Patent ID: 7755108

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 a lattice constant of the first nitride-based semiconductor layer; a first semiconductor layer formed on the second nitride-based semiconductor layer and made of a semiconductor having a lattice constant equal to that of the first nitride-based semiconductor layer; a second semiconductor layer formed on the first semiconductor layer and made of a non-doped or n-type semiconductor having a lattice constant smaller than that of the first nitride-based semiconductor layer; a first electrode formed on the second semiconductor layer; a second electrode formed spaced from the first electrode so as to surround the first electrode, and formed on any one of the second nitride-based semiconductor layer, the first semiconductor layer, and the second semiconductor layer; and an insulating film that covers the first semiconductor layer below a peripheral portion of the first electrode, wherein a recess structure portion is formed at a position near the peripheral portion of the first electrode on the second semiconductor layer, a bottom of the recess structure portion being reached to the first semiconductor layer, and the first electrode is formed so as to cover the first and second semiconductor layers which are surrounded by the recess structure portion, at least a part of the insulating film formed on the recess structure portion.