Abstract: A SiC semiconductor device capable of increasing a switching speed without destroying a gate insulating film. In addition, in a SiC-MOSFET including an n-type semiconductor substrate formed of SiC, a p-type semiconductor layer is entirely or partially provided on an upper surface of a p-type well layer that has a largest area of the transverse plane among a plurality of p-type well layers provided in an n-type drift layer and is arranged on an outermost periphery below and horizontally overlapping a gate electrode pad. It is preferable that a concentration of an impurity contained in the p-type semiconductor layer be larger than that of the p-type well layer.

Abstract: An insulated gate silicon carbide semiconductor device includes: a drift layer of a first conductivity type on a silicon carbide substrate of 4H type with a {0001} plane having an off-angle of more than 0° as a main surface; a first base region; a source region; a trench; a gate insulating film; a protective diffusion layer; and a second base region. The trench sidewall surface in contact with the second base region is a surface having a trench off-angle of more than 0° in a <0001> direction with respect to a plane parallel to the <0001> direction. The insulated gate silicon carbide semiconductor device can relieve an electric field of a gate insulating film and suppress an increase in on-resistance and provide a method for manufacturing the same.

Abstract: A SiC semiconductor device capable of increasing a switching speed without destroying a gate insulating film. In addition, in a SiC-MOSFET including an n-type semiconductor substrate formed of SiC, a p-type semiconductor layer is entirely or partially provided on an upper surface of a p-type well layer that has a largest area of the transverse plane among a plurality of p-type well layers provided in an n-type drift layer and is arranged on an outermost periphery immediately below a gate electrode pad. It is preferable that a concentration of an impurity contained in the p-type semiconductor layer be larger than that of the p-type well layer.

Abstract: A SiC semiconductor device capable of increasing a switching speed without destroying a gate insulating film. In addition, in a SiC-MOSFET including an n-type semiconductor substrate formed of SiC, a p-type semiconductor layer is entirely or partially provided on an upper surface of a p-type well layer that has a largest area of the transverse plane among a plurality of p-type well layers provided in an n-type drift layer and is arranged on an outermost periphery immediately below a gate electrode pad. It is preferable that a concentration of an impurity contained in the p-type semiconductor layer be larger than that of the p-type well layer.

Abstract: A gate insulating film covers a trench penetrating through a source region and a body region and reaching a drift layer in each of a first cell region and a second cell region. The gate electrode is provided in the trench. A high-concentration layer of the first conductivity type is provided between the drift layer and the body region in the first cell region and has a second impurity concentration higher than the first impurity concentration. A current restriction layer is provided between the drift layer and the body region in the second cell region and has the first conductivity type and a third impurity concentration higher than the first impurity concentration and lower than the second impurity concentration.

Abstract: A drift layer of a first conductivity type is made of silicon carbide. A body region of a second conductivity type is provided on the drift layer. A source region of the first conductivity type is provided on the body region. A source electrode is connected to the source region. A gate insulating film is provided on side and bottom surfaces of a trench which penetrates the body region and the source region. A gate electrode is provided in the trench with the gate insulating film interposed therebetween. A trench-bottom-surface protective layer of the second conductivity type provided below the bottom surface of the trench in the drift layer is electrically connected to the source electrode. The trench-bottom-surface protective layer has a high-concentration protective layer, and a first low-concentration protective layer provided below the high-concentration protective layer and having an impurity concentration lower than that of the high-concentration protective layer.

Abstract: A gate insulating film covers a trench penetrating through a source region and a body region and reaching a drift layer in each of a first cell region and a second cell region. The gate electrode is provided in the trench. A high-concentration layer of the first conductivity type is provided between the drift layer and the body region in the first cell region and has a second impurity concentration higher than the first impurity concentration. A current restriction layer is provided between the drift layer and the body region in the second cell region and has the first conductivity type and a third impurity concentration higher than the first impurity concentration and lower than the second impurity concentration.

Abstract: A semiconductor device having a low feedback capacitance and a low switching loss. The semiconductor device includes: a substrate; a drift layer formed on a surface of the semiconductor substrate; a plurality of first well regions formed on a surface of the drift layer; a source region which is an area formed on a surface of each of the first well regions and defining, as a channel region, the surface of each of the first well regions interposed between the area and the drift layer; a gate electrode formed over the channel region and the drift layer thereacross through a gate insulating film; and second well regions buried inside the drift layer below the gate electrode and formed to be individually connected to each of the first well regions adjacent to one another.

Abstract: A silicon carbide semiconductor device capable of effectively increasing a threshold voltage and a method for manufacturing the silicon carbide semiconductor device. The silicon carbide semiconductor device includes a gate insulating film formed on part of surfaces of the well regions and the source region; and a gate electrode formed on a surface of the gate insulating film so as to be opposite to an end portion of the source region and the well regions. Furthermore, the gate insulating film has, in an interface region between the well regions and the gate insulating film, defects that each form a first trap having an energy level deeper than a conduction band end of silicon carbide and that include a bond between silicon and hydrogen.

Abstract: A silicon carbide semiconductor device includes: a drift layer of a first conductivity type made of silicon carbide; a well region of a second conductivity type formed on the drift layer; a source region of a first conductivity type formed on the well region; a gate insulating film formed on an inner wall of a trench extending from a front surface of the source region through the well region, at least a part of a side surface of the gate insulating film being in contact with the drift layer; a gate electrode formed in the trench with the gate insulating film therebetween; a protective layer of the second conductivity type formed in the drift layer; and a depletion suppressing layer of the first conductivity type formed in the drift layer so as to be in contact with a side surface of the protective layer.

Abstract: A silicon-carbide semiconductor device that relaxes field intensity in a gate insulating film, and that has a low ON-resistance. The silicon-carbide semiconductor device includes: an n-type silicon-carbide substrate; a drift layer formed on a topside of the n-type silicon-carbide substrate; a trench formed in the drift layer and that includes therein a gate insulating film and a gate electrode; a p-type high-concentration well region formed parallel to the trench with a spacing therefrom and that has a depth larger than that of the trench; and a p-type body region formed to have a depth that gradually increases when nearing from a position upward from the bottom end of the trench by approximately the thickness of the gate insulating film at the bottom of the trench toward the lower end of the p-type high-concentration well region.

Abstract: A drift layer of a first conductivity type is made of silicon carbide. A body region of a second conductivity type is provided on the drift layer. A source region of the first conductivity type is provided on the body region. A source electrode is connected to the source region. A gate insulating film is provided on side and bottom surfaces of a trench which penetrates the body region and the source region. A gate electrode is provided in the trench with the gate insulating film interposed therebetween. A trench-bottom-surface protective layer of the second conductivity type provided below the bottom surface of the trench in the drift layer is electrically connected to the source electrode. The trench-bottom-surface protective layer has a high-concentration protective layer, and a first low-concentration protective layer provided below the high-concentration protective layer and having an impurity concentration lower than that of the high-concentration protective layer.

Abstract: A source region of a MOSFET includes a source contact region connected to a source electrode, a source extension region adjacent to a channel region of a well region, and a source resistance control region provided between the source extension region and the source contact region. The source resistance control region includes a low concentration source resistance control region which has an impurity concentration lower than that of the source contact region or the source extension region and a high concentration source resistance control region which is formed between the well region and the low concentration source resistance control region and has an impurity concentration higher than that of the low concentration source resistance control region.

Abstract: An insulated gate silicon carbide semiconductor device includes: a drift layer of a first conductivity type on a silicon carbide substrate of 4H type with a {0001} plane having an off-angle of more than 0° as a main surface; a first base region; a source region; a trench; a gate insulating film; a protective diffusion layer; and a second base region. The trench sidewall surface in contact with the second base region is a surface having a trench off-angle of more than 0° in a <0001> direction with respect to a plane parallel to the <0001> direction. The insulated gate silicon carbide semiconductor device can relieve an electric field of a gate insulating film and suppress an increase in on-resistance and provide a method for manufacturing the same.

Abstract: An insulated gate silicon carbide semiconductor device includes: a drift layer of a first conductivity type on a silicon carbide substrate of 4H type with a {0001} plane having an off-angle of more than 0° as a main surface; a first base region; a source region; a trench; a gate insulating film; a protective diffusion layer; and a second base region. The trench sidewall surface in contact with the second base region is a surface having a trench off-angle of more than 0° in a <0001> direction with respect to a plane parallel to the <0001> direction. The insulated gate silicon carbide semiconductor device can relieve an electric field of a gate insulating film and suppress an increase in on-resistance and provide a method for manufacturing the same.

Abstract: A source region of a MOSFET includes a source contact region connected to a source electrode, a source extension region adjacent to a channel region of a well region, and a source resistance control region provided between the source extension region and the source contact region. The source resistance control region includes a low concentration source resistance control region which has an impurity concentration lower than that of the source contact region or the source extension region and a high concentration source resistance control region which is formed between the well region and the low concentration source resistance control region and has an impurity concentration higher than that of the low concentration source resistance control region.

Abstract: A method for manufacturing a semiconductor device, includes: (a) providing a SiC epitaxial substrate in which on a SiC support substrate, a SiC epitaxial growth layer having an impurity concentration equal to or less than 1/10,000 of that of the SiC support substrate and having a thickness of 50 ?m or more is disposed; (b) forming an impurity region, which forms a semiconductor element, on a first main surface of the SiC epitaxial substrate by selectively injecting impurity ions; (c) forming an ion implantation region, which controls warpage of the SiC epitaxial substrate, on a second main surface of the SiC epitaxial substrate by injecting predetermined ions; and (d) heating the SiC epitaxial substrate after (b) and (c).

Abstract: A semiconductor device including a terminal region that can suppress a resist collapse in manufacturing and effectively relieve a concentration of electric fields and a method for manufacturing the semiconductor device. The semiconductor device includes a semiconductor element formed in a semiconductor substrate made of a silicon carbide semiconductor of a first conductivity type and a plurality of ring-shaped regions of a second conductivity type formed in the semiconductor substrate while surrounding the semiconductor element in plan view. At least one of the plurality of ring-shaped regions includes one or more separation regions of the first conductivity type that cause areas of the first conductivity type on an inner side and an outer side of one of the ring-shaped regions to communicate with each other in plan view.

Abstract: A method for manufacturing a semiconductor device, includes: (a) providing a SiC epitaxial substrate in which on a SiC support substrate, a SiC epitaxial growth layer having an impurity concentration equal to or less than 1/10,000 of that of the SiC support substrate and having a thickness of 50 ?m or more is disposed; (b) forming an impurity region, which forms a semiconductor element, on a first main surface of the SiC epitaxial substrate by selectively injecting impurity ions; (c) forming an ion implantation region, which controls warpage of the SiC epitaxial substrate, on a second main surface of the SiC epitaxial substrate by injecting predetermined ions; and (d) heating the SiC epitaxial substrate after (b) and (c).

Abstract: An IGBT includes an emitter electrode, base regions, an emitter region, a collector region, a collector electrode, a gate insulating film provided in contact with the silicon carbide semiconductor region, the emitter region, and the base region, and a gate electrode that faces the gate insulating film. A FWD includes a base contact region provided adjacent to the emitter region and electrically connected to the emitter electrode, and a cathode region disposed in the upper layer part on the other main surface side of the silicon carbide semiconductor region, provided adjacent to the collector region, and electrically connected to the collector electrode. The IGBT further includes a reduced carrier-trap region disposed in a principal current-carrying region of the silicon carbide semiconductor region located above the collector region and having a smaller number of carrier traps than the silicon carbide semiconductor region located above the cathode region.