Patent
US 12,060,653 B2BULK GAN CRYSTAL, C-PLANE GAN WAFER, AND METHOD FOR MANUFACTURING BULK GAN CRYSTAL
Yutaka Mikawa, Tetsuo Okano
MITSUBISHI CHEMICAL CORPORATION, Tokyo (JP)·Aug. 13, 2024·US
Copyright © 2026 Matter42. All rights reserved.
Patent
Atlas literature
Patent
US 12,060,653 B2Patent drawings and their descriptions. Click a drawing to enlarge it.
FIG. 1 illustrates one example of a bulk GaN crystal according to a preferred embodiment. Panel (a) of
FIG. 2 when XRD rocking curves are measured on the measurement line using the c-plane as a reflection surface and their peak angles w are plotted 55 against the …
FIG. 3 when XRD rocking curves are measured on the measurement line in the same manner and their peak 65 angles Go are plotted against the positions of the …
FIG. 4. Further, as required, the c-plane wafer 100 may be provided with various markings, such as an orientation flat or notch that 15 indicates the crystal …
FIG. 5, when the normal vector of the third main surface 101 is a vector N, the off-cut angle of the c-plane wafer 100 is an inclination 6 of the vector N from …
FIG. 6, the crystal growth apparatus includes an autoclave, and a capsule arranged therein. Inside the capsule, a dissolution zone and a growth zone, which are …
FIG. 7. The term “large-surface-area” used herein is not limited to a specific area; however, specifically, the bulk GaN crystal has a size in which two 80 …
FIG. 8.
FIG. 9. All of the plural through-holes penetrated through two wafers. That is, the through-holes formed in the portion where the wafers A and C overlapped …
FIG. 10 is a cross-sectional view that illustrates a type I through-hole pair in which one end and the other end of a Pt wire are passed through the respective …
FIG. 11, the wafer C whose outline is drawn with a dashed line is arranged on the 35 back side of the seed assembly and plays a role of a connecting plate that …
FIG. 12. The main surface had an area that could fit a circle of 7.5 cm in diameter (area=approximately 44 cm2) with a margin. 4.2. Evaluation of …
FIG. 13 are graphs showing the results of measuring the peak angles of (002) XRD rocking curves of a large-surface-area bulk GaN crystal at 5-mm intervals over …
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
A bulk GaN crystal, comprising a main surface selected from a surface inclined at 0° to 10° from the (0001) crystal plane and a surface inclined at 0° to 10° from the (000-1) crystal plane, wherein the main surface is a specific main surface A that satisfies the following conditions (i) and (ii): (i) a first line, which is a 80 mm-long virtual line segment extending in a first direction on the specific main surface A, can be drawn, and a difference between a maximum value and a minimum value of peak angles in (002) XRD rocking curves of the GaN crystal, which is measured between 17 measurement points arranged at a 5-mm pitch on the first line with the omega axis being perpendicular to the first direction, is 0.05° or less; and (ii) a second line, which is a 80 mm-long virtual line segment extending in a second direction perpendicular to the first direction on the specific main surface A, can be drawn, and a difference between a maximum value and a minimum value of peak angles in (002) XRD rocking curves of the GaN crystal, which is measured between 17 measurement points arranged at a 5-mm pitch on the second line with the omega axis being perpendicular to the second direction, is 0.05° or less.
The bulk GaN crystal according to claim 1, wherein the difference between the maximum value and the minimum value of the peak angles in the condition (i) and the difference between the maximum value and the minimum value of the peak angles in the condition (ii) are both 0.02° or less.
The bulk GaN crystal according to claim 1, wherein neither the 17 measurement points in the condition (i) nor the 17 measurement points in the condition (ii) includes a measurement point at which the peak angle is different by 0.01° or more from the peak angle at an adjacent measure-ment point.
The bulk GaN crystal according to claim 1, wherein the radius of curvature of the surface along the first direction, which is calculated from a rate of peak angle change in the condition (i), and the radius of curvature of the surface along the second direction, which is calculated from a rate of peak angle change in the condition (ii), are both 300 m or larger.
The bulk GaN crystal according to claim 1, having a dislocation density of lower than 1×106 cm⁻² in all of 100 µm×100 µm virtual regions that can be arbitrarily arranged on the specific main surface A, except for the portion having 35 a distance of less than 5 mm from the outer circumference in a plan view.
The bulk GaN crystal according to claim 1, having a dislocation density of lower than 1×105 cm⁻² in all of 2 mm×2 mm virtual regions that can be arbitrarily arranged on the specific main surface A, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view.
The bulk GaN crystal according to claim 1, satisfying one or more conditions selected from the following (a) to (g): (a) the H concentration is 1×1017 atoms/cm3 or higher; (b) the O concentration is 1×1017 atoms/cm3 or higher; (c) the concentration of at least one of Li, Na, and K is lower than 1×1015 atoms/cm3; (d) the F concentration is 1×1015 atoms/cm3 or higher; B₂ (e) the concentration of at least one of Cl, Br, and I is 1×1015 atoms/cm3 or higher; (f) the I concentration is 1×1015 atoms/cm3 or higher; and (g) the Si concentration is lower than 2×1015 atoms/cm3.
A method of producing a c-plane GaN wafer, the method comprising at least the steps of: preparing the bulk GaN crystal according to claim 1; and slicing the GaN crystal.
A bulk GaN crystal, comprising a first main surface and a second main surface that face the opposite direction from each other, wherein one of the first main surface and the second main surface is a surface inclined at 0° to 10° from the (0001) crystal plane while the other is a surface inclined at 0° to 10° from the (000-1) crystal plane, and the bulk GaN crystal satisfies the following conditions (i) and (ii): (i) a first line, which is a 80 mm-long virtual line segment extending in a first direction on the first main surface, can be drawn, and a difference between a maximum value and a minimum value of peak angles in (002) XRD rocking curves of the GaN crystal, which is measured between 17 measurement points arranged at a 5-mm pitch on the first line with the omega axis being perpendicular to the first direction, is 0.05° or less; and (ii) a second line, which is a 80 mm-long virtual line segment extending in a second direction perpendicular to the first direction on the first main surface, can be drawn, and a difference between a maximum value and a minimum value of peak angles in (002) XRD rocking curves of the GaN crystal, which is measured between 17 measurement points arranged at a 5-mm pitch on the second line with the omega axis being perpendicular to the second direction, is 0.050 or less.
The bulk GaN crystal according to claim 2, having a dislocation density of lower than 1×106 cm⁻² in all of 100 µm×100 µm virtual regions that can be arbitrarily arranged on the first main surface, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view, which dislocation density is calculated from the number of dislocations existing in each region and the area of the region.
The bulk GaN crystal according to claim 2, having a dislocation density of lower than 1×105 cm⁻² in all of 2 mm×2 mm virtual regions that can be arbitrarily arranged on the first main surface, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view, which dislocation density is calculated from the number of dislocations existing in each region and the area of the region.
A c-plane GaN wafer, comprising a main surface selected from a surface inclined at 0° to 10° from the (0001) crystal plane and a surface inclined at 0° to 10° from the (000-1) crystal plane, wherein the main surface is a specific main surface B that satisfies the following condition (111): (111) on the specific main surface B, a virtual line segment of 50 mm or longer can be drawn, and a variation range of an m-axis direction component of an off-cut angle and that of an a-axis direction component of the off-cut angle are both 0.05° or less, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view.
The c-plane GaN wafer according to claim 14, wherein the variation range of the m-axis direction compo-nent of the off-cut angle and that of the a-axis direction component of the off-cut angle are both 0.02° or less.
The c-plane GaN wafer according to claim 14, having a diameter selected from 50 mm to 55 mm, 75 mm to 80 mm, 100 mm to 105 mm, and 150 mm to 155 mm.
The c-plane GaN wafer according to claim 14, having a dislocation density of lower than 1×106 cm⁻² in all of 100 µm×100 µm virtual regions that can be arbitrarily arranged on the specific main surface B, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view.
The c-plane GaN wafer according to claim 14, having a dislocation density of lower than 1×105 cm⁻² in all of 2 mm×2 mm virtual regions that can be arbitrarily arranged on the specific main surface B, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view.
The c-plane GaN wafer according to claim 14, satis-fying one or more conditions selected from the following (a) to (g): (a) the H concentration is 1×1017 atoms/cm3 or higher; (b) the O concentration is 1×1017 atoms/cm3 or higher; (c) the concentration of at least one of Li, Na, and K is lower than 1×1015 atoms/cm3; (d) the F concentration is 1×1015 atoms/cm3 or higher; (e) the concentration of at least one of Cl, Br, and I is 1×1015 atoms/cm3 or higher; (f) the I concentration is 1×1015 atoms/cm3 or higher; and (g) the Si concentration is lower than 2×1015 atoms/cm3.
An epitaxial wafer, comprising: the c-plane GaN wafer according to claim 14; and at least one nitride semiconductor layer epitaxially grown on the c-plane GaN wafer.
A method of producing an epitaxial wafer, the method comprising the steps of: preparing the c-plane GaN wafer according to claim 14; and epitaxially growing at least one nitride semiconductor layer on the c-plane GaN wafer.
A method of producing a nitride semiconductor device, the method comprising the steps of: preparing the c-plane GaN wafer according to claim 14; and B₂ epitaxially growing at least one nitride semiconductor layer on the c-plane GaN wafer. 27.Amethod of producing a bulk GaN crystal, the method comprising the steps of: preparing the c-plane GaN wafer according to claim 14; and epitaxially growing a GaN crystal from a vapor phase on the c-plane GaN wafer. 28.Amethod of producing a bulk GaN crystal, the method comprising the step of growing a GaN crystal on a seed assembly by an ammonothermal method, wherein the seed assembly is constituted by plural c-plane GaN wafers, and a metal wire is used for immobilizing the plural c-plane GaN wafers with one another.
A c-plane GaN wafer, comprising a third main surface and a fourth main surface that face the opposite direction from each other, one of which third main surface and fourth main surface is a surface inclined at 0° to 10° from the (0001) crystal plane while the other is a surface inclined at 0° to 10° from the (000-1) crystal plane, wherein, on the third main surface, a virtual line segment of 50 mm or longer can be drawn, and a variation range of an m-axis direction component of an off-cut angle and that of an a-axis direction component of the off-cut angle are both 0.05° or less, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view.
The c-plane GaN wafer according to claim 15, having a dislocation density of lower than 1×106 cm⁻² in all of 100 µm×100 µm virtual regions that can be arbitrarily arranged on the third main surface, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view.
The c-plane GaN wafer according to claim 15, having a dislocation density of lower than 1×105 cm⁻² in 2 mm×2 mm virtual regions that can be arbitrarily arranged on the third main surface, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view.
The method of producing a bulk GaN crystal accord-ing to claim 28, wherein the orientations of the c-axes, a-axes, and m-axes of all of the c-plane GaN wafers con-stituting the seed assembly are aligned.
The method of producing a bulk GaN crystal accord-ing to claim 29, wherein, when the direction of N-polar side of main surfaces of the c-plane GaN wafers constituting the seed assembly is defined as front direction, two or more c-plane GaN wafers each having a rectangular or substan-tially rectangular main surface are arranged adjacent to each other on the front-direction side of the seed assembly, and a c-plane GaN wafer is arranged on the opposite side of the front direction of the seed assembly.
The method of producing a bulk GaN crystal accord-ing to claim 28, wherein, in the step of growing a GaN crystal by an ammonothermal method, a mineralizer con-taining a halogen-containing compound is used, and at least one metal wire selected from an Ag wire, a Pt wire and an Au wire is used as the metal wire. ∗ ∗ ∗ ∗ ∗
Layer stacks claimed or described, ordered top of device to substrate.
c-plane GaN wafer
epitaxial wafer
Materials described outside the worked examples.
bulk GaN crystal
GaN
nitride semiconductor layer
Additional fabrication and treatment steps described in the patent.
Measurements and analyses referenced in the patent, with their drawing references.
FIG. 2 when XRD rocking curves are measured on the measurement line using the c-plane as a reflection surface and their peak angles w are plotted 55 against the …
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
(002) XRD rocking curve peak angle variation along first direction | ≤ 0.05 deg | GaN |
(002) XRD rocking curve peak angle variation along second direction | ≤ 0.05 deg |
Patents and literature cited by this patent (applicant and examiner references).
Cited patents · 15
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n-TYPE GaN CRYSTAL, GaN WAFER, AND GaN CRYSTAL, GaN WAFER AND NITRIDE SEMICONDUCTOR DEVICE PRODUCTION METHOD
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US 12,060,653 B2Patent drawings and their descriptions. Click a drawing to enlarge it.
FIG. 1 illustrates one example of a bulk GaN crystal according to a preferred embodiment. Panel (a) of
FIG. 2 when XRD rocking curves are measured on the measurement line using the c-plane as a reflection surface and their peak angles w are plotted 55 against the …
FIG. 3 when XRD rocking curves are measured on the measurement line in the same manner and their peak 65 angles Go are plotted against the positions of the …
FIG. 4. Further, as required, the c-plane wafer 100 may be provided with various markings, such as an orientation flat or notch that 15 indicates the crystal …
FIG. 5, when the normal vector of the third main surface 101 is a vector N, the off-cut angle of the c-plane wafer 100 is an inclination 6 of the vector N from …
FIG. 6, the crystal growth apparatus includes an autoclave, and a capsule arranged therein. Inside the capsule, a dissolution zone and a growth zone, which are …
FIG. 7. The term “large-surface-area” used herein is not limited to a specific area; however, specifically, the bulk GaN crystal has a size in which two 80 …
FIG. 8.
FIG. 9. All of the plural through-holes penetrated through two wafers. That is, the through-holes formed in the portion where the wafers A and C overlapped …
FIG. 10 is a cross-sectional view that illustrates a type I through-hole pair in which one end and the other end of a Pt wire are passed through the respective …
FIG. 11, the wafer C whose outline is drawn with a dashed line is arranged on the 35 back side of the seed assembly and plays a role of a connecting plate that …
FIG. 12. The main surface had an area that could fit a circle of 7.5 cm in diameter (area=approximately 44 cm2) with a margin. 4.2. Evaluation of …
FIG. 13 are graphs showing the results of measuring the peak angles of (002) XRD rocking curves of a large-surface-area bulk GaN crystal at 5-mm intervals over …
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
A bulk GaN crystal, comprising a main surface selected from a surface inclined at 0° to 10° from the (0001) crystal plane and a surface inclined at 0° to 10° from the (000-1) crystal plane, wherein the main surface is a specific main surface A that satisfies the following conditions (i) and (ii): (i) a first line, which is a 80 mm-long virtual line segment extending in a first direction on the specific main surface A, can be drawn, and a difference between a maximum value and a minimum value of peak angles in (002) XRD rocking curves of the GaN crystal, which is measured between 17 measurement points arranged at a 5-mm pitch on the first line with the omega axis being perpendicular to the first direction, is 0.05° or less; and (ii) a second line, which is a 80 mm-long virtual line segment extending in a second direction perpendicular to the first direction on the specific main surface A, can be drawn, and a difference between a maximum value and a minimum value of peak angles in (002) XRD rocking curves of the GaN crystal, which is measured between 17 measurement points arranged at a 5-mm pitch on the second line with the omega axis being perpendicular to the second direction, is 0.05° or less.
The bulk GaN crystal according to claim 1, wherein the difference between the maximum value and the minimum value of the peak angles in the condition (i) and the difference between the maximum value and the minimum value of the peak angles in the condition (ii) are both 0.02° or less.
The bulk GaN crystal according to claim 1, wherein neither the 17 measurement points in the condition (i) nor the 17 measurement points in the condition (ii) includes a measurement point at which the peak angle is different by 0.01° or more from the peak angle at an adjacent measure-ment point.
The bulk GaN crystal according to claim 1, wherein the radius of curvature of the surface along the first direction, which is calculated from a rate of peak angle change in the condition (i), and the radius of curvature of the surface along the second direction, which is calculated from a rate of peak angle change in the condition (ii), are both 300 m or larger.
The bulk GaN crystal according to claim 1, having a dislocation density of lower than 1×106 cm⁻² in all of 100 µm×100 µm virtual regions that can be arbitrarily arranged on the specific main surface A, except for the portion having 35 a distance of less than 5 mm from the outer circumference in a plan view.
The bulk GaN crystal according to claim 1, having a dislocation density of lower than 1×105 cm⁻² in all of 2 mm×2 mm virtual regions that can be arbitrarily arranged on the specific main surface A, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view.
The bulk GaN crystal according to claim 1, satisfying one or more conditions selected from the following (a) to (g): (a) the H concentration is 1×1017 atoms/cm3 or higher; (b) the O concentration is 1×1017 atoms/cm3 or higher; (c) the concentration of at least one of Li, Na, and K is lower than 1×1015 atoms/cm3; (d) the F concentration is 1×1015 atoms/cm3 or higher; B₂ (e) the concentration of at least one of Cl, Br, and I is 1×1015 atoms/cm3 or higher; (f) the I concentration is 1×1015 atoms/cm3 or higher; and (g) the Si concentration is lower than 2×1015 atoms/cm3.
A method of producing a c-plane GaN wafer, the method comprising at least the steps of: preparing the bulk GaN crystal according to claim 1; and slicing the GaN crystal.
A bulk GaN crystal, comprising a first main surface and a second main surface that face the opposite direction from each other, wherein one of the first main surface and the second main surface is a surface inclined at 0° to 10° from the (0001) crystal plane while the other is a surface inclined at 0° to 10° from the (000-1) crystal plane, and the bulk GaN crystal satisfies the following conditions (i) and (ii): (i) a first line, which is a 80 mm-long virtual line segment extending in a first direction on the first main surface, can be drawn, and a difference between a maximum value and a minimum value of peak angles in (002) XRD rocking curves of the GaN crystal, which is measured between 17 measurement points arranged at a 5-mm pitch on the first line with the omega axis being perpendicular to the first direction, is 0.05° or less; and (ii) a second line, which is a 80 mm-long virtual line segment extending in a second direction perpendicular to the first direction on the first main surface, can be drawn, and a difference between a maximum value and a minimum value of peak angles in (002) XRD rocking curves of the GaN crystal, which is measured between 17 measurement points arranged at a 5-mm pitch on the second line with the omega axis being perpendicular to the second direction, is 0.050 or less.
The bulk GaN crystal according to claim 2, having a dislocation density of lower than 1×106 cm⁻² in all of 100 µm×100 µm virtual regions that can be arbitrarily arranged on the first main surface, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view, which dislocation density is calculated from the number of dislocations existing in each region and the area of the region.
The bulk GaN crystal according to claim 2, having a dislocation density of lower than 1×105 cm⁻² in all of 2 mm×2 mm virtual regions that can be arbitrarily arranged on the first main surface, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view, which dislocation density is calculated from the number of dislocations existing in each region and the area of the region.
A c-plane GaN wafer, comprising a main surface selected from a surface inclined at 0° to 10° from the (0001) crystal plane and a surface inclined at 0° to 10° from the (000-1) crystal plane, wherein the main surface is a specific main surface B that satisfies the following condition (111): (111) on the specific main surface B, a virtual line segment of 50 mm or longer can be drawn, and a variation range of an m-axis direction component of an off-cut angle and that of an a-axis direction component of the off-cut angle are both 0.05° or less, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view.
The c-plane GaN wafer according to claim 14, wherein the variation range of the m-axis direction compo-nent of the off-cut angle and that of the a-axis direction component of the off-cut angle are both 0.02° or less.
The c-plane GaN wafer according to claim 14, having a diameter selected from 50 mm to 55 mm, 75 mm to 80 mm, 100 mm to 105 mm, and 150 mm to 155 mm.
The c-plane GaN wafer according to claim 14, having a dislocation density of lower than 1×106 cm⁻² in all of 100 µm×100 µm virtual regions that can be arbitrarily arranged on the specific main surface B, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view.
The c-plane GaN wafer according to claim 14, having a dislocation density of lower than 1×105 cm⁻² in all of 2 mm×2 mm virtual regions that can be arbitrarily arranged on the specific main surface B, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view.
The c-plane GaN wafer according to claim 14, satis-fying one or more conditions selected from the following (a) to (g): (a) the H concentration is 1×1017 atoms/cm3 or higher; (b) the O concentration is 1×1017 atoms/cm3 or higher; (c) the concentration of at least one of Li, Na, and K is lower than 1×1015 atoms/cm3; (d) the F concentration is 1×1015 atoms/cm3 or higher; (e) the concentration of at least one of Cl, Br, and I is 1×1015 atoms/cm3 or higher; (f) the I concentration is 1×1015 atoms/cm3 or higher; and (g) the Si concentration is lower than 2×1015 atoms/cm3.
An epitaxial wafer, comprising: the c-plane GaN wafer according to claim 14; and at least one nitride semiconductor layer epitaxially grown on the c-plane GaN wafer.
A method of producing an epitaxial wafer, the method comprising the steps of: preparing the c-plane GaN wafer according to claim 14; and epitaxially growing at least one nitride semiconductor layer on the c-plane GaN wafer.
A method of producing a nitride semiconductor device, the method comprising the steps of: preparing the c-plane GaN wafer according to claim 14; and B₂ epitaxially growing at least one nitride semiconductor layer on the c-plane GaN wafer. 27.Amethod of producing a bulk GaN crystal, the method comprising the steps of: preparing the c-plane GaN wafer according to claim 14; and epitaxially growing a GaN crystal from a vapor phase on the c-plane GaN wafer. 28.Amethod of producing a bulk GaN crystal, the method comprising the step of growing a GaN crystal on a seed assembly by an ammonothermal method, wherein the seed assembly is constituted by plural c-plane GaN wafers, and a metal wire is used for immobilizing the plural c-plane GaN wafers with one another.
A c-plane GaN wafer, comprising a third main surface and a fourth main surface that face the opposite direction from each other, one of which third main surface and fourth main surface is a surface inclined at 0° to 10° from the (0001) crystal plane while the other is a surface inclined at 0° to 10° from the (000-1) crystal plane, wherein, on the third main surface, a virtual line segment of 50 mm or longer can be drawn, and a variation range of an m-axis direction component of an off-cut angle and that of an a-axis direction component of the off-cut angle are both 0.05° or less, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view.
The c-plane GaN wafer according to claim 15, having a dislocation density of lower than 1×106 cm⁻² in all of 100 µm×100 µm virtual regions that can be arbitrarily arranged on the third main surface, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view.
The c-plane GaN wafer according to claim 15, having a dislocation density of lower than 1×105 cm⁻² in 2 mm×2 mm virtual regions that can be arbitrarily arranged on the third main surface, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view.
The method of producing a bulk GaN crystal accord-ing to claim 28, wherein the orientations of the c-axes, a-axes, and m-axes of all of the c-plane GaN wafers con-stituting the seed assembly are aligned.
The method of producing a bulk GaN crystal accord-ing to claim 29, wherein, when the direction of N-polar side of main surfaces of the c-plane GaN wafers constituting the seed assembly is defined as front direction, two or more c-plane GaN wafers each having a rectangular or substan-tially rectangular main surface are arranged adjacent to each other on the front-direction side of the seed assembly, and a c-plane GaN wafer is arranged on the opposite side of the front direction of the seed assembly.
The method of producing a bulk GaN crystal accord-ing to claim 28, wherein, in the step of growing a GaN crystal by an ammonothermal method, a mineralizer con-taining a halogen-containing compound is used, and at least one metal wire selected from an Ag wire, a Pt wire and an Au wire is used as the metal wire. ∗ ∗ ∗ ∗ ∗
Layer stacks claimed or described, ordered top of device to substrate.
c-plane GaN wafer
epitaxial wafer
Materials described outside the worked examples.
bulk GaN crystal
GaN
nitride semiconductor layer
Additional fabrication and treatment steps described in the patent.
Measurements and analyses referenced in the patent, with their drawing references.
FIG. 2 when XRD rocking curves are measured on the measurement line using the c-plane as a reflection surface and their peak angles w are plotted 55 against the …
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
(002) XRD rocking curve peak angle variation along first direction | ≤ 0.05 deg | GaN |
(002) XRD rocking curve peak angle variation along second direction | ≤ 0.05 deg |
Patents and literature cited by this patent (applicant and examiner references).
Cited patents · 15
Related documents with shared materials, methods, properties, or citations.
n-TYPE GaN CRYSTAL, GaN WAFER, AND GaN CRYSTAL, GaN WAFER AND NITRIDE SEMICONDUCTOR DEVICE PRODUCTION METHOD
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US 12,060,653 B2Patent drawings and their descriptions. Click a drawing to enlarge it.
FIG. 1 illustrates one example of a bulk GaN crystal according to a preferred embodiment. Panel (a) of
FIG. 2 when XRD rocking curves are measured on the measurement line using the c-plane as a reflection surface and their peak angles w are plotted 55 against the …
FIG. 3 when XRD rocking curves are measured on the measurement line in the same manner and their peak 65 angles Go are plotted against the positions of the …
FIG. 4. Further, as required, the c-plane wafer 100 may be provided with various markings, such as an orientation flat or notch that 15 indicates the crystal …
FIG. 5, when the normal vector of the third main surface 101 is a vector N, the off-cut angle of the c-plane wafer 100 is an inclination 6 of the vector N from …
FIG. 6, the crystal growth apparatus includes an autoclave, and a capsule arranged therein. Inside the capsule, a dissolution zone and a growth zone, which are …
FIG. 7. The term “large-surface-area” used herein is not limited to a specific area; however, specifically, the bulk GaN crystal has a size in which two 80 …
FIG. 8.
FIG. 9. All of the plural through-holes penetrated through two wafers. That is, the through-holes formed in the portion where the wafers A and C overlapped …
FIG. 10 is a cross-sectional view that illustrates a type I through-hole pair in which one end and the other end of a Pt wire are passed through the respective …
FIG. 11, the wafer C whose outline is drawn with a dashed line is arranged on the 35 back side of the seed assembly and plays a role of a connecting plate that …
FIG. 12. The main surface had an area that could fit a circle of 7.5 cm in diameter (area=approximately 44 cm2) with a margin. 4.2. Evaluation of …
FIG. 13 are graphs showing the results of measuring the peak angles of (002) XRD rocking curves of a large-surface-area bulk GaN crystal at 5-mm intervals over …
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
A bulk GaN crystal, comprising a main surface selected from a surface inclined at 0° to 10° from the (0001) crystal plane and a surface inclined at 0° to 10° from the (000-1) crystal plane, wherein the main surface is a specific main surface A that satisfies the following conditions (i) and (ii): (i) a first line, which is a 80 mm-long virtual line segment extending in a first direction on the specific main surface A, can be drawn, and a difference between a maximum value and a minimum value of peak angles in (002) XRD rocking curves of the GaN crystal, which is measured between 17 measurement points arranged at a 5-mm pitch on the first line with the omega axis being perpendicular to the first direction, is 0.05° or less; and (ii) a second line, which is a 80 mm-long virtual line segment extending in a second direction perpendicular to the first direction on the specific main surface A, can be drawn, and a difference between a maximum value and a minimum value of peak angles in (002) XRD rocking curves of the GaN crystal, which is measured between 17 measurement points arranged at a 5-mm pitch on the second line with the omega axis being perpendicular to the second direction, is 0.05° or less.
The bulk GaN crystal according to claim 1, wherein the difference between the maximum value and the minimum value of the peak angles in the condition (i) and the difference between the maximum value and the minimum value of the peak angles in the condition (ii) are both 0.02° or less.
The bulk GaN crystal according to claim 1, wherein neither the 17 measurement points in the condition (i) nor the 17 measurement points in the condition (ii) includes a measurement point at which the peak angle is different by 0.01° or more from the peak angle at an adjacent measure-ment point.
The bulk GaN crystal according to claim 1, wherein the radius of curvature of the surface along the first direction, which is calculated from a rate of peak angle change in the condition (i), and the radius of curvature of the surface along the second direction, which is calculated from a rate of peak angle change in the condition (ii), are both 300 m or larger.
The bulk GaN crystal according to claim 1, having a dislocation density of lower than 1×106 cm⁻² in all of 100 µm×100 µm virtual regions that can be arbitrarily arranged on the specific main surface A, except for the portion having 35 a distance of less than 5 mm from the outer circumference in a plan view.
The bulk GaN crystal according to claim 1, having a dislocation density of lower than 1×105 cm⁻² in all of 2 mm×2 mm virtual regions that can be arbitrarily arranged on the specific main surface A, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view.
The bulk GaN crystal according to claim 1, satisfying one or more conditions selected from the following (a) to (g): (a) the H concentration is 1×1017 atoms/cm3 or higher; (b) the O concentration is 1×1017 atoms/cm3 or higher; (c) the concentration of at least one of Li, Na, and K is lower than 1×1015 atoms/cm3; (d) the F concentration is 1×1015 atoms/cm3 or higher; B₂ (e) the concentration of at least one of Cl, Br, and I is 1×1015 atoms/cm3 or higher; (f) the I concentration is 1×1015 atoms/cm3 or higher; and (g) the Si concentration is lower than 2×1015 atoms/cm3.
A method of producing a c-plane GaN wafer, the method comprising at least the steps of: preparing the bulk GaN crystal according to claim 1; and slicing the GaN crystal.
A bulk GaN crystal, comprising a first main surface and a second main surface that face the opposite direction from each other, wherein one of the first main surface and the second main surface is a surface inclined at 0° to 10° from the (0001) crystal plane while the other is a surface inclined at 0° to 10° from the (000-1) crystal plane, and the bulk GaN crystal satisfies the following conditions (i) and (ii): (i) a first line, which is a 80 mm-long virtual line segment extending in a first direction on the first main surface, can be drawn, and a difference between a maximum value and a minimum value of peak angles in (002) XRD rocking curves of the GaN crystal, which is measured between 17 measurement points arranged at a 5-mm pitch on the first line with the omega axis being perpendicular to the first direction, is 0.05° or less; and (ii) a second line, which is a 80 mm-long virtual line segment extending in a second direction perpendicular to the first direction on the first main surface, can be drawn, and a difference between a maximum value and a minimum value of peak angles in (002) XRD rocking curves of the GaN crystal, which is measured between 17 measurement points arranged at a 5-mm pitch on the second line with the omega axis being perpendicular to the second direction, is 0.050 or less.
The bulk GaN crystal according to claim 2, having a dislocation density of lower than 1×106 cm⁻² in all of 100 µm×100 µm virtual regions that can be arbitrarily arranged on the first main surface, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view, which dislocation density is calculated from the number of dislocations existing in each region and the area of the region.
The bulk GaN crystal according to claim 2, having a dislocation density of lower than 1×105 cm⁻² in all of 2 mm×2 mm virtual regions that can be arbitrarily arranged on the first main surface, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view, which dislocation density is calculated from the number of dislocations existing in each region and the area of the region.
A c-plane GaN wafer, comprising a main surface selected from a surface inclined at 0° to 10° from the (0001) crystal plane and a surface inclined at 0° to 10° from the (000-1) crystal plane, wherein the main surface is a specific main surface B that satisfies the following condition (111): (111) on the specific main surface B, a virtual line segment of 50 mm or longer can be drawn, and a variation range of an m-axis direction component of an off-cut angle and that of an a-axis direction component of the off-cut angle are both 0.05° or less, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view.
The c-plane GaN wafer according to claim 14, wherein the variation range of the m-axis direction compo-nent of the off-cut angle and that of the a-axis direction component of the off-cut angle are both 0.02° or less.
The c-plane GaN wafer according to claim 14, having a diameter selected from 50 mm to 55 mm, 75 mm to 80 mm, 100 mm to 105 mm, and 150 mm to 155 mm.
The c-plane GaN wafer according to claim 14, having a dislocation density of lower than 1×106 cm⁻² in all of 100 µm×100 µm virtual regions that can be arbitrarily arranged on the specific main surface B, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view.
The c-plane GaN wafer according to claim 14, having a dislocation density of lower than 1×105 cm⁻² in all of 2 mm×2 mm virtual regions that can be arbitrarily arranged on the specific main surface B, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view.
The c-plane GaN wafer according to claim 14, satis-fying one or more conditions selected from the following (a) to (g): (a) the H concentration is 1×1017 atoms/cm3 or higher; (b) the O concentration is 1×1017 atoms/cm3 or higher; (c) the concentration of at least one of Li, Na, and K is lower than 1×1015 atoms/cm3; (d) the F concentration is 1×1015 atoms/cm3 or higher; (e) the concentration of at least one of Cl, Br, and I is 1×1015 atoms/cm3 or higher; (f) the I concentration is 1×1015 atoms/cm3 or higher; and (g) the Si concentration is lower than 2×1015 atoms/cm3.
An epitaxial wafer, comprising: the c-plane GaN wafer according to claim 14; and at least one nitride semiconductor layer epitaxially grown on the c-plane GaN wafer.
A method of producing an epitaxial wafer, the method comprising the steps of: preparing the c-plane GaN wafer according to claim 14; and epitaxially growing at least one nitride semiconductor layer on the c-plane GaN wafer.
A method of producing a nitride semiconductor device, the method comprising the steps of: preparing the c-plane GaN wafer according to claim 14; and B₂ epitaxially growing at least one nitride semiconductor layer on the c-plane GaN wafer. 27.Amethod of producing a bulk GaN crystal, the method comprising the steps of: preparing the c-plane GaN wafer according to claim 14; and epitaxially growing a GaN crystal from a vapor phase on the c-plane GaN wafer. 28.Amethod of producing a bulk GaN crystal, the method comprising the step of growing a GaN crystal on a seed assembly by an ammonothermal method, wherein the seed assembly is constituted by plural c-plane GaN wafers, and a metal wire is used for immobilizing the plural c-plane GaN wafers with one another.
A c-plane GaN wafer, comprising a third main surface and a fourth main surface that face the opposite direction from each other, one of which third main surface and fourth main surface is a surface inclined at 0° to 10° from the (0001) crystal plane while the other is a surface inclined at 0° to 10° from the (000-1) crystal plane, wherein, on the third main surface, a virtual line segment of 50 mm or longer can be drawn, and a variation range of an m-axis direction component of an off-cut angle and that of an a-axis direction component of the off-cut angle are both 0.05° or less, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view.
The c-plane GaN wafer according to claim 15, having a dislocation density of lower than 1×106 cm⁻² in all of 100 µm×100 µm virtual regions that can be arbitrarily arranged on the third main surface, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view.
The c-plane GaN wafer according to claim 15, having a dislocation density of lower than 1×105 cm⁻² in 2 mm×2 mm virtual regions that can be arbitrarily arranged on the third main surface, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view.
The method of producing a bulk GaN crystal accord-ing to claim 28, wherein the orientations of the c-axes, a-axes, and m-axes of all of the c-plane GaN wafers con-stituting the seed assembly are aligned.
The method of producing a bulk GaN crystal accord-ing to claim 29, wherein, when the direction of N-polar side of main surfaces of the c-plane GaN wafers constituting the seed assembly is defined as front direction, two or more c-plane GaN wafers each having a rectangular or substan-tially rectangular main surface are arranged adjacent to each other on the front-direction side of the seed assembly, and a c-plane GaN wafer is arranged on the opposite side of the front direction of the seed assembly.
The method of producing a bulk GaN crystal accord-ing to claim 28, wherein, in the step of growing a GaN crystal by an ammonothermal method, a mineralizer con-taining a halogen-containing compound is used, and at least one metal wire selected from an Ag wire, a Pt wire and an Au wire is used as the metal wire. ∗ ∗ ∗ ∗ ∗
Layer stacks claimed or described, ordered top of device to substrate.
c-plane GaN wafer
epitaxial wafer
Materials described outside the worked examples.
bulk GaN crystal
GaN
nitride semiconductor layer
Additional fabrication and treatment steps described in the patent.
Measurements and analyses referenced in the patent, with their drawing references.
FIG. 2 when XRD rocking curves are measured on the measurement line using the c-plane as a reflection surface and their peak angles w are plotted 55 against the …
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
(002) XRD rocking curve peak angle variation along first direction | ≤ 0.05 deg | GaN |
(002) XRD rocking curve peak angle variation along second direction | ≤ 0.05 deg |
Patents and literature cited by this patent (applicant and examiner references).
Cited patents · 15
Related documents with shared materials, methods, properties, or citations.
n-TYPE GaN CRYSTAL, GaN WAFER, AND GaN CRYSTAL, GaN WAFER AND NITRIDE SEMICONDUCTOR DEVICE PRODUCTION METHOD
Comprehensive determination of Burgers vectors of threading dislocations in GaN substrates by combining reflection and transmission synchrotron-radiation x-ray topography
Patent
Atlas literature
Patent
US 12,060,653 B2Patent drawings and their descriptions. Click a drawing to enlarge it.
FIG. 1 illustrates one example of a bulk GaN crystal according to a preferred embodiment. Panel (a) of
FIG. 2 when XRD rocking curves are measured on the measurement line using the c-plane as a reflection surface and their peak angles w are plotted 55 against the …
FIG. 3 when XRD rocking curves are measured on the measurement line in the same manner and their peak 65 angles Go are plotted against the positions of the …
FIG. 4. Further, as required, the c-plane wafer 100 may be provided with various markings, such as an orientation flat or notch that 15 indicates the crystal …
FIG. 5, when the normal vector of the third main surface 101 is a vector N, the off-cut angle of the c-plane wafer 100 is an inclination 6 of the vector N from …
FIG. 6, the crystal growth apparatus includes an autoclave, and a capsule arranged therein. Inside the capsule, a dissolution zone and a growth zone, which are …
FIG. 7. The term “large-surface-area” used herein is not limited to a specific area; however, specifically, the bulk GaN crystal has a size in which two 80 …
FIG. 8.
FIG. 9. All of the plural through-holes penetrated through two wafers. That is, the through-holes formed in the portion where the wafers A and C overlapped …
FIG. 10 is a cross-sectional view that illustrates a type I through-hole pair in which one end and the other end of a Pt wire are passed through the respective …
FIG. 11, the wafer C whose outline is drawn with a dashed line is arranged on the 35 back side of the seed assembly and plays a role of a connecting plate that …
FIG. 12. The main surface had an area that could fit a circle of 7.5 cm in diameter (area=approximately 44 cm2) with a margin. 4.2. Evaluation of …
FIG. 13 are graphs showing the results of measuring the peak angles of (002) XRD rocking curves of a large-surface-area bulk GaN crystal at 5-mm intervals over …
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
A bulk GaN crystal, comprising a main surface selected from a surface inclined at 0° to 10° from the (0001) crystal plane and a surface inclined at 0° to 10° from the (000-1) crystal plane, wherein the main surface is a specific main surface A that satisfies the following conditions (i) and (ii): (i) a first line, which is a 80 mm-long virtual line segment extending in a first direction on the specific main surface A, can be drawn, and a difference between a maximum value and a minimum value of peak angles in (002) XRD rocking curves of the GaN crystal, which is measured between 17 measurement points arranged at a 5-mm pitch on the first line with the omega axis being perpendicular to the first direction, is 0.05° or less; and (ii) a second line, which is a 80 mm-long virtual line segment extending in a second direction perpendicular to the first direction on the specific main surface A, can be drawn, and a difference between a maximum value and a minimum value of peak angles in (002) XRD rocking curves of the GaN crystal, which is measured between 17 measurement points arranged at a 5-mm pitch on the second line with the omega axis being perpendicular to the second direction, is 0.05° or less.
The bulk GaN crystal according to claim 1, wherein the difference between the maximum value and the minimum value of the peak angles in the condition (i) and the difference between the maximum value and the minimum value of the peak angles in the condition (ii) are both 0.02° or less.
The bulk GaN crystal according to claim 1, wherein neither the 17 measurement points in the condition (i) nor the 17 measurement points in the condition (ii) includes a measurement point at which the peak angle is different by 0.01° or more from the peak angle at an adjacent measure-ment point.
The bulk GaN crystal according to claim 1, wherein the radius of curvature of the surface along the first direction, which is calculated from a rate of peak angle change in the condition (i), and the radius of curvature of the surface along the second direction, which is calculated from a rate of peak angle change in the condition (ii), are both 300 m or larger.
The bulk GaN crystal according to claim 1, having a dislocation density of lower than 1×106 cm⁻² in all of 100 µm×100 µm virtual regions that can be arbitrarily arranged on the specific main surface A, except for the portion having 35 a distance of less than 5 mm from the outer circumference in a plan view.
The bulk GaN crystal according to claim 1, having a dislocation density of lower than 1×105 cm⁻² in all of 2 mm×2 mm virtual regions that can be arbitrarily arranged on the specific main surface A, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view.
The bulk GaN crystal according to claim 1, satisfying one or more conditions selected from the following (a) to (g): (a) the H concentration is 1×1017 atoms/cm3 or higher; (b) the O concentration is 1×1017 atoms/cm3 or higher; (c) the concentration of at least one of Li, Na, and K is lower than 1×1015 atoms/cm3; (d) the F concentration is 1×1015 atoms/cm3 or higher; B₂ (e) the concentration of at least one of Cl, Br, and I is 1×1015 atoms/cm3 or higher; (f) the I concentration is 1×1015 atoms/cm3 or higher; and (g) the Si concentration is lower than 2×1015 atoms/cm3.
A method of producing a c-plane GaN wafer, the method comprising at least the steps of: preparing the bulk GaN crystal according to claim 1; and slicing the GaN crystal.
A bulk GaN crystal, comprising a first main surface and a second main surface that face the opposite direction from each other, wherein one of the first main surface and the second main surface is a surface inclined at 0° to 10° from the (0001) crystal plane while the other is a surface inclined at 0° to 10° from the (000-1) crystal plane, and the bulk GaN crystal satisfies the following conditions (i) and (ii): (i) a first line, which is a 80 mm-long virtual line segment extending in a first direction on the first main surface, can be drawn, and a difference between a maximum value and a minimum value of peak angles in (002) XRD rocking curves of the GaN crystal, which is measured between 17 measurement points arranged at a 5-mm pitch on the first line with the omega axis being perpendicular to the first direction, is 0.05° or less; and (ii) a second line, which is a 80 mm-long virtual line segment extending in a second direction perpendicular to the first direction on the first main surface, can be drawn, and a difference between a maximum value and a minimum value of peak angles in (002) XRD rocking curves of the GaN crystal, which is measured between 17 measurement points arranged at a 5-mm pitch on the second line with the omega axis being perpendicular to the second direction, is 0.050 or less.
The bulk GaN crystal according to claim 2, having a dislocation density of lower than 1×106 cm⁻² in all of 100 µm×100 µm virtual regions that can be arbitrarily arranged on the first main surface, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view, which dislocation density is calculated from the number of dislocations existing in each region and the area of the region.
The bulk GaN crystal according to claim 2, having a dislocation density of lower than 1×105 cm⁻² in all of 2 mm×2 mm virtual regions that can be arbitrarily arranged on the first main surface, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view, which dislocation density is calculated from the number of dislocations existing in each region and the area of the region.
A c-plane GaN wafer, comprising a main surface selected from a surface inclined at 0° to 10° from the (0001) crystal plane and a surface inclined at 0° to 10° from the (000-1) crystal plane, wherein the main surface is a specific main surface B that satisfies the following condition (111): (111) on the specific main surface B, a virtual line segment of 50 mm or longer can be drawn, and a variation range of an m-axis direction component of an off-cut angle and that of an a-axis direction component of the off-cut angle are both 0.05° or less, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view.
The c-plane GaN wafer according to claim 14, wherein the variation range of the m-axis direction compo-nent of the off-cut angle and that of the a-axis direction component of the off-cut angle are both 0.02° or less.
The c-plane GaN wafer according to claim 14, having a diameter selected from 50 mm to 55 mm, 75 mm to 80 mm, 100 mm to 105 mm, and 150 mm to 155 mm.
The c-plane GaN wafer according to claim 14, having a dislocation density of lower than 1×106 cm⁻² in all of 100 µm×100 µm virtual regions that can be arbitrarily arranged on the specific main surface B, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view.
The c-plane GaN wafer according to claim 14, having a dislocation density of lower than 1×105 cm⁻² in all of 2 mm×2 mm virtual regions that can be arbitrarily arranged on the specific main surface B, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view.
The c-plane GaN wafer according to claim 14, satis-fying one or more conditions selected from the following (a) to (g): (a) the H concentration is 1×1017 atoms/cm3 or higher; (b) the O concentration is 1×1017 atoms/cm3 or higher; (c) the concentration of at least one of Li, Na, and K is lower than 1×1015 atoms/cm3; (d) the F concentration is 1×1015 atoms/cm3 or higher; (e) the concentration of at least one of Cl, Br, and I is 1×1015 atoms/cm3 or higher; (f) the I concentration is 1×1015 atoms/cm3 or higher; and (g) the Si concentration is lower than 2×1015 atoms/cm3.
An epitaxial wafer, comprising: the c-plane GaN wafer according to claim 14; and at least one nitride semiconductor layer epitaxially grown on the c-plane GaN wafer.
A method of producing an epitaxial wafer, the method comprising the steps of: preparing the c-plane GaN wafer according to claim 14; and epitaxially growing at least one nitride semiconductor layer on the c-plane GaN wafer.
A method of producing a nitride semiconductor device, the method comprising the steps of: preparing the c-plane GaN wafer according to claim 14; and B₂ epitaxially growing at least one nitride semiconductor layer on the c-plane GaN wafer. 27.Amethod of producing a bulk GaN crystal, the method comprising the steps of: preparing the c-plane GaN wafer according to claim 14; and epitaxially growing a GaN crystal from a vapor phase on the c-plane GaN wafer. 28.Amethod of producing a bulk GaN crystal, the method comprising the step of growing a GaN crystal on a seed assembly by an ammonothermal method, wherein the seed assembly is constituted by plural c-plane GaN wafers, and a metal wire is used for immobilizing the plural c-plane GaN wafers with one another.
A c-plane GaN wafer, comprising a third main surface and a fourth main surface that face the opposite direction from each other, one of which third main surface and fourth main surface is a surface inclined at 0° to 10° from the (0001) crystal plane while the other is a surface inclined at 0° to 10° from the (000-1) crystal plane, wherein, on the third main surface, a virtual line segment of 50 mm or longer can be drawn, and a variation range of an m-axis direction component of an off-cut angle and that of an a-axis direction component of the off-cut angle are both 0.05° or less, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view.
The c-plane GaN wafer according to claim 15, having a dislocation density of lower than 1×106 cm⁻² in all of 100 µm×100 µm virtual regions that can be arbitrarily arranged on the third main surface, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view.
The c-plane GaN wafer according to claim 15, having a dislocation density of lower than 1×105 cm⁻² in 2 mm×2 mm virtual regions that can be arbitrarily arranged on the third main surface, except for the portion having a distance of less than 5 mm from the outer circumference in a plan view.
The method of producing a bulk GaN crystal accord-ing to claim 28, wherein the orientations of the c-axes, a-axes, and m-axes of all of the c-plane GaN wafers con-stituting the seed assembly are aligned.
The method of producing a bulk GaN crystal accord-ing to claim 29, wherein, when the direction of N-polar side of main surfaces of the c-plane GaN wafers constituting the seed assembly is defined as front direction, two or more c-plane GaN wafers each having a rectangular or substan-tially rectangular main surface are arranged adjacent to each other on the front-direction side of the seed assembly, and a c-plane GaN wafer is arranged on the opposite side of the front direction of the seed assembly.
The method of producing a bulk GaN crystal accord-ing to claim 28, wherein, in the step of growing a GaN crystal by an ammonothermal method, a mineralizer con-taining a halogen-containing compound is used, and at least one metal wire selected from an Ag wire, a Pt wire and an Au wire is used as the metal wire. ∗ ∗ ∗ ∗ ∗
Layer stacks claimed or described, ordered top of device to substrate.
c-plane GaN wafer
epitaxial wafer
Materials described outside the worked examples.
bulk GaN crystal
GaN
nitride semiconductor layer
Additional fabrication and treatment steps described in the patent.
Measurements and analyses referenced in the patent, with their drawing references.
FIG. 2 when XRD rocking curves are measured on the measurement line using the c-plane as a reflection surface and their peak angles w are plotted 55 against the …
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
(002) XRD rocking curve peak angle variation along first direction | ≤ 0.05 deg | GaN |
(002) XRD rocking curve peak angle variation along second direction | ≤ 0.05 deg |
Patents and literature cited by this patent (applicant and examiner references).
Cited patents · 15
Related documents with shared materials, methods, properties, or citations.
n-TYPE GaN CRYSTAL, GaN WAFER, AND GaN CRYSTAL, GaN WAFER AND NITRIDE SEMICONDUCTOR DEVICE PRODUCTION METHOD
Comprehensive determination of Burgers vectors of threading dislocations in GaN substrates by combining reflection and transmission synchrotron-radiation x-ray topography
FIG. 3 when XRD rocking curves are measured on the measurement line in the same manner and their peak 65 angles Go are plotted against the positions of the …
FIG. 12. The main surface had an area that could fit a circle of 7.5 cm in diameter (area=approximately 44 cm2) with a margin. 4.2. Evaluation of …
FIG. 13 are graphs showing the results of measuring the peak angles of (002) XRD rocking curves of a large-surface-area bulk GaN crystal at 5-mm intervals over …
IR absorption peak attributed to gallium vacancy-hydrogen complex | 3140–3200 cm⁻¹ | GaN |
Thickness | 50–55 mm | — |
Thickness | 75–80 mm | — |
Thickness | 100–105 mm | — |
Thickness | 150–155 mm | — |
Thickness | 3140–3200 cm | — |
Thickness | ≤ 5 mm | — |
Cited non-patent literature · 2
FIG. 3 when XRD rocking curves are measured on the measurement line in the same manner and their peak 65 angles Go are plotted against the positions of the …
FIG. 12. The main surface had an area that could fit a circle of 7.5 cm in diameter (area=approximately 44 cm2) with a margin. 4.2. Evaluation of …
FIG. 13 are graphs showing the results of measuring the peak angles of (002) XRD rocking curves of a large-surface-area bulk GaN crystal at 5-mm intervals over …
IR absorption peak attributed to gallium vacancy-hydrogen complex | 3140–3200 cm⁻¹ | GaN |
Thickness | 50–55 mm | — |
Thickness | 75–80 mm | — |
Thickness | 100–105 mm | — |
Thickness | 150–155 mm | — |
Thickness | 3140–3200 cm | — |
Thickness | ≤ 5 mm | — |
Cited non-patent literature · 2
FIG. 3 when XRD rocking curves are measured on the measurement line in the same manner and their peak 65 angles Go are plotted against the positions of the …
FIG. 12. The main surface had an area that could fit a circle of 7.5 cm in diameter (area=approximately 44 cm2) with a margin. 4.2. Evaluation of …
FIG. 13 are graphs showing the results of measuring the peak angles of (002) XRD rocking curves of a large-surface-area bulk GaN crystal at 5-mm intervals over …
IR absorption peak attributed to gallium vacancy-hydrogen complex | 3140–3200 cm⁻¹ | GaN |
Thickness | 50–55 mm | — |
Thickness | 75–80 mm | — |
Thickness | 100–105 mm | — |
Thickness | 150–155 mm | — |
Thickness | 3140–3200 cm | — |
Thickness | ≤ 5 mm | — |
Cited non-patent literature · 2
FIG. 3 when XRD rocking curves are measured on the measurement line in the same manner and their peak 65 angles Go are plotted against the positions of the …
FIG. 12. The main surface had an area that could fit a circle of 7.5 cm in diameter (area=approximately 44 cm2) with a margin. 4.2. Evaluation of …
FIG. 13 are graphs showing the results of measuring the peak angles of (002) XRD rocking curves of a large-surface-area bulk GaN crystal at 5-mm intervals over …
IR absorption peak attributed to gallium vacancy-hydrogen complex | 3140–3200 cm⁻¹ | GaN |
Thickness | 50–55 mm | — |
Thickness | 75–80 mm | — |
Thickness | 100–105 mm | — |
Thickness | 150–155 mm | — |
Thickness | 3140–3200 cm | — |
Thickness | ≤ 5 mm | — |
Cited non-patent literature · 2