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 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: 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: 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 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 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 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 group III nitride composite substrate with a diameter of 75 mm or more includes a support substrate having a thickness ts of 0.1 mm or more and 1 mm or less and a group III nitride film having a thickness tf, thinner than the thickness ts, of 0.01 mm or more and 0.25 mm or less that are bonded to each other. An absolute value |??| of a difference ?? in thermal expansion coefficient determined by subtracting a thermal expansion coefficient ?s of the support substrate from a thermal expansion coefficient ?f of the group III nitride film is 2.2×10?6 K?1 or less. A Young's modulus Es and the thickness ts of the support substrate, a Young's modulus Ef and the thickness tf of the group III nitride film, and the difference ?? in thermal expansion coefficient satisfy a relation: ts2/tf?6Ef·|??|/Es.

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: In a semiconductor device 100, it is possible to prevent C from piling up at a boundary face between an epitaxial layer 22 and a group III nitride semiconductor substrate 10 by the presence of 30×1010 pieces/cm2 to 2000×1010 pieces/cm2 of sulfide in terms of S and 2 at % to 20 at % of oxide in terms of O in a surface layer 12. By thus preventing C from piling up, a high-resistivity layer is prevented from being formed on the boundary face between the epitaxial layer 22 and the group III nitride semiconductor substrate 10. Accordingly, it is possible to reduce electrical resistance at the boundary face between the epitaxial layer 22 and the group III nitride semiconductor substrate 10, and improve the crystal quality of the epitaxial layer 22. Consequently, it is possible to improve the emission intensity and yield of the semiconductor device 100.

Abstract: The present invention provides: an epitaxial film forming method capable of fabricating a +c-polarity epitaxial film made of a Group III nitride semiconductor by sputtering; and a vacuum processing apparatus suitable for this epitaxial film forming method. In one embodiment of the present invention, a Group III nitride semiconductor thin film is epitaxially grown by sputtering on an ?-Al2O3 substrate heated to a desired temperature by using a heater. First, the ?-Al2O3 substrate is disposed on a substrate holder including the heater in such a way that the ?-Al2O3 substrate is disposed away from the heater by a predetermined distance. Then, an epitaxial film of a Group III nitride semiconductor thin film is formed on the ?-Al2O3 substrate in the state where the ?-Al2O3 substrate is disposed away from the heater by the predetermined distance.

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 composite substrate with a diameter of 75 mm or more includes a support substrate and a group III nitride film with a thickness of 50 nm or more and less than 10 ?m that are bonded to each other. 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 0.01 or more and 0.5 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 is 0.005 or more and 0.6 or less.

Abstract: A group III nitride composite substrate with a diameter of 75 mm or more includes a support substrate having a thickness ts of 0.1 mm or more and 1 mm or less and a group III nitride film having a thickness tf, thinner than the thickness ts, of 0.01 mm or more and 0.25 mm or less that are bonded to each other. An absolute value |??| of a difference ?? in thermal expansion coefficient determined by subtracting a thermal expansion coefficient ?s of the support substrate from a thermal expansion coefficient ?f of the group III nitride film is 2.2×10?6 K?1 or less. A Young's modulus Es and the thickness ts of the support substrate, a Young's modulus Ef and the thickness tf of the group III nitride film, and the difference ?? in thermal expansion coefficient satisfy a relation: ts2/tf?6Ef·|??|/Es.

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: 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 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: 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 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: 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 %.