A method of structuring and/or thinning a semiconductor wafer having a plurality of functional chip sites includes forming one or more semiconductor devices in a device region of each functional chip site at a frontside of the semiconductor wafer, and forming an electrode at one of the frontside or a backside of the semiconductor wafer. The side of the semiconductor wafer at which the electrode is formed is structured by applying voltage pulses between the electrode and a tool electrode positioned above the semiconductor wafer as part of an electrical discharge machining (EDM) process before the electrode is removed by the EDM process, and between the tool electrode and an intrinsic conductive layer formed on the side of the semiconductor wafer being structured after the electrode is removed by the EDM process.

A method includes providing a first layer of epitaxial silicon carbide supported by a silicon carbide substrate, providing a second layer of epitaxial silicon carbide on the first layer, forming a plurality of semiconductor devices in the second layer, and separating the substrate from the second layer at the first layer. The first layer includes a plurality of voids.

Provided are an insulated gate bipolar transistor and a preparation method therefor. An auxiliary groove gate, namely a structure of an auxiliary groove, an auxiliary gate layer and the corresponding gate oxide layer, is arranged below an emitting metal electrode between a first common groove and a second common groove so as to provide a carrier pathway when the insulated gate bipolar transistor is turned off, so that not only the turn-off speed of the insulated gate bipolar transistor is increased, but also the reverse-biased safety operation area characteristic of the insulated gate bipolar transistor is improved, thus improving the performance of the insulated gate bipolar transistor.

In a first main surface side of a silicon carbide semiconductor base, a trench is formed. A second base region of a second conductivity type is arranged at a position facing the trench in a depth direction. An end (toward a drain electrode) of the second base region of the second conductivity type, and an end (toward the drain electrode) of a first base region of the second conductivity type reach a position deeper than an end (toward the drain electrode) of a region of a first conductivity type. Thus, the electric field at a gate insulating film at the trench bottom is mitigated, suppressing the breakdown voltage of the active region and enabling breakdown voltage design of the edge termination region to be facilitated. Further, such a semiconductor device may be formed by an easy method of manufacturing.

A semiconductor device includes a trench structure extending from a first surface into a semiconductor body composed of silicon carbide. The trench structure includes an electrode and between the electrode and the first surface a gate electrode. A shielding region adjoining the electrode forms a first pn junction with a drift structure formed in the semiconductor body. A Schottky contact is formed between the drift structure and a first contact structure.

A method for patterning structures including providing a layer stack having a plurality of device layers and a hardmask layer disposed in a stacked arrangement, the layer stack having a plurality of trenches formed therein, the trenches extending through the hardmask layer and into at least one of the device layers, the trenches having lateral sidewalls with a first slope relative to a plane perpendicular to upper surfaces of the device layers, and performing a sputter etching process wherein ion beams are directed toward the hardmask layer to etch the hardmask layer and cause etched material from the hardmask layer to be redistributed along the lateral sidewalls of the trenches to provide the lateral sidewalls with a second slope relative to the plane perpendicular to the upper surfaces of the device layers, the second slope less than the first slope.

A trench silicon carbide metal-oxide semiconductor field effect transistor includes a silicon carbide semiconductor substrate and a trench metal-oxide semiconductor field effect transistor, the field effect transistor includes a trench vertically arranged and penetrating along a first horizontal direction, a gate insulating layer formed on an inner wall of the trench, a first poly gate formed on the gate insulating layer, a shield region formed outsides and below the trench, and a field plate arranged between a bottom wall of the trench and the shield region, and the field plate has semiconductor doping and is laterally in contact to a current spreading layer to deplete electrons of the current spreading layer when a reverse bias voltage is applied.

A plurality of trenches are formed so as to reach a prescribed depth from the surface of an n-type epitaxial layer. A refractory metal carbide film, such as a TaC film is formed via sputtering on the surface of sections (mesa regions) of the n-type epitaxial layer interposed between the adjacent trenches. Sections of the TaC film on the inner walls of the trenches are removed via etching. While the surface of the mesa regions is covered by the TaC film, the inside of the trenches is filled with a p-type epitaxial layer that is grown by CVD, thereby forming a parallel pn structure. Then, sections of the p-type epitaxial layer protruding above the surface of the parallel pn structure and the TaC film above the surface of the mesa regions are ground until top surfaces of n-type regions and p-type regions of the parallel pn structure are exposed.

To improve the performance of a semiconductor device, there is provided with a manufacturing method of a semiconductor device including a step of removing an oxide film formed on the surface of a silicon carbide substrate including the inner wall of a trench, before forming the hydrogen annealing.

A semiconductor device according to an embodiment includes a first electrode; a second electrode; a silicon carbide layer disposed between the first electrode and the second electrode; an n-type silicon carbide region disposed in the silicon carbide layer and having a first nitrogen concentration; a first p-type silicon carbide region disposed in the silicon carbide layer between the n-type silicon carbide region and the first electrode and having a second nitrogen concentration higher than the first nitrogen concentration; and a second p-type silicon carbide region disposed in the silicon carbide layer between the first p-type silicon carbide region and the first electrode, having a third nitrogen concentration higher than the second nitrogen concentration, and having a p-type impurity concentration higher than that of the first p-type silicon carbide region.