A semiconductor device includes a semiconductor substrate, a transistor section, a diode section, and a boundary section provided between the transistor section and the diode section in the semiconductor substrate. The transistor section has gate trench portions which are provided from an upper surface of the semiconductor substrate to a position deeper than that of an emitter region, and to each of which a gate potential is applied. An upper-surface-side lifetime reduction region is provided on the upper surface side of the semiconductor substrate in the diode section and a partial region of the boundary section, and is not provided in a region that is overlapped with the gate trench portion in the transistor section in a surface parallel to the upper surface of the semiconductor substrate.

A semiconductor device includes a semiconductor substrate, an emitter region, a base region and multiple accumulation areas, and an upper accumulation area in the multiple accumulation areas is in direct contact with a gate trench section and a dummy trench section, in an arrangement direction that is orthogonal to a depth direction and an extending direction, a lower accumulation area furthest from the upper surface of the semiconductor substrate in the multiple accumulation areas has: a gate vicinity area closer to the gate trench section than the dummy trench section in the arrangement direction; and a dummy vicinity area closer to the dummy trench section than the gate trench section in the arrangement direction, and having a doping concentration of the first conductivity type lower than that of the gate vicinity area.

A semiconductor device, including a semiconductor substrate, a transistor section and a diode section arranged in a predetermined arrangement direction and provided on the semiconductor substrate, is provided. The diode section includes a drift region of a first conductivity-type provided in the semiconductor substrate, a base region of a second conductivity-type extending to a height of an upper surface of the semiconductor substrate and provided above the drift region, first cathode regions of the first conductivity-type, and second and third cathode regions of the second conductivity-type. The first, second, and third cathode regions extend to a height of a lower surface of the semiconductor substrate in a depth direction and provided below the drift region. The first and second cathode regions are provided in contact with each other, alternating in the arrangement direction, and sandwiched between the third cathode regions in an extension direction orthogonal to the arrangement direction.

A semiconductor device including a semiconductor substrate, first and second transistor sections and a diode section provided on the substrate, is provided. The diode section is arranged to be adjacent to and sandwiched between the first and second transistor sections in a predetermined arrangement direction. The diode section includes a drift region; a base region above the drift region; first cathode regions and second cathode regions below the drift region. The first and second transistor sections each include a collector region. The first cathode regions are provided continuously between the collector regions of the first and second transistor sections. One end and another end of the first cathode regions in the arrangement direction are in contact with the collector regions of the first and second transistor sections, respectively. The first and second cathode regions are in contact with each other and alternating in a direction orthogonal to the arrangement direction.

A power semiconductor device includes a semiconductor wafer, a thyristor structure, and a bipolar junction transistor. The thyristor structure includes a first emitter layer of a first conductivity type adjacent the first main side, a first base layer of a second conductivity type, a second base layer of the first conductivity type, a second emitter layer of the second conductivity type, a gate electrode, a first main electrode, and a second main electrode arranged. The bipolar junction transistor includes a base electrode electrically separated from the gate electrode, a third main electrode arranged on the first main side and a fourth main electrode arranged on the second main side. The first main electrode is electrically connected to the third main electrode and the second main electrode is electrically connected to the fourth main electrode.

A transient voltage protection circuit includes a first input/output pad, a second input/output pad, and a trigger circuit coupled between the first input/output pad and the second input/output pad. The trigger circuit includes a first trigger element which includes a first input/output node, a second input/output node, a third input/output node, and a first substrate diode coupled to the third input/output node of the first trigger element. The trigger circuit further includes a first resistor coupled between the first input/output node of the first trigger element and the second input/output node of the first trigger element. The trigger circuit further includes a second trigger element which includes a first input/output node, a second input/output node, a third input/output node, wherein the second input/output node of the first trigger element is coupled to the first input/output node of the second trigger element, and a second substrate diode coupled to the third input/output node of the second trigger element. The trigger circuit further includes a second resistor coupled between the first input/output node of the second trigger element and the second input/output node of the second trigger element.

A semiconductor device includes: a semiconductor substrate having a drift layer; a base layer on the drift layer; a collector layer and a cathode layer arranged on the drift layer opposite to the base layer; multiple trenches penetrating the base layer and reaching the drift layer, and arranged along one direction; a gate electrode arranged in each trench via a gate insulating film; and an emitter region arranged in a surface portion of the base layer, and contacting with each trench. The semiconductor substrate includes an IGBT region having the emitter region and an FWD region in which an injection limiting region and a contact region are arranged in the surface portion of the base layer alternately along the one direction.

Provided is a semiconductor device including a semiconductor substrate provided with a transistor portion, wherein the semiconductor substrate includes, in the transistor portion, a drift region of a first conductivity type; an accumulation region of the first conductivity type that has a higher doping concentration than the drift region; a collector region of a second conductivity type; and a plurality of gate trench portions and a plurality of dummy trench portions that are provided extending in a predetermined extension direction in the top surface of the semiconductor substrate, and are arranged in an arrangement direction orthogonal to the extension direction, and the transistor portion includes a first region that includes a gate trench portion; and a second region in which the number of dummy trench portions arranged in a unit length in the arrangement direction is greater than in the first region.

A diode and a transistor are connected in parallel. The transistor is located on a first doped region forming a PN junction of the diode with a second doped region located under the first region. The circuit functions as an ionizing radiation detection cell by generating a current through the PN junction which changes by a voltage generated across the transistor. This change in voltage is compared to a threshold to detect the ionizing radiation.

Directly beneath p.sup.−-type base regions, n-type storage regions are provided. The storage regions contain hydrogen donors as an impurity and have an impurity concentration higher than that of the n.sup.−-type drift region. The storage regions are formed by hydrogen ion irradiation from a back surface of a semiconductor substrate. The storage regions have a peak hydrogen concentration and are at positions that coincide with where the hydrogen ions have been irradiated. By the hydrogen ion irradiation, a crystal defect region that is a carrier lifetime killer region is formed concurrently with the storage regions, closer to the back surface of the semiconductor substrate than are storage regions. The crystal defect region has a crystal defect density with a peak density at a position closer to the back surface of the semiconductor substrate than are the storage regions. A semiconductor device having such storage regions and a carrier lifetime killer region is enabled.