Abstract: A silicon carbide epitaxial substrate having a main surface (second main surface) includes: a base substrate; and a silicon carbide epitaxial layer formed on the base substrate and including the main surface (second main surface), the second main surface having a surface roughness of 0.6 nm or less, a ratio of standard deviation of a nitrogen concentration in the silicon carbide epitaxial layer at a surface layer including the main surface (second main surface) within a plane of the silicon carbide epitaxial substrate to an average value of the nitrogen concentration in the silicon carbide epitaxial layer at the surface layer within the plane of the silicon carbide epitaxial substrate being 15% or less.

Abstract: A semiconductor substrate has a main surface and formed of single crystal silicon carbide. The main surface includes a central area, which is an area other than the area within 5 mm from the outer circumference. When the central area is divided into square areas of 1 mm×1 mm, in any square area, density of dislocations of which Burgers vector is parallel to <0001> direction is at most 1×105 cm?2. Thus, a silicon carbide semiconductor substrate enabling improved yield of semiconductor devices can be provided.

Abstract: A semiconductor substrate has a main surface and formed of single crystal silicon carbide. The main surface includes a central area, which is an area other than the area within 5 mm from the outer circumference. When the central area is divided into square areas of 1 mm×1 mm, in any square area, density of dislocations of which Burgers vector is parallel to <0001> direction is at most 1×105 cm?2. Thus, a silicon carbide semiconductor substrate enabling improved yield of semiconductor devices can be provided.

Abstract: A silicon carbide crystal ingot having a surface greater than or equal to 4 inches, having an n-type dopant concentration greater than or equal to 1×1015 atoms/cm3 and less than or equal to 1×1020 atoms/cm3, a metal atom concentration greater than or equal to 1×1014 atoms/cm3 and less than or equal to 1×1018 atoms/cm3, and not exceeding the n-type dopant concentration, and a metal atom concentration gradient less than or equal to 1×1017 atoms/(cm3·mm), a silicon carbide single crystal wafer produced using the ingot, and a method for fabricating the silicon carbide crystal ingot.

Abstract: A single crystal silicon carbide substrate has a 4H-polytype crystal structure, has with nitrogen atoms doped as a conduction impurity with an atomic concentration of more than 1×1016/cm3, and has a main surface containing a circle having a diameter of 5 cm. The single crystal silicon carbide substrate includes only one of a facet region and a non-facet region. Thus, variation in nitrogen atom concentration in the single crystal silicon carbide substrate can be suppressed.

Abstract: A method for manufacturing a silicon carbide substrate includes the steps of: preparing a seed substrate made of silicon carbide; etching a main surface of the seed substrate prepared; obtaining an ingot by growing a silicon carbide single crystal film on a crystal growth surface formed by etching the main surface of the seed substrate; and obtaining a silicon carbide substrate by cutting the ingot. The step of etching the seed substrate includes: a first etching step of removing silicon atoms, which form the silicon carbide, from an etching region using chlorine gas, the etching region being a region including the main surface of the seed substrate; and a second etching step of removing carbon atoms, which form the silicon carbide, from the etching region from which the silicon atoms have been removed, using oxygen gas.

Abstract: A silicon carbide substrate has a first layer facing a semiconductor layer and a second layer stacked on the first layer. Dislocation density of the second layer is higher than dislocation density of the first layer. Thus, quantum efficiency and power efficiency of a light-emitting device can both be high.

Abstract: At least one single crystal substrate, each having a backside surface and made of silicon carbide, and a supporting portion having a main surface and made of silicon carbide, are prepared. In this preparing step, at least one of the backside surface and main surface is formed by machining. By this forming step, a surface layer having distortion in the crystal structure is formed on at least one of the backside surface and main surface. The surface layer is removed at least partially. Following this removing step, the backside surface and main surface are connected to each other.

Abstract: A silicon carbide substrate capable of stably forming a device of excellent performance, and a method of manufacturing the same are provided. A silicon carbide substrate is made of a single crystal of silicon carbide, and has a width of not less than 100 mm, a micropipe density of not more than 7 cm?2, a threading screw dislocation density of not more than 1×104 cm?2, a threading edge dislocation density of not more than 1×104 cm?2, a basal plane dislocation density of not more than 1×104 cm?2, a stacking fault density of not more than 0.1 cm?1, a conductive impurity concentration of not less than 1×1018 cm?2, a residual impurity concentration of not more than 1×1016 cm?2, and a secondary phase inclusion density of not more than 1 cm?3.

Abstract: Provided is a method for manufacturing a silicon carbide crystal, including the steps of: placing a seed substrate and a source material for the silicon carbide crystal within a growth container; and growing the silicon carbide crystal with a diameter of more than 4 inches on a surface of the seed substrate by a sublimation method, in the step of growing, a pressure within the growth container being changed from a predetermined pressure, at a predetermined change rate.

Abstract: A semiconductor device has a semiconductor layer and a substrate. The semiconductor layer constitutes at least a part of a current path, and is made of silicon carbide. The substrate has a first surface supporting the semiconductor layer, and a second surface opposite to the first surface. Further, the substrate is made of silicon carbide having a 4H type single-crystal structure. Further, the substrate has a physical property in which a ratio of a peak strength in a wavelength of around 500 nm to a peak strength in a wavelength of around 390 nm is 0.1 or smaller in photoluminescence measurement. In this way, the semiconductor device is obtained to have a low on-resistance.

Abstract: A single crystal silicon carbide substrate has a 4H-polytype crystal structure, has with nitrogen atoms doped as a conduction impurity with an atomic concentration of more than 1×1016/cm3, and has a main surface containing a circle having a diameter of 5 cm. The single crystal silicon carbide substrate includes only one of a facet region and a non-facet region. Thus, variation in nitrogen atom concentration in the single crystal silicon carbide substrate can be suppressed.

Abstract: A silicon carbide crystal ingot having a surface greater than or equal to 4 inches, having an n-type dopant concentration greater than or equal to 1×1015 atoms/cm3 and less than or equal to 1×1020 atoms/cm3, a metal atom concentration greater than or equal to 1×1014 atoms/cm3 and less than or equal to 1×1018 atoms/cm3, and not exceeding the n-type dopant concentration, and a metal atom concentration gradient less than or equal to 1×1017 atoms/(cm3·mm), a silicon carbide single crystal wafer produced using the ingot, and a method for fabricating the silicon carbide crystal ingot.

Abstract: A method of manufacturing a silicon carbide ingot having highly uniform characteristics includes a preparation step of preparing a base substrate made of single crystal silicon carbide and having an off angle of 0.1° or more and 10° or less in an off angle direction which is either a <11-20> direction or a <1-100> direction relative to a (0001) plane, and a film formation step of growing a silicon carbide layer on a surface of the base substrate. In the film formation step, a region having a (0001) facet 5 is formed on a surface of the grown silicon carbide layer at an end portion on an upstream side, the upstream side being a side where an angle of intersection between a <0001> direction axis of the base substrate and the surface of the base substrate in the off angle direction is an acute angle.

Abstract: Each of first and second material substrates made of single crystal silicon carbide has first and second back surfaces, first and second side surfaces, and first and second front surfaces. The first and second back surfaces are connected to a supporting portion. The first and second side surfaces face each other with a gap interposed therebetween, the gap having an opening between the first and second front surfaces. A closing portion for closing the gap over the opening is formed. A connecting portion for closing the opening is formed by depositing a sublimate from the first and second side surfaces onto the closing portion. The closing portion is removed. A silicon carbide single crystal is grown on the first and second front surfaces.

Abstract: A silicon carbide substrate includes: a base substrate having a diameter of 70 mm or greater; and a plurality of SiC substrates made of single-crystal silicon carbide and arranged side by side on the base substrate when viewed in a planar view. In other words, the plurality of SiC substrates are arranged side by side on and along the main surface of the base substrate. Further, each of the SiC substrates has a main surface opposite to the base substrate and having an off angle of 20° or smaller relative to a {0001} plane.

Abstract: A step of preparing a stack is performed to position each single-crystal substrate in a first single-crystal substrate group and a first base substrate face to face with each other, position each single-crystal substrate in a second single-crystal substrate group and a second base substrate face to face with each other, and stack the first single-crystal substrate group, the first base substrate, an insertion portion, the second single-crystal substrate group, and the second base substrate in one direction in this order. Next, the stack is heated so as to allow a temperature of the stack to reach a temperature at which silicon carbide can sublime and so as to form a temperature gradient in the stack with the temperature thereof getting increased in the above-described direction. In this way, silicon carbide substrates can be manufactured efficiently.

Abstract: A silicon carbide substrate, which achieves restrained warpage even when a different-type material layer made of a material other than silicon carbide, includes: a base layer made of silicon carbide; and a plurality of SiC layers arranged side by side on the base layer when viewed in a planar view and each made of single-crystal silicon carbide. A gap is formed between end surfaces of adjacent SiC layers.

Abstract: In a method of producing a SiC crystal by sublimation, the atmosphere gas for growing a SiC crystal contains He. The atmosphere gas may further contain N. The atmosphere gas may further contain at least one type of gas selected from the group consisting of Ne, Ar, Kr, Xe, and Rn. In the atmosphere gas, the partial pressure of He is preferably greater than or equal to 40%.

Abstract: A method for manufacturing a silicon carbide substrate achieves reduced manufacturing cost. The method includes the steps of: preparing a base substrate and a SiC substrate; fabricating a stacked substrate by stacking the base substrate and the SiC substrate; fabricating a connected substrate by heating the stacked substrate; transferring a void, formed at a connection interface, in a thickness direction of the connected substrate by heating the connected substrate to cause the base substrate to have a temperature higher than that of the SiC substrate; and removing the void by removing a region including a main surface of the base substrate opposite to the SiC substrate.