Patent ID: 7476956

Claim:
A group III nitride based diode, comprising: an n+ doped GaN layer; an n− doped GaN layer on said n+ GaN layer; a Schottky metal layer on said n− doped GaN layer having a work function, said n− GaN layer forming a junction with said Schottky metal, said junction having a barrier potential energy level that is dependent upon the work function of said Schottky metal; and a trench structure in said n− doped GaN layer, said trench structure comprising a plurality of trenches coated by a layer of high work function metal, wherein said trench structure comprises mesa regions between adjacent trenches of said plurality of trenches, said trenches having sidewalls and a bottom surface coated by said layer of high work function metal, said Schottky metal layer covering said trenches and mesa regions, said layer of high work function metal sandwiched between said Schottky metal layer and said sidewalls and between said Schottky metal layer and said bottom surfaces; and wherein said trench structure causes said diode to experience a reduced reverse leakage current under reverse bias compared to a diode same as said group III nitride based diode but without said trench structure and without any layer of high work function metal between the Schottky metal layer and the n− doped GaN layer therein.