Silicon carbide semiconductor device

A silicon carbide semiconductor device, comprising:

• a silicon carbide substrate;
• a drift layer of a first conductivity type disposed on the silicon carbide substrate, the drift layer has a main surface;
• a plurality of first doped regions of a second conductivity type opposite to the first conductivity type disposed in the drift layer, the first doped regions comprising a plurality of first sub-portions and a plurality of first extending portions extended horizontally along a first horizontal direction from the first sub-portions, the first doped regions forming a plurality of first p-n junctions and a plurality of JFET regions with the drift layer;
• a plurality of second doped regions of the first conductivity type disposed within the first doped regions, the second doped regions comprising a plurality of second sub-portions and a plurality of second extending portions extended horizontally along the first horizontal direction from the second sub-portions, the second doped regions forming a plurality of second p-n junctions with the first doped regions, a plurality of channel regions being provided between the first p-n junctions and the second p-n junctions along the main surface;
• a plurality of third doped regions of the second conductivity type disposed in the first sub-portions of the first doped regions and adjacent to the second sub-portions of the second doped regions;
• a plurality of trenches penetrating from the main surface into the drift layer, the plurality of trenches running horizontally through at least a portion of the JFET regions, wherein surfaces of the trenches are formed with the drift layer;
• and
• a gate electrode disposed in each of the trenches, the gate electrode being electrically isolated from the drift layer by a gate insulating layer, wherein the gate electrode is extended from the main surface to the gate insulating layer, and a top surface of the gate electrode is as high as the main surface;
• wherein a distance between a sidewall of the trench and the first extending portion is equal to or larger than 1 nm.