A Schottky metal is in Schottky-contact with a center portion of a surface of an epitaxial layer. A peripheral trench is formed by digging from the surface of the epitaxial layer on a boundary portion between an active region where the Schottky metal is in Schottky-contact with the surface of the epitaxial layer and a peripheral region outside of the active region in a surface layer portion of the epitaxial layer. An insulating film is formed on an entire area of inner wall surfaces of the peripheral trench. There is provided with a conductor which is connected to the Schottky metal and is opposed to the entire area of the inner wall surfaces of the peripheral trench via the insulating film in the peripheral trench.

A semiconductor device of the present invention includes a semiconductor layer, a gate trench that defines a source region of a first conductivity type in the semiconductor layer, a channel region of a second conductivity type of a lower part of the source region, a source trench that passes through the source region and the channel region, an impurity region of the second conductivity type of a bottom part and a side part of the source trench, a source electrode on the semiconductor layer, and a highly-concentrated impurity region of the second conductivity type, the highly-concentrated impurity region having a contact portion connected to the source electrode at a surface of the semiconductor layer, the highly-concentrated impurity region passing through the source region and extending to a position deeper than the source region, the highly-concentrated impurity region having a concentration higher than the impurity region.

Provided is a semiconductor device comprising a semiconductor substrate containing oxygen. An oxygen concentration distribution in a depth direction of the semiconductor substrate has a high oxygen concentration part where an oxygen concentration is higher on a further upper surface-side than a center in the depth direction of the semiconductor substrate than in a lower surface of the semiconductor substrate. The high oxygen concentration part may have a concentration peak in the oxygen concentration distribution. A crystal defect density distribution in the depth direction of the semiconductor substrate has an upper surface-side density peak on the upper surface-side of the semiconductor substrate, and the upper surface-side density peak may be arranged within a depth range in which the oxygen concentration is equal to or greater than 50% of a peak value of the concentration peak.

A structure includes a laterally diffused (LD) MOSFET with an n-type drift region disposed on a surface of a substrate and a p-type body region contained in the drift region. The structure further includes an n-type source region contained in the p-type body region; an n-type drain region contained in the n-type drift region; a gate electrode disposed on a gate dielectric overlying a portion of the p-type body region and the n-type drift region and an electrically conductive field shield member disposed within the n-type drift region at least partially beneath the p-type body region and generally parallel to the gate electrode. The electrically conductive buried field shield member is contained within and surrounded by a layer of buried field shield oxide and is common to both a first LD MOSFET and a second LD MOSFET that are connected in parallel. Methods to fabricate the structure are also disclosed.

Provided is a semiconductor device comprising: a semiconductor substrate; a gate trench section that is provided from an upper surface to an inside of the semiconductor substrate and extends in a predetermined extending direction on the upper surface of the semiconductor substrate; a mesa section in contact to the gate trench section in an arrangement direction orthogonal the extending direction; and an interlayer dielectric film provided above the semiconductor substrate; wherein the interlayer dielectric film is provided above at least a part of the gate trench section in the arrangement direction; a contact hole through which the mesa section is exposed is provided to the interlayer dielectric film; and a width of the contact hole in the arrangement direction is equal to or greater than a width of the mesa section in the arrangement direction.

A lateral diffusion metal oxide semiconductor (LDMOS) device includes a first fin-shaped structure on a substrate, a shallow trench isolation (STI) adjacent to the first fin-shaped structure, a first gate structure on the first fin-shaped structure, a spacer adjacent to the first gate structure, and a contact field plate adjacent to the first gate structure and directly on the STI. Preferably, a sidewall of the spacer is aligned with a sidewall of the first fin-shaped structure.

A transistor device includes a semiconductor substrate having a first major surface, a cell field, and an edge termination region laterally surrounding the cell field. The cell field includes elongate trenches that extend from the first major surface into the semiconductor substrate and that are positioned substantially parallel to one another such that one or more inner elongate trenches are arranged between two outermost elongate trenches and elongate mesas, each elongate mesa being formed between neighbouring elongate trenches. The elongate mesas include a drift region, a body region on the drift region and a source region on the body region. In a top view, one or both of the outermost elongate trenches has a different contour from the one or more inner elongate trenches.

A semiconductor device includes first and second trenches, and a first layer provided therebetween, in a principal surface of a semiconductor substrate, a second layer in contact with and sandwiching the first trench with the first layer, a third layer provided under the second layer and in contact with the second layer and the first trench, a fourth layer provided under and in contact with the third layer but separated from the first trench, and a fifth layer provided in the principal surface and sandwiching the second trench with the first layer. The second and fourth layers are semiconductors of a first conductivity type, and the first, third, and fifth layers are semiconductors of a second conductivity type. A gate trench electrode is provided inside the first trench via the insulating film, and an emitter trench electrode is provided inside the second trench via the insulating film.

A semiconductor device in which a transistor and a diode are formed on a common semiconductor substrate is provided. The semiconductor substrate includes a transistor region in which a transistor is formed and a diode region in which a diode is formed. At least one first electrode on a second main surface side of the transistor region and at least one second electrode on a second main surface side of the diode region are made of different materials.

A semiconductor device includes first to fourth electrodes, a semiconductor portion, and first and second insulating films. The semiconductor portion includes first to third semiconductor layers. The second electrode is in contact with the third semiconductor layer and is spaced from the second semiconductor layer, the third semiconductor layer, and the second electrode. The first insulating film covers the third electrode. The fourth electrode is connected to the second electrode, and is spaced from the first semiconductor layer and the third electrode. The second insulating film is provided on a side surface of the fourth electrode, faces the first semiconductor layer through an air gap, and increases in thickness toward the first direction.