Abstract: A group III nitride composite substrate includes a group III nitride film and a support substrate formed from a material different in chemical composition from the group III nitride film. The group III nitride film has a thickness of 10 ?m or more. A sheet resistance of a-group III-nitride-film-side main surface of the group III nitride composite substrate is 200 ?/sq or less. A method for manufacturing a group III nitride composite substrate includes the steps of bonding the group III nitride film and the support substrate to each other; and reducing the thickness of at least one of the group III nitride film and the support substrate bonded to each other. Accordingly, a group III nitride composite substrate of a low sheet resistance that is obtained with a high yield as well as a method for manufacturing the same are provided.

Abstract: A group III nitride crystal substrate is provided in which a uniform distortion at a surface layer of the crystal substrate represented by a value of |d1 ?d2 |/d2 obtained from a plane spacing d1 at the X-ray penetration depth of 0.3 ?m and a plane spacing d2 at the X-ray penetration depth of 5 ?m is equal to or lower than 1.9 ×10?3, and the main surface has a plane orientation inclined in the <10-10> direction at an angle equal to or greater than 10° and equal to or smaller than 80° with respect to one of (0001) and (000-1) planes of the crystal substrate. A group III nitride crystal substrate suitable for manufacturing a light emitting device with a blue shift of an emission suppressed, an epilayer-containing group III nitride crystal substrate, a semiconductor device and a method of manufacturing the same can thereby be provided.

Abstract: A Group III nitride crystal substrate is provided for growing an epitaxial layer in which the Group III nitride crystal substrate is used for growing an epitaxial layer on the Group III nitride crystal substrate. The Group III nitride crystal substrate has a surface roughness Ra of 0.5 nm or less and an affected layer in which crystal lattices are out of order and has a thickness of 50 nm or less. The Group III nitride crystal substrate either has a principal plane parallel to any plane of A-plane and M-plane in the wurtzite structure or has an off-angle formed by the principal plane of the Group III nitride crystal substrate and any plane of A-plane and M-plane in the wurtzite structure being 0.05° to 15°.

Abstract: A group III nitride composite substrate includes a support substrate and a group III nitride film. A ratio st/mt of a standard deviation st of the thickness of the group III nitride film, to a mean value mt of the thickness thereof is 0.001 or more and 0.2 or less, and a ratio so/mo of a standard deviation so of an absolute value of an off angle between a main surface of the group III nitride film and a plane of a predetermined plane orientation, to a mean value mo of the absolute value of the off angle thereof is 0.005 or more and 0.6 or less. Accordingly, there is provided a low-cost and large-diameter group III nitride composite substrate including a group III nitride film having a large thickness, a small thickness variation, and a high crystal quality.

Abstract: A silicon carbide single-crystal substrate includes a first surface, a second surface opposite to the first surface, and a peripheral edge portion sandwiched between the first surface and the second surface, A plurality of grinding traces are formed in a surface of the peripheral edge portion. A chamfer width as a distance from an outermost peripheral end portion of the peripheral edge portion to one of the plurality of grinding traces which is located on an innermost peripheral side of the peripheral edge portion in a direction parallel to the first surface is not less than 50 ?m and not more than 400 ?m. Thereby, a silicon carbide single-crystal substrate capable of suppressing occurrence of a crack, and a method for manufacturing the same can be provided.

Abstract: Silicon carbide single crystal is prepared. Using the silicon carbide single crystal as a material, a silicon carbide substrate having a first face and a second face located at a side opposite to the first face is formed. In the formation of the silicon carbide substrate, a first processed damage layer and a second processed damage layer are formed at the first face and second face, respectively. The first face is polished such that at least a portion of the first processed damage layer is removed and the surface roughness of the first face becomes less than or equal to 5 nm. At least a portion of the second processed damage layer is removed while maintaining the surface roughness of the second plane greater than or equal to 10 nm.

Abstract: A nitride crystal is characterized in that, in connection with plane spacing of arbitrary specific parallel crystal lattice planes of the nitride crystal obtained from X-ray diffraction measurement performed with variation of X-ray penetration depth from a surface of the crystal while X-ray diffraction conditions of the specific parallel crystal lattice planes are satisfied, a uniform distortion at a surface layer of the crystal represented by a value of |d1?d2|/d2 obtained from the plane spacing d1 at the X-ray penetration depth of 0.3 ?m and the plane spacing d2 at the X-ray penetration depth of 5 ?m is equal to or lower than 2.1×10?3.

Abstract: The present invention provides an epitaxial film forming method for epitaxially growing a high-quality group III nitride semiconductor thin film on an ?—Al2O3 substrate by a sputtering method. In the epitaxial film forming method according to an embodiment of the present invention, when an epitaxial film of a group III nitride semiconductor thin film is to be formed on the ?—Al2O3 substrate arranged on a substrate holder provided with a heater electrode and a bias electrode of a sputtering apparatus, in a state where the ?—Al2O3 substrate is maintained at a predetermined temperature by the heater electrode, high-frequency power is applied to a target electrode and high-frequency bias power is applied to a bias electrode and at that time, the powers are applied so that frequency interference between the high-frequency power and the high-frequency bias power does not occur.

Abstract: A silicon carbide single-crystal substrate includes a first surface, a second surface opposite to the first surface, and a peripheral edge portion sandwiched between the first surface and the second surface. A plurality of grinding traces are formed in a surface of the peripheral edge portion. A chamfer width as a distance from an outermost peripheral end portion of the peripheral edge portion to one of the plurality of grinding traces which is located on an innermost peripheral side of the peripheral edge portion in a direction parallel to the first surface is not less than 50 ?m and not more than 400 ?m. Thereby, a silicon carbide single-crystal substrate capable of suppressing occurrence of a crack, and a method for manufacturing the same can be provided.

Abstract: 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 60×1010 atoms/cm2 and not more than 2000×1010 atoms/cm2, 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.

Abstract: A group III nitride substrate in one embodiment has a surface layer. The surface layer contains 3 at. % to 25 at. % of carbon and 5×1010 atoms/cm2 to 200×1010 atoms/cm2 of a p-type metal element. The group III nitride substrate has a stable surface.

Abstract: A group III nitride substrate in one embodiment has a surface layer. The surface layer contains 3 at. % to 25 at. % of carbon and 5×1010 atoms/cm2 to 200×1010 atoms/cm2 of a p-type metal element. The group III nitride substrate has a stable surface.

Abstract: A silicon carbide substrate includes a base layer made of silicon carbide, silicon carbide layers made of single-crystal silicon carbide and arranged side by side on the base layer when viewed in plan view, and a filling portion made of silicon carbide and filling a gap formed between the adjacent silicon carbide layers. The filling portion has a surface roughness of not more than 50 ?m in RMS value.

Abstract: A substrate capable of achieving a lowered probability of defects produced in a step of forming an epitaxial film or a semiconductor element, a semiconductor device including the substrate, and a method of manufacturing a semiconductor device are provided. A substrate is a substrate having a front surface and a back surface, in which at least a part of the front surface is composed of single crystal silicon carbide, the substrate having an average value of surface roughness Ra at the front surface not greater than 0.5 nm, a standard deviation ? of that surface roughness Ra not greater than 0.2 nm, an average value of surface roughness Ra at the back surface not smaller than 0.3 nm and not greater than 10 nm, standard deviation ? of that surface roughness Ra not greater than 3 nm, and a diameter D of the front surface not smaller than 110 mm.

Abstract: Silicon carbide single crystal is prepared. Using the silicon carbide single crystal as a material, a silicon carbide substrate having a first face and a second face located at a side opposite to the first face is formed. In the formation of the silicon carbide substrate, a first processed damage layer and a second processed damage layer are formed at the first face and second face, respectively. The first face is polished such that at least a portion of the first processed damage layer is removed and the surface roughness of the first face becomes less than or equal to 5 nm. At least a portion of the second processed damage layer is removed while maintaining the surface roughness of the second plane greater than or equal to 10 nm.

Abstract: A silicon carbide substrate capable of reducing on-resistance and improving yield of semiconductor devices is made of single-crystal silicon carbide, and sulfur atoms are present in one main surface at a ratio of not less than 60×1010 atoms/cm2 and not more than 2000×1010 atoms/cm2, and oxygen atoms are present in the one main surface at a ratio of not less than 3 at % and not more than 30 at %.

Abstract: There is provided a method of processing a surface of a group III nitride crystal, that includes the steps of: polishing a surface of a group III nitride crystal with a polishing slurry containing abrasive grains; and thereafter polishing the surface of the group III nitride crystal with a polishing liquid at least once, and each step of polishing with the polishing liquid employs a basic polishing liquid or an acidic polishing liquid as the polishing liquid. The step of polishing with the basic or acidic polishing liquid allows removal of impurity such as abrasive grains remaining on the surface of the group III nitride crystal after it is polished with the slurry containing the abrasive grains.

Abstract: A first single crystal substrate has a first side surface and it is composed of silicon carbide. A second single crystal substrate has a second side surface opposed to the first side surface and it is composed of silicon carbide. A bonding portion connects the first and second side surfaces to each other between the first and second side surfaces. At least a part of the bonding portion is made of particles composed of silicon carbide and having a maximum length not greater than 1 ?m.

Abstract: A group III nitride crystal substrate is provided, wherein, a uniform distortion at a surface layer of the crystal substrate is equal to or lower than 1.7×10?3, and wherein a plane orientation of the main surface has an inclination angle equal to or greater than ?10° and equal to or smaller than 10° in a [0001] direction with respect to a plane including a c axis of the crystal substrate. A group III nitride crystal substrate suitable for manufacturing a light emitting device with a blue shift of an emission suppressed, an epilayer-containing group III nitride crystal substrate, a semiconductor device and a method of manufacturing the same can thereby be provided.

Abstract: A GaN substrate on which an epitaxially grown layer of good quality can be formed is obtained. A GaN substrate as a group III nitride substrate has a surface in which the number of chlorine atoms per square centimeter of the surface is not more than 2×1014, and the number of silicon atoms per square centimeter of the surface is not more than 3×1013, wherein a plane orientation of the surface is any of a (0001) plane, a (11-20) plane, a (10-12) plane, a (10-10) plane, a (20-21) plane, a (10-11) plane, a (11-21) plane, a (11-22) plane, and a (11-24) plane of a wurtzite structure.