A trench is formed that extends from a main surface into a crystalline silicon carbide semiconductor layer. A mask is formed that includes a mask opening exposing the trench and a rim section of the main surface around the trench. By irradiation with a particle beam a first portion of the semiconductor layer exposed by the mask opening and a second portion outside of the vertical projection of the mask opening and directly adjoining to the first portion are amorphized. A vertical extension of the amorphized second portion gradually decreases with increasing distance to the first portion. The amorphized first and second portions are removed.

A semiconductor device includes a semiconductor chip formed with an SiC-IGBT including an SiC semiconductor layer, a first conductive-type collector region formed such that the collector region is exposed on a second surface of the SiC semiconductor layer, a second conductive-type base region formed such that the base region contacts the collector region, a first conductive-type channel region formed such that the channel region contacts the base region, a second conductive-type emitter region formed such that the emitter region contacts the channel region to define a portion of a first surface of the SiC semiconductor layer, a collector electrode connected to the collector region, and an emitter electrode connected to the emitter region. A MOSFET of the device is connected in parallel to the SiC-IGBT, and includes a second conductive-type source region electrically connected to the emitter electrode and a second conductive-type drain region electrically connected to the collector electrode.

The present application provides (in addition to more broadly applicable inventions) improvements which are particularly applicable to two-sided power semiconductor devices which use bipolar conduction. In this class of devices, the inventor has realized that two or three of the four (or more) semiconductor doping components which form the carrier-emission structures and control structures in the active device (array) portion of a two-sided power device can also be used, with surprising advantages, to form field-limiting rings around the active arrays on both surfaces. Most preferably, in some but not necessarily all embodiments, a shallow implant of one conductivity type is used to counterdope the surface of a well having the other conductivity type. This shallow implant, singly or in combination with another shallow implant of the same conductivity type, works to shield the well from the effects of excess charge at or above the surface of the semiconductor material.

An embodiment of a semiconductor device comprises a first load terminal contact area at a first side of a semiconductor body. A second load terminal contact area is at a second side of the semiconductor body opposite to the first side. A control terminal contact area is at the second side of the semiconductor body. An isolation structure extends through the semiconductor body between the first and second sides. The isolation structure electrically isolates a first part of the semiconductor body from a second part of the semiconductor body. A first thickness of the first part of the semiconductor body is smaller than a second thickness of the second part of the semiconductor body.

There is provided a monolithic three dimensional array of charge storage devices which includes a plurality of device levels, wherein at least one surface between two successive device levels is planarized by chemical mechanical polishing.

An SiC semiconductor device has a p type region including a low concentration region and a high concentration region filled in a trench formed in a cell region. A p type column is provided by the low concentration region, and a p.sup.+ type deep layer is provided by the high concentration region. Thus, since a SJ structure can be made by the p type column and the n type column provided by the n type drift layer, an on-state resistance can be reduced. As a drain potential can be blocked by the p.sup.+ type deep layer, at turnoff, an electric field applied to the gate insulation film can be alleviated and thus breakage of the gate insulation film can be restricted. Therefore, the SiC semiconductor device can realize the reduction of the on-state resistance and the restriction of breakage of the gate insulation film.

A semiconductor device of the present invention includes a semiconductor layer of a first conductivity type having a cell portion and an outer peripheral portion disposed around the cell portion, and a surface insulating film disposed in a manner extending across the cell portion and the outer peripheral portion, and in the cell portion, formed to be thinner than a part in the outer peripheral portion.

A semiconductor device, including a semiconductor substrate having a diode portion, wherein the diode portion includes: an anode region which is provided on a front surface of the semiconductor substrate and is of a second conductivity type; a trench portion provided so as to extend in a predetermined extending direction on the front surface of the semiconductor substrate; a trench contact portion provided on the front surface of the semiconductor substrate; and a plug region which is provided at a lower end of the trench contact portion and is of a second conductivity type, and which has a doping concentration higher than that of the anode region, wherein a plurality of plug regions, each of which being the plug region, is provided separately from each other along the extending direction, is provided.

A method is for treating a doped gallium nitride substrate of a first conductivity type, having dislocations emerging on the side of at least one of its surfaces. The method may include: a) forming, where each dislocation emerges, a recess extending into the substrate from the at least one surface; and b) filling the recesses with doped gallium nitride of the second conductivity type.

There is provided a method of manufacturing a semiconductor device. The method of manufacturing the semiconductor device comprises a process of forming a semiconductor layer that is mainly made of a group III nitride and has n-type characteristics, by crystal growth; a film formation process of forming a through film that is mainly made of an element different from an element serving as an n-type impurity relative to the group III nitride, by growth on the semiconductor layer continuous with crystal growth of the semiconductor layer; an ion implantation process of implanting a p-type impurity into the semiconductor layer across the through film by ion implantation; a heating process of heating the semiconductor layer and the through film after completion of the ion implantation process, so as to activate a region of the semiconductor layer in which the p-type impurity is ion-implanted, to a p-type semiconductor region; and a removal process of removing the through film from the semiconductor layer, after completion of the heating process. This configuration improves the surface morphology of the p-type semiconductor region formed by ion implantation.