Analytical Model for RDF-Induced Threshold Voltage Fluctuations in Double-Gate MOSFET

Abstract

In this paper, a physics-based threshold voltage model of symmetrical double gate (DG) MOSFET, including the random dopants in the channel is presented. The model is derived from the solution of 2-D Poisson’s equation and is suitable for circuit simulation. The average potential considering random dopants in the channel is used to calculate the threshold voltage and provides accurate results. The developed threshold voltage model is validated with TCAD simulations for different device dimensions and doping concentrations. The standard deviation ( ${\sigma } {\text{V}}_{\text{TH}}$ ) is calculated from a threshold voltage distribution of 200 devices. The proposed model is useful to simulate variations in a large number of devices with randomly placed dopants, with less computational time. The model is integrated in the Cadence circuit simulator and analyzed the effect of random dopant fluctuation-induced ${\text{V}}_{\text{TH}}$ variations of n-channel DG MOSFET in the inverter circuit.