Abstract: In order to obtain a silicon carbide semiconductor device that ensures both stability of withstand voltage and reliability in high-temperature operations in its termination end-portion provided for electric-field relaxation in the perimeter of a cell portion driven as a semiconductor element, the termination end-portion is provided with an inorganic protection film having high heat resistance that is formed on an exposed surface of a well region as a first region formed on a side of the cell portion, and an organic protection film having a high electrical insulation capability with a little influence by electric charges that is formed on a surface of an electric-field relaxation region formed in contact relation to an outer lateral surface of the well region and apart from the cell portion, and on an exposed surface of the silicon carbide layer.

Abstract: A silicon carbide semiconductor device of the present invention comprises a silicon carbide drift layer formed on a silicon carbide substrate, a P-type region formed in a surface layer of the silicon carbide drift layer, and a Schottky electrode formed above the silicon carbide drift layer correspondingly to a forming portion of the P-type region. The P-type region is formed of a plurality of unit cells arranged therein. Each of the unit cells has at least a first distribution region in which the P-type impurity is distributed at first concentration and a second distribution region in which the P-type impurity is distributed at second concentration higher than the first concentration. With this structure, it is possible to provide a silicon carbide semiconductor device in which a sufficient breakdown voltage can be achieved with less number of ion implantations.

Abstract: A silicon oxide film is formed on an epitaxial layer by dry thermal oxidation, an ohmic electrode is formed on a back surface of a SiC substrate, an ohmic junction is formed between the ohmic electrode and the back surface of the SiC substrate by annealing the SiC substrate, the silicon oxide film is removed, and a Schottky electrode is formed on the epitaxial layer. Then, a sintering treatment is performed to form a Schottky junction between the Schottky electrode and the epitaxial layer.

Abstract: In the manufacture of a silicon carbide semiconductor device having a termination region being a JTE region or FLR, the margin of the amount of etching for removing a damage layer formed in the surface of the termination region is enlarged. A silicon carbide semiconductor device has a termination region being a JTE (Junction Termination Extension) region or an FLR (Field Limiting Ring) at a termination of the semiconductor elements. The termination region is formed by one step of ion implantation in which the kind of impurity and the implant energy are fixed. In the impurity concentration profile of the termination region in the depth direction, the concentration peak in the shallowest position is in a position deeper than 0.35 ?m from the surface, and the concentration in the surface portion is not more than one-tenth of the shallowest concentration peak.

Abstract: An SiC semiconductor device includes a semiconductor element formed in an SiC substrate, a source electrode and a gate pad formed by using an interconnect layer having barrier metal provided at the bottom surface thereof, and a temperature measuring resistive element formed by using part of the barrier metal in the interconnect line.

Abstract: A method of manufacturing an SiC semiconductor device according to the present invention includes the steps of (a) by using a single mask, etching regions of an SiC semiconductor layer which serve as an impurities implantation region and a mark region, to form recesses, (b) by using the same mask as in the step (a), performing ion-implantation in the recesses of the regions which serve as the impurities implantation region and the mark region, at least from an oblique direction relative to a surface of the SiC semiconductor layer and (c) positioning another mask based on the recess of the region which serves as the impurities implantation region or the mark region, and performing well implantation in a region containing the impurities implantation region.

Abstract: In the manufacture of a silicon carbide semiconductor device having a termination region being a JTE region or FLR, the margin of the amount of etching for removing a damage layer formed in the surface of the termination region is enlarged. A silicon carbide semiconductor device has a termination region being a JTE (Junction Termination Extension) region or an FLR (Field Limiting Ring) at a termination of the semiconductor elements. The termination region is formed by one step of ion implantation in which the kind of impurity and the implant energy are fixed. In the impurity concentration profile of the termination region in the depth direction, the concentration peak in the shallowest position is in a position deeper than 0.35 ?m from the surface, and the concentration in the surface portion is not more than one-tenth of the shallowest concentration peak.

Abstract: There was a problem that it was difficult to manufacture silicon carbide semiconductor devices with suppressed variations in characteristics without increasing the number of process steps. A silicon carbide semiconductor device according to the present invention includes an N type SiC substrate and an N type SiC epitaxial layer as a silicon carbide semiconductor substrate of a first conductivity type, a plurality of recesses intermittently formed in a surface of the N type SiC epitaxial layer, P type regions as second-conductivity-type semiconductor layers formed in the N type SiC epitaxial layer in the bottoms of the plurality of recesses, and a Schottky electrode selectively formed over the surface of the N type SiC epitaxial layer, wherein the plurality of recesses all have an equal depth.

Abstract: A method of manufacturing an SiC semiconductor device according to the present invention includes the steps of (a) by using a single mask, etching regions of an SiC semiconductor layer which serve as an impurities implantation region and a mark region, to form recesses, (b) by using the same mask as in the step (a), performing ion-implantation in the recesses of the regions which serve as the impurities implantation region and the mark region, at least from an oblique direction relative to a surface of the SiC semiconductor layer and (c) positioning another mask based on the recess of the region which serves as the impurities implantation region or the mark region, and performing well implantation in a region containing the impurities implantation region.

Abstract: An SiC semiconductor device includes a semiconductor element formed in an SiC substrate, a source electrode and a gate pad formed by using an interconnect layer having barrier metal provided at the bottom surface thereof, and a temperature measuring resistive element formed by using part of the barrier metal in the interconnect line.

Abstract: A method of manufacturing a silicon carbide semiconductor device is provided that includes a step of forming in a surface of a silicon carbide wafer of first conductivity type a first region of second conductivity type having a predetermined space thereinside by ion-implanting aluminum as a first impurity and boron as a second impurity; a step of forming a JTE region in the surface of the silicon carbide wafer from the first region by diffusing the boron ion-implanted in the first region toward its neighboring zones by an activation annealing treatment; a step of forming a first electrode on the surface of the silicon carbide wafer at the space inside the first region and at an inner part of the first region; and a step of forming a second electrode on the opposite surface of the silicon carbide wafer. Thereby, a JTE region can be formed that has a wide range of impurity concentration and a desired breakdown voltage without increasing the number of steps of the manufacturing process.

Abstract: A silicon oxide film is formed on an epitaxial layer by dry thermal oxidation, an ohmic electrode is formed on a back surface of a SiC substrate, an ohmic junction is formed between the ohmic electrode and the back surface of the SiC substrate by annealing the SiC substrate, the silicon oxide film is removed, and a Schottky electrode is formed on the epitaxial layer. Then, a sintering treatment is performed to form a Schottky junction between the Schottky electrode and the epitaxial layer.

Abstract: A method of manufacturing a silicon carbide semiconductor device according to the present invention includes the steps of (a) forming an implantation mask made up of a plurality of unit masks on a silicon carbide semiconductor layer, and (b) implanting predetermined ion in the silicon carbide semiconductor layer at a predetermined implantation energy by using the implantation mask. In the step (a), the implantation mask is formed such that a length from any point in the unit mask to an end of the unit mask can be equal to or less than a scattering length obtained when the predetermined ion is implanted in silicon carbide at the predetermined implantation energy and the implantation mask can have a plurality of regions different from each other in terms of a size and an arrangement interval of the unit masks.

Abstract: A method of manufacturing a silicon carbide semiconductor device having a silicon carbide layer, the method including a step of implanting at least one of Al ions, B ions and Ga ions having an implantation concentration in a range not lower than 1E19 cm?3 and not higher than 1E21 cm?3 from a main surface of the silicon carbide layer toward the inside of the silicon carbide layer while maintaining the temperature of the silicon carbide layer at 175° C. or higher, to form a p-type impurity layer; and forming a contact electrode whose back surface establishes ohmic contact with a front surface of the p-type impurity layer on the front surface of the p-type impurity layer.

Abstract: In the manufacture of a silicon carbide semiconductor device having a termination region being a JTE region or FLR, the margin of the amount of etching for removing a damage layer formed in the surface of the termination region is enlarged. A silicon carbide semiconductor device has a termination region being a JTE (Junction Termination Extension) region or an FLR (Field Limiting Ring) at a termination of the semiconductor elements. The termination region is formed by one step of ion implantation in which the kind of impurity and the implant energy are fixed. In the impurity concentration profile of the termination region in the depth direction, the concentration peak in the shallowest position is in a position deeper than 0.35 ?m from the surface, and the concentration in the surface portion is not more than one-tenth of the shallowest concentration peak.

Abstract: A MOSFET cell of a semiconductor device includes a polysilicon gate electrode and an n+-source region formed in an upper portion of an n?-drift layer. An interlayer insulating film covers the gate electrode. An Al source electrode extends on the interlayer insulating film. An Al gate pad is connected to the gate electrode. A barrier metal layer that prevents diffusion of aluminum is interposed between the source electrode and the interlayer insulating film, and between the gate pad and the gate electrode.

Abstract: A semiconductor device of the present invention includes: a semiconductor substrate of a first conductive type; an epitaxial layer of the first conductive type formed on the semiconductor substrate and having a protrusion formed on a surface thereof; a well region of a second conductive type formed on the surface of the epitaxial layer at each side of the protrusion; a source region of the first conductive type selectively formed in a surface of the well region; a gate insulating film formed so as to cover at least the protrusion and the surface of the well region; and a gate electrode formed on a part of the gate insulating film corresponding to the protrusion. The gate insulating film is thicker in a region thereof corresponding to an upper surface of the protrusion than the other regions thereof.

Abstract: A manufacturing method of a silicon carbide semiconductor device in which an electric field applied to a gate oxide film can be relaxed and thereby reliability can be ensured, and by the method manufacturing costs can be reduced. Well regions, channel regions, and gate electrodes are formed so that, given that extending lengths, with respect to the inner sides of source regions, of each of the well regions, the channel regions, and the gate electrodes are Lwell, Lch, and Lg, respectively, a relationship of Lch<Lg<Lwell is satisfied; and the channel regions are further formed by diffusing by activation annealing boron as a third impurity, having been implanted by activation annealing into the source regions, into a silicon carbide layer.

Abstract: An objective is to provide a manufacturing method of a silicon carbide semiconductor device in which an electric field applied to a gate oxide film can be relaxed and thereby reliability can be ensured, and by the manufacturing method increase of the manufacturing cost can also be prevented as much as possible. Well regions, channel regions, and gate electrodes are formed so that, given that extending lengths, with respect to the inner sides of source regions, of each of the well regions, the channel regions, and the gate electrodes are Lwell, Lch, and Lg, respectively, a relationship of Lch<Lg<Lwell is satisfied; and the channel regions are further formed by diffusing by activation annealing boron as a third impurity, having been implanted by activation annealing into the source regions, into a silicon carbide layer.

Abstract: A wafer WF is mounted in a substrate holder, and the substrate holder is placed in a film forming furnace. The film forming furnace is evacuated by a vacuum pump through a gas discharge part to remove remaining oxygen as completely as possible. Then, a temperature in the film forming furnace is heated to a range of 800° C. to 950° C. under reduced pressure while an inert gas such as Ar or helium (He) is being introduced through a gas introduction part. When the temperature reaches this temperature range, an inflow of the inert gas is stopped. Vaporized ethanol is introduced as a source gas into the film forming furnace through the gas introduction part, thus forming a graphite film on an entire surface of the wafer WF.