JP2011057479A - Template, method for manufacturing the template, crystal grown by using the template, and method and apparatus for producing the crystal - Google Patents

Abstract

An object of the present invention is to provide a template capable of suppressing the cracking of a GaN crystal and improving the crystal quality regardless of the thickness of the sapphire substrate.
A plate-like crystal substrate 22 and a crystal thin film 23 having a different lattice constant or thermal expansion coefficient on the surface of the crystal substrate 22 are provided, and the crystal substrate 22 is exposed to the crystal thin film 23. The intended purpose is achieved by providing the groove 24 and providing the exposed second groove 25 of the crystal substrate.
[Selection] Figure 2

Description

  The present invention relates to the production of crystals.

  As a method of manufacturing a GaN crystal substrate having a thickness of 200 μm or more, a GaN crystal thick film is grown on the template by a vapor phase growth method such as HVPE or MOCVD or a liquid phase growth method such as a Na flux method. There is a method of obtaining a GaN crystal substrate by separating and slicing with a wire saw or the like.

  GaN crystals produced by liquid layer growth such as Na flux method have lower dislocation density and smaller half width of XRD than GaN crystals obtained by vapor phase growth method such as HVPE method. It is characterized by superiority.

  A template used for manufacturing a GaN crystal substrate has been manufactured by growing a GaN crystal thin film of several to several tens of μm on the surface of a base substrate such as sapphire or SiC by vapor phase growth such as MOCVD.

  At present, the size of the GaN crystal substrate is 2 to 3 inches, and it is desired to reduce the cracking of the GaN crystal substrate during manufacturing and to increase the radius of curvature of the crystal lattice of the GaN crystal substrate.

  Of these, cracks in the GaN crystal substrate cause horizontal stress due to differences in the thermal expansion coefficient and lattice constant between the sapphire substrate and the GaN crystal grown on the top surface. Cracks sometimes occurred. As a means to suppress cracking of the GaN crystal formed on the upper surface of such a substrate, the stress caused by the stress generated in the sapphire substrate is used, and when this stress occurs excessively, the notch groove provided on the lower surface of the sapphire substrate is used. In order to reduce the stress of the GaN crystal by inducing cracks and breaking the sapphire substrate, a technique for reducing the stress of the GaN crystal has been proposed (for example, a similar technique is described in Patent Document 1 below).

  Further, the curvature radius of the crystal lattice of the GaN crystal is warped in the template due to the difference in the lattice constant between the sapphire substrate and the GaN crystal at the initial stage of crystal growth, and the radius of curvature is reduced. As means for increasing the radius of curvature of the crystal lattice of GaN crystal (suppressing warpage), a method using a substrate having a thickness of 1 mm or more has been proposed (for example, a similar technique is disclosed in the following patent document). 2).

Japanese Patent Laid-Open No. 11-040849 Japanese Patent Laid-Open No. 10-256661

  The problem in the conventional example is that the quality of the crystal deteriorates.

  That is, in the conventional example, in order to reduce the stress on the GaN crystal grown on the upper surface of the template, as described above, the lack of inducing cracks in advance on the lower surface of the template substrate (the surface on which the GaN crystal thin film is not formed). A groove was formed, and when excessive stress was applied to the substrate, the substrate was broken from the notched groove.

  The stress caused by the difference between the thermal expansion coefficients of the sapphire substrate and the GaN crystal has a maximum tensile stress on the upper surface of the sapphire substrate and a minimum on the lower surface. Further, when the sapphire substrate is thickened, the tensile stress on the back surface is further reduced, and eventually, compressive stress is generated. Thus, as the sapphire substrate is made thicker, the notch formed on the lower surface does not function effectively, and cracks are less likely to occur from the position of the notch. As a result, cracking occurs from other than the position of the notch, and as a result, cracking (cracking) occurs in the GaN crystal without being transmitted to the crack propagation prevention mask provided on the upper surface of the sapphire substrate.

  Accordingly, an object of the present invention is to provide a template that can suppress cracks in a GaN crystal and improve crystal quality.

To achieve this object, the present invention comprises a plate-like crystal substrate, and a crystal thin film formed on the upper surface of the crystal substrate,
Since the first groove for exposing the crystal substrate is provided in the crystal thin film, and the second groove is provided on the upper surface of the crystal substrate exposed by the first groove, the intended purpose is achieved. .

  According to the present invention, a plate-like crystal substrate and a crystal thin film formed on an upper surface of the crystal substrate are provided, and the first groove that exposes the crystal substrate is provided in the crystal thin film. Since the second groove is provided on the upper surface of the crystal substrate exposed by the groove, it is possible to improve the quality by suppressing cracks and the like of the thick film crystal grown on the crystal thin film.

  According to the present invention, a split groove for inducing a crack is formed on the upper surface of the crystal substrate, whereby the crack can be induced without being affected by the thickness of the crystal substrate. In addition, by making the depth of the second groove longer than the groove width, a function of preventing crack propagation to the thick crystal film can be added. Thereby, in order to improve the curvature of the thick film crystal, the quality can be improved without causing cracks in the thick film crystal even when the crystal substrate is thickened.

  The present invention is effective as a template having the crystal substrate and a crystal thin film having a different lattice constant or thermal expansion coefficient on the upper surface of the crystal substrate, and in particular, the crystal thin film is a group III nitride element crystal thin film, especially a GaN crystal. This is particularly effective when the crystal substrate is a sapphire substrate.

Configuration diagram of an apparatus according to an embodiment of the present invention Sectional drawing and top view of the template in embodiment of this invention Sectional drawing of the formation process of the 1st groove | channel in embodiment of this invention Sectional drawing of the formation process of the 2nd groove | channel and 3rd groove | channel in embodiment of this invention Sectional drawing of the growth process of the GaN crystal thick film in embodiment of this invention Sectional view after cutting out the GaN crystal substrate in the embodiment of the present invention

  Hereinafter, an embodiment of the present invention will be described in which a template crystal substrate is sapphire, a crystal thin film is gallium nitride (hereinafter referred to as GaN), a crystal thick film to be grown on the template is gallium nitride (GaN) crystal, and a crystal thick film growth method is used. This will be described as the Na flux method. However, the present invention is not limited to this. For example, in the present invention, a crystal is formed on a template made of a plate-like crystal substrate and a crystal thin film having a different lattice constant or thermal expansion coefficient on the upper surface of the crystal substrate. A thick film crystal having a lattice constant or thermal expansion coefficient different from that of the substrate can be produced in the same manner with reference to the following description even when a liquid phase growth method or a vapor phase growth method other than the Na flux method is used. Is possible.

(Embodiment)
Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a configuration diagram of a group III nitride crystal growth apparatus. By using this apparatus, a thick GaN crystal (hereinafter referred to as a GaN thick film crystal) can be grown on the template by the Na flux LPE method.

  First, a template 1 for growing a crystal, this template 1, metal gallium and sodium are measured in a predetermined amount and put in a crucible 2. The metal gallium and sodium are liquefied by heating to become the crystallized material 3 shown in FIG.

  Next, the crucible 2 is put into a hermetic crystal growth vessel 4, and then the crystal growth vessel 4 is put into a growth furnace 5. The growth furnace 5 is an electric furnace having an inner surface covered with a heat insulating material 6 and provided therein with a heater (an example of a heating means) 7 for heating the crystal growth vessel 4. It is managed while measuring with the thermocouple 8. Moreover, the growth furnace 5 is configured to include a drive unit 9 that can swing the whole.

  Nitrogen, which is a source gas, is supplied from the outside of the growth furnace 5 into the crystal growth vessel 4 housed in the growth furnace 5 via the source gas supply unit 11.

  The source gas supply unit 11 includes a source gas cylinder 10, a connection pipe 12 that connects the source gas cylinder 10 and the crystal growth vessel 4, a pressure regulator 13 that adjusts the pressure in the connection pipe 12, and a connection pipe 12 It has a configuration including a stop valve 14 as valve adjustment, a leak valve 15 for degassing the connection pipe 12, and a disconnecting portion 16 of the connection pipe 12.

  The crystal is grown by the apparatus configured as described above. As the process, first, as described above, gallium and sodium raw materials are put into the crucible 2, and nitrogen as a raw material gas is put into the crucible 2. Is supplied from the source gas cylinder 10 at a nitrogen atmosphere pressure of 50 atm. In this state, the crucible 2 is heated to a growth temperature of 850 ° C. by the growth furnace 5 to grow a GaN crystal on the template 21.

  Next, feature points in the embodiment of the present invention will be described.

<Template overview>
A template 21 according to the invention is shown in FIG. 2A is a cross-sectional view, and FIG. 2B is a top view.

  The template 21 includes a plate-like sapphire substrate 22 and a GaN crystal thin film 23 on the upper surface of the sapphire substrate 22. Further, the first groove 24 exposing the sapphire substrate 22 and the second groove 25 are provided on the upper surface of the sapphire substrate 22 of the first groove 24, and the lower surface of the upper surface is opposed to the second groove 25. A third groove 26 is provided.

<Sapphire substrate>
The sapphire substrate 22 is a substrate for forming the GaN crystal thin film 23. The surface on which the GaN crystal thin film is formed may be the (0001) plane (C plane), the (11-20) plane (A plane), the (1-102) plane (R plane), and the (1-100) plane. However, among these, the (0001) plane (C plane) is desirable. The substrate material may be any material other than sapphire (Al ₂ O ₃ ) that can grow GaN-based crystals such as spinel (Mg ₂ Al ₂ O ₃ ), 6H—SiC, and quartz. The thickness of the sapphire substrate 22 is not particularly specified, but in order to grow a GaN crystal thick film having a curvature radius of 6 m or more, a thickness of 1.0 mm or more is preferable, and a GaN crystal thickness having a curvature radius of 20 m or more. In order to grow the film, a thickness of 2.0 mm or more is preferable.

  On the other hand, from the viewpoint of the cost of the sapphire substrate itself and the removal processing time of the fire substrate 1 after the growth of the GaN crystal thick film, a thickness of about 5 mm or less is preferable.

<GaN crystal thin film>
The GaN crystal thin film 23 is preferably a GaN crystal not doped with n-type impurities (non-doped) or a GaN crystal containing n-type impurities in a range of 1 × 10 ²⁰ / cm ³ or less. The thickness of the GaN crystal film thickness 23 is preferably 7 μm to 50 μm. If the GaN crystal thin film 23 is thinner than 7 μm, it may disappear due to melting or the like at the initial stage of crystal growth of the GaN thick film crystal 27. This is disadvantageous in terms of cost.

<Shape of the first groove>
The first groove 24 separates the GaN crystal thin film 23, reduces stress due to the difference in thermal expansion coefficient with the sapphire substrate 22, and exposes the sapphire substrate 21 in advance when the second groove 25 is formed. Provided.

  The groove width of the first groove 24 is preferably 0.05 mm to 0.5 mm, and more preferably 0.1 mm to 0.3 mm. If the groove width is narrow, when the second groove 25 is processed, alignment or the like is difficult, and the GaN crystal thin film 23 may be damaged. If the groove width is wide, the GaN crystal thick film 27 grown on the groove part may not be bonded. In the crystal growth by the Na flux method, compared with the vapor phase growth method such as HVPE, it has the characteristic that it is very easy to grow in the lateral direction (groove direction), so it is possible to connect crystals even at 0.5 mm or more. is there.

  From both ends of the first groove 24, it is necessary to grow in the lateral direction (direction parallel to the sapphire substrate 21) along with the growth of the GaN crystal thick film 27 to cover the first groove 24. Therefore, the formation of the first groove 24 does not cause chipping, work-affected layer, or amorphization in the vicinity of the first groove 24 of the GaN crystal thin film 23, that is, the groove end face part also maintains the crystallinity. is required. For this purpose, a method using etching, a mask or the like is preferable to mechanical grinding or laser processing for dicing or the like.

<Second groove shape>
The second groove 25 induces cracks in the sapphire substrate 22 in order to relieve the compressive stress generated due to the difference in thermal expansion coefficient with the sapphire substrate 22 after the growth of the GaN crystal thick film 27, and the generated cracks It is provided so as not to propagate to the GaN thick film crystal 7. The position is formed at the position of the first groove 24 on the upper surface of the sapphire substrate 22. The groove width may be equal to or smaller than the groove width of the first groove 24.

  In order to surely generate cracks, the depth of the groove is preferably up to about 0.5 mm where the tensile stress of the sapphire substrate 22 is strongly generated. The reason is that the tensile stress of the sapphire substrate 22 is strong in the vicinity of the boundary with the GaN crystal thin film 23 and becomes weaker as it approaches the lower surface.

  In order to prevent the crack from propagating to the GaN thick film crystal, it is necessary to prevent the GaN crystal from growing in the groove portion, and the groove depth is preferably deeper than the groove width.

  The tip shape of the groove may be flat, semicircular, triangular or the like, but a shape close to an acute angle is preferable in order to make it easy to break.

<Third groove shape>
The third groove 26 is provided in order to increase the degree of stress concentration at the tip of the second groove 25 by narrowing the distance from the second groove 25 and to reliably break the sapphire substrate. The position is preferably formed on the lower surface of the sapphire substrate 22 at a position substantially opposite to the second groove 25. The groove width is not particularly defined. The shape of the tip is the same as that of the second groove 25 and may be flat, semicircular, triangular, etc. However, in order to increase the stress concentration and make it easy to crack, the tip shape should be close to an acute angle. good.

  Since the tip position of the third groove 26 affects the stress concentration at the groove tip, it relates to the ease of cracking of the sapphire substrate 1. The sapphire substrate 22 receives compressive stress from the difference in lattice constant between the GaN thick film 27 and the sapphire substrate 22 at the initial stage of crystal growth of the GaN thick film 27, and when the temperature is lowered after the crystal growth is completed, The tensile stress is received from the difference in thermal expansion coefficient from that of No. 22. Therefore, the tip position is preferably adjusted to a position where no cracks are generated during crystal growth of the GaN thick film 27 and cracks are generated when the temperature is lowered after the crystal growth is completed. Although it is desirable to obtain the position by a prior experiment, as a rough value, in order to prevent the sapphire substrate 22 from being broken by the compressive stress at the initial stage of crystal growth, the distance between the second groove 25 and the third groove 26 is It is preferably about 0.25 mm or more for a 2-inch substrate and about 0.3 mm or more for a 3-inch substrate. The tip position of the second groove 25 and the tip position of the third groove 26 are ½ the thickness of the GaN thick film crystal 27 and the sapphire substrate in order to generate cracks when the temperature is lowered after the crystal growth is completed. It is preferable that it is 1/2 or less of 22 thickness.

  The third groove 26 is provided so that cracks generated from the second groove 25 can be generated more easily and at the same time to cut the substrate. Depending on the shape of the second groove 25, the thickness of the sapphire substrate 22, etc. May not be provided.

<First groove pattern>
FIG. 2B shows a top view of the template 21.
The GaN crystal thin film 23 is divided into a plurality of regions by the first groove 24.
The direction of the first groove 24 is provided so that the line segment of the boundary line between the GaN crystal thin film 23 and the sapphire substrate 22 is parallel to (11-20) of the GaN crystal thin film. This is because when the GaN crystal thick film 27 is grown on the GaN crystal thin film 23, the growth rate of the (11-20) plane is faster than the growth rate of the (1-100) plane. It is effective for coating. Further, the (11-20) plane of the GaN crystal thin film is substantially parallel to the (10-10) plane of the sapphire substrate 22. The (11-20) plane of the sapphire substrate does not have a clear “cleavage”, but is a very fragile surface and is advantageous for inducing cracks.

  The direction of the first groove 24 is provided in two or three directions. When provided in three directions, the grooves in the three directions should not intersect at one point. If the three-direction lines are arranged so as to intersect at one point, the groove width at the intersection point is twice as large as the groove width, and may not be joined during the growth of the GaN crystal. A plurality of first grooves 24 may be received in each direction. The distance between the centers of the grooves in each direction is preferably 10 mm to 50 mm.

<Template manufacturing method>
Next, the template manufacturing method is performed as follows, for example.

  First, a method for forming the first groove will be described with reference to FIG.

  FIG. 3 shows a cross-sectional view of the first groove forming step. 3A shows a substrate preparation process, and FIG. 3B shows a mask material patterning process. FIG. 3C shows a GaN crystal thin film growth process, and FIG. 3D shows a mask material etching process.

  First, a sapphire substrate 22 as shown in FIG. The thickness of the sapphire substrate is preferably 0.2 mm or more and 5 mm or less for ease of handling. Although not shown in FIG. 3A, a GaN buffer layer of about 1 μm may be formed in advance on the surface of the sapphire substrate 22.

  Next, as shown in FIG. 3B, a silicon dioxide (SiO 2) film is formed on the upper surface of the sapphire substrate 22 as a mask material 30 by about 0.5 μm. As the mask material 30, a high melting point metal material such as Mo, Ta, or Pt may be used in addition to SiO 2. However, since SiO2 is excellent in etching property, the process is easy. The width of the mask material 30 is preferably 0.05 mm to 0.5 mm.

  Next, as shown in FIG. 3C, a GaN crystal thin film 23 is formed on the sapphire substrate 22 by vapor phase growth such as HVPE or MOCVD. An undoped GaN crystal thin film 23 having a film forming temperature of about 1100 ° C. and having a thickness of 7 μm to 50 μm is grown. As a result, since the GaN crystal thin film 23 does not grow on the mask material 30, the GaN crystal thin film 23 divided into a plurality of regions can be formed.

  Next, as shown in FIG. 3D, the SiO 2 film as the mask material 30 is removed by etching with hydrofluoric acid. Thereby, the upper surface of the sapphire substrate 22 is exposed.

  Next, a method for forming the second groove and the third groove will be described with reference to FIGS.

  FIG. 4 shows a cross-sectional view of the formation process of the second groove and the third groove.

  As shown in FIG. 4A, the second groove 25 is formed on the upper surface of the sapphire substrate 22 by dicing. In addition to dicing, processing may be performed using a scriber, laser, etching, or the like. However, it is important not to process the GaN crystal thin film 23.

  Next, as shown in FIG. 4B, a third groove 26 is formed at a position opposite to the second groove 25 on the lower surface of the sapphire substrate 3 by sapphire dicing. In addition to dicing, processing may be performed using laser, etching, or the like. Further, as shown in FIG. 4B, a third groove 26 is formed at a position facing the second groove 25 on the lower surface of the sapphire substrate 3 by sapphire dicing. In addition to dicing, processing may be performed using laser, etching, or the like. Further, after the processing, an annealing treatment at about 600 ° C. to 1000 ° C. may be performed to reduce microcracks or the like and processing distortion.

  Since the template 21 manufactured as described above can reduce stress, the warpage of the template 21 itself can be suppressed, and cracks and cracks of the GaN single crystal thin film 23 can be prevented.

<Method for producing GaN crystal thick film>
Subsequently, a process of growing a GaN crystal thick film on the template 21 of the first embodiment will be described. The growth method uses the Na flux method, which is a liquid phase growth method, using the apparatus shown in FIG.

  The growth process of the GaN crystal thick film will be described with reference to FIG.

  FIG. 5 shows a cross-sectional view of the growth process of the GaN crystal thick film.

  FIG. 5A shows the initial growth state of the GaN crystal thick film 27. The GaN crystal thick film 27 grows using the GaN crystal thin film 23 as a seed crystal. There is a difference in lattice constant between the GaN crystal thick film 3 and the sapphire substrate 22. Therefore, a tensile stress is generated in the GaN crystal thin film 23 and the GaN crystal thick film 27, and a compressive stress is generated in the sapphire substrate 22, and the surface of the template 21 is warped so as to be concave. Thereby, the radius of curvature of the crystal lattice of the GaN crystal thick film 27 is determined.

  On the other hand, the left and right GaN crystal thick films 27 are not coupled to each other in the first groove 24 and are discontinuous. Therefore, in the portion of the first groove 24, the tensile stress of the GaN crystal thick film 27 is released, and the crystal orientation is shifted on the left and right so as to partially alleviate the warpage of the crystal lattice. As a result, the GaN crystal thick film 27 as a whole relaxes the distortion of the crystal lattice in a pseudo manner, thereby producing an improvement effect of increasing the curvature radius.

  In the first groove 24, a GaN crystal thick film grows in the A-axis direction <11-20> from the GaN thin film 2 on both sides of the groove, so that the second groove 25 is coupled with the Na cracks 31 included. . Incidentally, the growth rate ratio between <0001> C-axis direction growth (longitudinal growth) and <11-20> A-axis direction growth (lateral growth) is about 2: 1.

  FIG. 5B shows a state after the crystal growth of the GaN crystal thick film 27. For example, if the width of the first groove 24 is 0.5 mm, the first GaN crystal thick film 27 is completely bonded when it grows 1 mm. If the width is 0.1 mm, the GaN crystal thick film 27 is 0.1 mm. It joins completely when it grows 2 mm.

  At this time, the GaN crystal thick film 27 is not grown in the second groove 25. Therefore, the second groove 25 remains in an air gap state. In the case of crystal growth by the Na flux method, this void is filled with Na, which is a flux, and in the case of a vapor phase growth method such as HVPE, the void is in a void state. Thereby, the second groove 25 has an effect of preventing the crack of the sapphire substrate 22 generated after the growth of the GaN crystal thick film 27 from propagating to the GaN crystal thick film 27.

  On the other hand, at the upper portion of the first groove 24, that is, at the meeting portion of the adjacent GaN crystal thick film 27, crystals with slightly shifted crystal orientations meet. Therefore, the half width of the meeting part is larger than that of the part other than the groove part. Therefore, manufacturing a device such as a laser diode above the first groove 24 may cause a deterioration in device characteristics. However, a photomask design should be designed so that a device chip is not disposed above the first groove 24 in the device process. Just do it.

  FIG. 5C shows a temperature drop state after crystal growth of the GaN crystal thick film 27. When the GaN crystal thick film 27 is cooled from 850 ° C., which is the crystal growth temperature, to room temperature, the sapphire substrate 22 and the GaN crystal thick film 27 have different thermal expansion coefficients. A compressive stress is generated in the crystal thick film 27. The tensile stress of the sapphire substrate 22 is large at a portion near the boundary with the GaN crystal thin film 23 and decreases as the back surface direction is approached. If the tensile stress at the tip of the second groove 25 exceeds the tensile strength of the sapphire substrate 7 including the effect of stress concentration, a crack 28 is generated. The crack 28 propagates through the sapphire substrate 22 and reaches the third groove 26, and the sapphire substrate 7 is separated. On the other hand, the crack 28 does not propagate to the GaN crystal thick film 27 because the second groove 25 is filled with Na flux (a void in the vapor phase growth method). Thereby, the compressive stress of the GaN crystal thick film 27 is reduced.

  Next, the cutting process of the GaN crystal substrate will be described with reference to FIG.

  FIG. 6 shows a cross-sectional view of the GaN crystal substrate 29 after the cutting process. The sapphire substrate 22 is separated and cut (dotted line part) with a wire saw or the like. Thereby, the GaN crystal substrate 29 without cracks (crack-free) can be obtained.

  Thereafter, the surface of the GaN crystal substrate 29 can be polished and CMPP processed to be used as a substrate for an electronic device such as a laser diode or a light emitting diode.

  As described above, the template described in the embodiment forms the first groove having crystallinity at the end of the groove, and the second groove for inducing cracks in the crystal substrate of the first groove. It is characterized by forming (dividing groove). Thereby, it is possible to suppress the deterioration of the crystallinity of the thick crystal film grown in the first groove portion.

  Further, the second groove can induce cracking of the crystal substrate without being affected by the thickness of the crystal substrate, and at the same time, the crystal thick film can be formed by making the depth of the second groove longer than the groove width. A crack propagation prevention function can also be added.

  Furthermore, by adding the third groove, the stress concentration in the second groove and the third groove can be further increased, and the crystal substrate can be reliably cracked. Therefore, in order to improve the curvature of the thick film crystal, for example, even when the crystal substrate is thickened, quality can be improved without causing cracks in the thick film crystal.

  The template of the present invention, the manufacturing method of the template, the crystal grown using the template, and the manufacturing method and manufacturing apparatus of the crystal can obtain a crystal substrate with an improved curvature radius of the crystal lattice without cracks. And the quality of the crystal can be improved. Therefore, for example, it is expected to be widely used as a method for producing a group III nitride crystal.

DESCRIPTION OF SYMBOLS 1 Template 2 Crucible 3 Crystallizing material 4 Crystal growth container 5 Growth furnace 6 Heat insulating material 7 Heater 8 Thermocouple 9 Drive part 10 Raw material gas cylinder 11 Raw material gas supply part 12 Connection piping 13 Pressure regulator 14 Stop valve 15 Leak valve 16 Detached part 21 Template 22 Sapphire Substrate 23 GaN Crystal Thin Film 24 First Groove 25 Second Groove 26 Third Groove 27 GaN Crystal Thick Film 28 Crack 29 GaN Crystal Substrate 30 Mask Material 31 Na Flux

Claims (18)

A plate-like crystal substrate, and a crystal thin film formed on the upper surface of the crystal substrate,
A template in which a first groove for exposing the crystal substrate is provided in the crystal thin film, and a second groove is provided on the upper surface of the crystal substrate exposed by the first groove. The template according to claim 1, wherein a third groove is provided on a lower surface of the crystal substrate corresponding to the position of the second groove. The template according to claim 1 or 2, wherein the first groove provided in the crystal thin film is provided in a state in which a line segment of a boundary line of the crystal thin film includes a (11-20) plane. The 1st groove | channel provided in the said crystal thin film has the intersection which cross | intersects, and these intersections make the intersection of 3 or more 1st groove | channels non-existence. Template. The template according to any one of claims 1 to 4, wherein the first groove provided in the crystal thin film is formed by etching. The template according to any one of claims 1 to 4, wherein the first groove provided in the crystal thin film is formed by a mask. The template according to any one of claims 1 to 6, wherein a groove provided in the crystal substrate has a groove depth deeper than a groove width. The template according to claim 1, wherein the crystal thin film is a nitride crystal. The template according to any one of claims 1 to 8, wherein the crystal substrate is a sapphire substrate. The template according to any one of claims 1 to 9, wherein the crystal substrate has a thickness of 1 mm or more and 5 mm or less. A method for producing a template comprising a plate-like crystal substrate and a crystal thin film formed on an upper surface of the crystal substrate, the template being used for crystal growth,
Providing a first groove for exposing the crystal substrate to the crystal thin film;
A second step of providing a second groove on the upper surface of the crystal substrate exposed by the first groove;
A template manufacturing method comprising: Providing a third groove on the lower surface of the crystal substrate corresponding to the position of the second groove;
The manufacturing method of Claim 11 provided with these. The template manufacturing method according to claim 11 or 12, wherein the crystal thin film is a group III nitride element crystal thin film. The template manufacturing method according to claim 11, wherein the substrate is a sapphire substrate or a SiC substrate. The method for manufacturing a template according to claim 11, wherein the substrate has a thickness of 1 mm to 5 mm. A group III nitride element crystal grown on the template according to any one of claims 1 to 10. A method for producing a crystal using the template according to any one of claims 1 to 10, wherein a group III nitride element crystal is grown on the template by a Na flux growth method,
In the crucible, the above-mentioned template and metallic gallium and sodium, which are raw materials for the group III nitride element crystal thin film, are housed, the crucible is heated at a predetermined temperature by a heating means, and a predetermined pressure is supplied by a raw material gas supply means. A method for producing a crystal, comprising growing a crystal on the template in a nitrogen atmosphere. A growth furnace,
A crystal growth vessel disposed in the growth furnace;
Heating means for heating the crystal growth vessel;
A source gas supply unit for supplying a source gas into the crystal growth vessel;
A crucible provided in the crystal growth vessel,
The crystal manufacturing apparatus provided with the template according to claim 1 in the crucible.

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