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 source region of a MOSFET includes: a source contact region connected to a source pad; a source extension region adjacent to a channel region in a well region; and a source resistance control region arranged between the source extension region and the source contact region. The source resistance control region is different in an impurity concentration from the source extension region and the source contact region. These three regions are connected in series between the source pad and the channel region in the well region.

Abstract: A semiconductor device includes a semiconductor substrate of a first conductivity type, a drift layer of the first conductivity type which is formed on a first main surface of the semiconductor substrate, a second well region of a second conductivity type which is formed to surround a cell region of the drift layer, and a source pad for electrically connecting the second well regions and a source region of the cell region through a first well contact hole provided to penetrate a gate insulating film on the second well region, a second well contact hole provided to penetrate a field insulating film on the second well region and a source contact hole.

Abstract: A power semiconductor device includes a second conductive type sense outer-peripheral well formed to surround a plurality of sense wells on the surface of a drift layer, a first conductive type main-cell source region selectively formed on the surface of the main cell well, a first conductive type sense source region selectively formed on the surface of the sense well, a first conductive type capacitor lower electrode region selectively formed on the surface of the sense outer-peripheral well, a gate insulation film formed on the channel regions and on the sense outer-peripheral well, a gate electrode formed on the gate insulation film, and a sense pad electrically connected to the sense well and the sense source region as well as on the sense outer-peripheral well and the capacitor lower electrode region.

Abstract: A semiconductor layer, a well region, and a source region form a unit cell. The unit cell is defined into a certain shape in plan view at a main surface of the semiconductor layer, and a plurality of the unit cells is coupled in a chain manner to form a unit chain structure with a constriction. The certain shape of the unit cell is defined by an outer edge of a virtual region of the semiconductor layer defined so as to include the source region and the well region inside and by respective outer edges of the source region and the well region at a joint with a different unit cell. An active region is composed of a plurality of the unit chain structures. The unit chain structures are arranged so as to avoid generation of a gap between the unit cells of adjacent ones of the unit chain structures.

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 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 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 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 power semiconductor device includes a second conductive type sense outer-peripheral well formed to surround a plurality of sense wells on the surface of a drift layer, a first conductive type main-cell source region selectively formed on the surface of the main cell well, a first conductive type sense source region selectively formed on the surface of the sense well, a first conductive type capacitor lower electrode region selectively formed on the surface of the sense outer-peripheral well, a gate insulation film formed on the channel regions and on the sense outer-peripheral well, a gate electrode formed on the gate insulation film, and a sense pad electrically connected to the sense well and the sense source region as well as on the sense outer-peripheral well and the capacitor lower electrode region.

Abstract: It is expected that both reduction of the resistance of a source region and reduction of a leakage current in a gate oxide film be achieved in an MOSFET in a silicon carbide semiconductor device. A leakage current to occur in a gate oxide film of the MOSFET is suppressed by reducing roughness at an interface between a source region and the gate oxide film. If an impurity concentration is to become high at a surface portion of the source region, the gate oxide film is formed by dry oxidation or CVD process. If the gate oxide film is formed by wet oxidation, the impurity concentration at the surface portion of the source region is controlled at a low level.

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 RESURF layer including a plurality of P-type implantation layers having a low concentration of P-type impurity is formed adjacent to an active region. The RESURF layer includes a first RESURF layer, a second RESURF layer, a third RESURF layer, a fourth RESURF layer, and a fifth RESURF layer that are arranged sequentially from the P-type base side so as to surround the P-type base. The second RESURF layer is configured with small regions having an implantation amount equal to that of the first RESURF layer and small regions having an implantation amount equal to that of the third RESURF layer being alternately arranged in multiple. The fourth RESURF layer is configured with small regions having an implantation amount equal to that of the third RESURF layer and small regions having an implantation amount equal to that of the fifth RESURF layer being alternately arranged in multiple.

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 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: In a power semiconductor device that switches at a high speed, a displacement current flows at a time of switching, so that a high voltage occurs which may cause breakdown of a thin insulating film such as a gate insulating film.

Abstract: A silicon carbide semiconductor device including an SBD measuring a temperature of a silicon carbide semiconductor element. The silicon carbide semiconductor device includes a MOSFET formed on a silicon carbide epitaxial substrate, and an SBD section measuring a temperature of the MOSFET. The SBD section includes an n-type cathode region in a surface portion of a silicon carbide drift layer; an anode titanium electrode formed on the cathode region, the electrode serving as a Schottky electrode; an n-type cathode contact region of a higher concentration than that of the cathode region, formed in the surface portion of the silicon carbide drift layer to make contact with the cathode region; a cathode ohmic electrode formed on the cathode contact region; and a first p-type well region formed within the silicon carbide drift layer to surround peripheries of the cathode region and the cathode contact region.

Abstract: A structure of a power semiconductor device, in which a P-well region having a large area and a gate electrode are opposed to each other through a field oxide film having a larger thickness than that of a gate insulating film such that the P-well region having a large area and the gate electrode are not opposed to each other through the gate insulating film, or the gate electrode is not provided above the gate insulating film that includes the P-well region having a large area therebelow.