Abstract: A silicon carbide semiconductor device includes: an n-type drift layer 2 provided within an SiC layer 30; a plurality of p-type well regions 3; a JFET region JR serving as a part of the drift layer 2 sandwiched between the well regions 3; and a gate insulating film 6 and a gate electrode 7 at least covering the JFET region JR. The gate insulating film 6 and the gate electrode 7 include a different-element-containing region 10 containing an element that is different from elements constituting the gate insulating film 6 and the gate electrode 7.

Abstract: The technique disclosed in the Description relates to a technique preventing dielectric breakdown while a silicon carbide semiconductor device is OFF, without degrading process throughput or yield. The silicon carbide semiconductor device relating to the technique disclosed in the Description includes a drift layer of a first conductivity type, a threading dislocation provided to penetrate the drift layer, and an electric-field reduction region of a second conductivity type disposed in a position in the surface layer of the drift layer, the position corresponding to the threading dislocation. The electric-field reduction region is an epitaxial layer.

Abstract: The technique disclosed in the Description relates to a technique preventing dielectric breakdown while a silicon carbide semiconductor device is OFF, without degrading process throughput or yield. The silicon carbide semiconductor device relating to the technique disclosed in the Description includes a drift layer of a first conductivity type, a threading dislocation provided to penetrate the drift layer, and an electric-field reduction region of a second conductivity type disposed in a position in the surface layer of the drift layer, the position corresponding to the threading dislocation. The electric-field reduction region is an epitaxial layer.

Abstract: A silicon carbide semiconductor device includes: an n-type drift layer 2 provided within an SiC layer 30; a plurality of p-type well regions 3; a JFET region JR serving as a part of the drift layer 2 sandwiched between the well regions 3; and a gate insulating film 6 and a gate electrode 7 at least covering the JFET region JR. The gate insulating film 6 and the gate electrode 7 include a different-element-containing region 10 containing an element that is different from elements constituting the gate insulating film 6 and the gate electrode 7.

Abstract: A semiconductor device capable of reducing ON-resistance changes with temperature, including a semiconductor substrate of a first conductivity type, a drift layer of the first conductivity type formed on the semiconductor substrate, a first well region of a second conductivity type formed in the front surface of the drift layer, a second well region of the second conductivity type formed in the front surface of the drift layer, and a gate structure that is formed on the front surface of the drift layer and forms a channel in the first well region and a channel in the second well region. A channel resistance of the channel formed in the first well region has a temperature characteristic that the channel resistance decreases with increasing temperature and a channel resistance of the channel formed in the second well region has a temperature characteristic that the channel resistance increases with increasing temperature.

Abstract: A semiconductor device capable of reducing ON-resistance changes with temperature, including a semiconductor substrate of a first conductivity type, a drift layer of the first conductivity type formed on the semiconductor substrate, a first well region of a second conductivity type formed in the front surface of the drift layer, a second well region of the second conductivity type formed in the front surface of the drift layer, and a gate structure that is formed on the front surface of the drift layer and forms a channel in the first well region and a channel in the second well region. A channel resistance of the channel formed in the first well region has a temperature characteristic that the channel resistance decreases with increasing temperature and a channel resistance of the channel formed in the second well region has a temperature characteristic that the channel resistance increases with increasing temperature.

Abstract: A semiconductor device that can improve reliability while suppressing increase of a conduction loss or a switching loss. In the semiconductor device, when a two-dimensional shape on a main surface of the semiconductor substrate is an unit cell, the shape being a repeating unit of a plurality of well regions periodically disposed in a surface layer of a drift layer, one unit cell and another unit cell adjacent in an x-axis direction are disposed misaligned in a y-axis direction, and one unit cell and another unit cell adjacent in the y-axis direction are disposed misaligned in the x-axis direction.

Abstract: A semiconductor device capable of suppressing time variation of a threshold voltage and a method of manufacturing the same. A semiconductor device according to the present invention comprises a drift layer formed on a semiconductor substrate, first well regions formed in a surface layer of the drift layer, being apart from one another, a gate insulating film formed, extending on the drift layer and each of the first well regions, a gate electrode selectively formed on the gate insulating film, a source contact hole penetrating through the gate insulating film and reaching the inside of each of the first well regions, and a residual compressive stress layer formed on at least a side surface of the source contact hole, in which a compressive stress remains.

Abstract: A silicon carbide semiconductor device that is able to increase the gate reliability, and to provide a method for manufacturing the silicon carbide semiconductor device, and that includes: a source electrode selectively formed on a source region; a gate insulating film formed so as to extend over the source region; and a gate electrode formed on the gate insulating film. The source region includes a first source region located below the source electrode, and a second source region surrounding the first source region. The doping concentration in a superficial layer of the second source region is lower than the doping concentration in a superficial layer of the first source region. The doping concentration in the second source region is higher in a deep portion than in a superficial portion thereof.

Abstract: A semiconductor device that can improve reliability while suppressing increase of a conduction loss or a switching loss. In the semiconductor device, when a two-dimensional shape on a main surface of the semiconductor substrate is an unit cell, the shape being a repeating unit of a plurality of well regions periodically disposed in a surface layer of a drift layer, one unit cell and another unit cell adjacent in an x-axis direction are disposed misaligned in a y-axis direction, and one unit cell and another unit cell adjacent in the y-axis direction are disposed misaligned in the x-axis direction.

Abstract: A semiconductor device capable of suppressing time variation of a threshold voltage and a method of manufacturing the same. A semiconductor device according to the present invention comprises a drift layer formed on a semiconductor substrate, first well regions formed in a surface layer of the drift layer, being apart from one another, a gate insulating film formed, extending on the drift layer and each of the first well regions, a gate electrode selectively formed on the gate insulating film, a source contact hole penetrating through the gate insulating film and reaching the inside of each of the first well regions, and a residual compressive stress layer formed on at least a side surface of the source contact hole, in which a compressive stress remains.

Abstract: A silicon carbide semiconductor device that is able to increase the gate reliability, and to provide a method for manufacturing the silicon carbide semiconductor device, and that includes: a source electrode selectively formed on a source region; a gate insulating film formed so as to extend over the source region; and a gate electrode formed on the gate insulating film. The source region includes a first source region located below the source electrode, and a second source region surrounding the first source region. The doping concentration in a superficial layer of the second source region is lower than the doping concentration in a superficial layer of the first source region. The doping concentration in the second source region is higher in a deep portion than in a superficial portion thereof.

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: A carbon film deposition apparatus includes an evaporator for evaporating an oxygen-containing hydrocarbon. The carbon film deposition apparatus also includes a gas inlet pipe for introducing the oxygen-containing hydrocarbon gas evaporated in the evaporator. The carbon film deposition apparatus further includes a deposition furnace for depositing a carbon protection film over all surfaces of a wafer by pyrolyzing the oxygen-containing hydrocarbon gas introduced through the gas inlet pipe.

Abstract: A method of manufacturing a silicon carbide semiconductor device includes ion-implanting an impurity in a surface of a silicon carbide wafer, and forming a carbon protection film of a predetermined thickness over all surfaces of the silicon carbide wafer, which has been ion-implanted with the impurity, by a chemical vapor deposition method that deposits a film by pyrolyzing a hydrocarbon gas. The method also includes annealing the silicon carbide wafer after the forming the carbon protection film.

Abstract: A p base ohmic contact of a silicon carbide semiconductor device consists of a p++ layer formed by high-concentration ion implantation and a metal electrode. Since the high-concentration ion implantation performed at the room temperature significantly degrades the crystal of the p++ layer to cause a process failure, a method for implantation at high temperatures is used. In terms of switching loss and the like of devices, it is desirable that the resistivity of the p base ohmic contact should be lower. In well-known techniques, nothing is mentioned on a detailed relation among the ion implantation temperature, the ohmic contact resistivity and the process failure. Then, in the ion implantation step, the temperature of a silicon carbide wafer is maintained in a range from 175° C. to 300° C., more preferably in a range from 175° C. to 200° C. The resistivity of the p base ohmic contact using a p++ region formed by ion implantation at a temperature in a range from 175° C. to 300° C.

Abstract: A method of manufacturing a silicon carbide semiconductor device includes a step of ion-implanting an impurity in a surface of a silicon carbide wafer (1 and 2); a step of forming a carbon protection film (6) of a predetermined thickness over the entire surface of the silicon carbide wafer (1 and 2) having been ion-implanted with the impurity, by a chemical vapor deposition method that deposits a film by pyrolyzing a hydrocarbon gas; and a step of annealing the silicon carbide wafer (1 and 2) having been formed with the carbon protection film (6). Thereby, the carbon protection film (6) can be formed that contains extremely few contaminants, and prevents step bunching from creating on the surface of the silicon carbide wafer (1 and 2) and crystal defects created therein due to unbalanced thermal stress form increasing.