Abstract
A circuit structure includes a substrate, a III-V semiconductor compound over the substrate, a AlxGa(1-X)N (AlGaN) layer over the III-V semiconductor compound, a gate over the AlGaN layer, a passivation film over the gate and over a portion of the AlGaN layer, a source structure, and a drain structure on an opposite side of the gate from the source structure, wherein X ranges from 0.1 to 1. The source structure has a source contact portion and an overhead portion. The overhead portion is over at least a portion of the passivation film between the source contact portion and the gate. A distance between the source contact portion and the gate is less than a distance between the gate and the drain structure.