A silicon carbide substrate has a first main surface, and a second main surface opposite to the first main surface. A region including at least one main surface of the first and second main surfaces is made of single-crystal silicon carbide. In the one main surface, sulfur atoms are present at not less than 60×10.sup.10 atoms/cm.sup.2 and not more than 2000×10.sup.10 atoms/cm.sup.2, and carbon atoms as an impurity are present at not less than 3 at % and not more than 25 at %. Thereby, a silicon carbide substrate having a stable surface, a semiconductor device using the substrate, and methods for manufacturing them can be provided.

A silicon carbide semiconductor device includes trenches formed in a lattice shape on the surface of a silicon carbide substrate on which a semiconductor layer is formed, and gate electrodes formed inside of the trenches via a gate insulating film. The depth of the trenches is smaller in a portion where the trenches are crossingly formed than in a portion where the trenches are formed in parallel to each other. Consequently, the silicon carbide semiconductor device is obtained that increases a withstand voltage between the gate electrodes and corresponding drain electrodes on the semiconductor device rear surface to prevent dielectric breakdown and, at the same time, has a large area of the gate electrodes, high channel density per unit area, and low ON resistance.

A semiconductor device includes a base region of second conductivity type formed on a drift layer of first conductivity type, a source region of first conductivity type located in the base region, a trench passing through the base region and the source region and dividing cell regions in plan view, a protective diffusion layer of second conductivity type disposed on a bottom of the trench, a gate electrode embedded in the trench with a gate insulating film therebetween, a source electrode electrically connected to the source region, and a protective contact region disposed at each of positions of three or more cell regions and connecting the protective diffusion layer and the source electrode to each other. The protective contact regions are disposed such that a triangle whose vertices are centers of three protective contact regions located closest to one another is an acute triangle.

A stack for a semiconductor device and a method for making the stack are disclosed. The stack includes a plurality of sacrificial layers in which each sacrificial layer has a first lattice parameter; and at least one channel layer that has a second lattice parameter in which the first lattice parameter is less than or equal to the second lattice parameter, and each channel layer is disposed between and in contact with two sacrificial layers and includes a compressive strain or a neutral strain based on a difference between the first lattice parameter and the second lattice parameter.

A method of polishing a SiC substrate by supplying a polishing liquid and bringing a polishing pad into contact with the SiC substrate is provided. The polishing liquid contains a permanganate, inorganic salts having an oxidizing ability, and water. The method includes: a first polishing step of polishing the SiC substrate by use of a first polishing pad; and a second polishing step of polishing the SiC substrate by use of a second polishing pad softer than the first polishing pad after the first polishing step.

In one general aspect, an apparatus can include a wide bandgap wafer having a backside and a frontside. The apparatus can include a detection facilitating layer capped on the backside of the wide bandgap wafer, the detection facilitating layer having a thickness less than a thickness of the wide bandgap wafer.

A semiconductor device of an embodiment includes a SiC layer including a first trench, a second trench having first and second regions, an n-type first SiC region, a p-type second SiC region, an n-type third SiC region, a p-type fourth SiC region between the first trench and the first SiC region, and a p-type fifth SiC region between the second trench and the first SiC region and having a first portion and a second portion, a gate electrode in the first trench, a first electrode in the second trench, and a second electrode. A distance between the first trench and the first region is greater than a distance between the first trench and the second region, the first portion is separated from the fourth SiC region, the second portion contacts the fourth SiC region, the first region contacts the first portion, and the second region contacts the second portion.

A method of forming a semiconductor device includes forming a trench in a semiconductor body; at least partially filling the trench with a filling material; introducing dopants into a portion of the filling material; and applying a first thermal processing to the semiconductor body to spread the dopants in the filling material along a vertical direction of the filling material by a diffusion process. The vertical doping profile of the dopants within the doped filling material is shaped during the first thermal processing. Additionally, the dopants are substantially confined to within the trench and substantially do not diffuse from the doped filling material into the semiconductor body during the first thermal processing. A second thermal processing is applied to the semiconductor body after the first thermal processing to cause diffusion of the dopants from the doped filling material into the semiconductor body adjoining the trench.

Implementations of a method of forming a plurality of semiconductor devices on a semiconductor substrate may include: providing a semiconductor substrate having a first surface, a second surface, a size, and a thickness where the second surface opposes the first surface and the thickness is between the first surface and the second surface. The method may include processing the semiconductor substrate through a plurality of semiconductor device fabrication processes to form a plurality of semiconductor devices on the first surface. The thickness may be between 100 microns and 575 microns and the size may be 150 mm. The semiconductor substrate may not be coupled with a carrier or support.

A method, apparatus, and system for forming a semiconductor structure. A first oxide layer located on a set of group III nitride layers formed on a silicon carbide substrate is bonded to a second oxide layer located on a carrier substrate to form an oxide layer located between the carrier substrate and the set of group III nitride layers. The silicon carbide substrate has a doped layer. The silicon carbide substrate having the doped layer is etched using a photo-electrochemical etching process, wherein a doping level of the doped layer is such that the doped layer is removed and a silicon carbide layer in the silicon carbide substrate remains unetched. The semiconductor structure is formed using the silicon carbide layer and the set of group III nitride layers.