JP6186763B2 - Method for producing group 13 nitride crystal, method for producing group 13 nitride crystal substrate, and group 13 nitride crystal substrate - Google Patents

Description

  The present invention relates to a method for producing a group 13 nitride crystal, a method for producing a group 13 nitride crystal substrate, and a group 13 nitride crystal substrate.

  Gallium nitride (GaN) -based semiconductors are used in semiconductor devices such as blue light-emitting diodes (LEDs), white LEDs, and semiconductor lasers (LDs: Laser Diodes). In particular, c-plane GaN substrates are used for semiconductor devices.

The GaN substrate is formed on a heterogeneous substrate such as a sapphire substrate or a GaAs substrate by using a growth method such as an ELO (Epitaxial Lateral Overgrowth) method, an advanced-DEEP method, or a VAS (Void-Assisted Separation) method, and an HVPE (Hydride Vapor Phase). After the GaN is grown thick by this method, the GaN thick film is manufactured from a different substrate. The GaN substrate manufactured in this way has a transition density reduced to about 10 ⁶ cm ⁻² and a size of 2 inches has been put into practical use.

  On the other hand, as one of the techniques for producing a GaN substrate using a liquid phase growth method, a flux method is disclosed in which nitrogen is dissolved in a mixed melt of metallic sodium and metallic Ga to crystal-grow GaN.

  The flux method is capable of crystal growth at a relatively low temperature of 700 ° C. to 900 ° C., and the internal pressure of the vessel is relatively low at about 3 MPa to 8 MPa. A method of manufacturing a GaN substrate using this flux method is disclosed (for example, see Patent Documents 1 to 3).

  Patent Document 1 discloses a method of growing a crystal by changing the stirring condition of the melt when the crystal is grown on the substrate. In Patent Document 1, first, the first agitation condition set so that the growth surface is uneven is employed for crystal growth, and then the second agitation condition is set so that the growth surface becomes smooth. It is disclosed that the crystal is grown by employing the above.

  Patent Document 2 discloses that a patterned mask film is formed on a semiconductor layer, and a group 13 nitride crystal is grown in layers using the semiconductor layer exposed from the mask film as a seed crystal. Patent Document 3 discloses a method in which a semiconductor crystal is grown in layers in the a-axis direction on the a-plane of a seed crystal.

  Here, a laser diode having a configuration in which an active layer made of InGaN is formed on the c-plane of a GaN substrate is realized. However, as the In composition of the InGaN quantum well in the active layer increases, the lattice constant difference between the active layer and the GaN substrate increases, thereby increasing the strain. As the strain increases, the c-plane is a polar plane, and the light emission efficiency of the laser diode is greatly reduced by the piezoelectric field.

  Therefore, a pure green laser using a semipolar substrate or a nonpolar substrate instead of a polar substrate such as the c-plane has been reported. For example, as a method of manufacturing a semipolar substrate or a nonpolar substrate using a flux method, a nitride crystal is grown on the c-plane and a crystal is grown in the c-axis direction. It is disclosed to produce a bulk crystal of a group 13 nitride crystal used in the above.

  However, when the crystal is grown in the c-axis direction, a melt component such as metal sodium, metal gallium, or a mixture of sodium and gallium is likely to enter the crystal during crystal growth. There was a need to do. For this reason, it has been difficult to produce a group 13 nitride crystal used for producing a semipolar substrate or a nonpolar substrate with suppressed inclusion by using the flux method.

  An object of the present invention is to provide a group 13 nitride crystal used for manufacturing a semipolar substrate or a nonpolar substrate with suppressed inclusion, using a flux method.

In order to solve the above-described problems and achieve the object, the present invention dissolves nitrogen from a gas phase in a mixed melt containing at least an alkali metal and a group 13 metal, and nitride crystals are mixed in the mixed melt. In the method for producing a group 13 nitride crystal for crystal growth, a linear growth start region along the main surface is formed on the main surface of the base substrate, the nitride crystal being made of a material capable of starting crystal growth. , in a region other than the growth initiation region in the main surface, a first step of forming a mask region on which the mask is formed made of a material that does not inhibit the crystal growth inhibition was and nitride crystal nucleation of the nitride crystal In the mixed melt, a second step of starting crystal growth of the nitride crystal from the growth start region, and a {10-11} plane of the nitride crystal grown from the growth start region as a main growth surface Crystal Length and a, and a third step to continue the crystal growth in the direction toward the mask region continuous with said growth initiation region from the growth initiation region, a method for producing a Group 13 nitride crystal.

  According to the present invention, a group 13 nitride crystal used for manufacturing a semipolar substrate or a nonpolar substrate with suppressed inclusion can be obtained using a flux method.

FIG. 1 is an explanatory diagram of a manufacturing process of a group 13 nitride crystal. FIG. 2 is a schematic diagram showing a substrate. FIG. 3 is a schematic diagram showing a group 13 nitride crystal. FIG. 4 is a schematic diagram of the manufacturing apparatus. FIG. 5 is a schematic view showing a substrate. FIG. 6 is a schematic view showing an example of a method for producing a group 13 nitride crystal. FIG. 7 is a schematic diagram showing a group 13 nitride crystal. FIG. 8 is a perspective view schematically showing a group 13 nitride crystal. FIG. 9 is a schematic view showing a substrate. FIG. 10 is a schematic view showing an example of a method for producing a group 13 nitride crystal. FIG. 11 is a schematic diagram showing a group 13 nitride crystal. FIG. 12 is a perspective view schematically showing a group 13 nitride crystal. FIG. 13 is an explanatory diagram of a processing method for a group 13 nitride crystal. FIG. 14 is an explanatory diagram of a method for processing a group 13 nitride crystal. FIG. 15 is an explanatory diagram of a processing method for a group 13 nitride crystal. FIG. 16 is an explanatory diagram of a processing method for a group 13 nitride crystal. FIG. 17 is an explanatory diagram of a processing method for a group 13 nitride crystal. FIG. 18 is an explanatory diagram of a processing method for a group 13 nitride crystal.

  A group 13 nitride crystal manufacturing method, a group 13 nitride crystal substrate manufacturing method, and a group 13 nitride crystal substrate according to the present embodiment will be described below with reference to the accompanying drawings. In the following description, the shapes, sizes, and arrangements of the constituent elements are only schematically shown in the drawings so that the invention can be understood, and the present invention is not particularly limited thereby. In addition, similar components shown in a plurality of drawings are denoted by the same reference numerals, and redundant description thereof may be omitted.

(First embodiment)
In the method for producing a group 13 nitride crystal according to the present embodiment, nitrogen is dissolved from a gas phase in a mixed melt containing at least an alkali metal and a group 13 metal, and the nitride crystal is grown in the mixed melt. This is a method for producing a group 13 nitride crystal. That is, the manufacturing method of the group 13 nitride crystal of the present embodiment is a manufacturing method using a flux method.

  The method for producing a group 13 nitride crystal of the present embodiment includes at least a first step, a second step, and a third step in this order. The first step forms, on the main surface of the base substrate, an elongated growth start region made of a material from which nitride crystals can start crystal growth, and a region other than the growth start region on the main surface, This is a step of forming a mask region made of a material that inhibits nucleation of nitride crystals and does not inhibit crystal growth of nitride crystals. The second step is a step of starting the crystal growth of the nitride crystal from the growth start region in the mixed melt. The third step is crystal growth with the {10-11} plane of the nitride crystal grown from the growth start region as the main growth surface, and in the direction from the growth start region toward the mask region continuous to the growth start region. This is a process of continuing crystal growth.

  In the method for manufacturing a group 13 nitride crystal according to the present embodiment, the first step, the second step, and the third step are included in this order, and used for manufacturing a semipolar substrate or a nonpolar substrate in which inclusion is suppressed. It is considered that a group 13 nitride crystal can be obtained.

  The reason for the above effect is not clear, but is presumed as follows. However, the present invention is not limited by the following estimation.

  In the crystal growth of the nitride crystal by the flux method, in this embodiment, the temperature, nitrogen partial pressure, gallium and sodium amount ratios are adjusted so that the degree of supersaturation of nitrogen in the mixed melt is relatively low. Therefore, crystal growth occurs with the {10-11} plane of the nitride crystal as the main growth plane from the growth start region.

  Since the {10-11} plane is likely to be a flat crystal plane, it is considered that inclusion is suppressed from being incorporated into the crystal. For this reason, in the manufacturing method of the present embodiment, without performing precise control of the melt by means such as stirring required in the conventional flux method liquid phase epitaxial growth in which crystal growth is performed with the c-plane as the main growth surface, It is considered that a group 13 nitride crystal with reduced inclusion can be produced.

  Therefore, in this Embodiment, it is estimated that the group 13 nitride crystal used for manufacture of the semipolar board | substrate with which inclusion was suppressed, or a nonpolar board | substrate can be manufactured using a flux method.

  In addition, since the growth start region for starting crystal growth is long, it is considered that even when a relatively large group 13 nitride crystal is manufactured, the crystal growth time is relatively short. .

  Details will be described below.

―Group 13 nitride crystal―
FIG. 1 is an explanatory diagram of the manufacturing process of the group 13 nitride crystal 105 of the present embodiment.

  First, the first step will be described. In the first step, a long growth start region 104 made of a material capable of starting crystal growth of a nitride crystal is formed on the main surface of the base substrate 101, and other than the growth start region 104 on the main surface. This is a step of making the region into a mask region 103 made of a material that inhibits nucleation of nitride crystals and does not inhibit crystal growth of nitride crystals.

  Fig.1 (a)-FIG.1 (c) are explanatory drawings which show an example of a 1st process.

  Specifically, first, a base substrate 101 is prepared as shown in FIG. As the base substrate 101, a crystal substrate suitable for a method for forming a mask region 103 and a growth start region 104 described later may be used.

For the base substrate 101, for example, a crystal substrate made of a material that is difficult to nucleate a group 13 nitride by the flux method, such as sapphire, SiC, MgAl ₂ O _4, or the like is used. Further, as the base substrate 101, a so-called template substrate in which a GaN thin film is epitaxially grown on a main surface made of a material in which a group 13 nitride is difficult to nucleate by a flux method such as sapphire, SiC, or ZnO substrate may be used. . Further, a self-standing GaN crystal substrate may be used as the base substrate 101.

  The plane orientation of the main surface of base substrate 101 (the surface on the side where mask region 103 and growth start region 104 are formed) is not particularly limited.

  In the present embodiment, in the second step and the third step, which will be described later, crystal growth is performed with the {10-11} plane as the main growth surface, but as described later, in the second step and the third step, The crystal growth conditions are optimized to the conditions for forming the {10-11} plane. For this reason, the surface orientation of the base substrate 101 is not particularly limited, and crystal growth described later can be performed by adjusting crystal growth conditions in the second step and the third step. For this reason, the surface orientation of the main surface of the base substrate 101 is not particularly limited.

  For example, the surface orientation of the main surface of the base substrate 101 may be any of a c-plane, an m-plane, and a plane inclined from the c-plane or the m-plane.

  Next, a mask region 103 and a growth start region 104 are formed on the main surface of the base substrate 101 (see FIG. 1C).

  FIG. 2 is a schematic diagram showing a substrate 100A in which a mask region 103 and a growth start region 104 are formed on a base substrate 101. As shown in FIG. FIG. 2A is a plan view showing the substrate 100A as viewed vertically from the mask region 103 side. FIG. 2B is a cross-sectional view taken along the line A-A ′ of FIG.

  The growth start region 104 is a long region. Specifically, the growth start region 104 is a region having a linear shape when the main surface side of the base substrate 101 is viewed from the vertical direction.

  The angle formed by the long direction of the growth start region 104 and the a-axis direction of the group 13 nitride layer 102 is not particularly limited.

  In the present embodiment, as shown in FIG. 2B, the longitudinal direction of the growth start region 104 and the a-axis direction of the group 13 nitride layer 102 constituting the growth start region 104 are not parallel to each other. (That is, the case where the angle α formed by the longitudinal direction of the growth start region 104 and the a-axis direction of the group 13 nitride layer 102 constituting the growth start region 104 is greater than 0 °).

  The width of the growth start region 104 (the length in the direction orthogonal to the longitudinal direction) is not particularly limited. For example, the width of the growth start region 104 is preferably 1 mm or less, and more preferably 200 μm or less. This is because, in crystal growth using the flux method, defects in the crystal on the base side are inherited by the crystal that grows, so that the group 13 nitride crystal 105 as the final product can be easily separated from the base substrate 101 side. This is because of this.

  A plurality of growth start regions 104 may be formed on the base substrate 101, or a single growth start region 104 may be formed. When a plurality of growth start regions 104 are provided on the base substrate 101, a group 13 nitride crystal 105 for crystal growth is formed so that the group 13 nitride crystals 105 grown from the growth start region 104 do not contact each other. It is preferable to arrange them in a direction intersecting the longitudinal direction of the growth start region 104 with an interval corresponding to the size of the growth start region 104.

  By setting the distance between the adjacent growth start regions 104 to a distance that the group 13 nitride crystals 105 after growth do not come into contact with each other, distortion caused by the adjacent group 13 nitride crystals 105 coming into contact with each other during crystal growth. And the occurrence of defects are suppressed.

  The growth start region 104 is made of a material that allows the nitride crystal to start crystal growth. Specifically, the growth start region 104 is made of a nitride crystal for crystal growth. For example, when the nitride crystal to be grown is a group 13 nitride such as GaN, the growth start region 104 is made of a group 13 nitride.

  The plane orientation of the growth start region 104 is not particularly limited. In the present embodiment, the case where the growth start region 104 is the (0001) plane (that is, the c plane) will be described.

  The mask region 103 is a region other than the growth start region 104 on the main surface side of the base substrate 101. Mask region 103 is made of a material that inhibits the nucleation of nitride crystals in the flux method and does not inhibit the crystal growth of nitride crystals by the flux method.

  As a constituent material of the mask region 103, for example, an oxide such as alumina is used.

  The formation method of the growth start area | region 104 and the mask area | region 103 is not specifically limited, According to a use, it can select suitably.

  FIGS. 1B and 1C are schematic views showing an example of a method for forming the growth start region 104 and the mask region 103.

  As shown in FIGS. 1B and 1C, a group 13 nitride layer 102 is formed on the main surface of the base substrate 101. The group 13 nitride layer 102 is a layer made of the constituent material of the growth start region 104. Specifically, the group 13 nitride layer 102 is formed on the base substrate 101 by epitaxially growing the group 13 nitride using the MOCVD method or the HVPE method. Thus, the template substrate 100 in which the group 13 nitride layer 102 is stacked on the base substrate 101 is manufactured.

  Next, a mask is formed on the group 13 nitride layer 102 in a region other than a region where the growth start region 104 is to be formed (that is, a region where the mask region 103 is to be formed) using a known resist or the like. To do. Thereafter, dry etching is performed to remove the group 13 nitride crystal in the region other than the region where the mask is formed in the mask region 103 (that is, the region where the growth start region 104 is to be formed). Layer 102 is exposed. Then, the mask is removed.

  As a result, the region covered with the mask at the time of the dry etching becomes the mask region 103, and the region exposed by the dry etching in the group 13 nitride layer 102 becomes the growth start region 104.

  Note that the method of forming the growth start region 104 and the mask region 103 is not limited to the method shown in FIGS. 1B and 1C.

For example, as the base substrate 101, a sapphire substrate having a group 13 nitride film formed on the main surface side, a so-called template substrate such as a SiC or ZnO substrate, or a self-supporting GaN crystal substrate is prepared. Then, a mask substrate made of the constituent material of the mask region 103 such as a sapphire substrate or a MgAl ₂ O ₄ substrate is prepared with a long through hole in the surface direction, and this mask substrate is formed on the main surface of the base substrate 101. Place. Then, a region of the base substrate 101 exposed from the mask substrate (a region corresponding to the through hole), that is, a region where the group 13 nitride crystal is exposed functions as the growth start region 104, and this mask substrate serves as a mask region. By functioning as 103, the growth start region 104 and the mask region 103 are formed.

  Further, as the base substrate 101, a substrate whose main surface side is made of a constituent material of a mask material is prepared. Then, the growth start region 104 and the mask region 103 may be formed by forming a group 13 nitride crystal film linearly on the substrate along the surface direction of the substrate.

  Further, for example, the group 13 nitride layer 102 is formed by epitaxially growing the group 13 nitride on the base substrate 101 made of a material in which the group 13 nitride is difficult to nucleate by the flux method, using the MOCVD method or the HVPE method. Form. Thus, the template substrate 100 in which the group 13 nitride layer 102 is stacked on the base substrate 101 is manufactured (see FIG. 1B).

  Next, a long mask is formed on the group 13 nitride layer 102 in a region where the growth start region 104 is to be formed using a known resist or the like. Thereafter, dry etching is performed to remove the group 13 nitride crystal in the region other than the region where the mask is formed in the group 13 nitride layer 102 to expose the surface of the base substrate 101. Next, the mask is removed.

  As a result, the region covered with the mask at the time of the dry etching in the group 13 nitride layer 102 becomes the growth start region 104, which is exposed by removing the group 13 nitride layer 102 by the dry etching. A region of the base substrate 101 made of a material in which the group 13 nitride hardly nucleates becomes a mask region 103.

  Next, the second step and the third step will be described.

  The second step is a step of starting crystal growth of nitride crystals from the growth start region 104 in the mixed melt.

  FIG. 1C is an explanatory diagram of the second step. In the second step, nitrogen is dissolved from the gas phase in a mixed melt containing an alkali metal (flux) and a group 13 metal, and the group 13 nitride crystal is grown from the growth start region 104 in the mixed melt. Let it begin.

  The mixed melt contains a flux and a raw material such as a group 13 metal.

  As the flux, sodium or a sodium compound (for example, sodium azide) is used. As another example, other alkali metals such as lithium and potassium, and compounds of the alkali metals may be used. Moreover, you may use alkaline earth metals, such as barium, strontium, and magnesium, and the compound of the said alkaline earth metal as a flux. Note that a plurality of types of alkali metals or alkaline earth metals may be mixed and used as the flux.

  As the Group 13 metal used as a raw material, gallium is preferably used, but as another example, other Group 13 metals such as boron, aluminum, and indium, or a mixture thereof may be used.

  In the mixed melt 24, a dopant material such as Ge, Mg, Fe, and Mn, an alkaline earth metal serving as a flux such as Ca, Ba, and Sr, carbon having a reduction effect on miscellaneous crystals, and the like are mixed. Also good.

  In the second step, the base substrate 101 on which the growth start region 104 and the mask region 103 are formed is placed in the mixed melt held in the reaction vessel (specifically, the bottom inside the reaction vessel, which will be described in detail later). Then, the crystal growth is started by adjusting the nitrogen partial pressure, the temperature of the mixed melt, the molar ratio of the raw material to the flux, and the like to the conditions under which the crystal growth of the nitride crystal starts from the growth start region 104.

  Specifically, in the second step, the nitrogen partial pressure is preferably in the range of 1 MPa to 6 MPa. In the second step, the temperature of the mixed melt (crystal growth temperature) is preferably in the range of 800 ° C to 900 ° C.

  For example, the ratio of the number of moles of alkali metal to the total number of moles of gallium and alkali metal (for example, sodium) is in the range of 50% to 90%, and the crystal growth temperature of the mixed melt is in the range of 850 ° C. to 900 ° C. Preferably, the nitrogen partial pressure is in the range of 1.5 MPa to 6 MPa.

  In a more preferred embodiment, the molar ratio of gallium to alkali metal is 0.3: 0.7, the crystal growth temperature is in the range of 860 ° C. to 870 ° C., and the nitrogen partial pressure is in the range of 2 MPa to 3.5 MPa. More preferably.

  FIG.1 (d) is explanatory drawing of a 3rd process. As shown in FIG. 1D, in the third step, crystal growth of the group 13 nitride crystal 105 is started from the growth start region 104.

  In the third step, crystal growth with the {10-11} plane of the nitride crystal grown from the growth start region 104 as a main growth surface, and the mask region 103 continuous from the growth start region 104 to the growth start region 104 are performed. This is a process of continuing crystal growth in the direction of heading.

  FIG.1 (e)-FIG.1 (g) are explanatory drawings of a 3rd process. The group 13 nitride crystal 105 that has started crystal growth from the growth start region 104 in the second step (see FIG. 1D), in the third step, crystal growth with the {10-11} plane as the main growth surface, Then, crystal growth is continued in the direction from the growth start region 104 toward the mask region 103 continuous with the growth start region 104.

  FIG. 3 is a schematic diagram showing the group 13 nitride crystal 105 having grown. FIG. 3A is a plan view of the grown group 13 nitride crystal 105 as viewed from the main surface side of the base substrate 101. FIG. 3B is a cross-sectional view taken along the line A-A ′ of FIG.

  In the third step, by optimizing the crystal growth conditions to the conditions under which the {10-11} plane is formed, the {10-11} plane is formed by continuing the crystal growth, and the {10-11} plane is grown. Surface crystal growth can be continued.

  Such crystallization conditions in the third step can be realized by adjusting the nitrogen partial pressure, the temperature of the mixed melt, the ratio of the number of moles of alkali metal to the total number of moles of gallium and alkali metal (for example, sodium), and the like.

  Specifically, in the third step, the nitrogen partial pressure is adjusted to a partial pressure at which the nitrogen in the melt has a relatively low supersaturation. Specifically, it is preferable to be within a range of 2 MPa to 3.5 MPa. Further, in the third step, the temperature of the mixed melt (crystal growth temperature) is problematic because a crucible made of a material such as YAG or alumina dissolves in or reacts with the melt. Adjust to no temperature. Specifically, it is preferable to set it within the range of 860 ° C to 870 ° C. Further, the ratio of the number of moles of alkali metal to the total number of moles of gallium and alkali metal (for example, sodium) is such that the {10-11} plane is easily formed under the aforementioned conditions of nitrogen and temperature, 50% to 80%. It is preferable to set it within the range of 60% to 75%.

  In addition, the 2nd process and the 3rd process are continued on the same conditions by making the 2nd process into the same crystal growth conditions (conditions, such as temperature, partial pressure, and alkali metal molar ratio) as the 3rd process. Can be advanced.

  FIG. 4 is a schematic diagram of the manufacturing apparatus 1 for performing the second step and the third step in the present embodiment.

  As shown in FIG. 4, the manufacturing apparatus 1 includes a closed pressure vessel 11 made of stainless steel. The pressure vessel 11 can be removed from the manufacturing apparatus 1 at the valve 21 portion, and only the pressure vessel 11 portion can be put in the glove box and operated.

  A reaction vessel 12 is provided in the pressure vessel 11. The reaction vessel 12 holds a flux (for example, sodium) and a mixed melt 24 containing a group 13 metal (for example, gallium). In the reaction vessel 12, a substrate 100A, which is a base substrate 101 on which a growth start region 104 and a mask region 103 are formed, is installed.

  The material of the reaction vessel 12 can be selected as appropriate. For example, a BN sintered body, a nitride such as P-BN, an oxide such as alumina or YAG, a carbide such as SiC, or the like can be used for the reaction vessel 12. The reaction vessel 12 can be removed from the pressure vessel 11.

The pressure vessel 11 is connected to a gas supply pipe 14 for supplying nitrogen (N ₂ ) gas, which is a raw material for the group 13 nitride crystal, and dilution gas for adjusting the total pressure. The gas supply pipe 14 is branched into a nitrogen supply pipe 17 and a gas supply pipe 20, and can be separated by valves 15 and 18, respectively.

  As the diluent gas, it is desirable to use an argon (Ar) gas that is an inert gas, but the present invention is not limited to this, and other inert gases such as helium (He) may be used as the diluent gas.

  Nitrogen gas is supplied from a nitrogen supply pipe 17 connected to a gas cylinder of nitrogen gas and the like, and after the pressure is adjusted by the pressure control device 16, the nitrogen gas is supplied to the gas supply pipe 14 through the valve 15. On the other hand, a dilution gas (for example, argon gas) is supplied from a gas supply pipe 20 connected to a gas cylinder of the dilution gas and the pressure is adjusted by a pressure control device 19, and then the gas supply pipe is connected via a valve 18. 14. The nitrogen gas and the dilution gas whose pressures are adjusted in this way are respectively supplied to the gas supply pipe 14 and mixed.

  Then, a mixed gas of nitrogen and dilution gas is supplied from the gas supply pipe 14 to the pressure vessel 11 through the valve 21.

  The gas supply pipe 14 is provided with a pressure gauge 22 so that the pressure in the pressure vessel 11 can be adjusted while the pressure gauge 22 monitors the total pressure in the pressure vessel 11.

  Nitrogen gas is a raw material of gallium nitride, and argon, which is an inert gas, is mixed with it to increase the total pressure and suppress the evaporation of sodium, while controlling the pressure of the nitrogen gas independently. It is. Thereby, crystal growth with high controllability becomes possible.

  In this embodiment, the nitrogen partial pressure can be adjusted by adjusting the pressures of the nitrogen gas and the dilution gas with the valves 15 and 18 and the pressure control devices 16 and 19 as described above. Further, since the total pressure in the pressure vessel 11 can be adjusted, the total pressure in the pressure vessel 11 can be increased to suppress evaporation of alkali metal (for example, sodium) in the reaction vessel 12. That is, it is possible to separately control the nitrogen partial pressure, which is a nitrogen material that affects the crystal growth conditions of gallium nitride, and the total pressure that affects the suppression of evaporation of sodium (flux).

  Further, a heater 13 is disposed outside the pressure vessel 11, and the temperature of the mixed melt 24 can be adjusted by heating the pressure vessel 11 and the reaction vessel 12.

  In carrying out the second step and the third step, first, a substance used as a flux and a raw material are charged into the reaction vessel 12. And after setting a raw material etc., it supplies with electricity to the heater 13, and the pressure vessel 11 and the reaction vessel 12 inside it are heated to crystal growth temperature. Then, a substance used as a flux in the reaction vessel 12 and raw materials are melted to form a mixed melt 24. Further, nitrogen as a raw material can be supplied into the mixed melt 24 by bringing the partial pressure of nitrogen into contact with the mixed melt 24 and dissolving it in the mixed melt 24.

  Then, under a predetermined crystal growth temperature and a predetermined nitrogen partial pressure, nitrogen dissolved in the mixed melt 24 from the gas phase reacts with the group 13 metal in the mixed melt 24 and is set in the mixed melt 24. Crystal growth of the nitride crystal is started from the growth start region 104 in the substrate 100a (second step).

  Further, by maintaining the crystal growth conditions in the third step, the group 13 nitride crystal 105 that has started crystal growth from the growth start region 104 performs crystal growth with the {10-11} plane as the main growth plane. The crystal growth is continued so as to cover the mask region 103.

  Through the first to third steps, a group 13 nitride crystal 105 having a {10-11} plane can be manufactured as shown in FIG.

  The manufactured group 13 nitride crystal 105 is a group 13 nitride crystal 105 having a {10-11} plane.

  In the example shown in FIGS. 1 and 3, a group 13 nitride crystal 105 having a {10-11} plane and a (0001) plane (c plane) is shown. In the example shown in FIGS. 1 and 3, the group 13 nitride crystal 105 has a case where the cross-sectional shape perpendicular to the longitudinal direction of the growth start region 104 is trapezoidal. A region corresponding to the upper base side of the trapezoidal shape is a c-plane.

  In the present embodiment, as described above, the angle α formed by the long direction of the growth start region 104 and the a-axis of the group 13 nitride layer 102 is greater than 0 (for example, 5 °). Adjusted as follows. Therefore, a plurality of {10-11} planes are formed on the crystal plane corresponding to the trapezoidal slope of the cross section perpendicular to the longitudinal direction of the growth start region 104 of the group 13 nitride crystal 105, and has irregularities. This is considered to be a surface (see FIG. 3A).

  Next, the fourth step will be described.

  FIG. 1H is an explanatory diagram of the fourth step. In the fourth step, the group 13 nitride crystal 105 crystal-grown in the second to third steps is separated from the substrate 100A.

  Specifically, the group 13 nitride crystal 105 grown in the third step is cooled to room temperature. Thereafter, the substrate 100A and the group 13 nitride crystal 105 are separated.

  In the cooling process of the group 13 nitride crystal 105 and the substrate 100A, the growth start region 104 or a crystal in the vicinity thereof breaks due to the difference in thermal expansion coefficient between the substrate 100A and the group 13 nitride crystal 105, and the substrate 100A In some cases, the grown group 13 nitride crystal 105 is already separated.

  Through the above process, the group 13 nitride crystal 105 can be manufactured.

(Second Embodiment)
In the first embodiment, the long direction of the growth start region 104 and the a-axis direction of the group 13 nitride layer 102 constituting the growth start region 104 are not parallel (that is, the growth start region 104). In the case where the angle α formed by the elongate direction and the a-axis direction of the group 13 nitride layer 102 is greater than 0 °.

  In the present embodiment, a case will be described in which the growth start region is formed so that the long direction of the growth start region is parallel to the a-axis direction of the group 13 nitride layer constituting the growth start region.

  FIG. 5 is a schematic diagram showing a substrate 200 </ b> A in which a mask region 203 and a growth start region 204 are formed on the base substrate 200. FIG. 5A is a plan view showing the substrate 200A as viewed vertically from the mask region 203 side. FIG. 5B is a cross-sectional view taken along the line A-A ′ of FIG.

  Note that the mask region 203 and the growth start region 204 correspond to the mask region 103 and the growth start region 104 of the first embodiment, respectively. In the present embodiment, the difference from the first embodiment is that the angle α is 0 ° as described above. In the present embodiment, base substrate 200 is made of a group 13 nitride. For example, as the base substrate 200, the template substrate 100 in which the group 13 nitride layer 102 is stacked on the base substrate 101 of the first embodiment may be used, or a substrate made of a group 13 nitride may be used. .

  As shown in FIG. 5, in the present embodiment, the longitudinal direction of the growth start region 204 and the a-axis direction of the group 13 nitride layer (underlying substrate 200) constituting the growth start region 204 are parallel to each other. (That is, the angle α formed between the longitudinal direction of the growth start region 204 and the group 13 nitride layer constituting the growth start region 204 is 0 °).

  The growth start region 204 is the c-plane of the group 13 nitride layer that is the base substrate 200, and this point is the same as in the first embodiment.

  In the present embodiment, similarly to the first embodiment, the group 13 nitride crystal 205 is manufactured through the first to fourth steps.

  FIG. 6 is a schematic diagram showing an example of a method for manufacturing the group 13 nitride crystal 205 in the present embodiment.

  FIG. 6A to FIG. 6B are explanatory diagrams of the first step. As shown in FIG. 6A, first, a base substrate 200 is prepared. In the example illustrated in FIG. 6, a case where a substrate in which a group 13 nitride easily nucleates is used as the base substrate 200 will be described. Specifically, a self-standing GaN crystal substrate may be used for the base substrate 200. Further, a case where the plane orientation of the main surface of the base substrate 200 is the c plane will be described.

  Next, a mask region 203 and a growth start region 204 are formed on the base substrate 200. In the method of forming the mask region 203 and the growth start region 204, the longitudinal direction of the growth start region 204 and the a-axis direction of the group 13 nitride layer (underlying substrate 200) constituting the growth start region 204 are parallel. Except for forming the growth start region 204 so that the angle α is 0 °, the description is omitted because it is the same as the first embodiment. Thereby, the template substrate 200A is manufactured.

  Next, in the second step, as in the first embodiment, crystal growth of the group 13 nitride crystal 205 is started from the growth start region 204 (FIG. 6C). Further, in the third step, as in the first embodiment, the group 13 nitride crystal 205 is crystal-grown with the {10-11} plane as the main growth plane (FIG. 6D to FIG. 6). (Refer FIG.6 (f)).

  FIG. 7 is a schematic diagram showing a group 13 nitride crystal 205 having grown crystals. FIG. 7A is a plan view of the grown group 13 nitride crystal 205 as seen from the main surface side of the base substrate 200. FIG. 7B is a cross-sectional view taken along the line A-A ′ of FIG. FIG. 8 is a perspective view schematically showing the group 13 nitride crystal 205.

  In the third step, as in the first embodiment, the {10-11} plane is formed by continuing the crystal growth by optimizing the crystal growth conditions to the conditions for forming the {10-11} plane. Thus, crystal growth with the {10-11} plane as the growth plane can be continued.

  In the present embodiment, the longitudinal direction of the growth start region 204 and the a-axis direction of the group 13 nitride layer (underlying substrate 200) constituting the growth start region 204 are parallel (angle α is 0 °). From this, it is considered that the crystal growth of the {10-11} plane preferentially proceeds as compared with the first embodiment. For this reason, the cross-sectional shape perpendicular to the longitudinal direction of the growth start region 204 of the obtained group 13 nitride crystal 205 is a triangular shape as shown in FIGS.

  In addition, it is considered that the crystal plane corresponding to the triangular slope of the cross-sectional shape of the group 13 nitride crystal 205 is a substantially flat {10-11} plane (see FIG. 7B).

  Since the fourth step is the same as that of the first embodiment, description thereof is omitted.

  Thus, the long direction of the growth start region 204 and the a-axis direction of the group 13 nitride layer (underlying substrate 200) constituting the growth start region 204 are parallel (angle α is 0 °). By forming the growth start region 204, as shown in FIG. 7B and FIG. 8, the cross-sectional shape of the group 13 nitride crystal 205 perpendicular to the longitudinal direction of the growth start region 204 is triangular. Group 13 nitride crystal 205 can be produced.

(Third embodiment)
In the first embodiment, the long direction of the growth start region 104 and the a-axis direction of the group 13 nitride layer 102 constituting the growth start region 104 are not parallel (that is, the growth start region 104). In the case where the angle α formed by the elongate direction and the a-axis direction of the group 13 nitride layer 102 is greater than 0 °. In the first embodiment, the case where the growth start region 104 is the c-plane of the group 13 nitride layer 102 has been described.

  On the other hand, in the present embodiment, the growth start region is the m-plane of the group 13 nitride layer, the long direction of the growth start region, and the a-axis direction of the group 13 nitride layer constituting the growth start region A case will be described in which the growth start region is formed so as to be parallel to each other.

  FIG. 9 is a schematic view showing a substrate 300 </ b> A in which a group 13 nitride layer 302, a mask region 303, and a growth start region 304 are formed on the base substrate 301. FIG. 9A is a plan view showing the substrate 300A viewed vertically from the mask region 303 side. FIG. 9B is a cross-sectional view taken along the line A-A ′ of FIG.

  The base substrate 301, the group 13 nitride layer 302, the mask region 303, and the growth start region 304 are the base substrate 101, the group 13 nitride layer 102, the mask region 103, and the growth start region of the first embodiment. It corresponds to each of 104.

  In the present embodiment, the difference from the first embodiment is that the angle α is 0 ° as described above. Further, the present embodiment is different from the first embodiment in that the growth start region 304 is the m-plane of the group 13 nitride layer 302.

  In the present embodiment, similarly to the first embodiment, the group 13 nitride crystal 305 (see FIG. 10) is manufactured through the first to fourth steps.

  FIG. 10 is a schematic diagram showing an example of a method for producing group 13 nitride crystal 305 in the present embodiment.

  FIG. 10A to FIG. 10B are explanatory diagrams of the first step. As shown in FIG. 10A, first, a template substrate 300 on which a group 13 nitride layer 302 having an m-plane as a main surface is formed on a base substrate 301 is prepared.

  Next, a mask region 303 and a growth start region 304 are formed. In the method of forming these mask region 303 and growth start region 304, the longitudinal direction of the growth start region 304 and the a-axis direction of the group 13 nitride layer 302 constituting the growth start region 304 are parallel (the angle α is Except for forming the growth start region 304 so as to be 0 °), the description is omitted because it is the same as the first embodiment. Thus, the substrate 300A is manufactured.

  Next, in the second step, crystal growth of the group 13 nitride crystal 305 is started from the growth start region 304 as in the first embodiment (FIG. 10C). Further, in the third step, as in the first embodiment, the group 13 nitride crystal 305 is crystal-grown with the {10-11} plane as the main growth plane (FIG. 10D to FIG. 10). (Refer FIG.10 (f)).

  FIG. 11 is a schematic diagram showing a group 13 nitride crystal 305 having grown crystal. FIG. 11A is a plan view of the group 13 nitride crystal 305 grown as a crystal, as viewed from the main surface side of the base substrate 301. FIG.11 (b) is A-A 'sectional drawing of Fig.11 (a). FIG. 12 is a perspective view schematically showing the group 13 nitride crystal 205.

  In the third step, as in the first embodiment, the {10-11} plane is formed by continuing the crystal growth by optimizing the crystal growth conditions to the conditions for forming the {10-11} plane. Thus, crystal growth with the {10-11} plane as the growth plane can be continued.

  In the present embodiment, the longitudinal direction of the growth start region 304 and the a-axis direction of the group 13 nitride layer 302 constituting the growth start region 304 are parallel (angle α is 0 °), and the growth start region Reference numeral 304 denotes an m-plane of the group 13 nitride layer 302.

  A nitride crystal grows while forming a {10-11} plane and a (000-1) N polar plane, but the (000-1) N polar plane has a very slow growth rate. Magnify in the direction. Therefore, the group 13 nitride crystal 305 manufactured in the present embodiment has a cross-sectional shape perpendicular to both the longitudinal direction of the growth start region 304 and the main surface of the substrate 300, and the group 13 nitride having a right triangle shape. Crystal 305 is formed. Specifically, the longitudinal direction of the growth start region 304 and the main surface of the substrate 300 with the (000-1) N polar surface perpendicular to the main surface of the base substrate 301 as the bottom surface and the {10-11} surface as the inclined surface. A group 13 nitride crystal 305 having a right-angled triangular cross section perpendicular to both surfaces is obtained.

  Further, it is considered that the crystal plane of the group 13 nitride crystal 305 corresponding to the inclined surface of the right triangle having the cross-sectional shape is a substantially flat {10-11} plane (see FIG. 12).

  Since the fourth step is the same as that of the first embodiment, description thereof is omitted.

  Thus, the longitudinal direction of the growth start region 304 and the a-axis direction of the group 13 nitride layer 302 constituting the growth start region 304 are parallel (angle α is 0 °), and the growth start region 304 is By setting the m-plane of the group 13 nitride layer 302, a group 13 nitride crystal 305 having a right triangular shape in cross section perpendicular to the longitudinal direction of the growth start region 304 can be manufactured (FIG. 11B). ) And FIG.

(Fourth embodiment)
In the present embodiment, a method for manufacturing a group 13 nitride crystal substrate from group 13 nitride crystals 105, 205, and 305 manufactured in the above embodiment will be described.

  The manufacturing method of the present embodiment includes a processing step of processing the group 13 nitride crystals 105, 205, and 305 manufactured in the above embodiment so that the nonpolar surface or the semipolar surface is the main surface.

  A nonpolar plane is a crystal plane of a group 13 nitride crystal having a hexagonal crystal structure in which the number of group 13 atoms and nitrogen atoms is the same in the crystal plane and the charge is not biased and has no polarity in the crystal axis direction. is there. Specifically, the nonpolar plane is an m plane or a plane of a hexagonal crystal. The semipolar plane is a crystal plane excluding the c plane and the nonpolar plane, which are polar planes in which the crystal plane is composed of only group 13 atoms or nitrogen atoms. Since the number of group 13 atoms and nitrogen atoms is not equal in the semipolar plane, the balance of charges is lost and the polarity is polar, but the degree is between the c-plane polar plane and the nonpolar plane, so it is defined as semipolar. ing. Specifically, there are {10-11} plane, {20-21} plane, {11-22} plane, {-1103} plane, etc. of hexagonal crystal (other than c plane and nonpolar plane) All crystal planes are semipolar planes).

  A known method may be used for the processing method and is not limited.

  FIG. 13 is an explanatory view showing an example of a processing method of the group 13 nitride crystal 205 manufactured in the second embodiment.

  As shown in FIG. 13A, for example, in the processing step, the surface of the group 13 nitride crystal 205 intersects the longitudinal direction of the growth start region 204 of the group 13 nitride crystal 205 {20− The group 13 nitride crystal 205 is sliced parallel to the 21} plane.

  Next, after polishing the surface of each group 13 nitride crystal substrate 206 that is the group 13 nitride crystal 205 after slicing, a CMP process (Chemical Mechanical Polishing) is performed. Thereby, a triangular group 13 nitride crystal substrate 206 having a {20-21} plane which is a semipolar plane as a main surface is obtained.

  The group 13 nitride crystal substrate 206 is a substrate obtained by processing the group 13 nitride crystal 205 whose main growth surface is the {10-11} plane. , Growth stripes parallel to the {10-11} plane are formed.

  These growth stripes are formed due to fluctuations in the growth rate during crystal growth. Here, since fluctuations in the crystal growth rate cause fluctuations in the incorporation of impurities, the growth fringes are observed as differences in emission intensity and emission color when observed with a fluorescence microscope.

Further, since the mixed melt in which the group 13 nitride crystal is grown contains alkali metal, the crystal of the group 13 nitride substrate of the present invention contains a trace amount of alkali metal as an impurity. In a GaN crystal grown using sodium as an alkali metal, 10 ¹⁴ to 10 ¹⁵ cm ⁻³ sodium is detected by SIMS analysis. The group 13 nitride crystal substrate 206 is a substrate obtained by processing the group 13 nitride crystal 205 whose main growth surface is the {10-11} plane. Inclusion of the mixture in the crystal as it is is suppressed.

  FIG. 14 is an explanatory view showing an example different from FIG. 13 of the processing method of the group 13 nitride crystal 205 manufactured in the second embodiment.

  First, both sides of the group 13 nitride crystal 205 shown in FIG. 13A are cut and formed into a triangular prism shape shown in FIG. Next, as shown in FIG. 14A, the group 13 nitride crystal 205 shaped into a triangular prism shape is sliced parallel to the {20-21} plane parallel to the longitudinal direction of the growth start region 204. (See FIG. 14 (b)).

  Next, the crystal 207 which is the sliced group 13 nitride crystal 205 is further processed into a desired size, and then the surface of the obtained crystal 208 is polished (see FIG. 14C). Further, a CMP process is performed (see FIG. 14D).

  Thereby, a group 13 nitride crystal substrate 209 having a {20-21} plane which is a semipolar plane as a main surface is obtained (see FIG. 14D).

  The obtained group 13 nitride crystal substrate 209 is a substrate obtained by processing the group 13 nitride crystal 205 whose main growth surface is the {10-11} plane. In 209, a growth stripe parallel to the {10-11} plane is formed.

  This growth stripe can be observed in the same manner as described above. In addition, since the group 13 nitride crystal substrate 209 is a substrate obtained by processing the group 13 nitride crystal 205 whose main growth surface is the {10-11} plane, the incorporation of inclusions is suppressed. .

  FIG. 15 is an explanatory diagram illustrating a case where the group 13 nitride crystal 205 manufactured in the second embodiment is processed so that a nonpolar surface is a main surface.

  First, both sides of the group 13 nitride crystal 205 shown in FIG. 13A are cut and formed into a triangular prism shape shown in FIG. Next, as shown in FIG. 15A, the group 13 nitride crystal 205 shaped into a triangular prism shape is sliced parallel to a {10-10} plane parallel to the longitudinal direction of the growth start region 204. (See FIG. 15 (a)).

  Next, the crystal 210 which is the sliced group 13 nitride crystal 205 is further processed into a desired size, and then the obtained crystals 210 or crystals 211 of various sizes are obtained (FIG. 15B and FIG. 15). 15 (c)) and further molded into a desired size (see FIG. 15 (d)).

  Further, the surface of the crystal 212 obtained by the molding is polished and further subjected to a CMP process (see FIG. 15E).

  As a result, a group 13 nitride crystal substrate 213 having a {10-10} plane which is a nonpolar plane as a main surface is obtained (see FIG. 15E).

  Since the obtained group 13 nitride crystal substrate 213 is a substrate obtained by processing group 13 nitride crystal 205 whose main growth surface is the {10-11} plane, this group 13 nitride crystal substrate is obtained. In 213, growth stripes parallel to the {10-11} plane are formed.

  This growth stripe can be observed in the same manner as described above. Further, since the group 13 nitride crystal substrate 213 is a substrate obtained by processing the group 13 nitride crystal 205 whose main growth surface is the {10-11} plane, the inclusion incorporation is suppressed. .

  FIG. 16 is an explanatory diagram showing a case where the group 13 nitride crystal 305 manufactured in the third embodiment is processed so as to have a semipolar surface as a main surface.

  First, as shown in FIG. 16A, the group 13 nitride crystal 305 manufactured in the third embodiment is sliced in parallel to the {20-21} plane intersecting the longitudinal direction of the growth start region 304. To do. Next, as shown in FIG. 16B, the surface of the sliced crystal is polished and then subjected to CMP treatment. By performing such processing, a triangular group 13 nitride crystal substrate 306 having a {20-21} plane as a main surface is obtained (FIG. 16B).

  Since the obtained group 13 nitride crystal substrate 306 is a substrate obtained by processing group 13 nitride crystal 305 whose main growth surface is a {10-11} plane, this group 13 nitride crystal substrate is obtained. In 306, a growth stripe parallel to the {10-11} plane is formed.

  This growth stripe can be observed in the same manner as described above. In addition, since the group 13 nitride crystal substrate 306 is a substrate obtained by processing the group 13 nitride crystal 305 whose main growth surface is the {10-11} plane, incorporation of inclusions is suppressed. .

  FIG. 17 is an explanatory view showing an example different from FIG. 16 of the processing method of the group 13 nitride crystal 305 manufactured in the third embodiment.

  First, both sides of the group 13 nitride crystal 305 shown in FIG. 16A are cut and formed into a triangular prism shape shown in FIG. Next, as shown in FIG. 17A, the group 13 nitride crystal 305 shaped into a triangular prism shape is sliced parallel to the {20-21} plane parallel to the longitudinal direction of the growth start region 304. (See FIG. 17 (a)).

  Next, after the crystal 307, which is the sliced group 13 nitride crystal 305, is further processed into a desired size, the surface of the obtained crystal 308 is polished (see FIG. 14B and FIG. 14C). ). Further, a CMP process is performed (see FIG. 14C).

  Thereby, a group 13 nitride crystal substrate 309 having a {20-21} plane which is a semipolar plane as a main surface is obtained (see FIG. 17D).

  Since the obtained group 13 nitride crystal substrate 309 is a substrate obtained by processing group 13 nitride crystal 305 whose main growth surface is the {10-11} plane, this group 13 nitride crystal substrate is obtained. In 309, a growth stripe parallel to the {10-11} plane is formed.

  This growth stripe can be observed in the same manner as described above. In addition, since the group 13 nitride crystal substrate 309 is a substrate obtained by processing the group 13 nitride crystal 305 whose main growth surface is the {10-11} plane, incorporation of inclusions is suppressed. .

  FIG. 18 is an explanatory diagram showing a case where the group 13 nitride crystal 305 manufactured in the third embodiment is processed so that a nonpolar surface is a main surface.

  First, both sides of the group 13 nitride crystal 305 shown in FIG. 16A are cut and formed into a triangular prism shape shown in FIG. Next, as shown in FIG. 18A, the group 13 nitride crystal 305 shaped into a triangular prism shape is sliced parallel to the {10-10} plane parallel to the longitudinal direction of the growth start region 304. (See FIG. 18 (a)).

  Next, after the sliced group 310 nitride crystal 305 crystal 310 is further processed into a desired size, the obtained crystals 310 or crystals 311 of a plurality of types of sizes are obtained (FIG. 18B and FIG. 18 (c)), and further molded into a desired size (see FIG. 18 (d)).

  Further, the surface of the crystal 311 obtained by the molding is polished and further subjected to CMP treatment (see FIG. 18D).

  As a result, a group 13 nitride crystal substrate 312 having a {10-10} plane which is a nonpolar plane as a main surface is obtained (see FIG. 18D).

  Since the obtained group 13 nitride crystal substrate 312 is a substrate obtained by processing group 13 nitride crystal 305 whose main growth surface is the {10-11} plane, this group 13 nitride crystal substrate is obtained. In 312, growth fringes parallel to the {10-11} plane are formed.

  This growth stripe can be observed in the same manner as described above. In addition, since the group 13 nitride crystal substrate 312 is a substrate obtained by processing the group 13 nitride crystal 305 whose main growth surface is the {10-11} plane, the inclusion incorporation is suppressed. .

  As described above, in this embodiment, group 13 nitride crystal substrates 206, 209, and 213 are manufactured from group 13 nitride crystals 105, 205, and 305 manufactured in the above embodiment.

  Therefore, the group 13 nitride substrates 206, 209, and 213 with reduced inclusion, distortion, and defects can be manufactured.

  In addition, the manufactured group 13 nitride substrate 206, 209, 213, 306, 309, 312 has a nonpolar or semipolar surface as a main surface, and a growth stripe parallel to the {10-11} surface is formed on the main surface. It is a substrate that has been.

  Therefore, it can be said that these group 13 nitride substrates 206, 209, and 213 are obtained by processing the substrates manufactured in the first to third embodiments. Therefore, it can be said that these group 13 nitride substrates 206, 209, 213, 306, 309, and 312 are group 13 nitride substrates with reduced inclusions, distortion, and defects.

  Next, a processing process for manufacturing a substrate having the {10-11} plane as a main surface will be described. The {10-11} plane which is a semipolar plane can be easily obtained by slicing a group 13 nitride crystal parallel to the {10-11} plane which is the main growth plane.

  In the case of the crystal 105 shown in FIG. 3, a group 13 nitride crystal having a {10-11} plane as a principal plane is obtained by slicing and processing the crystal 105 in parallel with the grown {10-11} plane. A substrate is obtained. At this time, by slicing the crystal 105 in parallel with the {10-11} plane formed by tilting α in the longitudinal direction of the growth start region 104 and processing the surface, the {10-11} plane having a large area is mainly processed. A group 13 nitride crystal substrate is obtained.

  Further, in the case of the crystal 205 shown in FIG. 8, a group 13 nitride having a {10-11} plane as a main surface is obtained by slicing and processing the crystal parallel to the grown {10-11} plane. A crystal substrate is obtained. At this time, by slicing and crystallizing the crystal 204 parallel to the {10-11} plane formed in parallel to the longitudinal direction of the growth start region 204, a large area {10-11} plane is obtained as the main surface. A group 13 nitride crystal substrate is obtained.

  Similarly, in the case of the crystal 305 shown in FIG. 12, the group 13 nitride having the {10-11} plane as the main surface is obtained by slicing and processing the crystal parallel to the grown {10-11} plane. A physical crystal substrate is obtained. At this time, by slicing and crystallizing the crystal 305 in parallel with the {10-11} plane formed parallel to the longitudinal direction of the growth start region 304, the {10-11} plane having a large area is the main surface. A group 13 nitride crystal substrate is obtained.

  The substrate having the {10-11} plane as the main surface manufactured in this way is obtained by processing the group 13 nitride crystals 105, 205, 305 whose main growth surface is the {10-11} plane. Incorporation of inclusions is suppressed because of the substrate.

  In addition, these group 13 nitride substrates 206, 209, 213, 306, 309, 312 and the aforementioned {10-11} plane substrate are nonpolar or semipolar planes. By using this to produce a light emitting device having an InGaN active layer, it is possible to suppress a decrease in light emission efficiency and blue shift of an InGaN active layer having a high In composition. As a result, a semiconductor laser that oscillates in the green wavelength region and a high-power LED can be manufactured.

  Examples are shown below to describe the present invention in more detail, but the present invention is not limited to these Examples. The reference numerals correspond to the respective configurations described above with reference to the drawings.

Example 1
In this example, the group 13 nitride crystal 105 was manufactured by performing crystal growth using the manufacturing apparatus 4 along the process shown in FIG.

  First, a φ2 inch c-plane sapphire substrate was used as the base substrate 101 (see FIG. 1A).

―First step―
Next, a template substrate 100 was fabricated by epitaxially growing a GaN layer as the group 13 nitride layer 102 on this sapphire substrate by MOCVD. (See FIG. 1 (b)). The epitaxial growth of the GaN layer by MOCVD was performed by a general two-step growth in which a low-temperature GaN buffer layer was grown and then a high-temperature GaN layer was grown.

  Next, a sapphire substrate having stripe-like through holes was prepared as a mask region 103 and placed on a GaN layer as a group 13 nitride layer 102. A region exposed from the through hole of the sapphire substrate (c-plane of the GaN layer) in this GaN layer was defined as a growth start region 104. Thus, a substrate 100A on which the group 13 nitride layer 102 and the mask region 103 were formed was manufactured.

  The length of the growth start region 104 in the longitudinal direction was 45 mm, and the width was 500 μm. Further, the angle α formed by the long direction of the growth start region 104 and the a-axis of the GaN layer constituting the growth start region 104 was about 5 ° (see FIG. 2).

-2nd process-3rd process-
Next, the 2nd process and the 3rd process were performed using manufacturing device 1 shown in FIG.

  First, the pressure vessel 11 was separated from the manufacturing apparatus 1 at the valve 21 portion and placed in a glove box having a high-purity Ar atmosphere with oxygen of 1 ppm or less and a dew point of −80 ° C. or less. Next, the substrate 100A manufactured in this example was placed in a reaction vessel 12 made of YAG and having an inner diameter of 92 mm. Next, 250 g of gallium (Ga) as a group 13 metal raw material and 195 g of sodium (Na) as a flux were charged into the reaction vessel 12. The molar ratio of gallium to sodium was 0.3: 0.7. Further, 0.9 g of carbon was added to the reaction vessel 12. Next, the reaction vessel 12 was installed in the pressure vessel 11.

  Next, the pressure vessel 11 was sealed, the valve 21 was closed, and the inside of the reaction vessel 12 was shut off from the external atmosphere. The series of operations in the manufacturing apparatus 1 were performed in a glove box having a high-purity Ar gas atmosphere. For this reason, the pressure vessel 11 was filled with Ar gas.

  Then, the pressure vessel 11 was taken out of the glove box and incorporated in the manufacturing apparatus 1. Specifically, the pressure vessel 11 was installed at a predetermined position of the heater 13 and connected to a nitrogen and argon gas supply pipe 14 at the valve 21 portion. Next, the valve 21 and the valve 18 are opened, Ar gas is introduced from the gas supply pipe 20, and the pressure is adjusted by the pressure control device 19 to adjust the total pressure in the pressure vessel 11 to 2.5 MPa. Closed.

  Next, nitrogen gas was introduced from the nitrogen supply pipe 17, the pressure was adjusted by the pressure control device 16, the valve 15 was opened, and the total pressure in the pressure-resistant vessel 11 was 4 MPa. That is, the partial pressure of nitrogen in the internal space 23 of the pressure vessel 11 was 1.5 MPa. Thereafter, the valve 15 was closed and the pressure control device 16 was set to 8 MPa.

  Next, the heater 13 was energized, and the reaction vessel 12 was heated to the crystal growth temperature. The crystal growth temperature was 870 ° C. At the crystal growth temperature, gallium and sodium in the reaction vessel 12 melted to form a mixed melt. The temperature of the mixed melt is the same as the temperature of the reaction vessel 12. When the temperature was raised to this temperature, in the apparatus of this example, the gas in the pressure vessel 11 was heated and the total pressure became 8 MPa. That is, the nitrogen partial pressure was 3 MPa.

  Subsequently, the valve 15 was opened and the nitrogen gas pressure was set to 8 MPa. This is because the nitrogen partial pressure in the pressure vessel 11 is maintained at 3 MPa even when nitrogen is consumed by crystal growth of gallium nitride.

  In this way, nitrogen was dissolved in the mixed melt, and crystal growth of GaN as the group 13 nitride crystal 105 was started from the growth start region 104 formed on the main surface of the substrate 100A (see FIG. 1D). .

  Then, crystal growth was continued for 1000 hours with the temperature in the reaction vessel 12 kept at 870 ° C. and the nitrogen gas partial pressure at 3 MPa. At this time, it was confirmed that GaN, which is a group 13 nitride crystal 105, spreads from the growth start region 104 (GaN layer) and grows on the sapphire substrate which is the mask region 103. Further, it was confirmed that the {10-11} plane became the main crystal growth plane and the crystal growth continued while the c plane was slightly formed (see FIGS. 1 (e) to 1 (g)). ).

  And after continuing crystal growth for 1000 hours, electricity supply to the heater 13 was stopped and the temperature of the mixed melt 24 was lowered to room temperature. When the pressure vessel 11 was opened after the pressure of the gas in the pressure vessel 11 was lowered, a GaN crystal was grown as a group 13 nitride crystal 105 on the substrate 100A in the reaction vessel 12.

-Fourth step-
After the crystal growth, when the sapphire substrate that is the mask region 103 is slightly shifted, the growth start region 104 portion formed on the substrate 100A in the GaN crystal that is the group 13 nitride crystal 105 is broken, and the GaN crystal is separated cleanly. (See FIG. 1 (h)).

―Evaluation of group 13 nitride crystals―
In the GaN crystal obtained by this crystal growth, the {10-11} plane is the main crystal growth plane, and a c-plane is slightly formed on the top of the crystal, so that it is perpendicular to the longitudinal direction of the growth start region 104. The cross-sectional shape was a trapezoid (see FIG. 3B).

  In the present embodiment, the angle formed by the long direction of the growth start region 104 and the a-axis of the GaN layer constituting the growth start region 104 is set to about 5 °. A plurality of {10-11} planes shifted toward the direction intersecting the longitudinal direction were formed on the crystal plane corresponding to the inclined surface, and the surface had irregularities. (See FIG. 3 (a)).

  The size of the grown GaN crystal as the group 13 nitride crystal 105 is such that the length in the direction along the longitudinal direction of the growth start region 104 is about 85 mm, and the width of the bottom surface corresponding to the lower side of the trapezoidal cross section is 40 mm. The upper portion corresponding to the upper side had a length of about 45 mm and a height of about 32 mm.

As a result of SIMS (Secondary Ion Mass Spectrometry) analysis of the GaN crystal as the group 13 nitride crystal 105, 10 ¹⁴ to 10 ¹⁵ cm ⁻³ of sodium was detected.

(Example 2)
In this example, the growth start region was formed so that the long direction of the growth start region was parallel to the a-axis of GaN constituting the growth start region, and crystal growth was performed.

  In this example, the group 13 nitride crystal 205 was manufactured by performing crystal growth using the manufacturing apparatus 4 along the steps shown in FIG.

  First, a φ2 inch GaN substrate having a c-plane as a main surface was prepared as the base substrate 200.

―First step―
Next, a mask region 203 having a straight through-hole formed in a sapphire substrate was prepared. Then, this mask region 203 was placed on a GaN substrate as the base substrate 200. A region (c-plane of the GaN substrate) exposed from the through hole of the mask region 203 in this GaN layer was used as the growth start region 204. Thus, a substrate 200A on which the mask region 203 and the growth start region 204 were formed was manufactured.

  The length in the longitudinal direction of the growth start region 204 was 45 mm and the width was 500 μm. Further, the longitudinal direction of the growth start region 204 and the a axis of the GaN substrate constituting the growth start region 204 were parallel (see FIG. 7).

-2nd process-3rd process-
Next, using the manufacturing apparatus 1 shown in FIG. 4, under the same crystal growth conditions as in Example 1, except that the substrate 200 </ b> A manufactured in this example was used instead of the substrate 100 </ b> A used in Example 1. The 2nd process and the 3rd process were performed.

  In this embodiment, in the mixed melt 24, a GaN crystal (see FIG. 6C) as the group 13 nitride crystal 205 that has started crystal growth from the growth start region 204 is transferred to the mask region by continuing the crystal growth. It was confirmed that the crystal grew on the sapphire substrate 203. Further, it was confirmed that the growth continued with the {10-11} plane of the GaN crystal as the group 13 nitride crystal 205 being the main growth plane due to the continuation of this crystal growth (FIG. 6D). -Refer FIG.6 (f)).

  After the crystal growth time of 1000 hours, the heater 13 was turned off, and the temperature of the mixed melt 24 was lowered to room temperature. When the pressure vessel 11 was opened after the pressure of the gas in the pressure vessel 11 was lowered, a GaN crystal was grown on the substrate 200A in the reaction vessel 12.

-Fourth step-
After the crystal growth, when the sapphire substrate that is the mask region 203 is slightly shifted, the growth start region 204 portion formed on the substrate 200A in the GaN crystal that is the group 13 nitride crystal 205 is broken and the GaN crystal is separated cleanly. (See FIG. 6 (g)).

―Evaluation of group 13 nitride crystals―
As shown in FIGS. 8 and 13A, the GaN crystal obtained by this crystal growth has a shape in which the surface not in contact with the mask region 203 is surrounded by the {10-11} plane, The {10-11} plane continuous to the ridge line parallel to the longitudinal direction of the growth start region 204 had the widest shape. Further, since the {10-11} plane grew as the main crystal growth surface, the GaN crystal obtained by crystal growth had a triangular cross-sectional shape perpendicular to the longitudinal direction of the growth start region 204 (FIG. 13 (b)).

  Further, in this embodiment, since the longitudinal direction of the growth start region 204 and the a-axis of the GaN substrate constituting the growth start region 204 are parallel, {10-11} corresponding to the slope of the cross-sectional shape triangle The surface was a surface formed substantially flat along the longitudinal direction (see FIGS. 13A and 7A).

  The size of the GaN crystal as the grown group 13 nitride crystal 205 is such that the length in the direction along the longitudinal direction of the growth start region 204 is about 85 mm, the width of the bottom surface corresponding to the lower side of the triangular cross section is 40 mm, The height was about 35 mm.

―Manufacture of group 13 nitride crystal substrate―
Next, the GaN crystal as the group 13 nitride crystal 205 produced in this example was processed to produce a group 13 nitride crystal substrate.

  First, as shown in FIG. 13A, the GaN crystal as the group 13 nitride crystal 205 produced in this example is parallel to the {20-21} plane intersecting the longitudinal direction of the growth start region 204. Sliced into Next, the surface of the sliced GaN crystal was polished and then subjected to CMP treatment.

  In this way, a triangular semipolar GaN crystal substrate (group 13 nitride crystal substrate 206) having a {20-21} plane as a main surface was obtained (see FIG. 13B).

―Evaluation of group 13 nitride crystal substrate―
When the main surface of the manufactured semipolar GaN crystal substrate (group 13 nitride crystal substrate 206) was observed with a fluorescence microscope, growth fringes could be observed. The growth stripe was formed in parallel to the {10-11} plane. In this semipolar GaN crystal substrate, 10 ¹⁴ to 10 ¹⁵ cm ⁻³ of sodium was detected by SIMS analysis.

(Example 3)
In this example, a GaN crystal as the group 13 nitride crystal 205 manufactured in the same manner as in Example 2 was processed differently from Example 2 to produce a Group 13 nitride crystal substrate.

First, as shown in FIG. 14A, both sides of the GaN crystal as the group 13 nitride crystal 205 produced in Example 2 were cut and formed into a triangular prism shape. Next, as shown in FIG. 14A, the molded GaN crystal was sliced parallel to the {20-21} plane parallel to the longitudinal direction of the growth start region 204. The maximum size of the sliced crystal 207 was 45 × 36 mm ² (see FIG. 14B).

  Next, the sliced crystal 207 was further molded into a desired size, the surface of the crystal 208 after molding was polished, and then subjected to CMP treatment (see FIG. 14C).

  Thus, a tetragonal semipolar GaN crystal substrate having a {20-21} plane as a main surface was obtained as the group 13 nitride crystal substrate 209 (see FIG. 14D).

―Evaluation of group 13 nitride crystal substrate―
When the main surface of the manufactured semipolar GaN crystal substrate (Group 13 nitride crystal substrate 209) was observed with a fluorescence microscope, growth fringes could be observed. The growth stripe was formed in parallel to the {10-11} plane. In this semipolar GaN crystal substrate, 10 ¹⁴ to 10 ¹⁵ cm ⁻³ of sodium was detected by SIMS analysis.

Example 4
In this example, a GaN crystal as the group 13 nitride crystal 205 manufactured in the same manner as in Example 2 was processed differently from Example 2 to produce a Group 13 nitride crystal substrate.

First, as shown in FIG. 15A, both sides of a GaN crystal as the group 13 nitride crystal 205 produced in Example 2 were cut and formed into a triangular prism shape. Next, as shown in FIG. 15A, the slice was parallel to the {10-10} plane parallel to the long direction of the growth start region 204. The size of the sliced crystal 210 varied, but the largest crystal 211 was 45 × 35 mm ² (see FIGS. 15B and 15C).

  Next, the sliced crystal 210 was further molded into a desired size, the surface of the crystal 212 after molding was polished, and then subjected to CMP treatment (see FIG. 15D).

  Thus, a square nonpolar GaN crystal substrate having a {10-10} plane as a main surface was obtained as the group 13 nitride crystal substrate 213 (see FIG. 15E).

―Evaluation of group 13 nitride crystal substrate―
When the main surface of the produced nonpolar GaN crystal substrate (group 13 nitride crystal substrate 213) was observed with a fluorescence microscope, growth fringes could be observed. The growth stripes were formed in parallel to the {10-11} plane (see FIG. 15 (e)). In this nonpolar GaN crystal substrate, 10 ¹⁴ to 10 ¹⁵ cm ⁻³ of sodium was detected by SIMS analysis.

(Example 5)
In this embodiment, the growth start region is the m-plane of the group 13 nitride layer, and the longitudinal direction of the growth start region is parallel to the a-axis direction of the group 13 nitride layer constituting the growth start region. Then, a growth start region was formed and crystal growth was performed.

  In this example, the group 13 nitride crystal 305 was manufactured by performing crystal growth using the manufacturing apparatus 4 along the steps shown in FIG.

―First step―
First, as a template substrate 300, a φ2-inch template substrate 300 having a m-plane as a main surface, in which GaN is formed as a group 13 nitride layer 302 on a sapphire substrate as a base substrate 301, was prepared (FIG. 10). (See (a)).

  Next, on the main surface of the template substrate 300, a sapphire substrate with a linear through hole was placed to form a mask region 303. Then, a region exposed from the through hole in the GaN layer as the group 13 nitride layer 302 (that is, the m-plane of the GaN layer) was defined as a growth start region 304 (FIG. 10B). Thus, the substrate 300A on which the mask region 303 and the growth start region 304 were formed was manufactured.

  The length in the longitudinal direction of the growth start region 304 was 40 mm and the width was 500 μm. Further, the longitudinal direction of the growth start region 304 and the a-axis of the GaN layer that is the group 13 nitride layer 302 constituting the growth start region 304 were parallel (see FIG. 9A).

-2nd process-3rd process-
Next, using the manufacturing apparatus 1 shown in FIG. 4, under the same crystal growth conditions as in Example 1, except that the substrate 300 </ b> A manufactured in this example was used instead of the substrate 100 </ b> A used in Example 1. The 2nd process and the 3rd process were performed.

  In this embodiment, in the mixed melt 24, the GaN crystal (see FIG. 10C) as the group 13 nitride crystal 305 that has started crystal growth from the growth start region 304 is changed into the mask region by continuing the crystal growth. It was confirmed that it spreads to 303 and grows. In this example, it was confirmed that the GaN crystal as the group 13 nitride crystal 305 grew while forming the {10-11} plane and the (000-1) N polar plane. 1) The growth rate of the N-polar plane was very slow, and the GaN crystal grew in the [0001] direction (see FIGS. 10 (d) to 10 (f)).

  After the crystal growth time of 1000 hours, the heater 13 was turned off, and the temperature of the mixed melt 24 was lowered to room temperature. When the pressure vessel 11 was opened after the pressure of the gas in the pressure vessel 11 was lowered, GaN crystals were grown on the substrate 300A in the reaction vessel 12.

-Fourth step-
After crystal growth, when the sapphire substrate, which is the mask region 303, is slightly shifted, the growth start region 304 portion formed on the substrate 300A in the GaN crystal, which is the group 13 nitride crystal 305, is broken and the GaN crystal is separated cleanly. (See FIG. 10 (g)).

―Evaluation of group 13 nitride crystals―
As shown in FIGS. 11 and 12, the GaN crystal, which is a group 13 nitride crystal 305 obtained by this crystal growth, has a (000-1) plane which is not in contact with the mask region 303 and a {10-11} plane. In the mask region 303, the {10-11} plane parallel to the longitudinal direction of the growth start region 304 was the widest shape.

  In addition, since the GaN crystal that is the group 13 nitride crystal 305 is grown while forming the {10-11} plane and the (000-1) N polar plane, it is perpendicular to the main surface of the base substrate 300 (000-1). A crystal in which the cross section perpendicular to the longitudinal direction of the growth start region 304 and the main surface of the template substrate 300 is a right-angled triangle with the N-polar plane as the bottom and the {10-11} plane as the slope (FIG. 11). (B), see FIG.

  Further, in this example, in this example, the long direction of the growth start region 204 and the a-axis of the GaN substrate constituting the growth start region 304 are parallel to each other. The {10-11} plane to be formed was a plane formed substantially flat along the longitudinal direction (see FIGS. 11A and 12).

  The size of the GaN crystal as the grown group 13 nitride crystal 305 is about 80 mm in the length direction along the longitudinal direction of the growth start region 304, about 35 mm in the perpendicular direction, and about 35 mm in height. (See FIG. 12).

―Manufacture of group 13 nitride crystal substrate―
Next, the GaN crystal as the group 13 nitride crystal 305 produced in this example was processed to produce a group 13 nitride crystal substrate.

  First, as shown in FIG. 16A, the GaN crystal as the group 13 nitride crystal 305 produced in this example is parallel to the {20-21} plane intersecting the long direction of the growth start region 304. Sliced into Next, the surface of the sliced GaN crystal was polished and then subjected to CMP treatment.

  Thus, a triangular semipolar GaN crystal substrate (group 13 nitride crystal substrate 306) having a {20-21} plane as a main surface was obtained (see FIG. 16B).

―Evaluation of group 13 nitride crystal substrate―
When the main surface of the manufactured semipolar GaN crystal substrate (group 13 nitride crystal substrate 306) was observed with a fluorescence microscope, growth fringes could be observed. The growth stripe was formed in parallel to the {10-11} plane. In this semipolar GaN crystal substrate, 10 ¹⁴ to 10 ¹⁵ cm ⁻³ of sodium was detected by SIMS analysis.

(Example 6)
In this example, a GaN crystal as the group 13 nitride crystal 305 manufactured in the same manner as in Example 5 was processed differently from that in Example 5 to produce a Group 13 nitride crystal substrate.

First, as shown in FIG. 17A, both sides of the GaN crystal as the group 13 nitride crystal 305 manufactured in Example 5 were cut and formed into a triangular prism shape. Next, as shown in FIG. 17A, the molded GaN crystal was sliced parallel to the {20-21} plane parallel to the long direction of the growth start region 304. The maximum size of the sliced crystal 307 was 40 × 35 mm ² (see FIG. 17B).

  Next, the sliced crystal 307 was further molded into a desired size, the surface of the crystal 308 after molding was polished, and then subjected to CMP treatment (see FIG. 17C).

  Thus, a tetragonal semipolar GaN crystal substrate having a {20-21} plane as a main surface was obtained as a group 13 nitride crystal substrate 309 (see FIG. 17D).

―Evaluation of group 13 nitride crystal substrate―
When the main surface of the manufactured semipolar GaN crystal substrate (group 13 nitride crystal substrate 309) was observed with a fluorescence microscope, growth fringes could be observed. The growth stripes were formed in parallel to the {10-11} plane (see FIG. 17 (d)). In this semipolar GaN crystal substrate, 10 ¹⁴ to 10 ¹⁵ cm ⁻³ of sodium was detected by SIMS analysis.

(Example 7)
In this example, a GaN crystal as the group 13 nitride crystal 305 manufactured in the same manner as in Example 5 was processed differently from that in Example 5 to produce a Group 13 nitride crystal substrate.

First, as shown in FIG. 16A, both sides of the GaN crystal as the group 13 nitride crystal 305 manufactured in Example 5 were cut and formed into a triangular prism shape. Next, as shown in FIG. 18A, the slice was parallel to the {10-10} plane parallel to the longitudinal direction of the growth start region 304. Although the size of the sliced crystal 310 varied, it was a maximum of 40 × 35 mm ² (see FIG. 18B).

  Next, the sliced crystal 310 was further molded into a desired size, the surface of the crystal 311 after molding was polished, and then subjected to CMP treatment (see FIG. 18C).

  Thus, a square nonpolar GaN crystal substrate having a {10-10} plane as a main surface was obtained as the group 13 nitride crystal substrate 312 (see FIG. 18D).

―Evaluation of group 13 nitride crystal substrate―
When the main surface of the produced nonpolar GaN crystal substrate (group 13 nitride crystal substrate 312) was observed with a fluorescence microscope, growth fringes could be observed. The growth stripes were formed in parallel to the {10-11} plane (see FIG. 18 (d)). In this nonpolar GaN crystal substrate, 10 ¹⁴ to 10 ¹⁵ cm ⁻³ of sodium was detected by SIMS analysis.

103, 203, 303 Mask region 104, 204, 304 Growth start region 105, 205, 305 Group 13 nitride crystal 206, 209, 213, 306, 309, 312 Group 13 nitride crystal substrate

International Publication No. 10/092736 JP 2005-12171 A JP 2010-37153 A

Claims (6)

In a method for producing a group 13 nitride crystal, wherein nitrogen is dissolved from a gas phase in a mixed melt containing at least an alkali metal and a group 13 metal, and a nitride crystal is grown in the mixed melt.
The main surface of the base substrate, made of a material nitride crystal may initiate crystal growth, thereby forming the main surface linear growth starting region along a, in a region other than the growth initiation region in the main surface A first step of forming a mask region in which a mask made of a material that inhibits nucleation of nitride crystals and does not inhibit crystal growth of nitride crystals;
A second step of starting the crystal growth of the nitride crystal from the growth start region in the mixed melt;
Crystal growth with a {10-11} plane of a nitride crystal grown from the growth start region as a main growth surface, and crystal growth from the growth start region toward the mask region continuous to the growth start region A third step to continue;
A method for producing a group 13 nitride crystal. 2. The method for producing a group 13 nitride crystal according to claim 1, wherein a plurality of the growth start regions are arranged at intervals along the main surface. 3. Said growth initiation region is a c-plane of the group 13 nitride layer, the longitudinal direction of said growth initiation region is substantially parallel to the a-axis of the group 13 nitride layer, according to claim 1 or claim 2 A method for producing a group 13 nitride crystal of Said growth initiation region is the m-plane of the group 13 nitride layer, the longitudinal direction of said growth initiation region is substantially parallel to the a-axis of the group 13 nitride layer, according to claim 1 or claim 2 A method for producing a group 13 nitride crystal of The group 13 nitride crystal produced by the method for producing a group 13 nitride crystal according to any one of claims 1 to 4 is processed so as to have a nonpolar plane or a semipolar plane as a principal plane. A manufacturing method of a group 13 nitride crystal substrate including a processing step.   A group 13 nitride crystal substrate having a nonpolar plane or a semipolar plane as a main surface, and the main surface has growth stripes parallel to a {10-11} plane.

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