Abstract: A gallium arsenide single crystal substrate having a main surface, in which a ratio of the number of As atoms existing as diarenic trioxide to the number of As atoms existing as diarsenic pentoxide is greater than or equal to 2 when the main surface is measured by X-ray photoelectron spectroscopy, in which an X-ray having energy of 150 eV is used and a take-off angle of a photoelectron is set to 5°. Arithmetic average roughness (Ra) of the main surface is less than or equal to 0.3 nm.

Abstract: A gallium arsenide single crystal substrate having a main surface, in which a ratio of the number of As atoms existing as diarsenic trioxide to the number of As atoms existing as diarsenic pentoxide is greater than or equal to 2 when the main surface is measured by X-ray photoelectron spectroscopy, in which an X-ray having energy of 150 eV is used and a take-off angle of a photoelectron is set to 5°. Arithmetic average roughness (Ra) of the main surface is less than or equal to 0.3 nm.

Abstract: Provided are a group III nitride composite substrate having a low sheet resistance and produced with a high yield, and a method for manufacturing the same, as well as a method for manufacturing a group III nitride semiconductor device using the group III nitride composite substrate. 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 is joined to the support substrate in one of a direct manner and an indirect manner. 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 is 200 ?/sq or less.

Abstract: Provided are a group III nitride composite substrate having a low sheet resistance and produced with a high yield, and a method for manufacturing the same, as well as a method for manufacturing a group III nitride semiconductor device using the group III nitride composite substrate. 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 is joined to the support substrate in one of a direct manner and an indirect manner. 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 is 200 ?/sq or less.

Abstract: Provided are a group III nitride composite substrate having a low sheet resistance and produced with a high yield, and a method for manufacturing the same, as well as a method for manufacturing a group III nitride semiconductor device using the group III nitride composite substrate. 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 is joined to the support substrate in one of a direct manner and an indirect manner. 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 is 200 ?/sq or less.

Abstract: Provided are a group III nitride composite substrate having a low sheet resistance and produced with a high yield, and a method for manufacturing the same, as well as a method for manufacturing a group III nitride semiconductor device using the group III nitride composite substrate. 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 is joined to the support substrate in one of a direct manner and an indirect manner. 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 is 200 ?/sq or less.

Abstract: Provided are a group III nitride composite substrate having a low sheet resistance and produced with a high yield, and a method for manufacturing the same, as well as a method for manufacturing a group III nitride semiconductor device using the group III nitride composite substrate. 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 is joined to the support substrate in one of a direct manner and an indirect manner. 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 is 200 ?/sq 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 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 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: Provided are a group III nitride composite substrate having a low sheet resistance and produced with a high yield, and a method for manufacturing the same, as well as a method for manufacturing a group III nitride semiconductor device using the group III nitride composite substrate. 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 is joined to the support substrate in one of a direct manner and an indirect manner. 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 is 200 ?/sq or less.

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 semiconductor laser device includes: a substrate having a principal plane; a photonic crystal layer having an epitaxial layer of gallium nitride formed on substrate in a direction in which principal plane extends and a low refractive index material having a refractive index lower than that of epitaxial layer; an n-type clad layer formed on substrate; a p-type clad layer formed on substrate; an active layer that is interposed between n-type clad layer and p-type clad layer and emits light when a carrier is injected thereinto; and a GaN layer that covers a region directly on photonic crystal layer. Thus, the semiconductor laser device can be manufactured without fusion.

Abstract: Assuming that r (m) represents the radius of a GaN substrate, t1 (m) represents the thickness of the GaN substrate, h1 (m) represents a warp of the GaN substrate before formation of an epitaxialwafer, t2 (m) represents the thickness of an AlxGa(1-X)N layer, h2 (m) represents a warp of the epitaxialwafer, a1 represents the lattice constant of GaN and a2 represents the lattice constant of AlN, the value t1 found by the following expression is decided as the minimum thickness (t1) of the GaN substrate: (1.5×1011×t13+1.2×1011×t23)×{1/(1.5×1011×t1)+1/(1.2×1011×t2)}/{15.96×x×(1?a2/a1)}×(t1+t2)+(t1×t2)/{5.32×x×(1?a2/a1)}?(r2+h2)/2h=0 A GaN substrate having a thickness of at least this minimum thickness (t1) and less than 400 ?m is formed.

Abstract: A primary surface 23a of a supporting base 23 of a light-emitting diode 21a tilts by an off-angle of 10 degrees or more and less than 80 degrees from the c-plane. A semiconductor stack 25a includes an active layer having an emission peak in a wavelength range from 400 nm to 550 nm. The tilt angle “A” between the (0001) plane (the reference plane SR3 shown in FIG. 5) of the GaN supporting base and the (0001) plane of a buffer layer 33a is 0.05 degree or more and 2 degrees or less. The tilt angle “B” between the (0001) plane of the GaN supporting base (the reference plane SR4 shown in FIG. 5) and the (0001) plane of a well layer 37a is 0.05 degree or more and 2 degrees or less. The tilt angles “A” and “B” are formed in respective directions opposite to each other with reference to the c-plane of the GaN supporting base.

Abstract: A group III nitride semiconductor light-emitting device includes a GaN crystal substrate and at least one group III nitride semiconductor layer disposed on a main surface of the GaN crystal substrate. The substrate includes a matrix crystal region and a c-axis-inverted crystal region. An off angle ? is formed between the main surface and a {0001} plane, and an off-angle component of a first direction has an absolute value |?1| of 0.03° or more and 1.1° or less and an off-angle component of a second direction has an absolute value |?2 of 0.75×|?1| or less, where the first direction is one of <10-10> and <1-210> directions and the second direction is the other thereof. Accordingly, the group III nitride semiconductor light-emitting device with excellent characteristics including the group III nitride semiconductor layer having good morphology and uniform physical properties and formed on the GaN crystal substrate is obtained.

Abstract: A fabrication method of a surface-emitting laser element includes a step of preparing a conductive GaN multiple-region substrate including a high dislocation density high conductance region, a low dislocation density high conductance region and a low dislocation density low conductance region, as a conductive GaN substrate; a semiconductor layer stack formation step of forming a group III-V compound semiconductor layer stack including an emission layer on the substrate; and an electrode formation step of forming a semiconductor layer side electrode and a substrate side electrode. The semiconductor layer and electrodes are formed such that an emission region into which carriers flow in the emission layer is located above and within the span of the low dislocation density high conductance region. Thus, a surface-emitting laser element having uniform light emission at the emission region can be obtained with favorable yield.

Abstract: The present GaN substrate can have an absorption coefficient not lower than 7 cm?1 for light having a wavelength of 380 nm and light having a wavelength of 1500 nm, an absorption coefficient lower than 7 cm?1 for at least light having a wavelength not shorter than 500 nm and not longer than 780 nm, and specific resistance not higher than 0.02 ?cm. Here, the absorption coefficient for light having a wavelength not shorter than 500 nm and not longer than 780 nm can be lower than 7 cm?1. Thus, a GaN substrate having a low absorption coefficient for light having a wavelength within a light emission wavelength region of a light-emitting device and specific resistance not higher than a prescribed value and being suitable for the light-emitting device is provided.

Abstract: A compound semiconductor substrate 10 according to the present invention is comprised of a Group III nitride and has a surface layer 12 containing a chloride of not less than 200×1010 atoms/cm2 and not more than 12000×1010 atoms/cm2 in terms of Cl and an oxide of not less than 3.0 at % and not more than 15.0 at % in terms of O, at a surface. The inventors conducted elaborate research and newly discovered that when the surface layer 12 at the surface of the compound semiconductor substrate 10 contained the chloride of not less than 200×1010 atoms/cm2 and not more than 12000×1010 atoms/cm2 in terms of Cl and the oxide of not less than 3.0 at % and not more than 15.0 at % in terms of O, Si was reduced at an interface between the compound semiconductor substrate 10 and an epitaxial layer 14 formed thereon and, as a result, the electric resistance at the interface was reduced.

Abstract: A method for forming a quantum well structure that can reduce the variation in the In composition in the thickness direction of a well layer and a method for manufacturing a semiconductor light emitting element are provided. In a step of forming a quantum well structure (active layer) by alternately growing barrier layers and well layers on a primary surface of a GaN substrate, the well layers are each formed by growing InGaN, the barrier layers are each grown at a first temperature, the well layers are each grown at a second temperature which is lower than that of the first temperature, and when the well layers are each formed, before a starting material gas for Ga (trimethylgallium) is supplied, a starting material gas for In is supplied.