the drain end in 16 nm MOSFETs. Discrete dopants near the source and drain ends of the channel region induce rather different fluctuations in gate capacitance and dynamic characteristics. Based upon the observed asymmetry properties, a lateral asymmetry channel doping profile engineering is then proposed to suppress the random-dopant-induced characteristic fluctuations in the examined devices and circuits. The results of this study indicate that the fluctuations in average gate capacitance, circuit gain, 3 db bandwidth and unity-gain bandwidth for the cases with dopants near the drain side could be simultaneously reduced by 62.6%, 22.2%, 63.1% and 41.4%, respectively. Consequently, such a lateral asymmetry channel doping profile could be considered to design intrinsic parameter fluctuation resistant transistors.