Ngk Insulators, Inc.

Takayuki Hirao

Katsuhiro Imai

Takanao Shimodaira

Takashi Yoshino

Mikiya Ichimura

Masahiro Sakai

Makoto Iwai

Hirokazu Nakanishi

Shuhei Higashihara

Tetsuya Uchikawa

Suguru Noguchi

Yoshitaka Kuraoka

Yoshinori Isoda

Makota Iwai

A group 13 nitride crystal layer is composed of a group 13 nitride crystal selected from gallium nitride, aluminum nitride, indium nitride or the mixed crystals thereof, and the group 13 nitride crystal layer includes an upper surface and bottom surface. The group 13 nitride crystal layer includes high-luminance layers and low-luminance layers being present alternately, and the low-luminance layers have thicknesses of 3 or larger and 10 or smaller provided that 1 is assigned to a thickness of the high-luminance layer, when a cross section of the group 13 nitride crystal layer cut in a direction perpendicular to the upper surface is observed by cathode luminescence.

Group 13 element nitride crystal layer, self-supporting 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 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.

An underlying substrate including a seed crystal layer of a group 13 nitride, wherein projections and recesses repeatedly appear in stripe shapes at a principal surface of the seed crystal layer, and the projections have a level difference of 0.3 to 40 &#x3bc;m and a width of 5 to 100 &#x3bc;m, and the recesses have a bottom thickness of 2 &#x3bc;m or more and a width of 50 to 500 &#x3bc;m.

Underlying substrate including a seed crystal layer of a group 13 nitride having stripe-shaped projections and recesses and an off-angle in a direction of an a-axis

A free-standing substrate of a polycrystalline nitride of a group 13 element contains a plurality of monocrystalline particles having a particular crystal orientation in approximately a normal direction. The polycrystalline nitride of the group 13 element is composed of gallium nitride, aluminum nitride, indium nitride or a mixed crystal thereof. The free-standing substrate has a top surface and bottom surface. The free-standing substrate contains at least one of zinc and calcium. A root mean square roughness Rms at the top surface is 3.0 nm or less.

Free-standing substrate comprising polycrystalline group 13 element nitride and light-emitting element using same

A free-standing substrate of a polycrystalline nitride of a group 13 element is composed of a plurality of monocrystalline particles having a particular crystal orientation in approximately a normal direction. The free-standing substrate has a top surface and a bottom surface. The polycrystalline nitride of the group 13 element is gallium nitride, aluminum nitride, indium nitride or a mixed crystal thereof and contains zinc at a concentration of 1&#xd7;10atoms/cmor more and 1&#xd7;10atoms/cmor less.

A group 13 element source, a flux comprising at least one of an alkali metal and an alkaline earth metal, and an additive being liquid at an ambient temperature are placed in a crystal growing vessel. The crystal growing vessel is heated and pressurized under a nitrogen atom-containing gas atmosphere to form a melt containing the group 13 element source, the flux and the additive. Evaporation of the additive is prevented until the flux is melted. The crystal of the nitride of the group 13 element is then grown in the melt.

Method and device for producing a group 13 element nitride crystal using a shielding object

It is produced a crystal of a nitride of a group 13 element in a melt including the group 13 element and a flux including at least an alkali metal under atmosphere comprising a nitrogen-containing gas. An amount of carbon is made 0.005 to 0.018 atomic percent, provided that 100 atomic percent is assigned to a total amount of said flux, said group 13 element and carbon in said melt.

Method for producing nitride of group-13 element, and melt composition

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 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.

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Nagoya, Japan

Takayuki Hirao