Patent ID: 8338861

Claim:
A III-nitride semiconductor device, comprising: a III-nitride heterojunction that includes a first III-nitride body having one band gap, and a second III-nitride body having another band gap disposed over said first III-nitride body to form a two dimensional electron gas; a passivation body formed over said second III-nitride body, said passivation body including a gate well having a first mouth at said second III-nitride body and a second mouth wider than said first mouth at the top of said passivation body, said second mouth defined by sidewalls within said passivation body, said passivation body comprising a first ledge and a second ledge to define said first mouth, wherein said first ledge is wider than said second ledge; and a gate arrangement disposed at least partially within said gate well, said gate arrangement including a gate insulation disposed at said first mouth of said well and a gate electrode over said gate insulation, said gate arrangement filling said second mouth of said gate well.