A Novel Approach to Model Threshold Voltage and Subthreshold Current of Graded-Doped Junctionless-Gate-All-Around (GD-JL-GAA) MOSFETs

Abstract

This present article interprets the analytical models of central channel potential, the threshold voltage, and subthreshold current for Graded-Doped Junctionless-Gate-All-Around (GD-JL-GAA) MOSFETs. The parabolic approximation equation with appropriate boundary conditions has been adopted to solve the 2D Poisson’s equation for determining the central channel potential. The minimum channel potential is obtained by potential channel expression, and it is utilized to determine the threshold voltage and subthreshold current by using the Drift-Diffusion method. The behaviour of GD-JL-GAA MOSFETs has been examined by varying physical device parameters such as doping concentration (NDn), channel thickness (tsi), oxide thickness (tox), and channel length ratio (L1 : L2). The mathematical analysis shows that the nominal gate leakage current in GD-JL-GAA MOSFETs due to high graded abrupt junction inside the channel region. The analytical model results have been verified with simulation data extracted from a TCAD simulator.