Semiconductor device

A semiconductor device comprising:

• a semiconductor layer of SiC which includes an active portion;
• a plurality of MIS transistors which are formed at the active portion, the active portion partitioned into the plurality of MIS transistors by a plurality of gate trenches, and each of the MIS transistors having a first conductive-type source region, a second conductive-type channel region, and a first conductive-type drain region sequentially along a side surface of the gate trench;
• a plurality of first gate finger trenches that are arranged as extended portions of the gate trenches at a gate finger portion;
• a gate electrode embedded in each of the gate trenches and the first gate finger trenches via a gate insulating film;
• a second conductive-type first bottom-portion impurity region which is formed at least at a bottom portion of the first gate finger trenches and at least a part of a bottom of the second conductive-type first bottom-portion impurity region is formed to become the same depth so as to define a horizontal straight line in a cross sectional view;
• a gate conductive layer that is electrically connected to the first gate finger trenches and the gate electrode;
• a source electrode formed over the semiconductor layer;
• a second conductive-type contact region formed between two adjacent gate trenches such that the second conductive-type contact region is in contact with the second conductive-type channel region, the second conductive-type contact region having a higher impurity concentration than the second conductive-type channel region;
• a second contact region being in contact with the second conductivity-type contact region, the second contact region having a different impurity concentration from the second conductive-type contact region;
• a first film formed on the semiconductor layer, the first film being formed between two adjacent gate trenches such that the first film straddles a boundary between the second conductive-type contact region and the second contact region, and the first film including a non-conductive material;
• and
• a first conductive film formed between the source electrode and the first film such that a layered structure of the first film and the first conductive film straddles the boundary between the second conductive-type contact region and the second contact region;
• wherein the source electrode has a protruding portion that protrudes in a thickness direction of the semiconductor layer and is bounded by the first conductive film in a direction that crosses the thickness direction.