An Analytical Model of Gate-All-Around Heterojunction Tunneling FET

Abstract

A compact analytical drain current model considering the inversion layer and source depletion is developed for the gate-all-around (GAA) heterojunction tunneling FET (H-TFET) with staggered-gap alignment. Poisson's equations are solved to obtain the continuous surface potential profile for the GAA H-TFET first, then the drain current is derived based on Kane's model by using the tangent line approximation method, and finally, the model is verified by TCAD simulation using GaAs <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5</sub> Sb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5</sub> /In <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.53</sub> Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.47</sub> As GAA H-TFET and published data. The impacts of bias, gate oxide dielectric constant, and interface fixed charge on the surface potential, electric field, and I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DS</sub> -V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">GS</sub> can be well predicted by the proposed model. The super-linear onset and saturation characteristics of I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DS</sub> -V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DS</sub> curves are also obtained.