This paper, for the first time, estimates the influences of the intrinsic-parameter fluctuations consisting of metal-gate work-function fluctuation (WKF), process-variation effect (PVE), and random-dopant fluctuation (RDF) on 16-nm-gate planar metal-oxide-semiconductor field-effect transistors (MOSFETs) and circuits. The WKF and RDF dominate the threshold-voltage fluctuation (σV th ); however, the WKF brings less impact on the gate capacitance and the cutoff frequency due to the screening effect of the inversion layer. The fluctuation of timing characteristics depends on the σV th and is therefore proportional to the trend of σV th . The power fluctuation consisting of the dynamic, short-circuit, and static powers is further investigated. The total power fluctuation for the planar MOSFET circuits is 15.2%, which is substantial in the reliability of circuits and systems. The static power is a minor part of the total power; however, its fluctuation is significant because of the serious fluctuation of the leakage current. For an amplifier circuit, the high-frequency characteristics, the circuit gain, the 3-dB bandwidth, the unity-gain bandwidth power, and the power-added efficiency are explored consequently. Similar to the trend of the cutoff frequency, the PVE and RDF dominate both the device and circuit characteristic fluctuations due to the significant gate-capacitance fluctuations, and the WKF is less important at this simulation scenario. The extensive study assesses the fluctuations on circuit performance and reliability, which can, in turn, be used to optimize nanoscale MOSFETs and circuits.

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In this study, a three-dimensional "atomistic" coupled device-circuit simulation approach is advanced to investigate the process-variation-effect (PVE) and random dopant fluctuation (RDF) induced characteristic fluctuations in planar metal-oxide-semiconductor field-effect-transistor (MOSFET) static random access memory (SRAM) from 65nm to 16-nm gate length. Our preliminary results show that the RDF dominates the fluctuation of static noise margin (SNM). As the gate length of the planar MOSFETs scales from 65 nm to 16 nm, the normalized RDF-induced SNM fluctuation increases from 4% to 80%. To reduce the device variability induced fluctuation in circuit, a device with vertical-doping-profile and raised V th is employed. The SNM is 3 times larger than the original 16-nm-gate SRAM. Moreover, the normalized RDF-induced SNM fluctuation is reduced by a factor of 2.67. Additionally, a 16-nm-gate silicon-on-insulator fin-type field-effect-transistor is used to further improve the SNM of SRAM. Due to the superior electrostatic integrity and larger effective device width than planar MOSFETs, the SNM of 16-nm-gate FinFET SRAM is six times larger than the original 16 nm SRAM with five times smaller SNM fluctuation. The study investigates the roll-off characteristics of SNM and provides an insight into design of fluctuation resistant nanoscale SRAM.

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