A Non-Charge-Sheet Analytic Model for Symmetric Double-Gate MOSFETs With Smooth Transition Between Partially and Fully Depleted Operation Modes

A non-charge-sheet analytic model for long-channel symmetric double-gate (DG) MOSFETs with smooth transition between partially and fully depleted (PD and FD) operation modes is presented in this paper. The 1-D Poisson's equation with the mobile and dopant charge terms is first solved to obtain the continuous channel potential in the symmetric DG structure physically. A non-charge-sheet analytic drain-current expression is then derived from Pao-Sah's dual integral as a function of the channel potentials at the source and drain terminals. The comparison between the analytical calculation and 2-D numerical simulation demonstrates that the developed model is not only valid for a wide range of doping concentrations and geometry sizes, but also able to capture the DG MOSFET specific characteristics such as the volume inversion and smooth transition between PD and FD operation modes. The presented model leads to a more clear understanding of DG MOSFET device physics, providing a physics-based DG MOSET compact modeling framework for circuit simulation.