FIELD EFFECT SEMICONDUCTOR DEVICE

PROBLEM TO BE SOLVED: To solve the problem that it is difficult to obtain an HEMT having a high breakdown voltage and low on-resistance. SOLUTION: The HEMT has: an electron running layer 4; an electron supply layer 5 arranged on the electron running layer 4; a source electrode 6; a drain electrode 7; a gate electrode 8; a gate field plate 12; a source field plate 13; and first and second insulation films 9, 10. A ratio LGF/LGFDof length LGFin the gate field plate to a distance LGFDbetween the edge at the side of the drain electrode of the gate field plate 12 and the drain electrode 8 is set to 1-70%. A ratio LSF/LGFDof a distance LSFbetween the edge at the side of the drain electrode of the source field plate 13 that of the gate field plate 12 to a distance LGFDbetween the edge at the side of the drain electrode of the gate field plate 12 and the drain electrode 8 is set to a range of 1-60%. COPYRIGHT: (C)2009,JPO&INPIT