Ngk Insulators, Inc.

Osaka University

Toyoda Gosei Co., Ltd.

Takanao Shimodaira

Takayuki Hirao

Katsuhiro Imai

Makoto Iwai

Fumio Kawamura

Takatomo Sasaki

Yusuke Mori

Masahiro Sakai

Takashi Yoshino

Mikiya Ichimura

Hirokazu Nakanishi

Shiro Yamasaki

Shuhei Higashihara

Shiro Yamazaki

Yoshinori Isoda

Koji Hirata

Tetsuya Uchikawa

Yoshihiko Yamamura

Suguru Noguchi

Takashi Wada

Makota Iwai

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 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 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.

It is provided a layer of a nitride of a group 13 element having a first main face and second main face. The layer of the nitride of the group 13 element includes a first void-depleted layer provided on the side of the first main face, a second void-depleted layer provided on the side of the second main face, and the void-distributed layer provided between the first void-depleted layer and second void-depleted layer.

Group 13 nitride layer, composite substrate, and functional element

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 crystal growth apparatus includes a pressure-resistant vessel; a plurality of support tables arranged inside the pressure-resistant vessel; inner vessels each placed over the support tables, respectively; growth vessels contained the inner vessels, respectively; a heating means for heating the growth vessels; and a central rotating shaft connected to the support tables. The central rotating shaft is distant from central axes of the inner vessels, respectively. A seed crystal, a raw material of the Group 13 element and a flux are charged in each of the growth vessels, and the growth vessels are heated to form a melt and a nitrogen-containing gas is supplied to the melt to grow a crystal of a nitride of said Group 13 element while the central rotating shaft is rotated.

System and method for producing group 13 nitride crystals comprised of growth vessels stacked within inner vessels placed over support tables with a central rotating shaft and revolving shafts attached to the support tables

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

A composite substrate includes a sapphire substrate and a layer of a nitride of a group 13 element provided on the sapphire substrate. The layer of the nitride of the group 13 element is composed of gallium nitride, aluminum nitride or gallium aluminum nitride. The composite substrate satisfies the following formulas (1), (2) and (3). A laser light is irradiated to the composite substrate from the side of the sapphire substrate to decompose crystal lattice structure at an interface between the sapphire substrate and the layer of the nitride of the group 13 element. 5.0&#x2264;(an average thickness (&#x3bc;m) of the layer of the nitride of the group 13 element/a diameter (mm) of the sapphire substrate)&#x2264;10.0 . . . (1); 0.1&#x2264; a warpage (mm) of said composite substrate&#xd7;(50/a diameter (mm) of said composite substrate)&#x2264;0.6 . . . (2); 1.10&#x2264;a maximum value (&#x3bc;m) of a thickness of said layer of said nitride of said group 13 element/a minimum value (&#x3bc;m) of said thickness of said layer of said nitride of said group 13 element . . . (3)

Method for separating group 13 element nitride layer, and composite substrate

A group 13 nitride crystal substrate according to the present invention is produced by growing a group 13 nitride crystal on a seed-crystal substrate by a flux method, wherein a content of inclusions in the group 13 nitride crystal grown in a region of the seed-crystal substrate except for a circumferential portion of the seed-crystal substrate, the region having an area fraction of 70% relative to an entire area of the seed-crystal substrate, is 10% or less, preferably 2% or less.

Group 3B nitride crystal substrate

Regarding a base substrate, a plurality of steps are formed stepwise on the principal surface (c-face). Each step has a height difference of 10 to 40 &#x3bc;m, and an edge is formed parallel to an a-face of a hexagonal crystal of GaN. Meanwhile, the terrace width of each step is set at a predetermined width. The predetermined width is set in such a way that after a GaN crystal is grown on the principal surface of the base substrate, the principal surface is covered up with grain boundaries when the grown GaN crystal is observed from the surface side. The plurality of steps can be formed through, for example, dry etching, sand blasting, lasing, and dicing.

Group 13 nitride crystal with stepped surface

The apparatus has a crucible for storing a solution; an inner container for storing a crucible; a heating container for storing the inner container, the heating container including heating elements, a container body provided with the heating elements and a lid combined with the container body; and a pressure vessel for storing the heating container and for charging an atmosphere comprising at least nitrogen gas. The lid also has a fitting surface to the container body that is inclined to a horizontal plane.

Nitride single crystal manufacturing apparatus

A growth apparatus is used having a plurality of crucibles each for containing the solution, a heating element for heating the crucible, and a pressure vessel for containing at least the crucibles and the heating element and for filling an atmosphere comprising at least nitrogen gas. One seed crystal is put in each of the crucibles to grow the nitride single crystal on the seed crystal.

Process for producing a nitride single crystal and apparatus therefor

A gallium nitride layer is produced using a seed crystal substrate by flux method. The seed crystal substrateA includes a supporting body, a plurality of seed crystal layersA each comprising gallium nitride single crystal and separated from one another, a low temperature buffer layerprovided between the seed crystal layersA and the supporting body and made of a nitride of a group III metal element, and an exposed layerexposed to spaces between the adjacent seed crystal layersA and made of aluminum nitride single crystal or aluminum gallium nitride single crystal. The gallium nitride layer is grown on the seed crystal layers by flux method.

Method for producing gallium nitride layer and seed crystal substrate used in same

To grow a gallium nitride crystal, a seed-crystal substrate is first immersed in a melt mixture containing gallium and sodium. Then, a gallium nitride crystal is grown on the seed-crystal substrate under heating the melt mixture in a pressurized atmosphere containing nitrogen gas and not containing oxygen. At this time, the gallium nitride crystal is grown on the seed-crystal substrate under a first stirring condition of stirring the melt mixture, the first stirring condition being set for providing a rough growth surface, and the gallium nitride crystal is subsequently grown on the seed-crystal substrate under a second stirring condition of stirring the melt mixture, the second stirring condition being set for providing a smooth growth surface.

Growing community of inventors

Nagoya, Japan

Takanao Shimodaira