Patent ID: 8796787

Claim:
A semiconductor device comprising: (a) a semiconductor chip having a first main surface provided with a source electrode of a power MOSFET and a second main surface provided with a drain electrode of the power MOSFET; (b) a drift region of a first conductivity type provided in substantially the entire first main surface of the semiconductor chip; (c) a substantially rectangular active cell region provided substantially at a middle portion of the first main surface, peripheral side regions provided outside the active cell region along individual sides of the active cell region, and peripheral corner regions provided between adjacent peripheral side regions; (d) a first super-junction structure having a first orientation and provided in substantially the entire surface of the cell region and in the drift region; (e) second and third super-junction structures each having a second orientation orthogonal to that of the first super-junction structure provided in the drift region of each of the peripheral side regions on opposite sides of the active cell region in a direction of the first orientation of the first super-junction structure; (f) fourth and fifth super-junction structures each having an orientation substantially the same as that of the first super-junction structure and provided in the drift region of each of the peripheral side regions on opposite sides of the active cell region in a direction orthogonal to the first orientation of the first super-junction structure; (g) a main junction region of a second conductivity type which is at an outer end portion of the active cell region and provided in a surface of the drift region so as to surround the active cell region; (h) a plurality of floating field plates provided over the first main surface via an insulating film and outside the main junction region so as to surround the active cell region; and (i) a resin molded body covering substantially the entire first main surface of the semiconductor chip, wherein, in a cross-sectional view, each of the floating field plates has a width and is positioned within a respective range that extends from a vicinity of an inner end of a column circular region of the second conductivity type that is proximate to the floating field plate, said vicinity being spaced from a middle line of the column circular region toward the active cell region such that the floating field plate extends over the middle line of the column circular region and covers an outer end of said column circular region.