Patent
US 12,258,678 B2GALLIUM NITRIDE SINGLE CRYSTAL SUBSTRATE
Takashi Sato, Tetsuji Fujimoto, Toshio Kitamura, Masatomo Shibata
SUMITOMO CHEMICAL COMPANY, LIMITED, Tokyo (JP)·Mar. 25, 2025·US
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US 12,258,678 B2Patent drawings and their descriptions. Click a drawing to enlarge it.
FIG. 1 is a flowchart showing a method for manufacturing 65 a gallium nitride single crystal substrate according to an embodiment of the present invention. B₂
FIG. 2A is a schematic cross-sectional view showing a part of the method for manufacturing a gallium nitride single crystal substrate according to an …
FIG. 3A is a schematic cross-sectional view showing a part of the method for manufacturing a gallium nitride single crystal substrate according to an …
FIG. 4A is a schematic cross-sectional view showing a part of the method for manufacturing a gallium nitride single crystal substrate according to an …
FIG. 5 is a SEM image showing an example of etch pits formed on the main surface of the gallium nitride single crystal substrate according to an embodiment of …
FIG. 6A is a histogram of etch pit diameters according to example 1.
FIG. 7A is a histogram of etch pit diameters according to example 2.
FIG. 8A is a histogram of etch pit diameters according to a comparative example.
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
A gallium nitride single crystal substrate, which is a gallium nitride single crystal substrate that has a diameter of B₂ 50 mm or more and whose low index crystal plane closest to a main surface is a (0001) plane, wherein a density of etch pits when applying etching to the main surface with an alkaline etching solution is less than 1×106 cm⁻², and among peaks appearing in a histogram of diameters of the etch pits, when a diameter of a first peak appearing on a smallest diameter-side is a, a total number of the etch pits with a diameter exceeding 4a is 1/1000 or less of a number of etch pits forming the first peak.
The gallium nitride single crystal substrate according claim 1, wherein a total number of the etch pits with a diameter of 2a or more is 1/10 or less of a number of etch pits forming the first peak.
The gallium nitride single crystal substrate according to claim 1, wherein the number of etch pits forming the first peak is 50% or more of a total.
The gallium nitride single crystal substrate according to claim 1, wherein when a frequency of the first peak is A, a number of peaks with a frequency ofA/10 or more appearing in the histogram is two, including the first peak.
The gallium nitride single crystal substrate according to claim 1, having a second peak in a diameter range of more than a and less than 2a, wherein a number of etch pits forming the second peak is smaller than a number of etch pits forming the first peak.
The gallium nitride single crystal substrate according to claim 1, wherein a density and a histogram of the etch pits are measured from a region with an area of 1 mm2 or more. ∗ ∗ ∗ ∗ ∗
Layer stacks claimed or described, ordered top of device to substrate.
gallium nitride single crystal substrate
Materials described outside the worked examples.
gallium nitride single crystal
GaN
Ge-doped GaN first layer
GaN:Ge
Additional fabrication and treatment steps described in the patent.
Measurements and analyses referenced in the patent, with their drawing references.
FIG. 5 is a SEM image showing an example of etch pits formed on the main surface of the gallium nitride single crystal substrate according to an embodiment of …
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
etch pit density on (0001) main surface after alkaline etching | ≤ 1000000 cm⁻² | GaN |
Pressure | 15–30 Pa |
Patents and literature cited by this patent (applicant and examiner references).
Cited patents · 3
Related documents with shared materials, methods, properties, or citations.
Patent
Atlas literature
Patent
US 12,258,678 B2Patent drawings and their descriptions. Click a drawing to enlarge it.
FIG. 1 is a flowchart showing a method for manufacturing 65 a gallium nitride single crystal substrate according to an embodiment of the present invention. B₂
FIG. 2A is a schematic cross-sectional view showing a part of the method for manufacturing a gallium nitride single crystal substrate according to an …
FIG. 3A is a schematic cross-sectional view showing a part of the method for manufacturing a gallium nitride single crystal substrate according to an …
FIG. 4A is a schematic cross-sectional view showing a part of the method for manufacturing a gallium nitride single crystal substrate according to an …
FIG. 5 is a SEM image showing an example of etch pits formed on the main surface of the gallium nitride single crystal substrate according to an embodiment of …
FIG. 6A is a histogram of etch pit diameters according to example 1.
FIG. 7A is a histogram of etch pit diameters according to example 2.
FIG. 8A is a histogram of etch pit diameters according to a comparative example.
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
A gallium nitride single crystal substrate, which is a gallium nitride single crystal substrate that has a diameter of B₂ 50 mm or more and whose low index crystal plane closest to a main surface is a (0001) plane, wherein a density of etch pits when applying etching to the main surface with an alkaline etching solution is less than 1×106 cm⁻², and among peaks appearing in a histogram of diameters of the etch pits, when a diameter of a first peak appearing on a smallest diameter-side is a, a total number of the etch pits with a diameter exceeding 4a is 1/1000 or less of a number of etch pits forming the first peak.
The gallium nitride single crystal substrate according claim 1, wherein a total number of the etch pits with a diameter of 2a or more is 1/10 or less of a number of etch pits forming the first peak.
The gallium nitride single crystal substrate according to claim 1, wherein the number of etch pits forming the first peak is 50% or more of a total.
The gallium nitride single crystal substrate according to claim 1, wherein when a frequency of the first peak is A, a number of peaks with a frequency ofA/10 or more appearing in the histogram is two, including the first peak.
The gallium nitride single crystal substrate according to claim 1, having a second peak in a diameter range of more than a and less than 2a, wherein a number of etch pits forming the second peak is smaller than a number of etch pits forming the first peak.
The gallium nitride single crystal substrate according to claim 1, wherein a density and a histogram of the etch pits are measured from a region with an area of 1 mm2 or more. ∗ ∗ ∗ ∗ ∗
Layer stacks claimed or described, ordered top of device to substrate.
gallium nitride single crystal substrate
Materials described outside the worked examples.
gallium nitride single crystal
GaN
Ge-doped GaN first layer
GaN:Ge
Additional fabrication and treatment steps described in the patent.
Measurements and analyses referenced in the patent, with their drawing references.
FIG. 5 is a SEM image showing an example of etch pits formed on the main surface of the gallium nitride single crystal substrate according to an embodiment of …
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
etch pit density on (0001) main surface after alkaline etching | ≤ 1000000 cm⁻² | GaN |
Pressure | 15–30 Pa |
Patents and literature cited by this patent (applicant and examiner references).
Cited patents · 3
Related documents with shared materials, methods, properties, or citations.
Patent
Atlas literature
Patent
US 12,258,678 B2Patent drawings and their descriptions. Click a drawing to enlarge it.
FIG. 1 is a flowchart showing a method for manufacturing 65 a gallium nitride single crystal substrate according to an embodiment of the present invention. B₂
FIG. 2A is a schematic cross-sectional view showing a part of the method for manufacturing a gallium nitride single crystal substrate according to an …
FIG. 3A is a schematic cross-sectional view showing a part of the method for manufacturing a gallium nitride single crystal substrate according to an …
FIG. 4A is a schematic cross-sectional view showing a part of the method for manufacturing a gallium nitride single crystal substrate according to an …
FIG. 5 is a SEM image showing an example of etch pits formed on the main surface of the gallium nitride single crystal substrate according to an embodiment of …
FIG. 6A is a histogram of etch pit diameters according to example 1.
FIG. 7A is a histogram of etch pit diameters according to example 2.
FIG. 8A is a histogram of etch pit diameters according to a comparative example.
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
A gallium nitride single crystal substrate, which is a gallium nitride single crystal substrate that has a diameter of B₂ 50 mm or more and whose low index crystal plane closest to a main surface is a (0001) plane, wherein a density of etch pits when applying etching to the main surface with an alkaline etching solution is less than 1×106 cm⁻², and among peaks appearing in a histogram of diameters of the etch pits, when a diameter of a first peak appearing on a smallest diameter-side is a, a total number of the etch pits with a diameter exceeding 4a is 1/1000 or less of a number of etch pits forming the first peak.
The gallium nitride single crystal substrate according claim 1, wherein a total number of the etch pits with a diameter of 2a or more is 1/10 or less of a number of etch pits forming the first peak.
The gallium nitride single crystal substrate according to claim 1, wherein the number of etch pits forming the first peak is 50% or more of a total.
The gallium nitride single crystal substrate according to claim 1, wherein when a frequency of the first peak is A, a number of peaks with a frequency ofA/10 or more appearing in the histogram is two, including the first peak.
The gallium nitride single crystal substrate according to claim 1, having a second peak in a diameter range of more than a and less than 2a, wherein a number of etch pits forming the second peak is smaller than a number of etch pits forming the first peak.
The gallium nitride single crystal substrate according to claim 1, wherein a density and a histogram of the etch pits are measured from a region with an area of 1 mm2 or more. ∗ ∗ ∗ ∗ ∗
Layer stacks claimed or described, ordered top of device to substrate.
gallium nitride single crystal substrate
Materials described outside the worked examples.
gallium nitride single crystal
GaN
Ge-doped GaN first layer
GaN:Ge
Additional fabrication and treatment steps described in the patent.
Measurements and analyses referenced in the patent, with their drawing references.
FIG. 5 is a SEM image showing an example of etch pits formed on the main surface of the gallium nitride single crystal substrate according to an embodiment of …
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
etch pit density on (0001) main surface after alkaline etching | ≤ 1000000 cm⁻² | GaN |
Pressure | 15–30 Pa |
Patents and literature cited by this patent (applicant and examiner references).
Cited patents · 3
Related documents with shared materials, methods, properties, or citations.
Patent
Atlas literature
Patent
US 12,258,678 B2Patent drawings and their descriptions. Click a drawing to enlarge it.
FIG. 1 is a flowchart showing a method for manufacturing 65 a gallium nitride single crystal substrate according to an embodiment of the present invention. B₂
FIG. 2A is a schematic cross-sectional view showing a part of the method for manufacturing a gallium nitride single crystal substrate according to an …
FIG. 3A is a schematic cross-sectional view showing a part of the method for manufacturing a gallium nitride single crystal substrate according to an …
FIG. 4A is a schematic cross-sectional view showing a part of the method for manufacturing a gallium nitride single crystal substrate according to an …
FIG. 5 is a SEM image showing an example of etch pits formed on the main surface of the gallium nitride single crystal substrate according to an embodiment of …
FIG. 6A is a histogram of etch pit diameters according to example 1.
FIG. 7A is a histogram of etch pit diameters according to example 2.
FIG. 8A is a histogram of etch pit diameters according to a comparative example.
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
A gallium nitride single crystal substrate, which is a gallium nitride single crystal substrate that has a diameter of B₂ 50 mm or more and whose low index crystal plane closest to a main surface is a (0001) plane, wherein a density of etch pits when applying etching to the main surface with an alkaline etching solution is less than 1×106 cm⁻², and among peaks appearing in a histogram of diameters of the etch pits, when a diameter of a first peak appearing on a smallest diameter-side is a, a total number of the etch pits with a diameter exceeding 4a is 1/1000 or less of a number of etch pits forming the first peak.
The gallium nitride single crystal substrate according claim 1, wherein a total number of the etch pits with a diameter of 2a or more is 1/10 or less of a number of etch pits forming the first peak.
The gallium nitride single crystal substrate according to claim 1, wherein the number of etch pits forming the first peak is 50% or more of a total.
The gallium nitride single crystal substrate according to claim 1, wherein when a frequency of the first peak is A, a number of peaks with a frequency ofA/10 or more appearing in the histogram is two, including the first peak.
The gallium nitride single crystal substrate according to claim 1, having a second peak in a diameter range of more than a and less than 2a, wherein a number of etch pits forming the second peak is smaller than a number of etch pits forming the first peak.
The gallium nitride single crystal substrate according to claim 1, wherein a density and a histogram of the etch pits are measured from a region with an area of 1 mm2 or more. ∗ ∗ ∗ ∗ ∗
Layer stacks claimed or described, ordered top of device to substrate.
gallium nitride single crystal substrate
Materials described outside the worked examples.
gallium nitride single crystal
GaN
Ge-doped GaN first layer
GaN:Ge
Additional fabrication and treatment steps described in the patent.
Measurements and analyses referenced in the patent, with their drawing references.
FIG. 5 is a SEM image showing an example of etch pits formed on the main surface of the gallium nitride single crystal substrate according to an embodiment of …
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
etch pit density on (0001) main surface after alkaline etching | ≤ 1000000 cm⁻² | GaN |
Pressure | 15–30 Pa |
Patents and literature cited by this patent (applicant and examiner references).
Cited patents · 3
Related documents with shared materials, methods, properties, or citations.
tetrachlorogermane
GeCl₄
GaCl gas
GaCl
NH₃ gas
NH₃
| — |
Pressure | 90–105 kPa | — |
Pressure | 90–95 kPa | — |
Pressure | 0–1 Pa | — |
Pressure | 0.3–30 Pa | — |
Thickness | 0.5–30 mm | — |
Thickness | 3–30 mm | — |
Pressure | 0.3–40 Pa | — |
Pressure | 0.3–50 Pa | — |
Thickness | 44–300 µm | — |
Thickness | 10–44 mm | — |
Pressure | 1.5–15 kPa | — |
Thickness | ≤ 0.5 mm | — |
Thickness | ≤ 1 nm | — |
Thickness | ≥ 4 mm | — |
tetrachlorogermane
GeCl₄
GaCl gas
GaCl
NH₃ gas
NH₃
| — |
Pressure | 90–105 kPa | — |
Pressure | 90–95 kPa | — |
Pressure | 0–1 Pa | — |
Pressure | 0.3–30 Pa | — |
Thickness | 0.5–30 mm | — |
Thickness | 3–30 mm | — |
Pressure | 0.3–40 Pa | — |
Pressure | 0.3–50 Pa | — |
Thickness | 44–300 µm | — |
Thickness | 10–44 mm | — |
Pressure | 1.5–15 kPa | — |
Thickness | ≤ 0.5 mm | — |
Thickness | ≤ 1 nm | — |
Thickness | ≥ 4 mm | — |
tetrachlorogermane
GeCl₄
GaCl gas
GaCl
NH₃ gas
NH₃
| — |
Pressure | 90–105 kPa | — |
Pressure | 90–95 kPa | — |
Pressure | 0–1 Pa | — |
Pressure | 0.3–30 Pa | — |
Thickness | 0.5–30 mm | — |
Thickness | 3–30 mm | — |
Pressure | 0.3–40 Pa | — |
Pressure | 0.3–50 Pa | — |
Thickness | 44–300 µm | — |
Thickness | 10–44 mm | — |
Pressure | 1.5–15 kPa | — |
Thickness | ≤ 0.5 mm | — |
Thickness | ≤ 1 nm | — |
Thickness | ≥ 4 mm | — |
tetrachlorogermane
GeCl₄
GaCl gas
GaCl
NH₃ gas
NH₃
| — |
Pressure | 90–105 kPa | — |
Pressure | 90–95 kPa | — |
Pressure | 0–1 Pa | — |
Pressure | 0.3–30 Pa | — |
Thickness | 0.5–30 mm | — |
Thickness | 3–30 mm | — |
Pressure | 0.3–40 Pa | — |
Pressure | 0.3–50 Pa | — |
Thickness | 44–300 µm | — |
Thickness | 10–44 mm | — |
Pressure | 1.5–15 kPa | — |
Thickness | ≤ 0.5 mm | — |
Thickness | ≤ 1 nm | — |
Thickness | ≥ 4 mm | — |