Abstract: The gate electrode is provided on the gate insulating film. The interlayer insulating film is provided to cover the gate electrode. The interlayer insulating film includes a first insulating film which is in contact with the gate electrode, contains silicon atoms, and contains neither phosphorus atoms nor boron atoms, a second insulating film which is provided on the first insulating film and contains silicon atoms and at least one of phosphorus atoms and boron atoms, and a third insulating film which contains silicon atoms and contains neither phosphorus atoms nor boron atoms. The second insulating film has a first surface which is in contact with the first insulating film, a second surface opposite to the first surface, and a third surface which connects the first surface and the second surface. The third insulating film is in contact with at least one of the second surface and the third surface.

Abstract: The gate electrode is provided on the gate insulating film. The interlayer insulating film is provided to cover the gate electrode. The interlayer insulating film includes a first insulating film which is in contact with the gate electrode, contains silicon atoms, and contains neither phosphorus atoms nor boron atoms, a second insulating film which is provided on the first insulating film and contains silicon atoms and at least one of phosphorus atoms and boron atoms, and a third insulating film which contains silicon atoms and contains neither phosphorus atoms nor boron atoms. The second insulating film has a first surface which is in contact with the first insulating film, a second surface opposite to the first surface, and a third surface which connects the first surface and the second surface. The third insulating film is in contact with at least one of the second surface and the third surface.

Abstract: A silicon carbide substrate having a gate insulating film provided in contact with a first main surface, having a gate electrode provided in contact with the gate insulating film, and having a source region exposed from first main surface is prepared. A first recess having a first inner wall surface is formed in an interlayer insulating film by performing a first isotropic etching with respect to the interlayer insulating film with use of a mask layer. A second recess having a second inner wall surface is formed by performing a first anisotropic etching with respect to the interlayer insulating film and the gate insulating film with use of the mask layer and thereby exposing the source region from gate insulating film. An interconnection is formed which is arranged in contact with the first inner wall surface and the second inner wall surface and electrically connected to a source electrode.

Abstract: A method of manufacturing a silicon carbide semiconductor device includes the following steps. A silicon carbide substrate is prepared. A first mask layer is formed in contact with a first main surface of the silicon carbide substrate. The first mask layer includes a first layer disposed in contact with the first main surface, an etching stop layer disposed in contact with the first layer and made of a material different from that for the first layer, and a second layer disposed in contact with a surface of the etching stop layer opposite to the surface in contact with the first layer. A recess is formed in the first mask layer by etching the second layer and the etching stop layer. A first impurity region is formed in the silicon carbide substrate using the first mask layer with the recess. The first mask layer does not include a metallic element.

Abstract: A silicon carbide semiconductor device includes a silicon carbide substrate, a main electrode, a first barrier layer, and an interconnection layer. The main electrode is directly provided on the silicon carbide substrate. The first barrier layer is provided on the main electrode, and is made of a conductive material containing no aluminum. The interconnection layer is provided on the first barrier layer, is separated from the main electrode by the first barrier layer, and is made of a material containing aluminum.

Abstract: A silicon carbide semiconductor device includes a silicon carbide substrate, a main electrode, a first barrier layer, and an interconnection layer. The main electrode is directly provided on the silicon carbide substrate. The first barrier layer is provided on the main electrode, and is made of a conductive material containing no aluminum. The interconnection layer is provided on the first barrier layer, is separated from the main electrode by the first barrier layer, and is made of a material containing aluminum.

Abstract: A method of manufacturing a silicon carbide semiconductor device includes the following steps. A silicon carbide substrate is prepared. A first mask layer is formed in contact with a first main surface of the silicon carbide substrate. The first mask layer includes a first layer disposed in contact with the first main surface, an etching stop layer disposed in contact with the first layer and made of a material different from that for the first layer, and a second layer disposed in contact with a surface of the etching stop layer opposite to the surface in contact with the first layer. A recess is formed in the first mask layer by etching the second layer and the etching stop layer. A first impurity region is formed in the silicon carbide substrate using the first mask layer with the recess. The first mask layer does not include a metallic element.

Abstract: A silicon carbide substrate having a gate insulating film provided in contact with a first main surface, having a gate electrode provided in contact with the gate insulating film, and having a source region exposed from first main surface is prepared. A first recess having a first inner wall surface is formed in an interlayer insulating film by performing a first isotropic etching with respect to the interlayer insulating film with use of a mask layer. A second recess having a second inner wall surface is formed by performing a first anisotropic etching with respect to the interlayer insulating film and the gate insulating film with use of the mask layer and thereby exposing the source region from gate insulating film. An interconnection is formed which is arranged in contact with the first inner wall surface and the second inner wall surface and electrically connected to a source electrode.

Abstract: An improved semiconductor device including an MOS capacitance is provided, having enhanced MOS capacitance accuracy. A well of a first conductivity type is formed at the main surface of a semiconductor substrate. The above-described well is removed immediately under a capacitance dope layer.

Abstract: An improved semiconductor device including an MOS capacitance is provided, having enhanced MOS capacitance accuracy. A well of a first conductivity type is formed at the main surface of a semiconductor substrate. The above-described well is removed immediately under a capacitance dope layer.