Improved Ohmic Contact Resistance and DC Performance of InAlN/GaN HEMTs with Si-Incorporated Contact Scheme

In this work, we propose a Si-incorporated ohmic contact scheme. An ultra-low contact resistance of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$&lt;0.1 \Omega \cdot ~\text{mm}$</tex> is demonstrated, representing an 82.7% reduction compared to the conventional scheme. This excellent ohmic contact significantly enhances the DC performance of InAlN/GaN HEMTs. Specifically, the maximum drain current (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{I}_{\text{DS}, \max }$</tex>) increases by over 30%, and the on-resistance (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{R}_{\text{ON}}$</tex>) decreases by over 20%. These results present a promising approach to promote GaN HEMTs in high-power and high-frequency switching applications.