Patent
US 8,795,431METHOD FOR PRODUCING GALLIUM NITRIDE LAYER AND SEED CRYSTAL SUBSTRATE USED IN SAME
Katsuhiro Imai
US
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US 8,795,431Patent drawings and their descriptions. Click a drawing to enlarge it.
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
A method of producing a gallium nitride layer using a seed crystal substrate by flux method, wherein said seed crystal substrate comprises a supporting body, a plurality of seed crystal layers each comprising gallium nitride single crystal and separated from one another, a low temperature buffer layer provided between said seed crystal layers and said supporting body and comprising a nitride of a group II I metal element, and an exposed layer exposed to spaces between said adjacent seed crystal layers and comprising aluminum nitride single crystal or aluminum gallium nitride single crystal, the method comprising the step of; growing said gallium nitride layer on said seed crystal layers by flux method.
The method of claim 1, further comprising an intermediate layer on said low temperature buffer layer, said intermediate layer comprising aluminum nitride single crystal or aluminum gallium nitride single crystal.
The method of claim 1, wherein said low temperature buffer layer comprises a plurality of separated parts, wherein spaces between said adjacent separated parts are communicated with said spaces between said seed crystal layers, respectively, and wherein said exposed layer is formed on a surface of said supporting body.
The method of claim 1, wherein said low temperature buffer layer comprises a plurality of separated parts, wherein spaces between said adjacent separated parts are communicated with said spaces between said seed crystal 27 FNGK₁₁₁₁PCT layers, respectively, and wherein said exposed layer is formed by surface nitridization treatment of said supporting body.
The method of claim 1, further comprising a layer of aluminum nitride single crystal or aluminum gallium nitride single crystal and provided between said low temperature buffer layer and said supporting body, wherein said low temperature buffer layer is separated into a plurality of separated parts, wherein spaces between said adjacent separated parts are communicated with said spaces between said seed crystal layers, respectively, and wherein said layer of aluminum nitride single crystal or aluminum gallium nitride single crystal is exposed to said spaces to provide said exposed layer.
A seed crystal substrate for growing a gallium nitride layer by flux method, said seed crystal substrate comprising: a supporting body; a plurality of seed crystal layers each comprising gallium nitride single crystal and separated from one another; a low temperature buffer layer provided between said seed crystal layers and said supporting body and comprising a nitride of a group III metal element; and an exposed layer exposed to spaces between said adjacent seed crystal layers and comprising aluminum nitride single crystal or aluminum gallium nitride single crystal.
8. The seed crystal substrate of claim 7, further comprising an intermediate layer on said low temperature buffer layer and comprising aluminum nitride single crystal or aluminum gallium nitride single crystal, said intermediate layer comprising said exposed layer.
The seed crystal substrate of claim 7, wherein said low temperature buffer layer comprises a plurality of separated parts, wherein spaces between said adjacent separated parts are communicated with said spaces between said seed crystal layers, respectively, and wherein said exposed layer is formed on a surface of said supporting body.
The seed crystal substrate of claim 7, wherein said low temperature buffer layer comprises a plurality of separated parts, wherein spaces between said adjacent separated parts are communicated with said spaces between said seed crystal layers, respectively, and wherein said exposed layer is formed by surface nitridization treatment of said supporting body.
The seed crystal substrate of claim 7, further comprising a layer of aluminum nitride single crystal or aluminum gallium nitride single crystal and provided between said low temperature buffer layer and said supporting body, wherein said low temperature buffer layer is separated into a plurality of separated parts, wherein spaces between said adjacent separated parts are communicated with said spaces between said seed crystal layers, respectively, and wherein said layer of aluminum nitride single crystal or aluminum gallium nitride single crystal is exposed to said spaces to provide said exposed layer. 29
Embodiments described in the patent, grouped by the materials and process steps they use.
6 materials4 process steps
Gallium nitride single crystal was grown on a c-face sapphire body (3-inch diameter). An AlN low temperature buffer layer, an AlN single crystal intermediate layer, and a GaN single crystal seed crystal layer were epitaxially grown by MOCVD. A SiO₂ stripe mask (width 0.05 mm, period 0.55 mm) was formed by photolithography in the central region (diameter 54 mm). The seed crystal layer was etched by ICP-RIE (Cl₂/BCl₃) until the intermediate layer was exposed, then the SiO₂ mask was removed. The resulting seed crystal substrate had GaN seed crystal layers (width 50 µm) with the AlN intermediate layer exposed in spaces between them. GaN single crystal was then grown by flux method (Ga metal 60 g, Na metal 60 g; 870°C, 4.0 MPa, 100 hours, with shaking/rotating agitation). The grown GaN crystal plate (thickness ~1.5 mm, region diameter 54 mm) was peeled off from the sapphire body over the whole surface without cracks. Dislocation density ≤10⁴/cm². Growth over whole surface rate: 100%; crack-free rate: 95%; collection yield: 95%.
4 materials4 process steps
Gallium nitride crystal plate produced using a c-face sapphire body (3-inch diameter). A GaN low temperature buffer layer, a GaN single crystal layer, an AlN single crystal intermediate layer, and a GaN single crystal seed crystal layer were epitaxially grown by MOCVD. The same patterning and flux growth procedure as Example 1 was then applied.
Layer stacks claimed or described, ordered top of device to substrate.
seed crystal substrate for GaN flux growth
Materials described outside the worked examples.
low temperature buffer layer nitride of group III metal element
supporting body
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
dislocation density | ≤1e4 /cm2 | GaN |
GaN crystal plate thickness | ~1.5 mm |
Related documents with shared materials, methods, properties, or citations.
Patent
Atlas literature
Patent
US 8,795,431Patent drawings and their descriptions. Click a drawing to enlarge it.
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
A method of producing a gallium nitride layer using a seed crystal substrate by flux method, wherein said seed crystal substrate comprises a supporting body, a plurality of seed crystal layers each comprising gallium nitride single crystal and separated from one another, a low temperature buffer layer provided between said seed crystal layers and said supporting body and comprising a nitride of a group II I metal element, and an exposed layer exposed to spaces between said adjacent seed crystal layers and comprising aluminum nitride single crystal or aluminum gallium nitride single crystal, the method comprising the step of; growing said gallium nitride layer on said seed crystal layers by flux method.
The method of claim 1, further comprising an intermediate layer on said low temperature buffer layer, said intermediate layer comprising aluminum nitride single crystal or aluminum gallium nitride single crystal.
The method of claim 1, wherein said low temperature buffer layer comprises a plurality of separated parts, wherein spaces between said adjacent separated parts are communicated with said spaces between said seed crystal layers, respectively, and wherein said exposed layer is formed on a surface of said supporting body.
The method of claim 1, wherein said low temperature buffer layer comprises a plurality of separated parts, wherein spaces between said adjacent separated parts are communicated with said spaces between said seed crystal 27 FNGK₁₁₁₁PCT layers, respectively, and wherein said exposed layer is formed by surface nitridization treatment of said supporting body.
The method of claim 1, further comprising a layer of aluminum nitride single crystal or aluminum gallium nitride single crystal and provided between said low temperature buffer layer and said supporting body, wherein said low temperature buffer layer is separated into a plurality of separated parts, wherein spaces between said adjacent separated parts are communicated with said spaces between said seed crystal layers, respectively, and wherein said layer of aluminum nitride single crystal or aluminum gallium nitride single crystal is exposed to said spaces to provide said exposed layer.
A seed crystal substrate for growing a gallium nitride layer by flux method, said seed crystal substrate comprising: a supporting body; a plurality of seed crystal layers each comprising gallium nitride single crystal and separated from one another; a low temperature buffer layer provided between said seed crystal layers and said supporting body and comprising a nitride of a group III metal element; and an exposed layer exposed to spaces between said adjacent seed crystal layers and comprising aluminum nitride single crystal or aluminum gallium nitride single crystal.
8. The seed crystal substrate of claim 7, further comprising an intermediate layer on said low temperature buffer layer and comprising aluminum nitride single crystal or aluminum gallium nitride single crystal, said intermediate layer comprising said exposed layer.
The seed crystal substrate of claim 7, wherein said low temperature buffer layer comprises a plurality of separated parts, wherein spaces between said adjacent separated parts are communicated with said spaces between said seed crystal layers, respectively, and wherein said exposed layer is formed on a surface of said supporting body.
The seed crystal substrate of claim 7, wherein said low temperature buffer layer comprises a plurality of separated parts, wherein spaces between said adjacent separated parts are communicated with said spaces between said seed crystal layers, respectively, and wherein said exposed layer is formed by surface nitridization treatment of said supporting body.
The seed crystal substrate of claim 7, further comprising a layer of aluminum nitride single crystal or aluminum gallium nitride single crystal and provided between said low temperature buffer layer and said supporting body, wherein said low temperature buffer layer is separated into a plurality of separated parts, wherein spaces between said adjacent separated parts are communicated with said spaces between said seed crystal layers, respectively, and wherein said layer of aluminum nitride single crystal or aluminum gallium nitride single crystal is exposed to said spaces to provide said exposed layer. 29
Embodiments described in the patent, grouped by the materials and process steps they use.
6 materials4 process steps
Gallium nitride single crystal was grown on a c-face sapphire body (3-inch diameter). An AlN low temperature buffer layer, an AlN single crystal intermediate layer, and a GaN single crystal seed crystal layer were epitaxially grown by MOCVD. A SiO₂ stripe mask (width 0.05 mm, period 0.55 mm) was formed by photolithography in the central region (diameter 54 mm). The seed crystal layer was etched by ICP-RIE (Cl₂/BCl₃) until the intermediate layer was exposed, then the SiO₂ mask was removed. The resulting seed crystal substrate had GaN seed crystal layers (width 50 µm) with the AlN intermediate layer exposed in spaces between them. GaN single crystal was then grown by flux method (Ga metal 60 g, Na metal 60 g; 870°C, 4.0 MPa, 100 hours, with shaking/rotating agitation). The grown GaN crystal plate (thickness ~1.5 mm, region diameter 54 mm) was peeled off from the sapphire body over the whole surface without cracks. Dislocation density ≤10⁴/cm². Growth over whole surface rate: 100%; crack-free rate: 95%; collection yield: 95%.
4 materials4 process steps
Gallium nitride crystal plate produced using a c-face sapphire body (3-inch diameter). A GaN low temperature buffer layer, a GaN single crystal layer, an AlN single crystal intermediate layer, and a GaN single crystal seed crystal layer were epitaxially grown by MOCVD. The same patterning and flux growth procedure as Example 1 was then applied.
Layer stacks claimed or described, ordered top of device to substrate.
seed crystal substrate for GaN flux growth
Materials described outside the worked examples.
low temperature buffer layer nitride of group III metal element
supporting body
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
dislocation density | ≤1e4 /cm2 | GaN |
GaN crystal plate thickness | ~1.5 mm |
Related documents with shared materials, methods, properties, or citations.
Patent
Atlas literature
Patent
US 8,795,431Patent drawings and their descriptions. Click a drawing to enlarge it.
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
A method of producing a gallium nitride layer using a seed crystal substrate by flux method, wherein said seed crystal substrate comprises a supporting body, a plurality of seed crystal layers each comprising gallium nitride single crystal and separated from one another, a low temperature buffer layer provided between said seed crystal layers and said supporting body and comprising a nitride of a group II I metal element, and an exposed layer exposed to spaces between said adjacent seed crystal layers and comprising aluminum nitride single crystal or aluminum gallium nitride single crystal, the method comprising the step of; growing said gallium nitride layer on said seed crystal layers by flux method.
The method of claim 1, further comprising an intermediate layer on said low temperature buffer layer, said intermediate layer comprising aluminum nitride single crystal or aluminum gallium nitride single crystal.
The method of claim 1, wherein said low temperature buffer layer comprises a plurality of separated parts, wherein spaces between said adjacent separated parts are communicated with said spaces between said seed crystal layers, respectively, and wherein said exposed layer is formed on a surface of said supporting body.
The method of claim 1, wherein said low temperature buffer layer comprises a plurality of separated parts, wherein spaces between said adjacent separated parts are communicated with said spaces between said seed crystal 27 FNGK₁₁₁₁PCT layers, respectively, and wherein said exposed layer is formed by surface nitridization treatment of said supporting body.
The method of claim 1, further comprising a layer of aluminum nitride single crystal or aluminum gallium nitride single crystal and provided between said low temperature buffer layer and said supporting body, wherein said low temperature buffer layer is separated into a plurality of separated parts, wherein spaces between said adjacent separated parts are communicated with said spaces between said seed crystal layers, respectively, and wherein said layer of aluminum nitride single crystal or aluminum gallium nitride single crystal is exposed to said spaces to provide said exposed layer.
A seed crystal substrate for growing a gallium nitride layer by flux method, said seed crystal substrate comprising: a supporting body; a plurality of seed crystal layers each comprising gallium nitride single crystal and separated from one another; a low temperature buffer layer provided between said seed crystal layers and said supporting body and comprising a nitride of a group III metal element; and an exposed layer exposed to spaces between said adjacent seed crystal layers and comprising aluminum nitride single crystal or aluminum gallium nitride single crystal.
8. The seed crystal substrate of claim 7, further comprising an intermediate layer on said low temperature buffer layer and comprising aluminum nitride single crystal or aluminum gallium nitride single crystal, said intermediate layer comprising said exposed layer.
The seed crystal substrate of claim 7, wherein said low temperature buffer layer comprises a plurality of separated parts, wherein spaces between said adjacent separated parts are communicated with said spaces between said seed crystal layers, respectively, and wherein said exposed layer is formed on a surface of said supporting body.
The seed crystal substrate of claim 7, wherein said low temperature buffer layer comprises a plurality of separated parts, wherein spaces between said adjacent separated parts are communicated with said spaces between said seed crystal layers, respectively, and wherein said exposed layer is formed by surface nitridization treatment of said supporting body.
The seed crystal substrate of claim 7, further comprising a layer of aluminum nitride single crystal or aluminum gallium nitride single crystal and provided between said low temperature buffer layer and said supporting body, wherein said low temperature buffer layer is separated into a plurality of separated parts, wherein spaces between said adjacent separated parts are communicated with said spaces between said seed crystal layers, respectively, and wherein said layer of aluminum nitride single crystal or aluminum gallium nitride single crystal is exposed to said spaces to provide said exposed layer. 29
Embodiments described in the patent, grouped by the materials and process steps they use.
6 materials4 process steps
Gallium nitride single crystal was grown on a c-face sapphire body (3-inch diameter). An AlN low temperature buffer layer, an AlN single crystal intermediate layer, and a GaN single crystal seed crystal layer were epitaxially grown by MOCVD. A SiO₂ stripe mask (width 0.05 mm, period 0.55 mm) was formed by photolithography in the central region (diameter 54 mm). The seed crystal layer was etched by ICP-RIE (Cl₂/BCl₃) until the intermediate layer was exposed, then the SiO₂ mask was removed. The resulting seed crystal substrate had GaN seed crystal layers (width 50 µm) with the AlN intermediate layer exposed in spaces between them. GaN single crystal was then grown by flux method (Ga metal 60 g, Na metal 60 g; 870°C, 4.0 MPa, 100 hours, with shaking/rotating agitation). The grown GaN crystal plate (thickness ~1.5 mm, region diameter 54 mm) was peeled off from the sapphire body over the whole surface without cracks. Dislocation density ≤10⁴/cm². Growth over whole surface rate: 100%; crack-free rate: 95%; collection yield: 95%.
4 materials4 process steps
Gallium nitride crystal plate produced using a c-face sapphire body (3-inch diameter). A GaN low temperature buffer layer, a GaN single crystal layer, an AlN single crystal intermediate layer, and a GaN single crystal seed crystal layer were epitaxially grown by MOCVD. The same patterning and flux growth procedure as Example 1 was then applied.
Layer stacks claimed or described, ordered top of device to substrate.
seed crystal substrate for GaN flux growth
Materials described outside the worked examples.
low temperature buffer layer nitride of group III metal element
supporting body
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
dislocation density | ≤1e4 /cm2 | GaN |
GaN crystal plate thickness | ~1.5 mm |
Related documents with shared materials, methods, properties, or citations.
Patent
Atlas literature
Patent
US 8,795,431Patent drawings and their descriptions. Click a drawing to enlarge it.
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
A method of producing a gallium nitride layer using a seed crystal substrate by flux method, wherein said seed crystal substrate comprises a supporting body, a plurality of seed crystal layers each comprising gallium nitride single crystal and separated from one another, a low temperature buffer layer provided between said seed crystal layers and said supporting body and comprising a nitride of a group II I metal element, and an exposed layer exposed to spaces between said adjacent seed crystal layers and comprising aluminum nitride single crystal or aluminum gallium nitride single crystal, the method comprising the step of; growing said gallium nitride layer on said seed crystal layers by flux method.
The method of claim 1, further comprising an intermediate layer on said low temperature buffer layer, said intermediate layer comprising aluminum nitride single crystal or aluminum gallium nitride single crystal.
The method of claim 1, wherein said low temperature buffer layer comprises a plurality of separated parts, wherein spaces between said adjacent separated parts are communicated with said spaces between said seed crystal layers, respectively, and wherein said exposed layer is formed on a surface of said supporting body.
The method of claim 1, wherein said low temperature buffer layer comprises a plurality of separated parts, wherein spaces between said adjacent separated parts are communicated with said spaces between said seed crystal 27 FNGK₁₁₁₁PCT layers, respectively, and wherein said exposed layer is formed by surface nitridization treatment of said supporting body.
The method of claim 1, further comprising a layer of aluminum nitride single crystal or aluminum gallium nitride single crystal and provided between said low temperature buffer layer and said supporting body, wherein said low temperature buffer layer is separated into a plurality of separated parts, wherein spaces between said adjacent separated parts are communicated with said spaces between said seed crystal layers, respectively, and wherein said layer of aluminum nitride single crystal or aluminum gallium nitride single crystal is exposed to said spaces to provide said exposed layer.
A seed crystal substrate for growing a gallium nitride layer by flux method, said seed crystal substrate comprising: a supporting body; a plurality of seed crystal layers each comprising gallium nitride single crystal and separated from one another; a low temperature buffer layer provided between said seed crystal layers and said supporting body and comprising a nitride of a group III metal element; and an exposed layer exposed to spaces between said adjacent seed crystal layers and comprising aluminum nitride single crystal or aluminum gallium nitride single crystal.
8. The seed crystal substrate of claim 7, further comprising an intermediate layer on said low temperature buffer layer and comprising aluminum nitride single crystal or aluminum gallium nitride single crystal, said intermediate layer comprising said exposed layer.
The seed crystal substrate of claim 7, wherein said low temperature buffer layer comprises a plurality of separated parts, wherein spaces between said adjacent separated parts are communicated with said spaces between said seed crystal layers, respectively, and wherein said exposed layer is formed on a surface of said supporting body.
The seed crystal substrate of claim 7, wherein said low temperature buffer layer comprises a plurality of separated parts, wherein spaces between said adjacent separated parts are communicated with said spaces between said seed crystal layers, respectively, and wherein said exposed layer is formed by surface nitridization treatment of said supporting body.
The seed crystal substrate of claim 7, further comprising a layer of aluminum nitride single crystal or aluminum gallium nitride single crystal and provided between said low temperature buffer layer and said supporting body, wherein said low temperature buffer layer is separated into a plurality of separated parts, wherein spaces between said adjacent separated parts are communicated with said spaces between said seed crystal layers, respectively, and wherein said layer of aluminum nitride single crystal or aluminum gallium nitride single crystal is exposed to said spaces to provide said exposed layer. 29
Embodiments described in the patent, grouped by the materials and process steps they use.
6 materials4 process steps
Gallium nitride single crystal was grown on a c-face sapphire body (3-inch diameter). An AlN low temperature buffer layer, an AlN single crystal intermediate layer, and a GaN single crystal seed crystal layer were epitaxially grown by MOCVD. A SiO₂ stripe mask (width 0.05 mm, period 0.55 mm) was formed by photolithography in the central region (diameter 54 mm). The seed crystal layer was etched by ICP-RIE (Cl₂/BCl₃) until the intermediate layer was exposed, then the SiO₂ mask was removed. The resulting seed crystal substrate had GaN seed crystal layers (width 50 µm) with the AlN intermediate layer exposed in spaces between them. GaN single crystal was then grown by flux method (Ga metal 60 g, Na metal 60 g; 870°C, 4.0 MPa, 100 hours, with shaking/rotating agitation). The grown GaN crystal plate (thickness ~1.5 mm, region diameter 54 mm) was peeled off from the sapphire body over the whole surface without cracks. Dislocation density ≤10⁴/cm². Growth over whole surface rate: 100%; crack-free rate: 95%; collection yield: 95%.
4 materials4 process steps
Gallium nitride crystal plate produced using a c-face sapphire body (3-inch diameter). A GaN low temperature buffer layer, a GaN single crystal layer, an AlN single crystal intermediate layer, and a GaN single crystal seed crystal layer were epitaxially grown by MOCVD. The same patterning and flux growth procedure as Example 1 was then applied.
Layer stacks claimed or described, ordered top of device to substrate.
seed crystal substrate for GaN flux growth
Materials described outside the worked examples.
low temperature buffer layer nitride of group III metal element
supporting body
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
dislocation density | ≤1e4 /cm2 | GaN |
GaN crystal plate thickness | ~1.5 mm |
Related documents with shared materials, methods, properties, or citations.
growth over whole surface rate | 100 % | GaN |
crack-free rate | 95 % | GaN |
collection yield of GaN crystal plate | 95 % | GaN |
growth over whole surface rate | 100 % | GaN |
crack-free rate | 95 % | GaN |
collection yield of GaN crystal plate | 95 % | GaN |
growth over whole surface rate | 100 % | GaN |
crack-free rate | 95 % | GaN |
collection yield of GaN crystal plate | 95 % | GaN |
growth over whole surface rate | 100 % | GaN |
crack-free rate | 95 % | GaN |
collection yield of GaN crystal plate | 95 % | GaN |