Patent ID: 8624265

Claim:
A semiconductor element, comprising: a semi-insulating substrate; a first first-conductivity-type layer of a first conductivity type provided selectively on a surface of the semi-insulating substrate; a first semiconductor layer provided on the semi-insulating substrate and the first first-conductivity-type layer, the first semiconductor layer containing Al x Ga 1-x N (0≦X<1); a second semiconductor layer provided on the first semiconductor layer, the second semiconductor layer containing Al y Ga 1-y N (0<Y≦1 and X<Y)) that is not of the first conductivity type; a first major electrode connected to the second semiconductor layer; a second major electrode connected to the second semiconductor layer; and a control electrode provided on the second semiconductor layer between the first major electrode and the second major electrode, the first first-conductivity-type layer being disposed under the control electrode such that a side edge of the first first-conductivity-type layer and a side of the control electrode that is facing the second major electrode are substantially aligned in a vertical direction.