JP5112983B2 - Group III nitride semiconductor manufacturing method and seed crystal for group III nitride semiconductor growth - Google Patents

Description

  The present invention relates to a group III nitride semiconductor manufacturing method for manufacturing a group III nitride semiconductor c-plane substrate by a Na flux method and a seed crystal for group III nitride semiconductor growth.

  A group III nitride semiconductor crystal growth method by the Na flux method has been developed, and is expected as a manufacturing method capable of obtaining a large-sized and high-quality GaN substrate. In this Na flux method, Na (sodium) and Ga (gallium) are melted and reacted with nitrogen under a pressure of several tens of atmospheres to grow GaN (gallium nitride).

In this Na flux method, a c-plane GaN substrate or a template substrate is conventionally used as a seed crystal, and the c-plane is grown on the seed crystal. Patent Document 1 discloses a method in which a-plane growth and m-plane growth are performed by using the a-plane and m-plane substrate of a group III nitride semiconductor as a seed crystal in the Na flux method. Patent Document 2 discloses a method for expanding the area of a c-plane substrate by using a c-plane GaN substrate as a seed crystal and growing it in a direction perpendicular to the c-axis.
JP2003-206198A Special table 2008-501600

  However, in the method of growing GaN on the c-plane on the c-plane, the growth rate is slow and it is difficult to obtain a thick c-plane GaN substrate.

  Accordingly, an object of the present invention is to obtain a c-plane group III nitride semiconductor substrate in a shorter time than in the conventional method for manufacturing a group III nitride semiconductor by the Na flux method.

A first invention is a method for producing a group III nitride semiconductor, in which a mixed melt containing at least a group III metal and an alkali metal is reacted with a gas containing at least nitrogen to grow a group III nitride semiconductor on a seed crystal. In the seed crystal, the a-plane of the group III nitride semiconductor is formed in a band shape whose longitudinal direction is the m-axis direction, and the group III nitride semiconductor crystal is plate-shaped in the a-axis direction on the a-plane of the seed crystal And growing the grown group III nitride semiconductor crystal into a plate shape of an isosceles triangle having an apex angle of 120 degrees and an opposite side length in the longitudinal direction of the seed crystal a plane. A group III nitride semiconductor manufacturing method is characterized in that a c-plane substrate of a group III nitride semiconductor is obtained by terminating crystal growth in step (b).

  The alkali metal is usually Na, but K (potassium) can also be used. Further, alkaline earth metals such as Mg (magnesium) and Ca (calcium), Li (lithium), and the like may be mixed. It is desirable to add carbon to the mixed melt. This is because generation of miscellaneous crystals is suppressed and crystal growth is promoted.

  In order to make the a-plane of the seed crystal into a belt-like shape whose longitudinal direction is the m-axis direction, for example, the longitudinal direction is the m-axis direction, and the longitudinal side surface in contact with the mixed melt 19 has a rod-like shape. A band-shaped recess or mask may be formed on the a-plane substrate of the physical semiconductor.

  The reason why the apex angle is an isosceles triangle is 120 degrees is because the m-plane is formed.

A second invention is a method for producing a group III nitride semiconductor, in which a mixed melt containing at least a group III metal and an alkali metal is reacted with a gas containing at least nitrogen to grow a group III nitride semiconductor on a seed crystal. in the seed crystal, I a-plane substrate der striped recess along the m-axis direction is formed a group III nitride semiconductor, a strip of the longitudinal and the m-axis direction of the group III nitride semiconductor It is a seed crystal in which an a-plane is formed, and a group III nitride semiconductor crystal is grown in a plate shape in the a-axis direction on the a-plane of the seed crystal, thereby obtaining a c-plane substrate of a group III nitride semiconductor. This is a group III nitride semiconductor manufacturing method characterized.

A third invention relates to a method for producing a group III nitride semiconductor, in which a mixed melt containing at least a group III metal and an alkali metal is reacted with a gas containing at least nitrogen to grow a group III nitride semiconductor on a seed crystal. in the seed crystal, a-plane substrate der the m-axis striped mask along the direction are formed III-nitride semiconductor, a strip of the longitudinal and the m-axis direction of the group III nitride semiconductor It is a seed crystal in which an a-plane is formed, and a group III nitride semiconductor crystal is grown in a plate shape in the a-axis direction on the a-plane of the seed crystal, thereby obtaining a c-plane substrate of a group III nitride semiconductor. This is a method for producing a group III nitride semiconductor.

  The mask material may be any material as long as it does not melt into the mixed melt and does not cause the group III nitride semiconductor to crystallize. For example, W (tungsten) can be used.

In the above second and third inventions, the group III nitride semiconductor crystal is in the shape of an isosceles triangle plate having an apex angle of 120 degrees and the opposite side length in the longitudinal direction of the seed crystal a plane. Crystal growth may be terminated at the stage of growth.
In the first to third inventions described above, the seed crystal may be a template substrate in which an a-plane group III nitride semiconductor is formed on a growth substrate made of a material different from the group III nitride semiconductor , and the concave portion is Further, it may be formed to a depth reaching the growth substrate .

  The material of the growth substrate is, for example, a sapphire substrate.

In the first invention, the seed crystal may have a rod-like shape in which the longitudinal direction is the m-axis direction and at least one of the longitudinal side surfaces is the a-plane of the group III nitride semiconductor.
According to a fourth aspect of the present invention, there is provided a mixed melt containing at least a group III metal and an alkali metal using a c-plane substrate obtained by the group III nitride semiconductor manufacturing method according to the first to third aspects as a seed crystal A method for producing a group III nitride semiconductor, comprising reacting a gas containing at least nitrogen and growing a group III nitride semiconductor on a c-plane substrate.

In a fifth aspect of the invention, when a c-plane substrate is produced by reacting a mixed melt containing at least a group III metal and an alkali metal with a gas containing at least nitrogen and growing a group III nitride semiconductor crystal. In the seed crystal to be used, the seed crystal is a group III nitride semiconductor a-plane substrate in which stripe-shaped recesses along the m-axis direction are formed, and the group III nitride semiconductor is formed in a band shape having the longitudinal direction as the m-axis direction This is a seed crystal for growing a group III nitride semiconductor, characterized in that it is a seed crystal in which the a-plane is formed.

In a sixth aspect of the invention, a c-plane substrate is produced by reacting a mixed melt containing at least a group III metal and an alkali metal with a gas containing at least nitrogen and growing a group III nitride semiconductor crystal. In the seed crystal to be used, the seed crystal is a group III nitride semiconductor a-plane substrate formed with stripe-shaped recesses along the m-axis direction, and the seed crystal has a stripe-shaped mask along the m-axis direction. A seed crystal for growing a group III nitride semiconductor, which is an a-plane substrate of a formed group III nitride semiconductor.

In the fifth and sixth inventions, the seed crystal may be a template substrate in which an a-plane group III nitride semiconductor is formed on a growth substrate made of a material different from the group III nitride semiconductor, It may be formed to a depth reaching the growth substrate .

  The present invention utilizes the phenomenon that in the crystal growth of a group III nitride semiconductor by the Na flux method, the growth rate of the a-plane is fast, and the growth rate of the c-plane and m-plane is much slower than that of the a-plane. It is. When a seed crystal in which the a-plane of a group III nitride semiconductor is formed in a strip shape with the longitudinal direction as the m-axis direction is used for the Na flux method, the crystal grows quickly in the a-axis direction on the a-plane, and the c-axis direction and m Since the crystal does not grow so much in the axial direction, a plate-like group III nitride semiconductor crystal having a principal surface of c-plane can be obtained. In addition, since crystal growth in the a-axis direction is faster than crystal growth in the c-axis direction and m-axis direction, the crystal growth time is significantly longer than when a c-plane substrate is obtained by conventional growth in the c-axis direction. It can be shortened.

It is efficient if the process is terminated at the stage of crystal growth until it becomes a plate shape of an isosceles triangle having an apex angle of 120 degrees. The reason for this is crystal growth in the a-axis direction until it is formed into an isosceles triangle plate shape, and the crystal growth rate is fast, but after the m-plane is formed into an isosceles triangle plate shape. This is because the crystal planes in contact with the mixed melt are the c-plane and m-plane, and the crystal growth is slow because the crystal growth is in the c-axis direction and the m-axis direction.

In addition, according to the fourth invention, a high-quality group III nitride semiconductor with fewer dislocations can be obtained. The reason for this is that dislocations occur along the a-axis direction, which is the crystal growth direction, in the c-plane substrate obtained by the first to third inventions. This is because when the crystal is grown by this method, dislocations do not propagate in the c-axis direction, which is the growth direction.

  Hereinafter, specific examples of the present invention will be described with reference to the drawings. However, the present invention is not limited to the examples.

  Example 1 is a Group III nitride semiconductor manufacturing method for obtaining a c-plane substrate by the Na flux method. First, the structure of the group III nitride semiconductor manufacturing apparatus used for this manufacturing method is demonstrated.

  FIG. 1 is a diagram showing a configuration of a group III nitride semiconductor manufacturing apparatus. As shown in FIG. 1, the Group III nitride semiconductor manufacturing apparatus is a crucible that holds a reaction vessel 10, a mixed melt 19 of a Group III metal and an alkali metal, and a seed crystal 14. 11, a heating device 12 that heats the reaction vessel 10, a supply pipe 16 that supplies nitrogen, and an exhaust pipe 17 that exhausts the reaction vessel 10 from the inside to the outside.

  The reaction vessel 10 is made of cylindrical stainless steel and has pressure resistance and heat resistance. A crucible 11 is arranged inside the reaction vessel 10.

  The crucible 11 is made of cylindrical alumina. A dummy substrate 15 in which a mixed melt 19 of a group III metal and an alkali metal and a seed crystal 14 are arranged is held. Na is usually used as the alkali metal, but K (potassium) may be used, and an alkaline earth metal such as Li (lithium), Mg, or Ca may be added. Moreover, it is desirable that C (carbon) is added. This is because generation of miscellaneous crystals is suppressed and crystal growth is promoted.

  The heating device 12 is disposed on the side portion outside the reaction vessel 10. This heating device 12 controls the temperature inside the reaction vessel 10.

  The seed crystal 14 is a rod-shaped rectangular parallelepiped made of a group III nitride semiconductor. The longitudinal direction is the m-axis direction, and among the four longitudinal side surfaces, the opposing side surfaces 141 and 142 are a-planes, and the side surfaces 143 and 144 that are orthogonal to the side surfaces 141 and 142 are c-planes. Is an N-polar surface, and the side surface 144 is a Ga-polar surface (see FIG. 2). Further, surfaces 145 and 146 orthogonal to these side surfaces 141 to 144 are m-planes. Therefore, the a-plane of the seed crystal 14 is formed in a band shape whose longitudinal direction is the m-axis direction. Such a seed crystal 14 can be obtained, for example, by cutting a c-plane substrate of a group III nitride semiconductor in a stripe shape along the a axis. The seed crystal 14 is arranged on the dummy substrate 15 such that the vertical direction is the c-axis direction, the horizontal direction is the a-axis direction, and the m-axis direction, and the N-polar surface is in contact with the dummy substrate 15. Therefore, the side surfaces 141 and 142 which are a-planes of the seed crystal 14 are arranged so as to be parallel to the vertical direction, and the side surfaces 143 and 144 which are c-planes are perpendicular to the vertical direction, and the side surfaces 143 which are N-polar planes. Is a lower surface in contact with the dummy substrate 15, and a side surface 141 that is a Ga polar surface is an upper surface in contact with the mixed melt 19. A plurality of seed crystals 14 may be arranged on the dummy substrate 15.

  The supply pipe 16 and the exhaust pipe 17 are open and connected to the inside of the reaction vessel 10. The supply pipe 16 supplies nitrogen into the reaction container 10, and the exhaust pipe 17 exhausts the reaction container 10 from the inside to the outside. The pressure inside the reaction vessel 10 is controlled by the nitrogen supply amount and the exhaust amount through the supply pipe 16 and the exhaust pipe 17. Note that a gaseous compound containing nitrogen, such as ammonia, may be supplied instead of nitrogen. Further, an inert gas such as argon may be mixed with nitrogen or a gaseous compound containing nitrogen and supplied.

  In this group III nitride semiconductor manufacturing apparatus, the temperature is controlled by the heating device 12 and the pressure is controlled by the supply pipe 16 and the exhaust pipe 17, whereby the group III metal and nitrogen in the mixed melt 19 held in the crucible 11 are obtained. In this apparatus, a group III nitride semiconductor crystal is grown on the seed crystal 14 by reaction. The group III nitride semiconductor crystal is grown in a plate shape from the a-plane (side surfaces 141 and 142) of the seed crystal 14. The principal surface of the group-III nitride semiconductor crystal grown in a plate shape is perpendicular to the a-plane and therefore becomes the c-plane. That is, a c-plane substrate can be obtained by crystal-growing a group III nitride semiconductor in a plate shape from a band-shaped a-plane whose longitudinal direction is the m-axis direction. In order to grow in a plate shape, it is sufficient that the growth rate in the a-axis direction is sufficiently faster than the growth rate in the c-axis direction or the m-axis direction, and the temperature and pressure ranges normally used in the Na flux method may be used. This condition is satisfied. That is, the temperature may be in the range of 800 to 900 ° C. and the pressure in the range of 3.5 to 5.0 MPa. More desirably, the temperature is in the range of 850 to 880 ° C. and the pressure is in the range of 3.8 to 4.2 MPa. This is because the growth rate in the a-axis direction is faster than the growth rates in the c-axis direction and the m-axis direction.

  FIG. 3 shows a case where GaN is grown under the conditions of a temperature of 870 ° C. and a pressure of 4.2 MPa with a crystal growth time of 20 hours. The seed crystal 14 is made of GaN, and the mixed melt 19 is a mixture of Ga, Na, and C. The ratio of C is 0.5 mol% with respect to Na. On the side surfaces 141 and 142, which are a-planes of the seed crystal 14, are formed GaN c-plane substrates 18 grown by the Na flux method. The c-plane substrate 18 has a planar shape with an isosceles triangle shape and a thickness with a width L in the c-axis direction of the seed crystal 14. The apex angle of the isosceles triangle is about 120 degrees, and the opposite side is the length of the seed crystal 14 in the longitudinal direction (m-axis direction). Further, the side surfaces 18a and 18b of the c-plane substrate 18 forming 120 degrees are m-planes. Therefore, the total shape of the seed crystal 14 and the two c-plane substrates 18 is a hexagonal shape having a side surface as an m-plane and a c-plane substrate with a film thickness of L.

  FIG. 4 shows a case where GaN is grown under the same conditions as described above except that the crystal growth time is 120 hours. As can be seen from a comparison with FIG. 3 in which the crystal growth time is 20 hours, the crystal is further grown from the state of FIG. 3 in the m-axis direction and the c-axis direction. The c-plane substrate has a larger area and a thicker shape. Further, as a result of crystal growth in the m-axis direction, a width X was grown in the a-axis direction, which was almost the same as the growth width Y in the c-axis direction.

  As shown in FIG. 3, the growth is in the a-axis direction until the m-plane is formed and becomes an isosceles triangle, and the crystal growth time is fast, so that the crystal growth time is 20 hours. After the equilateral triangle is formed, the crystal growth rate is slow because the growth is in the m-axis direction and the c-axis direction. It takes 100 hours to obtain the shape shown in FIG.

  From this, it can be seen that the c-plane substrate of the group III nitride semiconductor can be efficiently manufactured by terminating the crystal growth at the stage where the isosceles triangular plate is formed.

  In Example 1, the group III nitride semiconductor is crystal-grown from both surfaces 141 and 142 which are a-planes of the seed crystal 14, but one of the side surfaces 141 and 142 is formed on the dummy substrate 15. By arranging so as to be in contact with each other, only the other side surface may be in contact with the mixed melt 19, and the crystal may be grown in the a-axis direction (horizontal direction) only from one side surface.

  The Group III nitride semiconductor manufacturing method of Example 2 uses a seed crystal 24 shown in FIG. 5 instead of the seed crystal 14 and the dummy substrate 15 used in the Group III nitride semiconductor manufacturing method of Example 1.

  The seed crystal 24 is obtained by forming a stripe-shaped recess 243 along the m-axis direction on a group-III nitride semiconductor a-plane substrate 241 and forming a mask 242 in the recess 243. The mask 242 may be formed only on the bottom surface of the recess 243 or may be formed so as to fill the recess 243. The mask 242 is tungsten. A material other than tungsten may be used as long as it does not melt in the mixed melt 19 and does not allow the group III nitride semiconductor to grow on the mask. By making the structure of the seed crystal 24 in this way, a structure is formed in which a plurality of band-shaped a-planes whose longitudinal direction is the m-axis direction are formed. The seed crystal 24 is disposed in the mixed melt 19 such that the a-plane is the upper surface, that is, the vertical direction is the a-axis direction, and the a-plane is in contact with the mixed melt 19.

  The seed crystal 24 may be a template substrate in which a group III nitride semiconductor having an a-plane as a main surface is formed on a different substrate such as a sapphire substrate.

  FIG. 6 is a diagram showing a result of crystal growth of a group III nitride semiconductor using the seed crystal 24 by the Na flux method. Since the group III nitride semiconductor crystal grows in the a-axis direction on the plurality of a-planes formed in the band shape and does not grow on the mask 242, the plurality of c-plane substrates 28 are once formed as shown in FIG. Can get to. The c-plane substrate 28 is an isosceles triangle having a vertex angle of 120 degrees as in the case of the c-plane substrate of Example 1, and the side surface is an m-plane.

  The Group III nitride semiconductor manufacturing method of Example 3 uses a seed crystal 34 shown in FIG. 7 in place of the seed crystal 14 and the dummy substrate 15 used in the Group III nitride semiconductor manufacturing method of Example 1.

  The seed crystal 34 is a template substrate in which a group III nitride semiconductor 342 having an a-plane as a main surface is formed on an r-plane sapphire substrate 341. The group III nitride semiconductor 342 is formed with stripe-shaped recesses 343 whose longitudinal direction is the m-axis direction. The recess 343 has a depth reaching the sapphire substrate 341, and the sapphire substrate 341 is exposed. As a result, a plurality of belt-shaped a-planes whose longitudinal direction is the m-axis direction are formed. Like the seed crystal 24 of the second embodiment, the seed crystal 34 is arranged in the mixed melt 19 so that the a-plane is the upper surface, that is, the vertical direction is the a-axis direction. Is in contact with Note that a mask such as tungsten may be formed on the exposed surface of the sapphire substrate.

  Even when a group III nitride semiconductor is crystal-grown using this seed crystal 34 by the Na flux method, a plurality of group III nitride semiconductor c-plane substrates can be obtained at the same time as in the second embodiment.

  The c-plane substrate 18 shown in FIG. 3 produced in Example 1 is used as a seed crystal, and the group III nitride is formed on the c-plane of the c-plane substrate 18 by the Na flux method using the group III nitride semiconductor manufacturing apparatus shown in Example 1. Growing physical semiconductors. As a result, as shown in FIG. 8, the group III nitride semiconductor crystal grows on the c-plane substrate and the c-plane of the seed crystal 14 to form a thicker c-plane substrate. The grown group III nitride semiconductor crystal 40 has few dislocations and is of high quality. This is due to the following reason. Since the c-plane substrate 18 obtained in Example 1 was a-plane growth, dislocation occurred along the a-axis direction. On the other hand, the group III nitride semiconductor crystal 40 grown using the c-plane substrate 18 as a seed crystal grows in the c-axis direction. Therefore, dislocations along the a-axis of the c-plane substrate 18 do not propagate to the group III nitride semiconductor crystal 40, and the high-quality group III nitride semiconductor 40 with few dislocations can be grown.

  The seed crystal is not limited to those shown in Examples 1 to 3, and any seed crystal may be used as long as the a-plane of the group III nitride semiconductor is formed in a strip shape with the longitudinal direction being the m-axis direction.

  In all of Examples 2 to 3, the a-plane of the seed crystal is perpendicular to the vertical direction, but it is only necessary that the a-plane of the seed crystal is in contact with the mixed melt. For example, the a-plane of the seed crystal may be parallel to the vertical direction so as to contact the mixed melt.

  Further, the configuration of the group III nitride semiconductor manufacturing apparatus is not limited to that shown in the embodiment, and may be a manufacturing apparatus having a mechanism for rotating a crucible, for example. Moreover, the manufacturing apparatus provided with the mechanism in which a seed crystal is rotated in the state hold | maintained in the vicinity of the interface of a mixed melt may be sufficient.

  The present invention can be used for manufacturing a c-plane substrate of a group III nitride semiconductor.

The figure which showed the structure of the group III nitride semiconductor manufacturing apparatus of Example 1. FIG. The figure shown about the seed crystal. The figure shown about the c-plane board | substrate 18 grown into the seed crystal 14. FIG. The figure shown about the c-plane board | substrate 18 grown into the seed crystal 14. FIG. The figure shown about the seed crystal 24. FIG. The figure shown about the c-plane board | substrate 28 grown into the seed crystal 24. FIG. The figure shown about the seed crystal. The figure which shows the result of having further grown the crystal | crystallization using the c-plane substrate 18 as a seed crystal.

10: reaction vessel 11: crucible 12: heating device 14, 24, 34, 44: seed crystal 15: dummy substrate 16: supply tube 17: exhaust tube 18, 28: c-plane substrate

Claims (12)

In a Group III nitride semiconductor manufacturing method in which a mixed melt containing at least a Group III metal and an alkali metal is reacted with a gas containing at least nitrogen to grow a Group III nitride semiconductor on a seed crystal.
In the seed crystal, the a-plane of the group III nitride semiconductor is formed in a band shape having the longitudinal direction as the m-axis direction,
A group III nitride semiconductor crystal is grown on the a-plane of the seed crystal in a plate shape in the a-axis direction, and the grown group III nitride semiconductor crystal has an apex angle of 120 degrees and the opposite side length is the seed crystal. The c-plane substrate of the group III nitride semiconductor is obtained by terminating crystal growth at the stage of growth until it becomes a plate shape of an isosceles triangle that is the length in the longitudinal direction of the a-plane.
A method for producing a Group III nitride semiconductor. In a Group III nitride semiconductor manufacturing method in which a mixed melt containing at least a Group III metal and an alkali metal is reacted with a gas containing at least nitrogen to grow a Group III nitride semiconductor on a seed crystal.
The seed crystal is a group III nitride semiconductor a-plane substrate in which stripe-shaped recesses along the m-axis direction are formed, and the a-plane of the group III nitride semiconductor is formed in a band shape having the longitudinal direction as the m-axis direction. Is a seed crystal formed,
A group III nitride semiconductor crystal is grown on the a-plane of the seed crystal in a plate shape in the a-axis direction to obtain a group III nitride semiconductor c-plane substrate.
A method for producing a Group III nitride semiconductor. In a Group III nitride semiconductor manufacturing method in which a mixed melt containing at least a Group III metal and an alkali metal is reacted with a gas containing at least nitrogen to grow a Group III nitride semiconductor on a seed crystal.
The seed crystal is a group III nitride semiconductor a-plane substrate in which a striped mask along the m-axis direction is formed, and the a-plane of the group III nitride semiconductor in a band shape with the longitudinal direction as the m-axis direction. Is a seed crystal formed,
A group III nitride semiconductor crystal is grown on the a-plane of the seed crystal in a plate shape in the a-axis direction to obtain a group III nitride semiconductor c-plane substrate.
A method for producing a Group III nitride semiconductor.   Crystal growth is completed when the group III nitride semiconductor crystal is grown to an isosceles triangular plate shape with an apex angle of 120 degrees and the opposite side length in the longitudinal direction of the seed crystal a surface. The method for producing a group III nitride semiconductor according to claim 2 or 3, wherein:   5. The template substrate according to claim 1, wherein the seed crystal is a template substrate in which an a-plane group III nitride semiconductor is formed on a growth substrate made of a material different from that of the group III nitride semiconductor. 3. The method for producing a group III nitride semiconductor according to item 1. The seed crystal is a template substrate in which an a-plane group III nitride semiconductor is formed on a growth substrate made of a material different from the group III nitride semiconductor.
The recess is formed to a depth reaching the growth substrate.
Group III nitride semiconductor production method according to claim 2 you wherein a. The seed crystal has a rod-like shape in which the longitudinal direction is the m-axis direction and at least one of the longitudinal side surfaces is the a-plane of the group III nitride semiconductor.
The method for producing a group III nitride semiconductor according to claim 1. A mixed melt containing at least a group III metal and an alkali metal, using, as a seed crystal, the c-plane substrate obtained by the method for producing a group III nitride semiconductor according to any one of claims 1 to 7, and at least Reacting with a gas containing nitrogen to grow a group III nitride semiconductor on the c-plane substrate;
A method for producing a Group III nitride semiconductor. In a seed crystal used for producing a c-plane substrate by reacting a mixed melt containing at least a group III metal and an alkali metal with a gas containing at least nitrogen and growing a group III nitride semiconductor crystal,
The seed crystal is a group-III nitride semiconductor a-plane substrate in which stripe-shaped recesses along the m-axis direction are formed, and the group-a nitride semiconductor a-plane is formed in a band shape having the longitudinal direction as the m-axis direction. A seed crystal that is formed,
A seed crystal for growing a group III nitride semiconductor. In a seed crystal used for producing a c-plane substrate by reacting a mixed melt containing at least a group III metal and an alkali metal with a gas containing at least nitrogen and growing a group III nitride semiconductor crystal,
The seed crystal is a group III nitride semiconductor a-plane substrate on which a stripe-shaped mask is formed along the m-axis direction, and the a-plane of the group III nitride semiconductor has a strip shape with the longitudinal direction as the m-axis direction. A seed crystal that is formed,
A seed crystal for growing a group III nitride semiconductor.   11. The template substrate according to claim 9 or 10, wherein the seed crystal is a template substrate in which an a-plane group III nitride semiconductor is formed on a growth substrate made of a material different from the group III nitride semiconductor. Seed crystal for group III nitride semiconductor growth. The seed crystal is a template substrate in which an a-plane group III nitride semiconductor is formed on a growth substrate made of a material different from the group III nitride semiconductor.
The recess is formed to a depth reaching the growth substrate.
The seed crystal for growing a group III nitride semiconductor according to claim 9.

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