Improvement of the off-state breakdown voltage with field plate and low-density drain in AlGaN/GaN high-electron mobility transistors

We present an AlGaN/GaN high-electron mobility transistor（HEMT） device with both field plate（FP） and lowdensity drain（LDD）. The LDD is realized by the injection of negatively charged fluorine（F-） ions under low power in the space between the gate and the drain electrodes. With a small-size FP and a LDD length equal to only 31% of the gate-drain spacing, the device effectively modifies the electric field distribution and achieves a breakdown voltage enhancement up to two times when compared with a device with only FP.