Sumitomo Electric Industries, Limited

Fumitake Nakanishi

Yusuke Yoshizumi

Keiji Ishibashi

Naoki Matsumoto

Seiji Nakahata

Koji Uematsu

Akihiro Hachigo

Masaki Ueno

Yohei Enya

Hidenori Mikami

Yuki Hiromura

Yoshiyuki Yamamoto

Takuya Yanagisawa

Yuki Seki

Hideki Matsubara

Yoshiki Miura

Shinsuke Fujiwara

Hiroki Mori

Makoto Kiyama

Takashi Misaki

Issei Satoh

Hirohisa Saito

Toshihiro Kotani

Susumu Yoshimoto

Shinji Matsukawa

Hirohisa Saitou

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.

Gallium arsenide single crystal substrate and method for producing gallium arsenide single crystal substrate

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 &#x3bc;m or more. A sheet resistance of a group III-nitride-film-side main surface is 200 &#x3a9;/sq or less.

Group III nitride composite substrate and method for manufacturing the same, and method for manufacturing group III nitride semiconductor device

A group III nitride composite substrate with a diameter of 75 mm or more includes a support substrate having a thickness tof 0.1 mm or more and 1 mm or less and a group III nitride film having a thickness t, thinner than the thickness t, of 0.01 mm or more and 0.25 mm or less that are bonded to each other. An absolute value |&#x394;&#x3b1;| of a difference &#x394;&#x3b1; in thermal expansion coefficient determined by subtracting a thermal expansion coefficient &#x3b1;of the support substrate from a thermal expansion coefficient &#x3b1;of the group III nitride film is 2.2&#xd7;10Kor less. A Young's modulus Eand the thickness tof the support substrate, a Young's modulus Eand the thickness tof the group III nitride film, and the difference &#x394;&#x3b1; in thermal expansion coefficient satisfy a relation: t/t&#x2267;6E&#xb7;|&#x394;&#x3b1;|/E.

Group III nitride composite substrate and method for manufacturing the same, laminated group III nitride composite substrate, and group III nitride semiconductor device and method for manufacturing the same

A group III nitride composite substrate includes a support substrate and a group III nitride film. A ratio s/mof a standard deviation sof the thickness of the group III nitride film, to a mean value mof the thickness thereof is 0.001 or more and 0.2 or less, and a ratio s/mof a standard deviation sof 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 mof 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.

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.

Semiconductor laser device and manufacturing method thereof

Assuming that r (m) represents the radius of a GaN substrate, t(m) represents the thickness of the GaN substrate, h(m) represents a warp of the GaN substrate before formation of an epitaxialwafer, t(m) represents the thickness of an AlGaN layer, h(m) represents a warp of the epitaxialwafer, arepresents the lattice constant of GaN and arepresents the lattice constant of AlN, the value tfound by the following expression is decided as the minimum thickness (t) of the GaN substrate:(1.5&#xd7;101+1.2&#xd7;102)&#xd7;{1/(1.5&#xd7;101)+1/(1.2&#xd7;102)}/{15.96&#xd7;&#xd7;(1&#x2212;2/1)}&#xd7;(1+2)+(1&#xd7;2)/{5.32&#xd7;&#xd7;(1&#x2212;2/1)}&#x2212;()/2=0A GaN substrate having a thickness of at least this minimum thickness (t) and less than 400 &#x3bc;m is formed.

Method of manufacturing GaN substrate, method of manufacturing epitaxialwafer, method of manufacturing semiconductor device and epitaxialwafer

A primary surfaceof a supporting baseof a light-emitting diodetilts by an off-angle of 10 degrees or more and less than 80 degrees from the c-plane. A semiconductor stackincludes 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 Sshown in FIG.) of the GaN supporting base and the (0001) plane of a buffer layeris 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 Sshown in FIG.) and the (0001) plane of a well layeris 0.05 degree or more and 2 degrees or less. The tilt angles &#x201c;A&#x201d; and &#x201c;B&#x201d; are formed in respective directions opposite to each other with reference to the c-plane of the GaN supporting base.

Group III nitride semiconductor element and epitaxial wafer

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.

Surface-emitting laser element, fabrication method thereof, surface-emitting laser array, and fabrication method thereof

The present GaN substrate can have an absorption coefficient not lower than 7 cmfor light having a wavelength of 380 nm and light having a wavelength of 1500 nm, an absorption coefficient lower than 7 cmfor 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 &#x3a9;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. 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.

GaN substrate and light-emitting device

A compound semiconductor substrateaccording to the present invention is comprised of a Group III nitride and has a surface layercontaining a chloride of not less than 200&#xd7;10atoms/cmand not more than 12000&#xd7;10atoms/cmin 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 layerat the surface of the compound semiconductor substratecontained the chloride of not less than 200&#xd7;10atoms/cmand not more than 12000&#xd7;10atoms/cmin 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 substrateand an epitaxial layerformed thereon and, as a result, the electric resistance at the interface was reduced.

Compound semiconductor substrate, semiconductor device, and processes for producing them

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.

Method for forming quantum well structure and method for manufacturing semiconductor light emitting element

Assuming that r (m) represents the radius of a GaN substrate, t(m) represents the thickness of the GaN substrate, h(m) represents a warp of the GaN substrate before formation of an epitaxialwafer, t(m) represents the thickness of an AlGaN layer, h(m) represents a warp of the epitaxialwafer, arepresents the lattice constant of GaN and arepresents the lattice constant of AlN, the value tfound by the following expression is decided as the minimum thickness (t) of the GaN substrate:(1.5&#xd7;10&#xd7;t+1.2&#xd7;10&#xd7;t)&#xd7;{1/(1.5&#xd7;10&#xd7;t)+1/(1.2&#xd7;10&#xd7;t)}/{15.96&#xd7;x&#xd7;(1&#x2212;aa)}&#xd7;(tt)+(tt)/{5.32&#xd7;x&#xd7;(1&#x2212;aa)}&#x2212;(r+h)/2h=0A GaN substrate having a thickness of at least this minimum thickness (t) and less than 400 &#x3bc;m is formed.

Growing community of inventors

Itami, Japan

Fumitake Nakanishi