JP2013001624A - Group iii nitride composite substrate, and evaluation method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a group III nitride composite substrate and an evaluation method thereof, capable of evaluating whether or not a group III nitride thin film is arranged on a group III nitride support substrate, even if both the group III nitride support substrate and the group III nitride thin film have the substantially same chemical composition.SOLUTION: This group III nitride composite substrate 1 satisfies at least one condition of a deviation angle between a condition wherein a deviation angle Δφ between an optionally specified a-axis 21a of the group III nitride thin film 21 and an a-axis 10a of the group III nitride support substrate 10 which is the nearest to the a-axis 21a of the group III nitride thin film 21 is larger than 0° and smaller than 60°, and a condition wherein a deviation angle Δψ between a c-axis 21c of the group III nitride thin film 21 and a c-axis 10c of the group III nitride support substrate 10 is larger than 0° and smaller than 90°.

Description

  The present invention relates to a group III nitride composite substrate suitably used for a semiconductor device and an evaluation method thereof.

  In a group III nitride semiconductor device, a plurality of group III nitride semiconductor layers are generally formed as a semiconductor layer on a sapphire substrate. For this reason, in the group III nitride semiconductor device, threading dislocations are generated at a high density in the group III nitride semiconductor layer due to the difference in physical properties between the sapphire substrate and the group III nitride semiconductor layer, and the threading dislocations are generated in the semiconductor device. It was a cause of deteriorating the characteristics. For example, when the semiconductor device is an LED (light emitting diode), threading dislocations generated in the light emitting layer in the group III nitride semiconductor layer behave as non-light emitting recombination centers. The emission intensity of the area is reduced, and the brightness of the LED is reduced.

  On the other hand, high-brightness LEDs (Group III nitride semiconductor devices) using a Group III nitride substrate with a low density of threading dislocations whose physical properties are the same as or similar to those of a Group III nitride semiconductor layer have been developed. . However, since such a group III nitride substrate is expensive, there is a problem that the manufacturing cost of the group III nitride semiconductor device is increased.

  In order to solve the above problem, Japanese translations of PCT publication No. 2004-517472 (patent document 1) transfers a seed layer (thin film) such as GaN onto a support (support substrate) by adhesion of molecules to an adhesive interface, A method for forming an epitaxy of an effective layer and separating an assembly constituted by a seed layer and an effective layer from a support at an adhesive interface is disclosed.

JP-T-2004-517472

  In the method disclosed in JP-T-2004-517472 (Patent Document 1), an effective layer such as GaN is epitaxially grown as a support (support substrate) on a seed layer (thin film) such as GaN formed on the support. In view of the above, it is preferable that the epitaxial layer has a high temperature durability of about 1000 ° C. or higher, and the thermal expansion coefficient thereof is the same as or close to that of the seed layer and the effective layer. From this point of view, in order to form a group III nitride semiconductor device by epitaxially growing a group III nitride semiconductor effective layer on the seed layer, the support (support substrate) and the seed layer (thin film) have the same chemical composition. It is preferably formed of a group III nitride. That is, a group III nitride support substrate and a group III nitride thin film disposed on the group III nitride support substrate to form a group III nitride semiconductor device, the group III nitride support substrate and the group III nitride It is preferable to form a composite substrate in which the nitride thin film is formed of a group III nitride having the same chemical composition.

  However, in a composite substrate in which the group III nitride supporting substrate and the group III nitride thin film are formed of group III nitride having the same chemical composition, the group III nitride thin film is surely arranged on the group III nitride supporting substrate. It is extremely difficult to evaluate whether or not

  Therefore, in the present invention, even when the group III nitride supporting substrate and the group III nitride thin film have substantially the same chemical composition, the group III nitride thin film is disposed on the group III nitride supporting substrate. It is an object of the present invention to provide a group III nitride composite substrate that can be evaluated whether or not it exists and a method for evaluating the same.

  The present invention includes a group III nitride support substrate and a group III nitride thin film disposed on the group III nitride support substrate, wherein the group III nitride thin film and the group III nitride support substrate have substantially the same chemical composition. A group III nitride composite substrate formed of a group III nitride, wherein the a axis of the group III nitride thin film is arbitrarily specified, and the group III nitride closest to the a axis of the group III nitride thin film The deviation angle Δφ between the object support substrate and the a-axis is greater than 0 ° and less than 60 °, and the displacement between the c-axis of the group III nitride thin film and the c-axis of the group III nitride support substrate This is a group III nitride composite substrate that satisfies the condition of at least one deviation angle in which the angle Δψ is larger than 0 ° and smaller than 90 °.

  In the group III nitride composite substrate according to the present invention, the shift angle Δφ can be made larger than 1 ° and smaller than 59 °. Further, the deviation angle Δψ can be made larger than 0.01 ° and smaller than 10 °.

  The present invention is also a method for evaluating a group III nitride composite substrate as described above, wherein in a group III nitride thin film and a group III nitride support substrate, the diffraction of a surface not parallel to the (0001) plane is maintained and φ X-ray diffraction method that scans the angle, and scans the ω angle while maintaining the diffraction of the plane parallel to the (0001) plane by making X-rays incident from the shift direction of the shift angle Δψ or the direction opposite to the shift direction. This is an evaluation method for a group III nitride composite substrate in which the arrangement of the group III nitride thin film and the group III nitride support substrate is evaluated by using at least one X-ray diffraction method.

  According to the present invention, even if the group III nitride supporting substrate and the group III nitride thin film have substantially the same chemical composition, the group III nitride thin film is disposed on the group III nitride supporting substrate. It is possible to provide a group III nitride composite substrate and a method for evaluating the same.

It is the schematic which shows an example of the group III nitride composite substrate concerning this invention. It is the schematic which shows an example of the method of manufacturing the group III nitride composite substrate concerning this invention. It is the schematic which shows an example of the X-ray diffraction of the crystal | crystallization used in the evaluation method of the group III nitride composite substrate concerning this invention. 1 is a schematic view showing a group III nitride composite substrate in Example 1. FIG. 3 is a schematic diagram showing X-ray diffraction of a group III nitride composite substrate in Example 1. FIG. 6 is a schematic view showing a group III nitride composite substrate in Example 2. FIG. 6 is a schematic diagram showing X-ray diffraction of a group III nitride composite substrate in Example 2. FIG. 6 is a schematic view showing a group III nitride composite substrate in Example 3. FIG. 6 is a schematic diagram showing X-ray diffraction of a group III nitride composite substrate in Example 3. FIG. 6 is a schematic view showing a group III nitride composite substrate in Example 4. FIG. 6 is a schematic diagram showing X-ray diffraction of a group III nitride composite substrate in Example 4. FIG. 6 is a schematic view showing a group III nitride composite substrate in Example 5. FIG. 6 is a schematic diagram showing X-ray diffraction of a group III nitride composite substrate in Example 5. FIG. 3 is a schematic view showing a group III nitride composite substrate in Comparative Example 1. FIG. 6 is a schematic diagram showing X-ray diffraction of a group III nitride composite substrate in Comparative Example 1. FIG.

[Embodiment 1]
(Group III nitride composite substrate)
Referring to FIG. 1, a group III nitride composite substrate 1 according to an embodiment of the present invention includes a group III nitride support substrate 10 and a group III nitride thin film 21 disposed on the group III nitride support substrate 10. And a group III nitride thin film 21 and a group III nitride supporting substrate 10 are formed of group III nitride having substantially the same chemical composition, and an a-axis 21a arbitrarily specified for the group III nitride thin film 21; The deviation angle Δφ between the group III nitride thin film 21 and the a axis 10a of the group III nitride supporting substrate 10 closest to the a axis 21a is larger than 0 ° and smaller than 60 °, and the group III nitride The deviation angle Δψ between the c-axis 21c of the thin film 21 and the c-axis 10c of the group III nitride support substrate 10 satisfies the condition of at least one deviation angle that is greater than 0 ° and less than 90 °.

  The group III nitride composite substrate 1 of the present embodiment includes a group III nitride support substrate 10 and a group III nitride thin film 21 disposed on the group III nitride support substrate 10. Since group 21 and group III nitride support substrate 10 are formed of group III nitride having substantially the same chemical composition, is group III nitride thin film 21 surely disposed on group III nitride support substrate 10? It was difficult to evaluate whether or not.

That is, in the group III nitride composite substrate 1 of the present embodiment, the group III nitride forming the group III nitride thin film 21 and the group III nitride supporting substrate 10 have substantially the same chemical composition. Those in a range that cannot be distinguished from each other in diffraction. That is, the group III nitride forming the group III nitride thin film 21 and the group III nitride support substrate 10 is both Al _x Ga _1-x N (0 ≦ x ≦ 1, x = 0, GaN, x = 1 The group III nitride thin film 21 is Al _x1 Ga _1-x1 N (0 ≦ x1 ≦ 1) and the group III nitride supporting substrate 10 is Al _x0 Ga _1-x0 N (0 ≦ x0 ≦ 1) and | x1-x0 | ≦ 0.05 is also included.

  In the group III nitride composite substrate 1 of the present embodiment, the group III nitride thin film 21 and the group III nitride support substrate 10 each have a wurtzite crystal structure that is a hexagonal system. Therefore, each of the group III nitride thin film 21 and the group III nitride support substrate 10 includes a c-axis that is a six-fold rotational symmetry axis, and six a-axes that are six-fold rotational symmetry perpendicular to the c-axis. Have. Here, the c-axis is the <0001> direction axis, and the a-axis is the <11-20> direction axis.

  The group III nitride composite substrate 1 of this embodiment includes an a-axis 21a arbitrarily specified for the group-III nitride thin film 21 and a group-III nitride support substrate closest to the a-axis 21a of the group-III nitride thin film 21. 10 is larger than 0 ° and smaller than 60 °, and the c-axis 21c of the group III nitride thin film 21 and the c-axis 10a of the group III nitride supporting substrate 10 The diffraction intensity peak of the group III nitride thin film 21 measured by X-ray diffraction and the group III nitride are satisfied in order to satisfy the condition of at least one of the angle of deviation Δψ between which is larger than 0 ° and smaller than 90 °. By separating the diffraction intensity peak of the support substrate 10, it can be evaluated that the group III nitride thin film 21 is surely disposed on the group III nitride support substrate 10. From this point of view, the deviation angle Δφ is preferably larger than 1 ° and smaller than 59 °, more preferably larger than 15 ° and smaller than 45 °. The deviation angle Δψ is preferably larger than 0.01 °, more preferably larger than 0.1 °. The nitride crystal has a different thermal expansion coefficient between the c-axis direction and the a-axis direction, so that the difference in thermal expansion coefficient between the group III nitride thin film 21 and the group III nitride support substrate 10 is reduced. The deviation angle Δψ is preferably smaller than 10 °, and more preferably smaller than 1 °.

  As for the group III nitride composite substrate 1, the outer edge of the group III nitride thin film 21 is drawn slightly inside the outer edge of the group III nitride support substrate 10 in FIG. This is to make it clear that the group III nitride thin film 21 is disposed on the object support substrate 10, and the outer edges of the group III nitride thin film 21 and the group III nitride support substrate 10 usually coincide.

  Further, the group III nitride composite substrate 1 is depicted in FIG. 1 as having a group III nitride thin film 21 bonded and disposed directly on the group III nitride support substrate 10. The nitride support substrate 10 and the group III nitride thin film 21 may be disposed to be joined with at least one intermediate layer (not shown) interposed therebetween.

  Referring to FIG. 1, group III nitride composite substrate 1 makes it easy to dispose group III nitride thin film 21 on group III nitride support substrate 10 at the predetermined deviation angles Δφ and Δψ. From the viewpoint, it is preferable that the group III nitride supporting substrate 10 and the group III nitride thin film 21 are provided with OF (orientation flat) 10 of, 21 of and IF (identification flat) 10 if, 21 if, respectively.

(Method for producing group III nitride composite substrate)
The method for producing the group III nitride composite substrate 1 of the present embodiment is not particularly limited, but the deviation angle Δφ is larger than 0 ° and smaller than 60 °, and the deviation angle Δφ is larger than 0 ° and From the viewpoint of at least one of being less than 90 °, a method of bonding the group III nitride thin film 21 on the group III nitride supporting substrate 10 is preferable.

  Referring to FIG. 2, specifically, the method of manufacturing the group III nitride composite substrate 1 of the present embodiment includes one of the group III nitride substrates 20 for forming a thin film as shown in FIG. FIG. 2B shows a step of implanting ions I such as hydrogen, helium, nitrogen, and oxygen into a surface having a depth D from the main surface side (this surface becomes the ion implantation region 20i). As shown in FIG. 2 (C), the main surface of the thin film forming group III nitride substrate 20 on which the ions are implanted and the one main surface of the group III nitride support substrate 10 are bonded together. ) By applying heat, stress, etc. to the group III nitride supporting substrate 10 and the group III nitride substrate 20 for forming a thin film, as shown in FIG. In the implantation region 20i, a group III nitride for forming a thin film Comprising a step (separation step) of separating the plate 20 in the III-nitride film 21 and the rest of the thin film forming a group III nitride substrate 22.

The above procedure, III-nitride composite substrate 1 that has been joined by the bonding group III nitride supporting substrate 10 having a thickness of T _D on III-nitride films 21 are obtained. Here, the thickness T _D of the group III nitride thin film 21 is substantially equal to the ion implantation depth D. In the ion implantation step, ions having a small radius are preferable and hydrogen ions are most preferable from the viewpoint of reducing damage to the substrate.

This method utilizes the embrittlement of the ion implantation region 20i in the group III nitride substrate 20 for forming a thin film, and the ion implantation depth D can be adjusted with high accuracy. _This is a method suitable for manufacturing a group III nitride composite substrate 1 having a group III nitride thin film 21 having a small _D , preferably about 10 nm to 100 μm, more preferably about 10 nm to 10 μm.

The group III nitride supporting substrate 10 and the group III nitride substrate 20 for forming a thin film may be bonded together with at least one intermediate layer (not shown) interposed therebetween. For example, an intermediate layer such as a SiO ₂ layer is formed on at least one of the group III nitride support substrate 10 and the group III nitride substrate 20 for thin film formation, and the group III nitride support substrate is interposed with the intermediate layer interposed therebetween. 10 and the group III nitride substrate 20 for forming a thin film are bonded together to increase the bonding strength between the group III nitride supporting substrate 10 and the group III nitride thin film 21 and to easily separate them. be able to. Further, between the group III nitride support substrate 10 and the group III nitride substrate 20 for forming a thin film, as an intermediate layer, a thin SiO ₂ layer, an amorphous Si layer, and a thick SiO _{2 are} sequentially formed from the group III nitride support substrate 10 side. By laminating the layers together, it is possible to increase the bonding strength between the group III nitride supporting substrate 10 and the group III nitride thin film 21 and to further separate them again.

  In the bonding step, the group III nitriding is performed from the viewpoint of facilitating the bonding of the group III nitride supporting substrate 10 and the group III nitride substrate 20 for thin film formation at the predetermined deviation angles Δφ and Δψ. OF 10 of, 20 of and IF (identification flat) 10 if, 20 if are preferably provided at predetermined positions of the object supporting substrate 10 and the group III nitride substrate 20 for forming a thin film, respectively. Then, OF10of of group III nitride support substrate 10 and OF20of of group III nitride substrate 20 for thin film formation, IF10if of group III nitride support substrate 10 and IF20if of group III nitride substrate 20 for thin film formation, A group III nitride composite substrate 1 in which the group III nitride support substrate 10 and the group III nitride substrate 20 for thin film formation are joined at the predetermined deviation angles Δφ and Δψ is obtained by superimposing and sticking them together. .

[Embodiment 2]
Referring to FIGS. 1 and 3, the evaluation method for Group III nitride composite substrate 1 according to another embodiment of the present invention is a method for evaluating Group III nitride composite substrate 1 according to Embodiment 1, and includes Group III In the nitride thin film 21 and the group III nitride support substrate 10, an X-ray diffraction method that scans the φ angle while maintaining diffraction of a plane that is not parallel to the (0001) plane, and the shift direction of the shift angle Δψ or the shift direction thereof By using at least one X-ray diffraction method of X-ray diffraction, in which X-rays are incident from the opposite direction and the ω angle is scanned while maintaining diffraction of a plane parallel to the (0001) plane, The arrangement of the thin film and the group III nitride support substrate is evaluated.

  Referring to FIG. 3, in X-ray diffraction in which incident X-rays 111 irradiated to main surface 100s of crystal 100 are diffracted by diffraction surface 100d of crystal 100 and emitted as outgoing X-rays 112, generally, the main surface Φ axis perpendicular to 100 s, d axis 124 perpendicular to the diffractive surface 100 d, ω axis (2θ axis) parallel to the principal surface 100 s and perpendicular to the plane formed by the incident X-ray 111 and the outgoing X-ray 112 A χ axis parallel to the main surface 100 s and parallel to the plane formed by the incident X-ray 111 and the outgoing X-ray 112 is conceivable. The angles around the φ axis, the ω axis (2θ axis), and the χ axis are referred to as the φ angle, the ω angle (2θ angle), and the χ angle, respectively. Here, the θ angle is the Bragg angle. An angle formed between the φ axis and the d axis is referred to as a ψ angle.

  Referring to FIGS. 1, 3-7, and 10-11, in group III nitride composite substrate 1, arbitrarily specified a-axis 21 a of group III nitride thin film 21 and a-axis of group III nitride thin film 21 When the deviation angle Δφ from the a-axis 10a of the group III nitride support substrate 10 closest to 21a is larger than 0 ° and smaller than 60 °, the surface is not parallel to the (0001) plane (for example, (10-11) The X-ray diffraction peak derived from the group III nitride thin film 21 and the X-ray diffraction peak derived from the group III nitride supporting substrate 10 are obtained by the X-ray diffraction method of scanning the φ angle while maintaining the diffraction of the surface). Since it can be identified by separating, it can be evaluated that the group III nitride thin film 21 is surely arranged on the group III nitride supporting substrate 10.

  Referring to FIGS. 1, 3 and 6-13, in group III nitride composite substrate 1, a shift between c-axis 21 c of group III nitride thin film 21 and c-axis 10 c of group III nitride supporting substrate 10 is performed. When the angle Δψ is larger than 0 ° and smaller than 90 °, a plane (for example, a (0002) plane that is incident with X-rays from the shift direction of the shift angle Δψ or a direction opposite to the shift direction and parallel to the (0001) plane The X-ray diffraction peak derived from the group III nitride thin film 21 and the X-ray diffraction peak derived from the group III nitride supporting substrate 10 are separated by the X-ray diffraction method that scans the ω angle while maintaining the diffraction of Therefore, it can be evaluated that the group III nitride thin film 21 is surely arranged on the group III nitride support substrate 10.

Example 1
1. Production of Group III Nitride Composite Substrate With reference to FIG. 2A, the surface orientation of the front principal surface is (0001), the surface orientation of the back principal surface is (000-1), the diameter is 100 mm, and the thickness is 600 μm. A thin film forming GaN substrate (a thin film forming group III nitride substrate 20) was prepared. Next, OF20of having a plane orientation of {11-20} and IF20if having a plane orientation of {10-10} were fabricated by dicing on the GaN support substrate. Here, the accuracy of the surface orientation of the front principal surface, the back principal surface, the OF, and the IF was confirmed by X-ray diffraction. Next, hydrogen ions were implanted into a surface having a depth of 0.6 μm from the back surface side of the GaN substrate for forming a thin film (ion implantation region 20i). Here, the acceleration voltage of hydrogen ions was 90 keV, and the dose amount of hydrogen ions was 6 × 10 ¹⁷ cm ⁻² .

  Referring to FIG. 2B, a GaN supporting substrate (Group III nitridation) having a surface main surface of (0001), a back main surface of (000-1), a diameter of 100 mm, and a thickness of 600 μm. An object support substrate 10) was prepared. Next, OF10of having a plane orientation of {10-10} and IF10if having a plane orientation of {11-20} were fabricated on this GaN support substrate by dicing. Here, the accuracy of the surface orientation of the front principal surface, the back principal surface, the OF, and the IF was confirmed by X-ray diffraction, and as a result, the off angle from the surface orientation was 0.05 ° or less.

  Next, the back main surface, which is the main surface on the ion implantation side of the GaN substrate for thin film formation (Group III nitride substrate 20 for thin film formation), and the front main surface of the GaN support substrate (Group III nitride support substrate 10), After forming a clean surface by plasma etching in Ar gas, bonding was performed by bonding in the air so that each of OF20of, 10of and IF20if, 10if overlapped.

Next, referring to FIG. 2C, the bonded GaN substrate for thin film formation (Group III nitride substrate 20 for thin film formation) and GaN support substrate (Group III nitride support substrate 10) are placed in an N ₂ gas atmosphere. By heat-treating at 300 ° C. for 2 hours, the GaN substrate for thin film formation (Group III nitride substrate 20 for thin film formation) is converted into the GaN thin film (Group III nitride thin film 21) and the remaining GaN for thin film formation in the ion implantation region 20i. By separating the substrate (the remaining Group III nitride substrate 22 for forming a thin film), a 600 μm thick GaN support substrate (Group III nitride support substrate 10) and a 0.6 μm thick joint bonded thereon are obtained. A GaN composite substrate (Group III nitride composite substrate 1) composed of the GaN thin film (Group III nitride thin film 21) was obtained.

  Referring to FIG. 4, with respect to the obtained GaN composite substrate (Group III nitride composite substrate 1), the GaN thin film (Group III nitride thin film 21) has a (0001) surface orientation of the front principal surface, and OF21of The plane orientation is {11-20}, the plane orientation of IF21if is {10-10}, and the GaN support substrate (Group III nitride support substrate 10) has a plane orientation of (0001) on the front principal surface and OF10of The plane orientation of {10-10} and IF10if was {11-20}. Further, the deviation angle Δψ between the c-axis of the GaN thin film (Group III nitride thin film 21) and the c-axis of the GaN support substrate (Group III nitride support substrate 10) is GaN composite substrate (Group III nitride composite substrate 1). The angle was 0 ° in both the direction perpendicular to the surface of IF1if and the direction perpendicular to the surface of OF1of. The results are summarized in Table 1.

2. Evaluation of Group III Nitride Composite Substrate by X-Ray Diffraction About the obtained GaN composite substrate (Group III nitride composite substrate 1), a GaN thin film (Group III nitride) on a GaN support substrate (Group III nitride support substrate 10) Whether or not the thin film 21) was surely arranged was evaluated by the following X-ray diffraction.

  X-ray diffraction was performed using a Panalical X'Pert MRD. In X-ray diffraction, in addition to the x-axis, y-axis, and z-axis, there are a φ-axis that indicates rotation within the main surface and a ψ-axis that indicates the tilt angle in the y-axis direction. The incident axis of the X-ray is the ω axis, and the ω axis has the same central axis as the 2θ axis which is one of the axes for measuring the diffraction intensity. In this apparatus, when a diffraction surface is designated, the apparatus automatically calculates a displacement value for each axis and moves.

  4 and 5, the direction perpendicular to the IF1if plane of the GaN composite substrate (Group III nitride composite substrate 1) (that is, the <10-10> direction of the GaN thin film (Group III nitride thin film 21), When the ω angle is scanned while maintaining the (0002) plane diffraction using incident X-rays from the <11-20> direction of the GaN support substrate (group III nitride support substrate 10), there is one diffraction peak. However, it was not possible to evaluate whether or not the GaN thin film (Group III nitride thin film 21) was surely disposed on the GaN support substrate (Group III nitride support substrate 10).

  The direction perpendicular to the surface of OF1of of the GaN composite substrate (Group III nitride composite substrate 1) (that is, the <11-20> direction of the GaN thin film (Group III nitride thin film 21), the GaN support substrate (Group III nitride support substrate) When the ω angle is scanned while maintaining (0002) plane diffraction using incident X-rays from <10-10> direction of 10), only one diffraction peak can be observed. It was not possible to evaluate whether or not the GaN thin film (Group III nitride thin film 21) was indeed disposed on the Group III nitride supporting substrate 10).

  When the φ angle is scanned while maintaining (10-11) plane diffraction, six strong diffraction peaks and six weak diffraction peaks can be observed, and a GaN support substrate (Group III nitride support) can be observed. It was possible to evaluate that the GaN thin film (Group III nitride thin film 21) was indeed arranged on the substrate 10). The results are summarized in Table 1.

(Example 2)
1. Production of Group III Nitride Composite Substrate Referring to FIGS. 2 and 6, the surface orientation of the front principal surface is inclined by 0.35 ° in the <10-10> direction perpendicular to the surface of IF20if from (0001), Of the plane is tilted by 0.35 ° in the <10-10> direction perpendicular to the plane of IF20if from (000-1), OF20of of the plane orientation of {11-20} and IF20if of the plane orientation of {10-10} A group III nitride composite substrate was produced in the same manner as in Example 1 except that the GaN substrate for forming a thin film (Group III nitride substrate 20 for forming a thin film) was used.

  Referring to FIG. 6, for the obtained GaN composite substrate (Group III nitride composite substrate 1), the GaN thin film (Group III nitride thin film 21) has a surface orientation of (0001) to IF21if. Is tilted by 0.35 ° in the <10-10> direction perpendicular to the surface, the orientation of OF21of is {11-20}, the orientation of IF21if is {10-10}, and a GaN support substrate (Group III nitride support) In the substrate 10), the surface orientation of the front principal surface was (0001), the surface orientation of OF10of was {10-10}, and the surface orientation of IF10if was {11-20}. Further, the deviation angle Δψ between the c-axis of the GaN thin film (Group III nitride thin film 21) and the c-axis of the GaN support substrate (Group III nitride support substrate 10) is GaN composite substrate (Group III nitride composite substrate 1). The direction perpendicular to the surface of IF1if was 0.35 °, and the direction perpendicular to the surface of OF1of was 0 °. The results are summarized in Table 1.

2. Evaluation of Group III Nitride Composite Substrate by X-Ray Diffraction About the obtained GaN composite substrate (Group III nitride composite substrate 1), a GaN thin film (Group III nitride) on a GaN support substrate (Group III nitride support substrate 10) Whether or not the thin film 21) was surely arranged was evaluated by the same X-ray diffraction as in Example 1.

  6 and 7, the direction perpendicular to the IF1if plane of the GaN composite substrate (Group III nitride composite substrate 1) (that is, the <10-10> direction of the GaN thin film (Group III nitride thin film 21), When the ω angle is scanned while maintaining (0002) plane diffraction using incident X-rays from the <11-20> direction of the GaN support substrate (group III nitride support substrate 10), A diffraction peak and a weak diffraction peak can be observed, and it is confirmed that the GaN thin film (Group III nitride thin film 21) is surely arranged on the GaN support substrate (Group III nitride support substrate 10). I was able to evaluate.

  The direction perpendicular to the surface of OF1of of the GaN composite substrate (Group III nitride composite substrate 1) (that is, the <11-20> direction of the GaN thin film (Group III nitride thin film 21), the GaN support substrate (Group III nitride support substrate) When the ω angle is scanned while maintaining (0002) plane diffraction using incident X-rays from <10-10> direction of 10), only one diffraction peak can be observed. It was not possible to evaluate whether or not the GaN thin film (Group III nitride thin film 21) was indeed disposed on the Group III nitride supporting substrate 10).

  When the φ angle is scanned while maintaining (10-11) plane diffraction, six strong diffraction peaks and six weak diffraction peaks can be observed, and a GaN support substrate (Group III nitride support) can be observed. It was possible to evaluate that the GaN thin film (Group III nitride thin film 21) was indeed arranged on the substrate 10). The results are summarized in Table 1.

(Example 3)
1. Production of Group III Nitride Composite Substrate Referring to FIGS. 2 and 8, the surface orientation of the front principal surface is inclined by 0.35 ° in the <10-10> direction perpendicular to the surface of IF20if from (0001), Of the plane is tilted by 0.35 ° in the <10-10> direction perpendicular to the plane of IF20if from (000-1), OF20of of the plane orientation of {11-20} and IF20if of the plane orientation of {10-10} Of the thin film forming GaN substrate (III-nitride substrate 20 for forming a thin film), and the surface orientation of the front principal surface is (0001) and OF10of and {10- A group III nitride composite substrate was produced in the same manner as in Example 1 except that a GaN support substrate (group III nitride support substrate 10) on which IF 10if having a surface orientation of 10} was formed was used.

  Referring to FIG. 8, with respect to the obtained GaN composite substrate (Group III nitride composite substrate 1), the GaN thin film (Group III nitride thin film 21) has a surface orientation from (0001) to IF21if. Is tilted by 0.35 ° in the <10-10> direction perpendicular to the surface, the orientation of OF21of is {11-20}, the orientation of IF21if is {10-10}, and a GaN support substrate (Group III nitride support) In the substrate 10), the surface orientation of the front main surface was (0001), the surface orientation of OF10of was {11-20}, and the surface orientation of IF10if was {10-10}. Further, the deviation angle Δψ between the c-axis of the GaN thin film (Group III nitride thin film 21) and the c-axis of the GaN support substrate (Group III nitride support substrate 10) is GaN composite substrate (Group III nitride composite substrate 1). The direction perpendicular to the surface of IF1if was 0.35 °, and the direction perpendicular to the surface of OF1of was 0 °. The results are summarized in Table 1.

2. Evaluation of Group III Nitride Composite Substrate by X-Ray Diffraction About the obtained GaN composite substrate (Group III nitride composite substrate 1), a GaN thin film (Group III nitride) on a GaN support substrate (Group III nitride support substrate 10) Whether or not the thin film 21) was surely arranged was evaluated by the same X-ray diffraction as in Example 1.

  Referring to FIGS. 8 and 9, the direction perpendicular to the surface of IF1if of the GaN composite substrate (Group III nitride composite substrate 1) (that is, the <10-10> direction of the GaN thin film (Group III nitride thin film 21), When the ω angle is scanned while maintaining the (0002) plane diffraction using incident X-rays from the <10-10> direction of the GaN support substrate (group III nitride support substrate 10), A diffraction peak and a weak diffraction peak can be observed, and it is confirmed that the GaN thin film (Group III nitride thin film 21) is surely arranged on the GaN support substrate (Group III nitride support substrate 10). I was able to evaluate.

  The direction perpendicular to the surface of OF1of of the GaN composite substrate (Group III nitride composite substrate 1) (that is, the <11-20> direction of the GaN thin film (Group III nitride thin film 21), the GaN support substrate (Group III nitride support substrate) In the case of scanning the ω angle while maintaining the (0002) plane diffraction using the incident X-ray from the <11-20> direction of 10), only one diffraction peak can be observed. It was not possible to evaluate whether or not the GaN thin film (Group III nitride thin film 21) was indeed disposed on the Group III nitride supporting substrate 10).

  When the φ angle is scanned while maintaining (10-11) plane diffraction, only six strong diffraction peaks can be observed, and a GaN thin film (Group III) is formed on the GaN support substrate (Group III nitride support substrate 10). It was not possible to evaluate whether the nitride thin film 21) was indeed arranged. The results are summarized in Table 1.

Example 4
1. Production of Group III Nitride Composite Substrate Referring to FIGS. 2 and 10, the surface orientation of the front principal surface is inclined by 0.35 ° in the <10-10> direction perpendicular to the surface of IF20if from (0001), Of the plane is tilted by 0.35 ° in the <10-10> direction perpendicular to the plane of IF20if from (000-1), OF20of of the plane orientation of {11-20} and IF20if of the plane orientation of {10-10} Is used, and the surface orientation of the front principal surface is 0. 0 in the <10-10> direction perpendicular to the surface of OF10of from (0001). OF10of and {11- with a tilt of 35 °, a tilt of 0.35 ° in the <10-10> direction perpendicular to the plane of OF10of from (000-1), and a plane orientation of the back main surface of {10-10} 20} plane orientation IF10if is formed And except for using the GaN supporting substrate (III-nitride supporting substrate 10), the same procedure as in Example 1 to prepare a group III nitride composite substrate.

  Referring to FIG. 10, with respect to the obtained GaN composite substrate (Group III nitride composite substrate 1), the GaN thin film (Group III nitride thin film 21) has a surface orientation from (0001) to IF21if. Is tilted by 0.35 ° in the <10-10> direction perpendicular to the surface, the orientation of OF21of is {11-20}, the orientation of IF21if is {10-10}, and a GaN support substrate (Group III nitride support) The substrate 10) has a surface orientation of (10) to the <10-10> direction perpendicular to the surface of OF10of from (0001), the surface orientation of OF10of is {10-10}, and the surface of IF10if The direction was {11-20}. Further, the deviation angle Δψ between the c-axis of the GaN thin film (Group III nitride thin film 21) and the c-axis of the GaN support substrate (Group III nitride support substrate 10) is GaN composite substrate (Group III nitride composite substrate 1). The direction perpendicular to the surface of IF1if was 0.35 °, and the direction perpendicular to the surface of OF1of was 0.35 °. The results are summarized in Table 1.

2. Evaluation of Group III Nitride Composite Substrate by X-Ray Diffraction About the obtained GaN composite substrate (Group III nitride composite substrate 1), a GaN thin film (Group III nitride) on a GaN support substrate (Group III nitride support substrate 10) Whether or not the thin film 21) was surely arranged was evaluated by the same X-ray diffraction as in Example 1.

  Referring to FIGS. 10 and 11, the direction perpendicular to the surface of IF1if of the GaN composite substrate (Group III nitride composite substrate 1) (that is, the <10-10> direction of the GaN thin film (Group III nitride thin film 21), When the ω angle is scanned while maintaining (0002) plane diffraction using incident X-rays from the <11-20> direction of the GaN support substrate (group III nitride support substrate 10), A diffraction peak and a weak diffraction peak can be observed, and it is confirmed that the GaN thin film (Group III nitride thin film 21) is surely arranged on the GaN support substrate (Group III nitride support substrate 10). I was able to evaluate.

  The direction perpendicular to the surface of OF1of of the GaN composite substrate (Group III nitride composite substrate 1) (that is, the <11-20> direction of the GaN thin film (Group III nitride thin film 21), the GaN support substrate (Group III nitride support substrate) When the ω angle is scanned while maintaining the (0002) plane diffraction using incident X-rays from <10-10> direction of 10), one diffraction peak having a high intensity and one diffraction peak having a low intensity are scanned. It was possible to observe that the GaN thin film (Group III nitride thin film 21) was surely arranged on the GaN support substrate (Group III nitride support substrate 10).

  When the φ angle is scanned while maintaining (10-11) plane diffraction, six strong diffraction peaks and six weak diffraction peaks can be observed, and a GaN support substrate (Group III nitride support) can be observed. It was possible to evaluate that the GaN thin film (Group III nitride thin film 21) was indeed arranged on the substrate 10). The results are summarized in Table 1.

(Example 5)
1. Production of Group III Nitride Composite Substrate Referring to FIGS. 2 and 12, the surface orientation of the front principal surface is inclined by 0.35 ° in the <10-10> direction perpendicular to the surface of IF20if from (0001), Of the plane is tilted by 0.35 ° in the <10-10> direction perpendicular to the plane of IF20if from (000-1), OF20of of the plane orientation of {11-20} and IF20if of the plane orientation of {10-10} And a <10-10> direction other than the direction in which the surface orientation of the front principal surface is perpendicular to the surface from (0001) to IF10if, using the GaN substrate for forming a thin film (Group III nitride substrate 20 for forming a thin film) Is tilted by 0.35 ° to the <10-10> direction other than the direction perpendicular to the surface of IF10if from (000-1), and the surface orientation of {11-20} Of OF10of and the plane orientation of {10-10} Except that F10if is a GaN supporting substrate formed (III-nitride supporting substrate 10), the same procedure as in Example 1 to prepare a group III nitride composite substrate.

  Referring to FIG. 12, with respect to the obtained GaN composite substrate (Group III nitride composite substrate 1), the GaN thin film (Group III nitride thin film 21) has a surface orientation from (0001) to IF21if. Is tilted by 0.35 ° in the <10-10> direction perpendicular to the surface, the orientation of OF21of is {11-20}, the orientation of IF21if is {10-10}, and a GaN support substrate (Group III nitride support) In the substrate 10), the surface orientation of the front principal surface is inclined by 0.35 ° in the <10-10> direction other than the direction perpendicular to the surface of IF10if from (0001), and the surface orientation of OF10of is {11-20} The plane orientation of IF10if was {10-10}. Further, the deviation angle Δψ between the c-axis of the GaN thin film (Group III nitride thin film 21) and the c-axis of the GaN support substrate (Group III nitride support substrate 10) is GaN composite substrate (Group III nitride composite substrate 1). The direction perpendicular to the surface of IF1if was 0.525 °, and the direction perpendicular to the surface of OF1of was 0.30 °. The results are summarized in Table 1.

2. Evaluation of Group III Nitride Composite Substrate by X-Ray Diffraction About the obtained GaN composite substrate (Group III nitride composite substrate 1), a GaN thin film (Group III nitride) on a GaN support substrate (Group III nitride support substrate 10) Whether or not the thin film 21) was surely arranged was evaluated by the same X-ray diffraction as in Example 1.

  Referring to FIGS. 12 and 13, the direction perpendicular to the surface of IF1if of the GaN composite substrate (Group III nitride composite substrate 1) (that is, the <10-10> direction of the GaN thin film (Group III nitride thin film 21), When the ω angle is scanned while maintaining the (0002) plane diffraction using incident X-rays from the <10-10> direction of the GaN support substrate (group III nitride support substrate 10), A diffraction peak and a weak diffraction peak can be observed, and it is confirmed that the GaN thin film (Group III nitride thin film 21) is surely arranged on the GaN support substrate (Group III nitride support substrate 10). I was able to evaluate.

  The direction perpendicular to the surface of OF1of of the GaN composite substrate (Group III nitride composite substrate 1) (that is, the <11-20> direction of the GaN thin film (Group III nitride thin film 21), the GaN support substrate (Group III nitride support substrate) When the ω angle is scanned while maintaining the (0002) plane diffraction using the incident X-ray from the <11-20> direction of 10), one strong diffraction peak and one weak diffraction peak It was possible to observe that the GaN thin film (Group III nitride thin film 21) was surely arranged on the GaN support substrate (Group III nitride support substrate 10).

  When the φ angle is scanned while maintaining (10-11) plane diffraction, only six strong diffraction peaks can be observed, and a GaN thin film (Group III) is formed on the GaN support substrate (Group III nitride support substrate 10). It was not possible to evaluate whether the nitride thin film 21) was indeed arranged. The results are summarized in Table 1.

(Comparative Example 1)
1. Production of Group III Nitride Composite Substrate The surface orientation of the front principal surface is tilted by 0.35 ° in the <10-10> direction perpendicular to the IF20if surface from (0001), and the surface orientation of the back principal surface is (000-1) Thin film forming GaN substrate on which OF20of of {11-20} plane orientation and IF20if of {10-10} plane orientation are formed with an inclination of 0.35 ° in the <10-10> direction perpendicular to the plane of IF20if (Thin film forming group III nitride substrate 20), and the surface orientation of the front main surface is from <0001> to the <10-10> direction perpendicular to the surface of IF10if (that is, the same direction as the inclination of the thin film forming GaN substrate) ) And a plane orientation of the back main surface from (000-1) to the <10-10> direction perpendicular to the IF10if plane (that is, the same direction as the inclination of the GaN substrate for thin film formation). Tilt, {11-20 Group III nitride in the same manner as in Example 1 except that a GaN support substrate (Group III nitride support substrate 10) in which OF10of of the plane orientation of IF and IF10if of the plane orientation of {10-10} is formed is used. A composite substrate was produced.

  Referring to FIG. 14, with respect to the obtained GaN composite substrate (Group III nitride composite substrate 1), the GaN thin film (Group III nitride thin film 21) has a surface orientation from (0001) to IF21if. Is tilted by 0.35 ° in the <10-10> direction perpendicular to the surface, the orientation of OF21of is {11-20}, the orientation of IF21if is {10-10}, and a GaN support substrate (Group III nitride support) The substrate 10) has a surface orientation of the front principal surface of (0001) to a <10-10> direction perpendicular to the surface of IF10if (that is, the same direction as the inclination of the GaN substrate for thin film formation), and the OF10of The plane orientation was {11-20}, and the plane orientation of IF10if was {10-10}. Further, the deviation angle Δψ between the c-axis of the GaN thin film (Group III nitride thin film 21) and the c-axis of the GaN support substrate (Group III nitride support substrate 10) is GaN composite substrate (Group III nitride composite substrate 1). The direction perpendicular to the plane of IF1if was 0 °, and the direction perpendicular to the plane of OF direction 1of was also 0 °. The results are summarized in Table 1.

2. Evaluation of Group III Nitride Composite Substrate by X-Ray Diffraction About the obtained GaN composite substrate (Group III nitride composite substrate 1), a GaN thin film (Group III nitride) on a GaN support substrate (Group III nitride support substrate 10) Whether or not the thin film 21) was surely arranged was evaluated by the same X-ray diffraction as in Example 1.

  Referring to FIGS. 14 and 15, the direction perpendicular to the surface of IF1if of the GaN composite substrate (Group III nitride composite substrate 1) (that is, the <10-10> direction of the GaN thin film (Group III nitride thin film 21), When the (0002) plane diffraction is maintained and the ω angle is scanned using incident X-rays from the <10-10> direction of the GaN support substrate (group III nitride support substrate 10), there is one diffraction peak. However, it was not possible to evaluate whether or not the GaN thin film (Group III nitride thin film 21) was surely disposed on the GaN support substrate (Group III nitride support substrate 10).

  The direction perpendicular to the surface of OF1of of the GaN composite substrate (Group III nitride composite substrate 1) (that is, the <11-20> direction of the GaN thin film (Group III nitride thin film 21), the GaN support substrate (Group III nitride support substrate) In the case of scanning the ω angle while maintaining the (0002) plane diffraction using the incident X-ray from the <11-20> direction of 10), only one diffraction peak can be observed. It was not possible to evaluate whether or not the GaN thin film (Group III nitride thin film 21) was indeed disposed on the Group III nitride supporting substrate 10).

  When the φ angle is scanned while maintaining (10-11) plane diffraction, only six strong diffraction peaks can be observed, and a GaN thin film (Group III) is formed on the GaN support substrate (Group III nitride support substrate 10). It was not possible to evaluate whether the nitride thin film 21) was indeed arranged.

  Referring to Table 1, a group III nitride support substrate 10 and a group III nitride thin film 21 disposed on the group III nitride support substrate are included, and the group III nitride thin film 21 and the group III nitride support substrate 10 are included. Even in the group III nitride composite substrate 1 formed of group III nitride having substantially the same chemical composition, the a-axis 21a arbitrarily specified for the group III nitride thin film 21 and the group III nitride thin film 21 A deviation angle Δφ from the a-axis 10a of the group III nitride support substrate 10 closest to the a-axis 21a is greater than 0 ° and less than 60 °, and the c-axis 21c of the group III nitride thin film 21; Forming a group III nitride composite substrate 1 that satisfies at least one deviation angle condition in which the deviation angle Δψ between the group III nitride support substrate 10 and the c-axis 10c is larger than 0 ° and smaller than 90 ° By An X-ray diffraction method that scans the φ angle while maintaining diffraction of a surface that is not parallel to the (0001) plane, and X-rays are incident from the shift direction of the shift angle Δψ or the direction opposite to the shift direction, and the (0001) plane By using at least one X-ray diffraction method that scans the ω angle while maintaining the diffraction of the plane parallel to the surface, the group III nitride thin film 21 is surely formed on the group III nitride support substrate 10. It was possible to evaluate whether or not it was placed in.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  1 Group III nitride composite substrate, 1 if, 10 if, 20 if, 21 if IF, 1 n, 10 n, 21 n Main surface normal axis, 1 of, 10 of, 20 of, 21 of OF, 10 Group III nitride supporting substrate, 10 a, 21 a a axis 10c, 21c c-axis, 20, 22 Group III nitride substrate for thin film formation, 20i ion implantation region, 100 crystal, 100d diffraction surface, 100s main surface, 111 incident X-ray, 112 outgoing X-ray, 121 χ-axis, 122 ω axis (2θ axis), 123 φ axis, 124 d axis.

Claims (4)

A group III nitride support substrate and a group III nitride thin film disposed on the group III nitride support substrate,
A group III nitride composite substrate in which the group III nitride thin film and the group III nitride supporting substrate are formed of group III nitride having substantially the same chemical composition;
The deviation angle Δφ between the arbitrarily specified a-axis of the group III nitride thin film and the a-axis of the group III nitride supporting substrate closest to the a axis of the group III nitride thin film is from 0 ° At least a deviation angle Δψ between the c-axis of the group III nitride thin film and the c-axis of the group III nitride supporting substrate is greater than 0 ° and less than 90 °. A group III nitride composite substrate that satisfies the condition of one shift angle.   The group III nitride composite substrate according to claim 1, wherein the deviation angle Δφ is larger than 1 ° and smaller than 59 °.   The group III nitride composite substrate according to claim 1, wherein the deviation angle Δψ is greater than 0.01 ° and smaller than 10 °. A method for evaluating a group III nitride composite substrate according to claim 1,
In the group III nitride thin film and the group III nitride supporting substrate, an X-ray diffraction method that scans the φ angle while maintaining diffraction of a plane that is not parallel to the (0001) plane, and the shift direction of the shift angle Δψ or the By using at least one X-ray diffraction method of X-ray diffraction, in which X-rays are incident from the direction opposite to the deviation direction and the ω angle is scanned while maintaining the diffraction of the plane parallel to the (0001) plane,
A method for evaluating a group III nitride composite substrate, wherein the arrangement of the group III nitride thin film and the group III nitride supporting substrate is evaluated.

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