Abstract: A silicon carbide substrate allowing reduction in cost for manufacturing a semiconductor device including a silicon carbide substrate includes a base substrate composed of silicon carbide and an SiC layer composed of single crystal silicon carbide different from the base substrate and arranged on the base substrate in contact therewith. Thus, the silicon carbide substrate 1 is a silicon carbide substrate capable of making effective use of silicon carbide single crystal.

Abstract: An IGBT, which is a vertical type IGBT allowing for reduced on-resistance while restraining defects from being produced, includes: a silicon carbide substrate, a drift layer, a well region, an n+ region, an emitter contact electrode, a gate oxide film, a gate electrode, and a collector electrode. The silicon carbide substrate includes: a base layer made of silicon carbide and having p type conductivity; and a SiC layer made of single-crystal silicon carbide and disposed on the base layer. The base layer has a p type impurity concentration exceeding 1×1018 cm?3.

Abstract: A MOSFET, which is a semiconductor device allowing for reduced on-resistance while restraining stacking faults from being produced due to heat treatment in a device manufacturing process, includes: a silicon carbide substrate; an active layer made of single-crystal silicon carbide and disposed on one main surface of the silicon carbide substrate; a source contact electrode disposed on the active layer; and a drain electrode formed on the other main surface of the silicon carbide substrate. The silicon carbide substrate includes: a base layer made of silicon carbide; and a SiC layer made of single-crystal silicon carbide and disposed on the base layer. Further, the base layer has an impurity concentration greater than 2×1019 cm?3, and the SiC layer has an impurity concentration greater than 5×1018 cm?3 and smaller than 2×1019 cm?3.

Abstract: A JFET, which is a semiconductor device allowing for reduced manufacturing cost, includes: a silicon carbide substrate; an active layer made of single-crystal silicon carbide and disposed on one main surface of the silicon carbide substrate; a source electrode disposed on the active layer; and a drain electrode formed on the active layer and separated from the source electrode. The silicon carbide substrate includes: a base layer made of single-crystal silicon carbide, and a SiC layer made of single-crystal silicon carbide and disposed on the base layer. The SiC layer has a defect density smaller than that of the base layer.

Abstract: The invention relates to a GaN-crystal free-standing substrate obtained from a GaN crystal grown by HVPE with a (0001) plane serving as a crystal growth plane and at least one plane of a {10-11} plane and a {11-22} plane serving as a crystal growth plane that constitutes a facet crystal region, except for the side surface of the crystal, wherein the (0001)-plane-growth crystal region has a carbon concentration of 5×1016 atoms/cm3 or less, a silicon concentration of 5×1017 atoms/cm3 or more and 2×1018 atoms/cm3 or less, and an oxygen concentration of 1×1017 atoms/cm3 or less; and the facet crystal region has a carbon concentration of 3×1016 atoms/cm3 or less, a silicon concentration of 5×1017 atoms/cm3 or less, and an oxygen concentration of 5×1017 atoms/cm3 or more and 5×1018 atoms/cm3 or less.

Abstract: The present invention is to provide a method for growing a group III nitride crystal that has a large size and has a small number of pits formed in the main surface of the crystal by using a plurality of tile substrates. A method for growing a group III nitride crystal includes a step of preparing a plurality of tile substrates 10 including main surfaces 10m having a shape of a triangle or a convex quadrangle that allows two-dimensional close packing of the plurality of tile substrates; a step of arranging the plurality of tile substrates 10 so as to be two-dimensionally closely packed such that, at any point across which vertexes of the plurality of tile substrates 10 oppose one another, 3 or less of the vertexes oppose one another; and a step of growing a group III nitride crystal 20 on the main surfaces 10m of the plurality of tile substrates arranged.

Abstract: A method for manufacturing a silicon carbide substrate includes the steps of: preparing a base substrate made of silicon carbide and a SiC substrate made of single-crystal silicon carbide; forming a Si film made of silicon on a main surface of the base substrate; fabricating a stacked substrate by placing the SiC substrate on and in contact with the Si film; and connecting the base substrate and the SiC substrate to each other by heating the stacked substrate to convert, into silicon carbide, at least a region making contact with the base substrate and a region making contact with the SiC substrate in the Si film.

Abstract: A method for manufacturing a silicon carbide substrate includes the steps of: preparing a base substrate made of silicon carbide and a SiC substrate made of single-crystal silicon carbide; and connecting the base substrate and SiC substrate to each other by forming an intermediate layer, which is made of carbon that is a conductor, between the base substrate and the SiC substrate.

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 method for forming an epitaxial wafer is provided as one enabling growth of a gallium nitride based semiconductor with good crystal quality on a gallium oxide region. In step S107, an AlN buffer layer 13 is grown. In step S108, at a time t5, a source gas G1 containing hydrogen, trimethylaluminum, and ammonia, in addition to nitrogen, is supplied into a growth reactor 10 to grow the AlN buffer layer 13 on a primary surface 11a. The AlN buffer layer 13 is so called a low-temperature buffer layer. After a start of film formation of the buffer layer 13, in step S109 supply of hydrogen (H2) is started at a time t6. At the time t6, H2, N2, TMA, and NH3 are supplied into the growth reactor 10. A supply amount of hydrogen is increased between times t6 and t7, and at the time t7 the increase of hydrogen is terminated to supply a constant amount of hydrogen. At the time t7, H2, TMA, and NH3 are supplied into the growth reactor 10.

Abstract: A gallium nitride based semiconductor device is provided which includes a gallium nitride based semiconductor film with a flat c-plane surface provided on a gallium oxide wafer. A light emitting diode LED includes a gallium oxide support base 32 having a primary surface 32a of monoclinic gallium oxide, and a laminate structure 33 of Group III nitride. A semiconductor mesa of the laminate structure 33 includes a low-temperature GaN buffer layer 35, an n-type GaN layer 37, an active layer 39 of a quantum well structure, and a p-type gallium nitride based semiconductor layer 37. The p-type gallium nitride based semiconductor layer 37 includes, for example, a p-type AlGaN electron block layer and a p-type GaN contact layer. The primary surface 32a of the gallium oxide support base 32 is inclined at an angle of not less than 2 degrees and not more than 4 degrees relative to a (100) plane of monoclinic gallium oxide.

Abstract: A silicon carbide substrate has a substrate region and a support portion. The substrate region has a first single crystal substrate. The support portion is joined to a first backside surface of the first single crystal. The dislocation density of the first single crystal substrate is lower than the dislocation density of the support portion. At least one of the substrate region and the support portion has voids.

Abstract: Affords III-nitride crystals having a major surface whose variance in crystallographic plane orientation with respect to an {hkil} plane chosen exclusive of the {0001} form is minimal. A method of manufacturing the III-nitride crystal is one of: conditioning a plurality of crystal plates (10) in which the deviation in crystallographic plane orientation in any given point on the major face (10m) of the crystal plates (10), with respect to an {hkil} plane chosen exclusive of the {0001} form, is not greater than 0.5?; arranging the plurality of crystal plates (10) in a manner such that the plane-orientation deviation, with respect to the {hkil} plane, in any given point on the major-face (10m) collective surface (10a) of the plurality of crystal plates (10) will be not greater than 0.

Abstract: A method of fabricating a gallium nitride-based semiconductor electronic device is provided, the method preventing a reduction in adhesiveness between a gallium nitride-based semiconductor layer and a conductive substrate. A substrate 11 is prepared. The substrate 11 has a first surface 11a and a second surface 11b, the first surface 11a allowing a gallium nitride-based semiconductor to be deposited thereon. The substrate 11 includes a support 13 of a material different from the gallium nitride-based semiconductor. The support is exposed on the second surface 11b of the substrate 11. An array of grooves 15 is provided in the second surface 11b. A semiconductor region including at least one gallium nitride-based semiconductor layer is deposited on the first surface 11a of the substrate 11, and thereby an epitaxial substrate E is fabricated.

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: A base portion is made of silicon carbide and has a main surface. At least one silicon carbide layer is provided on the main surface of the base portion in a manner exposing a region of the main surface along an outer edge of the main surface. At least one protection layer is provided on this region of the main surface of the base portion along the outer edge of the main surface. Thus, a silicon carbide substrate can be polished with high in-plane uniformity.

Abstract: A first silicon carbide substrate having a first back-side surface and a second silicon carbide substrate having a second back-side surface are prepared. The first and second silicon carbide substrates are placed so as to expose each of the first and second back-side surfaces in one direction. A connecting portion is formed to connect the first and second back-side surfaces to each other. The step of forming the connecting portion includes a step of forming a growth layer made of silicon carbide on each of the first and second back-side surfaces, using a sublimation method of supplying a sublimate thereto in the one direction.