Semiconductor device

A semiconductor device, comprising:

• a semiconductor layer located on a principal surface of a supporting substrate;
• a body region located in an upper portion of the semiconductor layer, the body region having a first conductivity type;
• a drain region located in an upper portion of the semiconductor layer, the drain region having a second conductivity type, the drain region being apart from the body region;
• a source region located in an upper portion of the body region, the source region having the second conductivity type;
• a drift region located between the drain region and the body region in the semiconductor layer, the drift region having the second conductivity type;
• a first insulator region located in an upper portion of the semiconductor layer, the first insulator region being located between the body region and the drain region, the first insulator region overlapping the drift region;
• a gate insulation film located on the semiconductor layer, the gate insulation film being located from a part on the body region to an end portion of the first insulator region;
• a gate electrode located on at least part of the gate insulation film and at least part of the first insulator region;
• at least one first conductive plate located on the first insulator region, the at least one first conductive plate being located between the gate electrode and the drain region, the at least one first conductive plate being in an electrically floating state;
• a second insulator region located on the first insulator region, the gate electrode, and the at least one first conductive plate;
• at least one second conductive plate located on the second insulator region where at least the gate electrode and the at least one first conductive plate are not located, the at least one second conductive plate being in an electrically floating state;
• a third insulator region located on the second insulator region, above the gate electrode and on the at least one second conductive plate;
• source wiring located above the third insulator region, the source wiring electrically connected to the source region;
• and
• drain wiring located above the third insulator region, the drain wiring electrically connected to the drain region,
• wherein in plan view, the source region and the drain region are elongated along a longitudinal direction that is a direction in which facing lengths are longest, and are disposed side by side in a short-side direction that is a direction orthogonal to the longitudinal direction,
• in plan view, the at least one first conductive plate and the at least one second conductive plate each have a linear region elongated along the longitudinal direction to face each other, and a curved region connecting terminal end portions of the linear regions in the longitudinal direction in a folded line or circular arc shape,
• in plan view, high voltage wiring of either one of the source wiring and the drain wiring is elongated in the short-side direction to intersect the linear regions of the at least one first conductive plate and the at least one second conductive plate, and
• in plan view, low voltage wiring of the other one of the source wiring and the drain wiring is elongated in the short-side direction to intersect at least one of (i) the linear region of the at least one first conductive plate and (ii) the linear region of the one second conductive plate.