In this work we apply the current-based threshold voltage definition (equality between the drift and diffusion components of drain current) to intrinsic symmetric double-gate MOSFETs. We show that the half maximum point of the g(m)/I-D (transconductance-to-current ratio) curve in the linear region corresponds exactly to the condition I-Ddrift = I-Ddiff when mobility variation is neglected. Numerical simulations show that the threshold voltages determined from the g(m)/I-D curve and from the I-Ddrift = I-Ddiff condition differ by about phi(t)/2 (one half of the thermal voltage) when considering realistic mobility variations. Simulation results show that the threshold voltages determined with the g(m)/I-D procedure are close to those obtained with the Y (=I-D/root g(m)) function method for a considerable range of silicon film thicknesses, channel lengths, and temperature values. The current-based procedure has also been successfully applied experimentally to a FinFET over a wide temperature range. (C) 2010 Elsevier Ltd. All rights reserved.