Patent ID: 7449730

Claim:
A nitride-based semiconductor device comprising: a diode provided on a semiconductor substrate, the diode including a first nitride-based semiconductor layer made of non-doped Al X Ga 1-X N (0≦X<1); a second nitride-based semiconductor layer formed on the first nitride-based semiconductor layer and made of non-doped or n-type Al Y Ga 1-Y N (0<Y≦1, X<Y) having a lattice constant smaller than that of the first nitride-based semiconductor layer; a first electrode formed on the second nitride-based semiconductor layer; a second electrode formed on the second nitride-based semiconductor layer spaced from the first electrode so as to surround the first electrode; and an insulating film that covers the second nitride-based semiconductor layer below a peripheral portion of the first electrode, wherein a recess structure portion is formed by removing a part of the second nitride-based semiconductor layer at a position near the peripheral portion of the first electrode on the second nitride-based semiconductor layer, and the first electrode is formed so as to cover the second nitride-based semiconductor layer surrounded by the recess structure portion and at least a part of the insulating film formed on the recess structure portion.