According to one embodiment, a semiconductor device includes a supporter including a first surface, first, second, and third conductive parts, a semiconductor region, and an insulating part. A first direction from the first toward second conductive part is along the first surface. The semiconductor region includes first, second, and third partial regions. A second direction from the first toward second partial region is along the first surface and crosses the first direction. The third partial region is between the first partial region and the second conductive part in the first direction. The third partial region includes a counter surface facing the second conductive part. A direction from the counter surface toward the third conductive part is along the second direction. The insulating part includes an insulating region. At least a portion of the insulating region is between the counter surface and the third conductive part.

A main semiconductor device element is SiC-MOSFETs with a trench gate structure, the main semiconductor device element having main MOS regions responsible for driving the MOSFETs and main SBD regions that are regions responsible for SBD operation. The main MOS regions and the main SBD regions are adjacent to one another and each pair of a main MOS region and a main SBD region adjacent thereto share one trench. In the main SBD regions, first and second p-type regions, and Schottky electrodes at the front surface of the semiconductor substrate and forming Schottky junctions with an n.sup.−-type drift region are provided. The first p-type regions are provided along sidewalls of the trenches, in contact with the first p.sup.+-type regions at the bottoms of the trenches. The second p-type regions are provided between the first p-type regions and the Schottky electrodes, and are electrically connected to these regions.

A semiconductor device according to the present disclosure includes a sense source electrode provided separately from a source electrode, and diodes. The diodes are provided between the sense source electrode and a drift layer. A turn-on voltage of each diode is lower than an operating voltage of a p-n diode formed of a sense well region and the drift layer or of a dummy sense well region and the drift layer. The diodes allow a current to flow from the sense source electrode toward a drain electrode. The diodes are provided in such a way that they are mixed with facing areas in a dummy sense region in which dummy sense well regions and the diodes are disposed. Each facing area is an area where one of the dummy sense well regions faces one of the gate electrodes via one of the gate insulating films.

A SiC MOSFET device having low specific on resistance is described. The device has N+, P-well and JFET regions extended in one direction (Y-direction) and P+ and source contacts extended in an orthogonal direction (X-direction). The polysilicon gate of the device covers the JFET region and is terminated over the P-well region to minimize electric field at the polysilicon gate edge. In use, current flows vertically from the drain contact at the bottom of the structure into the JFET region and then laterally in the X direction through the accumulation region and through the MOSFET channels into the adjacent N+ region. The current flowing out of the channel then flows along the N+ region in the Y-direction and is collected by the source contacts and the final metal. Methods of making the device are also described.

A trench power semiconductor device is provided. A trench gate structure of the trench power semiconductor device located in a cell trench of an epitaxial layer includes a first dielectric layer, a second dielectric layer, a gate electrode, a third dielectric layer, and a shielding layer. The second dielectric layer is interposed between the first and third dielectric layers, and the second dielectric layer is made from different material than the first dielectric layer. After performing a selective etching step on the second dielectric layer, a recess can be formed among the first, second and third dielectric layers. The gate electrode includes a conductive layer formed in the recess region, and the shielding electrode is surrounded by the third dielectric layer and insulated from the conductive layer.

In an SiC-MOSFET with a built-in Schottky diode, a bipolar current may be passed in a second well region formed at a terminal part to reduce the breakdown voltage of the terminal part. In the SiC-MOSFET with the built-in Schottky diode, a source electrode forming non-ohmic connection such as Schottky connection with the second well region is provided on the second well region formed below a gate pad in the terminal part. By the absence of ohmic connection between the second well region and the source electrode, reduction in breakdown voltage is suppressed at the terminal part.

A semiconductor device includes first and second field electrode structures that extend from a first surface into a semiconductor portion. The first field electrode structures include a first field dielectric insulating spicular first field electrodes against the semiconductor portion. The second field electrode structures include a second field dielectric insulating spicular second field electrodes against the semiconductor portion. The second field dielectric is thicker than the first field dielectric. Openings of the first and second field electrode structures in the first surface may be non-circular symmetric, wherein the openings of the second field electrode structures are tilted with respect to the openings of the first field electrode structures. Alternatively or in addition, the openings of the second field electrode structures in the first surface may be greater than the openings of the first field electrode structures.

A semiconductor device includes a semiconductor layer of a first conductivity type having a first main surface at one side and a second main surface at another side, a trench gate structure including a gate trench formed in the first main surface of the semiconductor layer, and a gate electrode embedded in the gate trench via a gate insulating layer, a trench source structure including a source trench formed deeper than the gate trench and across an interval from the gate trench in the first main surface of the semiconductor layer, a source electrode embedded in the source trench, and a deep well region of a second conductivity type formed in a region of the semiconductor layer along the source trench, a ratio of a depth of the trench source structure with respect to a depth of the trench gate structure being not less than 1.5 and not more than 4.0, a body region of the second conductivity type formed in a region of a surface layer portion of the first main surface of the semiconductor layer between the gate trench and the source trench, a source region of the first conductivity type formed in a surface layer portion of the body region, and a drain electrode connected to the second main surface of the semiconductor layer.

A semiconductor device includes a semiconductor body and a device cell in the semiconductor body. The device cell includes: drift, source, body and diode regions; a pn junction between the diode and drift regions; a trench with first and second opposing sidewalls and a bottom, the body region adjoining the first sidewall, the diode region adjoining the second sidewall, and the pn junction adjoining the trench bottom; a gate electrode in the trench and dielectrically insulated from the source, body, diode and drift regions by a gate dielectric; a further trench extending from a first surface of the semiconductor body into the semiconductor body; a source electrode arranged in the further trench adjoining the source and diode regions. The diode region includes a lower diode region arranged below the trench bottom. The lower diode region has a maximum of a doping concentration distant to the trench bottom.

A high-speed diode includes an n-type semiconductor layer and a p-type semiconductor layer which is laminated on the n-type semiconductor layer, where a pn junction is formed in a boundary portion between the n-type semiconductor layer and the p-type semiconductor layer, and crystal defects are formed such that the frequency of appearance is gradually decreased from the upper surface of the p-type semiconductor layer toward the bottom surface of the n-type semiconductor layer.