Provided is a semiconductor device including: at least a semiconductor layer having a corundum structure, the semiconductor layer including a first surface having at least a first side and a second side shorter than the first side, the first surface being a c-plane or an m-plane, a direction of the first side being a direction of a c-axis or a direction of an m-axis.

A method for forming a wide band gap semiconductor device is provided. The method includes forming a gate insulation layer on a wide band gap semiconductor substrate and annealing the gate insulation layer using at least a first reactive gas species and a second reactive gas species, wherein the first reactive gas species differs from the second reactive gas species. The method can include forming a gate electrode on the gate insulation layer after annealing the gate insulation layer.

A semiconductor substrate includes a base portion, an auxiliary layer and a surface layer. The auxiliary layer is formed on the base portion. The surface layer is formed on the auxiliary layer. The surface layer is in contact with a first main surface of the semiconductor substrate. The auxiliary layer has a different electrochemical dissolution efficiency than the base portion and the surface layer. At least a portion of the auxiliary layer and at least a portion of the surface layer are converted into a porous structure. Subsequently, an epitaxial layer is formed on the first main surface.

A semiconductor device includes a first conductivity type semiconductor layer having a first and second surfaces, device and outer regions, a channel region of a second conductivity type in a surface layer portion of the first surface in the device region, an emitter region of a first conductivity type in a surface layer portion of the channel region, a gate electrode at the first surface in the device region, the gate electrode facing the channel region across a gate insulating film, a collector region of a second conductivity type in a surface layer portion of the second surface in the device region, an inner cathode region of a first conductivity type in the surface layer portion of the second surface in the device region, and an outer cathode region of a first conductivity type in the surface layer portion of the second surface in the outer region.

According to one embodiment, a semiconductor device includes a first element, a second element, a first terminal, a second terminal, a third terminal, a fourth terminal, a fifth terminal, a sixth terminal, and a circuit section. Each of the first element and the second element includes a first electrode, a second electrode, a third electrode, a fourth electrode, and a semiconductor member. The semiconductor member includes a first semiconductor region of a first conductivity type, a second semiconductor region of the first conductivity type, a third semiconductor region of a second conductivity type, a fourth semiconductor region of the second conductivity type, a fifth semiconductor region of the first conductivity type, and a sixth semiconductor region of the second conductivity type. The first semiconductor region includes a first partial region, a second partial region, a third partial region, and a fourth partial region.

A semiconductor module includes a laminated substrate including an insulating board and a plurality of circuit boards that are arranged on an upper face of the insulating board, the plurality of circuit boards including first and second circuit boards, a semiconductor element disposed on the first circuit board and including, on an upper face of the semiconductor element, a main electrode, a gate pad, and a gate runner electrically connected to the gate pad, and a first wiring member electrically connecting the main electrode to the second circuit board. The gate runner extends so as to divide the main electrode into a plurality of electrodes including a first main electrode at a first side and a second main electrode at a second side, and the first wiring member is arranged to cross over the gate runner.

A power module apparatus includes a power module having a package configured to seal a perimeter of a semiconductor device, and a heat radiator bonded to one surface of the package; a cooling device having a coolant passage through which coolant water flows, in which the heat radiator is attached to an opening provided on a way of the coolant passage, wherein the heat radiator of the power module is attached to the opening of the cooling device so that a height (ha) and a height (hb) are substantially identical to each other. The power module in which the heat radiator is attached to the opening formed at the upper surface portion of the cooling device can also be efficiently cooled, and thereby it becomes possible to reduce degradation due to overheating.

An insulated gate structure includes a wide bandgap material layer having a channel region of a first conductivity type. A gate insulating layer is arranged directly on the channel region and has a first nitride layer that is arranged directly on the channel region. The gate insulating layer has a concentration of carbon atoms that is less than 10.sup.18 atoms/cm.sup.3 at a distance of 3 nm from an interface between the wide bandgap material layer and the first nitride layer. An electrically conductive gate electrode layer overlies the gate insulating layer so that the gate electrode layer is separated from the wide bandgap material layer by the gate insulating layer.

Provided is a semiconductor device including a semiconductor substrate; a transistor portion provided in the semiconductor substrate; a current sensing portion for detecting current flowing through the transistor portion; an emitter electrode set to an emitter potential of the transistor portion; a sense electrode electrically connected to the current sensing portion; and a Zener diode electrically connected between the emitter electrode and the sense electrode. Provided is a semiconductor device fabricating method including providing a transistor portion in a semiconductor substrate; providing a current sensing portion for detecting current flowing through the transistor portion; providing an emitter electrode set to an emitter potential of the transistor portion; providing a sense electrode electrically connected to the current sensing portion; and providing a Zener diode electrically connected between the emitter electrode and the sense electrode.

A semiconductor device according to an embodiment includes a first electrode, a semiconductor layer, a second electrode, a first insulating portion, and a second insulating portion. The semiconductor layer is provided on the first electrode. The second electrode is provided on the semiconductor layer and contains aluminum. The first insulating portion includes a first portion and a second portion. The first portion is provided between the semiconductor layer and an outer peripheral portion of the second electrode. The second portion is provided around the first portion along a first plane perpendicular to a first direction, the first direction being a direction from the first electrode toward the semiconductor layer, the second portion being provided with a protruding portion on an upper surface thereof. The second insulating portion is provided on the outer peripheral portion of the second electrode and on the second portion.