A semiconductor device is provided, wherein a semiconductor substrate includes: a first trench portion provided from a front surface of the semiconductor substrate to a predetermined depth, and having a longer portion and a shorter portion as seen from above; and a first conductivity-type floating semiconductor region at least partially exposed on the front surface and surrounded by the first trench portion, an interlayer insulating film has openings to electrically connect an emitter electrode and the floating semiconductor region, the openings include: a first opening closest to an outer end of the floating semiconductor region in a direction parallel to the longer portion; and a second opening second closest to the outer end in the direction parallel to the longer portion, and a distance between the first opening and the second opening is shorter than a distance between any adjacent two of the openings other than the first opening.

Provided is a semiconductor device that includes a semiconductor substrate that is provided with a first conductivity type drift region, a transistor portion that includes a second conductivity type collector region in contact with a lower surface of the semiconductor substrate, and a diode portion that includes a first conductivity type cathode region in contact with the lower surface of the semiconductor substrate, and is alternately disposed with the transistor portion along an arrangement direction in an upper surface of the semiconductor substrate. In the transistor portions, a width in the arrangement direction of two or more transistor portions sequentially selected from the transistor portions nearer to the center in the arrangement direction of the semiconductor substrate is larger than a width in the arrangement direction of one of the other transistor portions.

A method includes forming first and second trenches in a semiconductor substrate. The method further includes filling the first and second trenches with polysilicon. The polysilicon is oppositely doped from the semiconductor substrate. A Schottky contact is formed on the semiconductor substrate between the first and second trenches. The method also includes forming an anode for the Schottky contact. The anode is coupled to the polysilicon in the first and second trenches.

Provided is a semiconductor device that can detect the cracking progress with high precision. A semiconductor device is formed using a semiconductor substrate, and includes an active region in which a semiconductor element is formed, and an edge termination region outside the active region. A crack detection structure is termed in the edge termination region of the semiconductor substrate. The crack detection structure includes: a trench formed in the semiconductor substrate and extending in a circumferential direction of the edge termination region; an inner-wall insulating film formed on an inner wall of the trench; an embedded electrode formed on the inner-wall insulating film and embedded into the trench; and a monitor electrode formed on the semiconductor substrate and connected to the embedded electrode.

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.

Provided is a method of forming a trench gate MOSFET. A hard mask layer is formed on a substrate. The substrate is partially removed by using the hard mask layer as a mask, so as to form a trench in the substrate. A first insulating layer and a first conductive layer are formed in the lower portion of the trench. A sacrificial layer is formed on the side surface of the upper portion of the trench, and the sacrificial layer is connected to the hard mask layer. An interlayer insulating layer is formed on the first conductive layer by a thermal oxidation process when the sacrificial layer and the hard mask layer are present. A second insulating layer and a second conductive layer are formed in the upper portion of the trench. A trench gate MOSFET is further provided.

A semiconductor Schottky rectifier built in an epitaxial semiconductor layer over a substrate has an anode structure and a cathode structure extending from the surface of the epitaxial layer. The cathode contact structure has a trench structure near the epi-layer and a vertical sidewall surface covered with a gate oxide layer. The cathode structure further comprises a polysilicon element adjacent to the gate oxide layer.

A semiconductor apparatus includes: a semiconductor substrate; a diffusion layer; a first depletion prevention region; a channel stopper electrode, a monitor electrode and an insulating film. The inner edge portion of the monitor electrode is positioned between the diffusion layer and the first depletion prevention region. A distance between the outer edge portion of the channel stopper electrode and the inner edge portion of the monitor electrode is a first distance. A distance between the diffusion layer and the first depletion prevention region is a second distance. The first and second distances are set so that a discharge voltage between the channel stopper electrode and the monitor electrode becomes greater than an avalanche breakdown voltage at a PN junction portion of the diffusion layer and the semiconductor substrate.

An insulated gate bipolar transistor includes a source electrode, a collector electrode, a source layer, a base layer, a drift layer and a collector layer. Trench gate electrodes extend through the base layer into the drift layer. A channel is located between the source layer, the base layer and the drift layer. A trench Schottky electrode is adjacent to one of the trench gate electrodes and includes an electrically conductive Schottky layer arranged lateral to the base layer and extends through the base layer into the drift layer. The Schottky layer is electrically connected to the source electrode. Collection areas are located in the drift layer at a respective trench gate electrode bottom of the trench gate electrodes or of the trench Schottky electrode. The Schottky layer forms a Schottky contact to the collection area at a contact area.

A high voltage trench field plate power MOSFET device is fabricated in a substrate having first and second trenches separated from one another by a narrow epitaxial semiconductor drift pillar structure, where insulated gate electrode layers and insulated field plate layers are formed in the first and second trenches, and where a body well region is formed in an upper portion of the narrow epitaxial semiconductor drift pillar structure to include source contact regions in an active area, and to include an integrated ballast resistor section which connects one or more of the source contact regions to the termination area and which has no source contact regions.