A continuous compact model of drain current in independently driven double-gate (IDG) metal-oxide-semiconductor field-effect transistors (MOSFETs) is presented. The model describes drift-diffusion transport and is continuous over all operation regimes, which makes it very suitable for implementation in circuit simulators. Our approach takes into account two-dimensional (2D) electrostatics and vertical carrier quantum confinement in the channel through the inversion charge evaluated quantum-mechanically. The model effectively reproduces the threshold voltage and the current modulation by the back-gate bias, as well as the quantum confinement effects on the inversion charge. A full 2D quantum-mechanical numerical simulation code (solving the 2D Poisson equation self-consistently coupled with the 1D Schrodinger equation) is used to validate the model. The model is shown to fit with good accuracy the numerically simulated quantum drain current in double-gate devices with either independent or connected gates. (C) 2011 The Japan Society of Applied Physics