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 semiconductor device capable of suppressing generation of a high electric field and preventing a dielectric breakdown from occurring, and a method of manufacturing the same. The method of manufacturing a semiconductor device includes (a) preparing an n+ substrate to be a ground constituted by a silicon carbide semiconductor of a first conductivity type, (b) forming a recess structure surrounding an element region on the n+ substrate by using a resist pattern, and (c) forming a guard ring injection layer to be an impurity layer of a second conductivity type in a recess bottom surface and a recess side surface in the recess structure by impurity injection through the resist pattern, and a corner portion of the recess structure is covered with the impurity layer.

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.

Abstract: In a semiconductor device according to the present invention, a p-type well region disposed in an outer peripheral portion of the power semiconductor device is divided into two parts, that is, an inside and an outside, and a field oxide film having a greater film thickness than the gate insulating film is provided on a well region at the outside to an inside of an inner periphery of the well region. Therefore, it is possible to prevent, in the gate insulating film, a dielectric breakdown due to the voltage generated by the flow of the displacement current in switching.

Abstract: In a high speed switching power semiconductor device having a sense pad, a high voltage is generated during switching operations in well regions under the sense pad due to a displacement current flowing through its flow path with a resistance, whereby the power semiconductor device sometimes breaks down by dielectric breakdown of a thin insulating film such as a gate insulating film. In a power semiconductor device according to the invention, sense-pad well contact holes are provided on well regions positioned under the sense pad and penetrate a field insulating film thicker than the gate insulating film to connect to the source pad, thereby improving reliability.

Abstract: A power semiconductor module (1) includes a first MOS transistor (16) connected to a positive side power supply terminal via a first conductor pattern (11), a first free wheeling diode (17) connected to the positive side power supply terminal via a second conductor pattern (12), a second MOS transistor (18) connected to a negative side power supply terminal via a third conductor pattern (13), and a second free wheeling diode (19) connected to the negative side power supply terminal via a fourth conductor pattern (14). These semiconductor elements (16-19) are connected to a load side output terminal via a common fifth conductor pattern (15). The semiconductor element (16, 17) connected to the positive side power supply terminal and the semiconductor element (18, 19) connected to the negative side power supply terminal are arranged alternately, substantially linearly.

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 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 silicon carbide MOSFET that exhibits a high source-to-drain withstand voltage and that involves a smaller difference between gate-to-drain capacitance achieved in an activated state and gate-to-drain capacitance achieved in a deactivated state. A silicon carbide drift layer of a first conductivity type is provided on a silicon carbide substrate of a first conductivity type; a pair of base regions are provided in a surface layer portion of the silicon carbide drift layer and exhibit a second conductivity type; a pair of source regions are provided in interiors of surface layer portions of the pair of base regions and exhibit a first conductivity type; and semi-insulating regions are provided between the silicon carbide substrate and the pair of base regions.

Abstract: In a semiconductor device according to the present invention, a p-type well region disposed in an outer peripheral portion of the power semiconductor device is divided into two parts, that is, an inside and an outside, and a field oxide film having a greater film thickness than the gate insulating film is provided on a well region at the outside to an inside of an inner periphery of the well region. Therefore, it is possible to prevent, in the gate insulating film, a dielectric breakdown due to the voltage generated by the flow of the displacement current in switching.

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: In a cell region of a first major surface of a semiconductor substrate of a first conductivity type, a first well of a second conductivity type is in an upper surface. A diffusion region of a first conductivity type is in the upper surface in the first well. A first gate insulating film is on the first well, and a first gate electrode on the first gate insulating film. A second well of a second conductivity type is in the upper surface of the first major surface on a peripheral portion of the cell region. A second gate insulating film is on the second well, and a thick field oxide film is on the peripheral side than the second gate insulating film. A second gate electrode is sequentially on the second gate insulating film and the field oxide film and electrically connected to the first gate electrode. A first electrode is connected to the first, second well and the diffusion region. A second electrode is connected on a second major surface of the semiconductor substrate.

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 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.

Abstract: A power semiconductor module (1) includes a first MOS transistor (16) connected to a positive side power supply terminal via a first conductor pattern (11), a first free wheeling diode (17) connected to the positive side power supply terminal via a second conductor pattern (12), a second MOS transistor (18) connected to a negative side power supply terminal via a third conductor pattern (13), and a second free wheeling diode (19) connected to the negative side power supply terminal via a fourth conductor pattern (14). These semiconductor elements (16-19) are connected to a load side output terminal via a common fifth conductor pattern (15). The semiconductor element (16, 17) connected to the positive side power supply terminal and the semiconductor element (18, 19) connected to the negative side power supply terminal are arranged alternately, substantially linearly.

Abstract: A silicon carbide MOSFET that exhibits a high source-to-drain withstand voltage and that involves a smaller difference between gate-to-drain capacitance achieved in an activated state and gate-to-drain capacitance achieved in a deactivated state. A silicon carbide drift layer of a first conductivity type is provided on a silicon carbide substrate of a first conductivity type; a pair of base regions are provided in a surface layer portion of the silicon carbide drift layer and exhibit a second conductivity type; a pair of source regions are provided in interiors of surface layer portions of the pair of base regions and exhibit a first conductivity type; and semi-insulating regions are provided between the silicon carbide substrate and the pair of base regions.

Abstract: To provide a method of manufacturing a field emission display having an improved electron emission effect by means of laser irradiation and accordingly mitigating a luminance fluctuation among pixels, and other such techniques. Provided is a method of manufacturing a field emission display which includes a cathode substrate and a fluorescent screen glass opposed to the cathode substrate and emits light when an electron emitted from a carbon nanotube printed layer (7) containing a carbon nanotube of the cathode electrode enters a fluorescent material of the fluorescent screen glass, the method including a laser beam irradiation step of irradiating a surface of the carbon nanotube printed layer (7) with a laser beam having its energy density to be spatially modulated to expose and raise the carbon nanotube of the carbon nanotube printed layer so as to form a laser irradiation part (B) and a non-laser irradiation part (C).

Abstract: A cold cathode display device which has a small thickness and a large display area, in which an anode can be sufficiently distant from an extraction electrode to ensure a breakdown voltage and an electron beam diameter can be made sufficiently smaller than the size of a phosphor, and a method of manufacturing such a cold cathode display device. A focus electrode is added to a conventional cold cathode display device. The focus electrode is located such that extraction electrodes and cathodes are interposed between the focus electrode and a back substrate. The focus electrode includes electron passage windows located opposite the cathodes and electron passage windows. The focus electrode is attached to, and supported by, the extraction electrodes via an insulating material with a distance being maintained between the focus and extraction electrodes.

Abstract: A method of reducing a fluctuation in a cut-off voltage of a cathode for an electron tube in which a metal layer for protrusively deforming a cathode substrate when heated is formed on a surface of the cathode substrate, and an electron emissive material layer is formed on the front face of the cathode substrate directly or through the metal layer and a heater for heating the electron emissive material layer to emit a thermion from a front face of the electron emissive material layer is provided. When the front face of the electron emissive material layer is consumed and retreats, the protrusive deformation of the cathode substrate by the metal layer is induced by a heating operation of the heater so that the front face of the electron emissive material layer is correspondingly deformed protrusively.

Abstract: To provide a method of manufacturing a field emission display having an improved electron emission effect by means of laser irradiation and accordingly mitigating a luminance fluctuation among pixels, and other such techniques. Provided is a method of manufacturing a field emission display which includes a cathode substrate and a fluorescent screen glass opposed to the cathode substrate and emits light when an electron emitted from a carbon nanotube printed layer (7) containing a carbon nanotube of the cathode electrode enters a fluorescent material of the fluorescent screen glass, the method including a laser beam irradiation step of irradiating a surface of the carbon nanotube printed layer (7) with a laser beam having its energy density to be spatially modulated to expose and raise the carbon nanotube of the carbon nanotube printed layer so as to form a laser irradiation part (B) and a non-laser irradiation part (C).