An Improvement to the Numerical Robustness of the Surface Potential Approximation for Double-Gate MOSFETs

In developing the drain current model of a symmetric double-gate MOSFET, one encounters a transcendental equation relating the value of an intermediate variable beta to the gate and drain voltages. In this brief, we present an enhancement to an existing approximation for beta, which improves its numerical robustness. We also benchmark our suggested enhancement and show that our enhancement is as computationally efficient as the original approximation but is numerically much more robust, with an accuracy that is comparable to the original approximation.