HAD fabricated on UTB AlGaN/GaN heterostructure for high‐sensitivity zero‐bias microwave detection

A novel technology based on aluminium gallium nitride (AlGaN)/GaN hybrid-anode diode (HAD) for precise modulation of turn-on voltage is proposed and experimentally demonstrated. By delicately tailoring the as-grown barrier thickness, the turn-on voltage of the HAD and yet the non-linearity at zero bias (i.e. 0 V) for efficient microwave detection can be flexibly modulated. An AlGaN/GaN ultra-thin-barrier HAD (UTB-HAD) was designed and fabricated for zero-bias microwave detection. The AlGaN-barrier thickness was optimised to be 5 nm by TCAD simulation, which yields a strong non-linearity at zero bias featuring a high-curvature coefficient (γ) of 27 V−1 in the fabricated UTB-HAD. The first-order voltage sensitivity β V is projected to be as high as 2.7 mV/μW. The proposed approach of precise sensitivity modulation is of great interests for high-efficient zero-bias microwave detection applications.