Analytical subthreshold channel potential model of asymmetric gate underlap gate-all-around MOSFET

In this paper an analytic subthreshold potential model for undoped cylindrical gate-all-around (GAA) MOSFET with asymmetric gate underlap is developed. This model is derived by solving the Poisson's equation with the parabolic potential approximation, channel length transformation and conformal mapping. The analytic body center potential solution is presented. Compared with TCAD simulations, the proposed model shows good agreements, with different dimensions of the structure and varied bias conditions. The model here is appropriate for predicting the effect of gate misalignment or asymmetric gate underlap in GAA MOSFETs' design.