Quasi Vertical FinFET with Step Graded Doping for Obtaining 0.037 mΩ.cm² ON Resistance

Vertical Gallium Nitride FinFET have demonstrated a great potential for better power switching based applications. This paper reports a quasi-structure with a graded doping profile in the drift region. The drift layer is split into five sub-regions and doping is done in linear and step graded manner. The devices are then compared with conventional uniformly doped device and the proposed design shows that step graded doping can reduce the ON resistance without much degradation in breakdown. The step graded drift layer doping exhibits an improved-ON current of 1.5 kA/cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> with a specific ON resistance of 0.037 mΩ.cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and a breakdown voltage of 52 V. The proposed device shows an improved performance over conventional uniform doping in terms of ON resistance reduction.