Ngk Insulators, Inc.

Masahiro Sakai

Takashi Yoshino

Takanao Shimodaira

Takayuki Hirao

Katsuhiro Imai

Mikiya Ichimura

Hirokazu Nakanishi

Makoto Iwai

Mitsuhiro Tanaka

Shohei Oue

Takashi Egawa

Tomoyoshi Tai

Masashi Goto

Shuhei Higashihara

Makoto Miyoshi

Shoichiro Yamaguchi

Yoshitaka Kuraoka

Yukihisa Osugi

Hiroki Kobayashi

Yukihisa Ohsugi

Makota Iwai

Hiroyasu Ishikawa

There is provided a Group-III element nitride semiconductor substrate including a first surface and a second surface, in which even when devices to be produced on the first surface are increased in size, variations in device characteristics between the devices in the same substrate are suppressed. A Group-III element nitride semiconductor substrate includes a first surface and a second surface. The Group-III element nitride semiconductor substrate satisfies at least one of the following items (1) to (3): (1) The main surface has a maximum height Wz of a surface waviness profile of 150 nm or less; (2) The main surface has a root mean square height Wq of the surface waviness profile of 25 nm or less; (3) The main surface has an average length WSm of surface waviness profile elements of 0.5 mm or more.

Group-III element nitride semiconductor substrate

Group-III element nitride semiconductor substrate including a first surface and a second surface that are easy to visually distinguish from each other. An end portion is easily detected with an optical sensor, a large effective area (area that can be used in device production) can be secured, and warping of the entirety of the substrate is reduced. A Group-III element nitride semiconductor substrate includes a first surface; and a second surface, wherein the first surface is a mirror surface, the second surface has a second-surface central region and a second-surface outer peripheral region, the second-surface central region is a mirror surface, and the second-surface outer peripheral region is a non-mirror surface.

A layer of a crystal of a group 13 nitride selected from gallium nitride, aluminum nitride, indium nitride and the mixed crystals thereof has an upper surface and a bottom surface. The upper surface of a crystal layer of the group 13 nitride includes a linear high-luminance light-emitting part and a low-luminance light-emitting region adjacent to the high-luminance light-emitting part, observed by cathode luminescence. The high-luminance light-emitting part includes a portion extending along an m-plane of the crystal of the group 13 nitride. The crystal of the nitride of the group 13 element contains oxygen atoms in a content of 1&#xd7;10atom/cmor less, silicon atoms, manganese atoms, carbon atoms, magnesium atoms and calcium atoms in contents of 1&#xd7;10atom/cmor less, chromium atoms in a content of 1&#xd7;10atom/cmor less and chlorine atoms in a content of 1&#xd7;10atom/cmor less.

Group 13 element nitride layer, free-standing substrate and functional element

A layer of a crystal of a group 13 nitride selected from gallium nitride, aluminum nitride, indium nitride and the mixed crystals thereof has an upper surface and a bottom surface. The upper surface includes a linear high-luminance light-emitting part and a low-luminance light-emitting region adjacent to the high-luminance light-emitting part. The high-luminance light-emitting part includes a portion extending along an m-plane of the crystal of the group 13 nitride. A normal line to the upper surface has an off-angle of 2.0&#xb0; or less with respect to &#x3c;0001&#x3e; direction of the crystal of the nitride of the group 13 element.

A base substrate includes a supporting substrate comprising aluminum oxide, and a base crystal layer provided on a main face of the supporting substrate, comprising a crystal of a nitride of a group 13 element and having a crystal growth surface. At lease one of a metal of a group 13 element and a reaction product of a material of the supporting substrate and the crystal of the nitride of the group 13 element is present between the raised part and the supporting substrate. The reaction product contains at least aluminum and a group 13 element.

Base substrate, functional element, and method for manufacturing base substrate

A layer of a crystal of a nitride of a group 13 element selected from gallium nitride, aluminum nitride, indium nitride and the mixed crystals thereof includes an upper surface and a bottom surface. The upper surface includes a linear high-luminance light-emitting part and a low-luminance light-emitting region adjacent to the high-luminance light-emitting part, and the high-luminance light-emitting part has a portion extending along an m-plane of the crystal of the nitride of the group 13 element, when the upper surface is observed by cathode luminescence. The upper surface has an arithmetic average roughness Ra of 0.05 nm or more and 1.0 nm or less.

A base substrate includes a supporting substrate and a base crystal layer provided on a main face of the supporting substrate composed of a crystal of a groupnitride and having a crystal growth surface. The base crystal layer includes a raised part. A reaction product of a material of the supporting substrate and the crystal of the groupnitride, metal of a groupelement and/or void is present between the raised part and supporting substrate.

Base substrate, functional element, and production method for base substrate

A crystal of a group 13 nitride has an upper surface and lower surface and is composed of a crystal of a group 13 nitride selected from gallium nitride, aluminum nitride, indium nitride or the mixed crystals thereof. When the upper surface of the layer of the crystal of the group 13 nitride is observed by cathode luminescence, the upper surface includes a linear high-luminance light-emitting part and a low-luminance light-emitting region adjacent to the high-luminance light-emitting part. A half value width of reflection at the (0002) plane of a X-ray rocking curve on the upper surface is 3000 seconds or less and 20 seconds or more.

A layer of a crystal of a groupnitride selected from gallium nitride, aluminum nitride, indium nitride and the mixed crystals thereof has an upper surface and a bottom surface. The upper surface of the crystal layer of the groupnitride includes a linear high-luminance light-emitting part and a low-luminance light-emitting region adjacent to the high-luminance light-emitting part, observed by cathode luminescence. The high-luminance light-emitting part includes a portion extending along an m-plane of the crystal of the groupnitride.

A self-supporting substrate includes a first nitride layer grown by a hydride vapor deposition method or ammonothermal method and comprising a nitride of one or more elements selected from the group consisting of gallium, aluminum and indium; and a second nitride layer grown by a sodium flux method on the first nitride layer and comprising a nitride of one or more elements selected from the group consisting of gallium, aluminum and indium. The first nitride layer includes a plurality of single crystal grains arranged therein and extending between a pair of main faces of the first nitride layer. The second nitride layer includes a plurality of single crystal grains arranged therein and extending between a pair of main faces of the second nitride layer. The first nitride layer has a thickness larger than a thickness of the second nitride layer.

Free-standing substrate, function element and method for producing same

A seed crystal layer is provided on a supporting body. A laser light is irradiated from a side of the supporting body to provide an altered portion along an interface between the supporting body and seed crystal layer. The altered layer is composed of a nitride of a group 13 element and has a portion into which dislocation defects are introduced or an amorphous portion.

Methods of producing seed crystal substrates and group 13 element nitride crystals, and seed crystal substrates

It is used a crucible containing a flux and a source material, a reaction vessel containing the crucible, an intermediate vessel containing the reaction vessel, and a pressure vessel containing the intermediate vessel and used to fill a gas comprising at least a nitrogen atom. When the flux and the source material are melted by heating to grow the nitride crystal, a vapor of an organic compound is provided in a space outside of the reaction vessel and inside of the intermediate vessel.

Method for producing nitride crystal

The maximum value of peak intensities of cathode luminescence of a wavelength corresponding to a band gap of gallium nitride and in a measured visual field of 0.1 mm&#xd7;0.1 mm is 140 percent or higher of an average value of the peak intensities of the cathode luminescence, provided that the peak intensities of the cathode luminescence are measured on a surface of the gallium nitride substrate.

Gallium nitride substrates and functional devices

In the case that a functional layer, made of a nitride of a group 13 element, is formed on a composite substrate including a sapphire body and a gallium nitride crystal layer disposed over the sapphire body, the deviation of the function is prevented. The composite substrateincludes a sapphire bodyA and a gallium nitride crystal layerdisposed over the sapphire body. Aa warpage of the composite substrate is in a range of not less than +40 &#x3bc;m and not more than +80 &#x3bc;m per 5.08 cm in length.

Composite substrates and functional device

It is provided a method of producing a crystal of a nitride of a group 13 element in a melt by flux method. The melt is generated by heating a composition including a material for the group 13 element, a material for at least one of an alkali metal and an alkaline earth metal and a liquid material for germanium. Upon producing a crystal of a nitride of a group 13 element in a melt by flux method, it is thereby possible to reduce in-plane distribution of a property such as carrier density of the thus obtained crystal of a nitride of a group 13 element.

Growing community of inventors

Nagoya, Japan

Masahiro Sakai