JPWO2013035356A1 - Crystal manufacturing method - Google Patents

Abstract

In the crystal manufacturing method of the present invention, a film-formed region that has been formed or a crystallized region that has been crystallized is between the film-forming region where film formation is performed and the heat-execution region where heating is performed. In the existing state, the film forming process and the heating process are executed in parallel. The film forming process may be performed, for example, by an aerosol deposition method in which the raw material powder is sprayed onto the seed substrate 21 in an atmosphere at a pressure lower than the atmospheric pressure. The heat treatment may be performed by irradiation with a laser or the like from the heating device 40. In this film formation crystallization process, it is preferable to perform the film formation process and the heat treatment in a state where there is an area having a width of 5 mm or more between the film formation execution area and the heat execution area.

Description

  The present invention relates to a crystal manufacturing method.

  Conventionally, as a crystal manufacturing method, there is a method of preparing a raw material melt of a single crystal to be produced and precipitating it on a seed single crystal. However, this method has been difficult to apply to materials having a very high melting point or being easily decomposed, such as high melting point oxides such as ZnO, nitrides (for example, GaN), and carbides (for example, SiC). Therefore, for example, in GaN, a Na flux method has been proposed in which a raw material is dissolved using Na as a flux and precipitated into seeds to obtain a single crystal (see, for example, Patent Document 1). Further, a GaN layer is formed on a heterogeneous substrate such as sapphire using a hydride vapor phase epitaxy, and the heterogeneous substrate is removed after the growth of the GaN layer to obtain a self-supporting GaN single crystal substrate. A method has been proposed (see, for example, Patent Document 2). Alternatively, an aerosol deposition method has been proposed in which an aerosol of raw material powder is sprayed onto a single crystal substrate to form a film containing the raw material component on the substrate, and then a single crystal is grown by performing a heat treatment ( For example, see Patent Document 3).

US Pat. No. 5,868,837 JP 2003-178984 A JP 2006-298747 A

  However, the crystal manufacturing method described in Patent Document 1 sometimes has a slow growth rate of, for example, 0.02 mm / h or less. Moreover, in the crystal manufacturing method described in Patent Document 2, it is vapor phase growth, and it may be difficult to form a thick bulk single crystal of several millimeters or more. In the crystal manufacturing method described in Patent Document 3, a process of forming a film on a substrate made of a single crystal and then performing a heat treatment to grow the single crystal is repeated. Therefore, in order to obtain a good crystal efficiently, It wasn't enough yet.

  This invention is made | formed in view of such a subject, and it aims at providing the crystal manufacturing method which can produce a more favorable crystal | crystallization more efficiently.

  As a result of diligent research to achieve the main object described above, the present inventors have made a film formation process by spraying a raw material powder onto a seed substrate and the film formed on the seed substrate is crystallized by irradiation heat. If the heat treatment is performed simultaneously in parallel, and each treatment is performed with a predetermined distance between the film formation treatment region and the heat treatment region, a better crystal can be produced more efficiently. The inventors have found what can be done and have completed the present invention.

That is, the crystal production method of the present invention comprises:
A film forming execution region in which a raw material powder containing a raw material component is sprayed from a nozzle on a seed substrate containing a single crystal to form a film containing the raw material component, and a film containing the raw material component on the seed substrate A film-formed region that has been formed, and a heating execution region in which the film formed on the seed substrate is heated by irradiation heat to crystallize the film exist on the seed substrate,
The film formation region or the crystallized region that has been crystallized is present between the film formation region and the heating execution region on the film formation region of the seed substrate. A film forming process for injecting raw material powder from the nozzle and a heating process for heating the heating execution region where the film is formed on the seed substrate by irradiation heat to crystallize the film are executed in parallel. A film-forming crystallization step.

  The crystal production method of the present invention can produce better crystals more efficiently. The reason for this is not clear, but is presumed as follows. For example, in the aerosol deposition method (AD method) performed under reduced pressure and the powder jet deposition method (PJD method) performed under pressure, a phenomenon in which powder that collides with a substrate is densely fixed by plastic deformation due to impact force. The film is formed by repeating the above. Here, in general, when the seed substrate is at a high temperature and the air flow including the raw material powder is at a low temperature, the phenomenon that the air flow is pushed back from the substrate surface due to the temperature difference between the seed substrate and the air flow of the raw material powder. It is known that film formation becomes difficult due to the effect of the thermophoresis effect including (Non-patent Document 1: “From the basics to the application of the aerosol deposition method”, CMC Publications p.8-11 (2008)). In the crystal manufacturing method of the present invention, the film formation process and the heat treatment are performed in parallel in a state where the film formation area or the crystallized area exists between the film formation execution area and the heating execution area. It is possible to form a film while further reducing the influence of the above-described thermophoresis effect. Therefore, a better crystal can be produced. In addition, because of the use of irradiation heat, the film is locally heated in the heating execution area away from the film formation execution area while keeping the temperature below a certain level in the film formation execution area (maintaining the conditions under which a dense film can be formed). By doing so, crystallization can proceed. Thus, the film forming process and the heat treatment can be performed in parallel. For this reason, crystallization can be performed efficiently. Moreover, continuous crystal growth is possible by repeating the film formation process and the heat treatment in a predetermined order.

The block diagram which shows the outline of a structure of the crystal manufacturing apparatus 20. FIG. Explanatory drawing of the area | region formed on the seed substrate 21. FIG. Explanatory drawing of a film-forming crystallization process. Explanatory drawing of another film-forming crystallization process. The block diagram which shows the outline of a structure of the crystal manufacturing apparatus 50. FIG.

  Next, modes for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram showing an outline of the configuration of a crystal manufacturing apparatus 20 used in the crystal manufacturing method of the present invention. The crystal manufacturing apparatus 20 is configured as an apparatus used in an aerosol deposition method (AD method) in which a raw material powder is jetted onto a seed substrate in an atmosphere at a pressure lower than atmospheric pressure. The crystal manufacturing apparatus 20 forms an aerosol generating unit 22 that generates an aerosol of raw material powder containing raw material components, and forms a film containing the raw material components by injecting the raw material powder onto the seed substrate 21 and crystallizes this film. And a heating device 40 that heats a film formed on the seed substrate 21 with irradiation heat.

  The aerosol generation unit 22 contains a raw material powder, receives an supply of a carrier gas from a gas cylinder (not shown), and generates an aerosol, and a raw material supply pipe 24 that supplies the generated aerosol to the crystal generation unit 30. It has. The crystal generation unit 30 includes a seed substrate 21, a film formation chamber 31 that injects aerosol into the seed substrate 21 under reduced pressure conditions, and a substrate installation stage that is disposed inside the film formation chamber 31 and fixes the seed substrate 21. 34 and an XY stage 33 that moves the substrate placement stage 34 in the X-axis-Y-axis direction. Further, the crystal generation unit 30 includes a spray nozzle 36 that has a rectangular slit 37 formed at the tip thereof and sprays aerosol onto the seed substrate 21, and a vacuum pump 38 that decompresses the film forming chamber 31. In the upper part of the film forming chamber 31, a transmission window 32 is disposed between the heating device 40 and the substrate setting stage 34, so that the laser from the heating device 40 can be irradiated onto the substrate setting stage 34. .

The heating device 40 heats the film-formed body formed on the seed substrate 21 from the outside of the film-forming chamber 31, and includes an optical system 41 that can adjust the irradiation range, and a laser generator that generates a heating laser. Device 42. The optical system 41 is constituted by a plurality of lenses and the like, and has a function of focusing a laser on an arbitrary region on the substrate installation stage 34 through a transmission window 32 provided on the upper part of the film forming chamber 31. Yes. The laser generator 42 is a device that oscillates and outputs a laser as a heating source. The laser generator 42 is configured to output a CO ₂ laser. The heating source is not particularly limited. For example, in addition to a CO ₂ laser, an infrared lamp can be applied in addition to various lasers such as a YAG laser, an excimer laser, and a semiconductor laser. The heating device 40 sets the irradiation area by the optical system 41, and then transmits the laser output from the laser generator 42 on the seed substrate 21 installed on the substrate installation stage 34 via the optical system 41 and the transmission window 32. This film is heated by irradiating the formed film.

  In the crystal manufacturing apparatus 20, a process of forming a film on the seed substrate 21 and performing crystallization is repeatedly executed in parallel. FIG. 2 is an explanatory diagram of a region formed on the seed substrate 21. On the seed substrate 21, the film forming body 10 including the crystals generated on the seed substrate 21 is formed. On the seed substrate 21 (film formation body 10), there are a film formation execution region 12, a film formation region 13, a heat execution region 14, a crystallized region 15, and an unprocessed region (not shown). The film formation execution area 12 is an area in which a raw material powder containing a raw material component is sprayed from the injection nozzle 36 onto the seed substrate 21 to form a film containing the raw material component. The film-formed region 13 is a region where a film containing a raw material component has been formed on the seed substrate 21. The heating execution region 14 is a region for heating and crystallizing the film formed on the seed substrate 21. The heating execution area 14 is an area in which laser is irradiated from the heating device 40 to the heating area 45 set by the optical system 41 and crystallization is executed by the irradiation heat. The crystallized region 15 is a region that has been crystallized after heat treatment. The unprocessed area is an area where the above processing is not performed, and is an area that does not exist after the formation of the second layer film. The film formation area 12, the film formation area 13, the heat execution area 14, and the crystallized area 15 may be rectangular areas having the same width. In this way, it is easy to perform a film forming process and a heating process described later in parallel.

  Next, a crystal manufacturing method using this crystal manufacturing apparatus 20 will be described below. In the crystal manufacturing method of the present invention, the seed substrate 21 (film-forming body 10) is formed in a state in which the film-formed region 13 or the crystallized region 15 exists between the film-forming region 12 and the heating region 14. A film forming process in which the raw material powder is injected from the injection nozzle 36 onto the film forming execution area 12 and the heating execution area 14 in which the film is formed on the seed substrate 21 (film forming body 10) are heated by irradiation heat to form the film. It includes a film-forming crystallization step in which a heat treatment for crystallization is performed in parallel. The film formation process and heat treatment in this film formation crystallization process will be described below.

  In the film forming process, as shown in FIG. 2, the injected raw material particles collide with the seed substrate 21 (film forming body 10) and are impact-solidified on the substrate to generate a film body. In this film forming process, the raw material powder containing the raw material components is not particularly limited as long as it can produce a single crystal, and examples thereof include powders containing oxides, nitrides, and carbides. Among these, examples of the oxide include ZnO. Examples of the nitride include GaN, AlN, InN, and mixed crystals thereof (AlGaInN), and among these, GaN is preferable. Moreover, as a carbide | carbonized_material, SiC etc. are mentioned, for example. In the AD method, the raw material powder is preferably primary particles that do not aggregate (particles that do not include grain boundaries in the particles), and the particle size is preferably 0.05 μm or more and 10 μm or less, for example, 0.2 μm or more and 2 μm. The following is more preferable. This particle diameter means the median diameter (D50) measured by dispersing in a dispersion medium (such as an organic solvent or water) using a laser diffraction / scattering particle size distribution measuring apparatus. The raw material powder may be previously milled by a ball mill, a planetary ball mill, a jet mill or the like. As a result, the surface properties and crystallinity of the particles change, and the film formation rate in the AD method can be improved. Moreover, you may heat-process with respect to raw material powder. As a result, the density of the film formed by the AD method can be improved. In the film forming process, the seed substrate 21 may be made of the same component as the raw material component, and examples thereof include oxides, nitrides, and carbides. The seed substrate 21 only needs to include a single crystal, and may be, for example, a single crystal substrate or a support substrate having a single crystal film formed on the surface thereof. Of these, a single crystal substrate is more preferable.

In the film forming process, the carrier gas and the pressure adjusting gas are more preferably inert gases. For example, when the raw material powder is a nitride, N ₂ gas is preferred. As the injection conditions, a film is formed when injected at room temperature, and the carrier structure, the pressure adjusting gas, and the vacuum chamber are such that the crystal structure is 100 nm or less and the density is 95% or more. It is preferable to adjust the pressure. By doing so, the single crystallization temperature can be lowered. The crystallite diameter can be measured by TEM observation, and the density can be measured by image analysis by cross-sectional SEM observation. The injection nozzle 36 is preferably formed with a slit having a long side and a short side. The slit may be formed in a range where the long side is 1 mm or more and 10 mm or less, and may be formed in a range where the short side is 0.1 mm or more and 1 mm or less. The thickness of the film formed by spraying the raw material powder is preferably 5 μm or less, more preferably 3 μm or less for each film forming process. The thickness of this film is preferably 0.1 μm or more. When the thickness of this film is 5 μm or less, the denseness is further improved. In addition, pores tend to remain as the thickness increases, such as exceeding 5 μm. Here, by setting the thickness to 5 μm or less for each film forming process, it is possible to further suppress the peeling of the film that may be caused by the subsequent heat treatment. In this film forming process, when the raw material powder is sprayed from the spray nozzle 36, the film forming process may be executed by scanning the spray nozzle 36 over the film forming execution region 12. The scanning of the spray nozzle 36 is not particularly limited, but is preferably performed in the longitudinal direction of the film formation execution region 12, and the film formation process may be performed several times on the same region, that is, may be performed so as to be overcoated. . The film forming process is preferably executed as an unprocessed area or a crystallized area adjacent to the film formed area where the previous film forming process was performed as a new film forming execution area. By doing so, since the film-formed regions are continuous, it is possible to further suppress the occurrence of defects that may occur at the interface between the film-formed regions.

The heat treatment is performed, for example, under the condition of a predetermined single crystallization temperature at which the film-formed body including the raw material component formed on the seed substrate 21 is single-crystallized. For example, the single crystallization temperature depends on the type of raw material component (for example, GaN, ZnO), the crystal structure, the microstructure of the film formation such as the crystal grain size and density, and the type of irradiation heat (laser species, etc.) Thus, the temperature at which single crystallization proceeds is determined empirically. This single crystallization temperature may be, for example, 900 ° C. or higher, 1000 ° C. or higher, or 1200 ° C. or higher. This single crystallization temperature is preferably in a range lower than the melting point or decomposition temperature of the raw material powder. This heat treatment is preferably performed by irradiation heat of at least one of a CO ₂ laser, a YAG laser, an excimer laser, a semiconductor laser, and an infrared lamp. When using an infrared lamp as a heating device, it may be installed near the seed substrate in the chamber and the substrate part may be heated, or it may be installed outside the chamber and light introduced through an optical fiber or a light guide tube, etc. May be heated.

  In the heat treatment, the laser may be scanned so that the heating region 45 moves in the region of the heating execution region 14. The scanning of the laser may be performed by scanning the heating execution region 14 once or a plurality of times. Alternatively, the optical system 41 may be set so that the laser hits the entire heating execution region, and the laser is not scanned. Moreover, it is preferable to perform the heat treatment as a new heating execution region 14 in the film-formed region 13 adjacent to the crystallized region 15 on which the previous heat treatment was performed. In this way, the temperature difference between the crystallized region 15 having a relatively high temperature and the heating execution region 14 to be newly crystallized becomes smaller, and the generation of defects that may occur at the interface between the regions can be further suppressed. it can. In the film formation crystallization step, it is preferable to perform the film formation process and the heat treatment in a state where there is an area having a width of 5 mm or more between the film formation execution area and the heat execution area. For example, the widths of the film formation area 12, the film formation area 13, the heat execution area 14, and the crystallized area 15 shown in FIG. 2 may be predetermined widths of 5 mm or more. For example, when the film formation execution region and the heating execution region are close to each other, the film formation may be difficult due to the effect of the thermophoresis effect due to the temperature difference between the seed substrate 21 and the air flow of the raw material powder. Here, since there is a width of 5 mm or more between the film formation execution region and the heating execution region, the influence of the thermophoresis effect can be further suppressed, and more precise film formation can be performed in parallel with the heat treatment. . The wider the width between the film formation area and the heat execution area, the more the thermophoresis effect can be suppressed. However, if the width is too wide, the production efficiency decreases, so the width is not more than 5 times the width of the film formation area. (For example, 50 mm or less), more preferably a width of 4 times or less is preferable. The slit 37 is preferably formed in accordance with the width between the film formation execution region and the heating execution region. In addition, the obtained crystal is preferably a single crystal, but may include a portion that is not a single crystal, or may be polycrystalline and three-dimensionally oriented.

  Next, a process for performing the film forming process and the heating process in parallel in the film forming and crystallization process will be described. FIG. 3 is an explanatory diagram of the jet nozzle 36 and the laser scanning method in the film-forming crystallization step. As shown in FIG. 3, in the film-forming crystallization step, each process is sequentially performed on regions 1 to 4 in which the width of the seed substrate 21 (for example, 20 mm) is divided into four by the width of the slit 37 (for example, 5 mm). did. First, in the film-forming crystallization step, the raw material powder is sprayed from the slit 37 to the region 1 and the spray nozzle 36 and the seed substrate 21 are relatively scanned in a direction perpendicular to the long side of the slit 37. Then, a film is formed on the seed substrate 21 (FIG. 3A). In the film forming process, for example, the spray nozzle 36 may be reciprocated once while spraying the raw material powder. At this time, the areas 2 to 4 are unprocessed areas. When the film formation process is finished in the area 1 and the area 1 becomes the film-formed area, the injection nozzle 36 is moved in the long side direction of the slit 37 and the film formation process is executed in the area 2 adjacent to the area 1 ( FIG. 3 (b)). When the film forming process is finished in the area 2 and the area 2 becomes the film-formed area, the injection nozzle 36 is moved in the long side direction of the slit 37 and the film forming process is executed in the area 3 adjacent to the area 2 ( FIG. 3 (c)). At the same time, crystallization is performed by irradiation heat from the heating device 40 using the region 1 that is a film-formed region as a heating execution region. In the heat treatment, laser irradiation is performed while scanning the heating execution region from the heating device 40 provided outside the film forming chamber 31 through the transmission window 32. In the laser scanning, the heating region 45 may be moved once from one end to the other end of the heating execution region. Here, a film-formed region (region 2) exists between the film-forming execution region and the heating execution region, and this interval is, for example, 5 mm. Subsequently, when the region 3 becomes a film-formed region and the region 1 becomes a crystallized region, the film-forming process is executed using the region 4 adjacent to the region 3 as the film-forming execution region, and the region 2 adjacent to the region 1 is set. The heat treatment is executed as the heating execution region (FIG. 3D). Subsequently, when the region 4 becomes the film-formed region and the region 2 becomes the crystallized region, the film-forming process is executed with the region 1 which is the crystallized region as the film-forming execution region, and the region 3 adjacent to the region 2 Is used as a heating execution region (FIG. 3E). Here, there is a crystallized region between the film formation region and the heating region, and this interval is, for example, 5 mm. Subsequently, when the region 1 becomes a film-formed region and the region 3 becomes a crystallized region, the film-forming process is executed using the region 2 adjacent to the region 1 as the film-forming execution region, and the region 4 adjacent to the region 3 is changed. The heat treatment is executed as the heating execution region (FIG. 3 (f)). Then, when the region 2 becomes the film-formed region and the region 4 becomes the crystallized region, the film-forming process is executed with the region 3 adjacent to the region 2 as the film-forming execution region, and the region 1 that is the crystallized region is changed. A heat treatment is executed as the heating execution region (similar to FIG. 3C). This process is repeated a predetermined number of times to produce a crystal having a desired thickness. That is, in the film-forming crystallization process, the raw material powder is ejected from the slit-shaped ejection nozzle 36 having the long side and the short side, and the spray nozzle 36 and the seed substrate 21 are relatively moved in the direction perpendicular to the long side. And a film forming process for forming a film on the film forming area of the seed substrate 21 is executed to form a new film-formed area. Subsequently, the spray nozzle 36 and the seed substrate 21 are relatively scanned in the long side direction of the slit 37, and the film forming process is performed using the area adjacent to the new film-formed area as a new film forming execution area. Then, the process of executing the heating process using the previously formed film-formed area adjacent to the new film-formed area as the heating execution area is repeatedly executed. In this way, if there is always a region adjacent to the film-formed region, this region is set as the film-forming execution region, and if there is a region adjacent to the crystallized region, this region is set as the heating-execution region. Processing is performed in parallel to perform crystal growth.

  According to the crystal manufacturing method of the embodiment described above, the film formation process and the heat treatment are performed in parallel in a state in which the film formation area or the crystallized area exists between the film formation area and the heating execution area. Therefore, the influence of the thermophoresis effect can be further reduced to form a film. Therefore, a better crystal can be produced. In addition, because of the use of irradiation heat, the film is locally heated in the heating execution area away from the film formation execution area while keeping the temperature below a certain level in the film formation execution area (maintaining the conditions under which a dense film can be formed). By doing so, crystallization can proceed. As described above, the film forming process and the heating process, which cannot be realized by heating the entire inside of the film forming chamber 31, can be performed in parallel. For this reason, crystallization can be performed efficiently. Moreover, continuous crystal growth is possible by repeating film formation and heating in a predetermined order. Furthermore, since a film forming process with a predetermined thickness (for example, 5 μm) or less is performed, the generation of pores can be further suppressed, and a high-quality single crystal without voids can be obtained. Furthermore, a high-quality single crystal can be produced even for a material system in which it is difficult to obtain a raw material melt. In the film formation process, the area adjacent to the film-formed area where the previous film-formation process was performed is executed as a new film-formation execution area. The occurrence of defects that can occur can be further suppressed. In addition, in the heat treatment, since the region adjacent to the crystallized region 15 where the previous heat treatment was performed is executed as a new heating execution region, the crystallized region having a relatively high temperature and the newly crystallized heating are performed. The temperature difference from the execution area becomes smaller, and the occurrence of defects that may occur at the interface between the areas can be further suppressed.

  It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that the present invention can be implemented in various modes as long as it belongs to the technical scope of the present invention.

  For example, in the above-described embodiment, as illustrated in FIG. 3, the film formation process and the heating process are sequentially performed on the areas 1 to 4 divided into four equal parts. As long as a predetermined area exists between the execution area and the execution area, the number of areas and the order of processing are not particularly limited thereto. FIG. 4 is an explanatory diagram of another film-forming crystallization process. As shown in FIG. 4, in the film-forming crystallization step, the heating region 45 may be scanned in the scanning direction of the spray nozzle 36 while being followed to perform crystallization. At this time, the film forming process and the film forming process are performed so that there is a film forming area having a predetermined interval between the film forming execution area where the raw material powder is discharged from the slit 37 and the heating execution area where the laser is irradiated. Heat treatment shall be performed. Even in this case, the film-formed region exists between the film-forming execution region and the heat-executing region, so that the influence of the thermophoresis effect can be further suppressed, and the film-forming process and the heat treatment can be executed in parallel. A better crystal can be produced more efficiently. In this case, in order to control the film thickness, for example, the number of slits 37 may be two or more. In FIG. 4, the areas 1 to 4 are provided. However, the number of areas may be any number as long as it is 1 or more.

  In the embodiment described above, the film formation execution region 12, the film formation region 13, the heating execution region 14, and the crystallized region 15 are rectangular regions, and in the film formation crystallization step, a rectangular film formation execution is performed. The film forming process for injecting the raw material powder into the area 12 is executed, and the heating process for heating the rectangular heating execution area 14 with the irradiation heat is executed. However, the present invention is not limited to this. For example, the film formation area 12, the film formation area 13, the heat execution area 14, and the crystallized area 15 may be arbitrary shapes, or may be polygonal areas such as triangles and hexagons.

  In the above-described embodiment, the crystal manufacturing apparatus 20 used in the aerosol deposition method in which the raw material powder is sprayed onto the seed substrate at an atmospheric pressure lower than the atmospheric pressure is used. As shown in FIG. 5, a crystal manufacturing apparatus 50 used in a powder jet deposition method in which a raw material powder is sprayed onto a seed substrate in an atmospheric pressure or an atmosphere of atmospheric pressure or higher may be used. . FIG. 5 is a configuration diagram showing an outline of the configuration of the crystal manufacturing apparatus 50 used in the crystal manufacturing method of the present invention. The crystal manufacturing apparatus 50 forms a film containing a raw material component by jetting the raw material powder onto a seed substrate 51 and a jet powder generation unit 52 that generates a raw material fluid including the raw material powder and a carrier gas, and crystallizes this film. And a heating device 70 that heats a film formed on the seed substrate 51 with irradiation heat. The jet powder generation unit 52 includes a pressure tank 53 that contains raw material powder and receives a supply of carrier gas from a gas cylinder (not shown), and a raw material supply pipe 54 that supplies the generated aerosol to the crystal generation unit 60. The crystal generation unit 60 includes a film formation chamber 61 that injects a raw material fluid onto the seed substrate 51 under normal pressure, a substrate installation stage 64 that is disposed inside the film formation chamber 61 and fixes the seed substrate 51, and a substrate installation stage 64. And an XY stage 63 that moves in the X-axis-Y-axis direction. In addition, the crystal generation unit 60 includes a transmission window 62 that transmits the laser from the heating device 70, and an injection nozzle 66 that has a slit 67 formed at the tip and injects a raw material fluid onto the seed substrate 51. The heating device 70 is the same as the heating device 40, and includes an optical system 71 capable of adjusting the irradiation range, and a laser generator 72 that generates a laser for heating. Using this crystal manufacturing apparatus 50, in the same manner as described above, the raw material powder is formed on the film formation execution region in a state where the film formation region or the crystallized region exists between the film formation execution region and the heating execution region. Is performed in parallel with the film forming process in which the film is ejected from the spray nozzle 66 and the heating execution region is heated by irradiation heat to crystallize the film forming body. At this time, as the injection conditions, a film is formed when injected at room temperature, and the carrier gas is adjusted so that the film structure is a crystallite diameter of 100 nm or less and a density of 95% or more. Also good. Other conditions can be performed in accordance with the conditions of the AD method described above. Even in this case, a better crystal can be produced more efficiently.

  In the above-described embodiment, the injection nozzle is provided with the slit, but is not particularly limited as long as the raw material powder can be injected, and may be a circular, elliptical, or polygonal hole. .

  In the above-described embodiment, the crystal manufacturing apparatus 20 and the crystal manufacturing apparatus 50 are used. However, the present invention is not particularly limited thereto, and any apparatus other than the crystal manufacturing apparatuses 20 and 50 can be used as long as the film formation crystallization step can be performed. May be used.

  Below, the example which manufactured the crystal manufacturing method concretely is demonstrated as an Example.

[Example 1]
A GaN powder (manufactured by High Purity Chemical Laboratory, average primary particle size 0.2 μm) was used as a raw material powder, and a GaN single crystal substrate (20 mm × 20 mm square, (002) plane) was used as a seed substrate. Further, a GaN single crystal was manufactured using an AD method crystal manufacturing apparatus shown in FIG. As production conditions, first, the injection conditions were N ₂ for the carrier gas and the pressure adjusting gas. A stainless steel nozzle having a slit with a long side of 5 mm and a short side of 0.3 mm was used. The nozzle scan condition was a scan speed of 1 mm / s. Here, it moved 20 mm in the direction perpendicular to the long side of the slit and moved forward, and then moved 20 mm in the return direction, that is, the injection nozzle was reciprocated once in region 1 (FIG. 3A). As a result, a film having a thickness of 4 μm was formed. Next, the injection nozzle 36 was moved 5 mm in the long side direction of the slit, and the injection nozzle was reciprocated once in the region 2 (FIG. 3B). Subsequently, the ejection nozzle 36 was moved 5 mm in the long side direction of the slit, and the ejection nozzle was reciprocated once in the region 3 (FIG. 3C). At the same time, crystallization was performed in the region 1 as a film-formed region by irradiation heat from a heating device (heating execution region). In the heat treatment, laser irradiation was performed while scanning the heating execution region through a transmission window from a heating device disposed outside the film formation chamber. As heating conditions, a CO ₂ laser was used, the beam diameter was 6 mm, the scanning speed was 0.5 mm / s, one way was 20 mm × 1 time, and the output was adjusted so that the film on the seed substrate was about 1050 ° C. Further, the width of the film-formed region between the film formation execution region and the heating execution region, that is, the interval between the film formation execution region and the heat execution region was 5 mm. The film formation execution process and the heat execution process for the regions 1 to 4 were performed 100 cycles to produce a 400 μm thick crystal. In this one cycle film formation, the carrier gas set pressure was adjusted to 0.06 MPa, the flow rate was set to 6 L / min, the pressure adjusting gas flow rate was set to 0 L / min, and the chamber pressure was adjusted to 100 Pa or less. In one cycle of film formation at room temperature under these conditions, a film structure having a crystallite diameter of 100 nm or less and a density of 95% or more was obtained. The film-forming crystallization process was executed under these injection conditions. By this step, crystals were obtained on the seed substrate.

[Example 2]
ZnO powder (manufactured by High Purity Chemical Laboratory, average primary particle size 0.5 μm) was used as a raw material powder, and a ZnO single crystal substrate (20 mm × 20 mm square, (002) plane) was used as a seed substrate. For crystal production, the same apparatus as in Example 1 was used, and the film formation conditions by the AD method were the same as in Example 1 except that the carrier gas and the pressure adjusting gas were He. At this time, in one cycle of film formation at room temperature, a film structure having a crystallite diameter of 100 nm or less and a density of 98% or more was obtained. The laser output was adjusted so that the film on the seed substrate would be 1250 ° C. By this step, crystals were obtained on the seed substrate.

[Example 3]
ZnO powder (manufactured by High Purity Chemical Laboratory, average primary particle size 0.5 μm) was used as the raw material powder, and a sapphire substrate (20 mm × 20 mm square, c-plane) was used as the seed substrate. For crystal production, the same apparatus as in Example 1 was used, and the film formation conditions by the AD method were the same as in Example 2. At this time, in one cycle of film formation at room temperature, a film structure having a crystallite diameter of 100 nm or less and a density of 98% or more was obtained. The laser output was adjusted so that the film on the seed substrate would be 1250 ° C. By this step, crystals were obtained on the seed substrate.

[Example 4]
The raw material powder and seed substrate were the same as in Example 2, and the same apparatus as in Example 1 was used for crystal production. The film forming conditions by the AD method are other than preheating the substrate setting stage on which the seed substrate is placed at 400 ° C., arranging two injection nozzles adjacent to each other in the slit short side direction, and setting the nozzle scanning conditions as follows: These are the same as in Example 2. Nozzle scanning was performed at a scanning speed of 1 mm / s and one time 20 mm × 1. By increasing the number of nozzles, a film having a thickness of 4 μm could be formed by only one-way scanning. The heating conditions are the same as in Example 2 except that the scanning speed is 1 mm / s. At this time, in one cycle of film formation at room temperature, a film structure having a crystallite diameter of 100 nm or less and a density of 98% or more was obtained. The laser output was adjusted so that the film on the seed substrate was about 1250 ° C. By this step, crystals were obtained on the seed substrate. In this way, the deposition rate can be improved by using multiple nozzles, and the time to reach the single crystallization temperature by laser heating can be shortened by preheating the seed substrate, thereby increasing the laser scanning speed. Thus, a single crystal equivalent to that in Example 1 could be produced in half the time. From the results of Example 4, it was found that the growth rate of the single crystal can be increased.

[Comparative Example 1]
The raw material powder and seed substrate were the same as in Example 2, and the same apparatus as in Example 1 was used for crystal production. The manufacturing conditions are the same as in Example 2 except that the film formation execution region and the heating execution region are adjacent to each other (the width between the film formation execution region and the heat execution region is 0 mm). Since the film formation execution region and the heat execution region are adjacent to each other, a thermophoresis effect due to a temperature difference between the seed substrate and the air flow of the raw material powder occurs, making it difficult to form a stable film and reducing the film formation speed.

[Electron microscope (SEM) photography]
As evaluation of Examples 1 to 4 and Comparative Example 1 produced, cross-sectional SEM imaging was performed. For SEM photography, a scanning electron microscope (JEOL JSM-6390) was used. The sample was polished along the film surface and observed at a magnification of 1000 times. At this time, in Example 1, no voids could be confirmed, whereas in Comparative Example 1, 20 or more voids were observed. Moreover, about the single crystal of Examples 2-4, when the SEM observation of the cross section was performed by the method similar to Example 1, the space | gap was not confirmed also about Examples 2-4. In addition, when the XRD profile was measured with an XRD measurement device (Bruker AXS, “D8ADVANCE”) for the film surface, only the diffraction peak due to the (002) plane was observed in Example 1, and the morphology appeared on the film surface. Single crystallization was confirmed because the in-plane directions of a regular hexagon were aligned. Further, when the XRD profiles for the film surfaces of Examples 2 to 4 were measured, only the diffraction peak due to the (002) plane was observed, and the in-plane orientation of the regular hexagon as the morphology appearing on the film surface was aligned. Thus, single crystallization was also confirmed in Examples 2 to 4. On the other hand, in Comparative Example 1, diffraction peaks other than (002) were also observed, and it was confirmed that the degree of single crystallization was low.

  This application is based on Japanese Patent Application No. 2011-194756 filed on Sep. 7, 2011, the contents of which are incorporated herein by reference in their entirety.

  The present invention can be used in the technical field of manufacturing a single crystal.

  DESCRIPTION OF SYMBOLS 10 Film-forming body, 12 Film-forming execution area | region, 13 Film-forming area | region, 14 Heating execution area | region, 15 Crystallized area | region, 20 Crystal manufacturing apparatus, 21 seed | species board | substrate, 22 Aerosol production | generation part, 23 Aerosol production | generation chamber, 24 Raw material supply Tube, 30 Crystal generation unit, 31 Film formation chamber, 32 Transmission window, 33 XY stage, 34 Substrate installation stage, 36 Injection nozzle, 37 Slit, 38 Vacuum pump, 40 Heating device, 41 Optical system, 42 Laser generator , 45 heating region, 50 crystal production apparatus, 51 seed substrate, 52 jet powder generation unit, 53 pressure tank, 54 raw material supply pipe, 60 crystal generation unit, 61 film formation chamber, 62 transmission window, 63 XY stage, 64 Substrate installation stage, 66 injection nozzle, 67 slit, 70 heating device, 71 optical system, 72 laser generator.

Claims (9)

A film forming execution region in which a raw material powder containing a raw material component is sprayed from a nozzle on a seed substrate containing a single crystal to form a film containing the raw material component, and a film containing the raw material component on the seed substrate A film-formed region that has been formed, and a heating execution region in which the film formed on the seed substrate is heated by irradiation heat to crystallize the film exist on the seed substrate,
The film formation region or the crystallized region that has been crystallized is present between the film formation region and the heating execution region on the film formation region of the seed substrate. A film forming process for injecting raw material powder from the nozzle and a heating process for heating the heating execution region where the film is formed on the seed substrate by irradiation heat to crystallize the film are executed in parallel. Film-forming crystallization process,
A crystal production method comprising:   2. The film formation crystallization step is performed in a state in which a region having a width of 5 mm or more exists between the film formation execution region and the heating execution region. The crystal production method according to 1.   3. The crystal manufacturing method according to claim 1, wherein in the film formation crystallization step, the film formation process for injecting the raw material powder containing the same component as the seed substrate is executed.   The said film-forming crystallization process of any one of Claims 1-3 which performs the said film-forming process whose raw material component and the said seed substrate which are contained in the said raw material powder are nitride or an oxide. Crystal manufacturing method.   5. The crystal manufacturing method according to claim 1, wherein in the film formation crystallization step, the film formation process in which a raw material component contained in the raw material powder is gallium nitride or zinc oxide is executed. The film formation region, the film formation region, the heating execution region, and the crystallized region are rectangular regions,
In the film-forming crystallization step, the film-forming process for injecting the raw material powder to the rectangular film-forming execution area is executed, and the heating process for heating the rectangular heating-execution area with irradiation heat is executed. The crystal manufacturing method according to any one of claims 1 to 5.   In the film-forming crystallization step, the raw material powder is ejected from the slit-shaped nozzle having a long side and a short side, and the nozzle and the seed substrate are relatively scanned in a direction perpendicular to the long side. Then, after the film formation process for forming the film is performed on the film formation execution region of the seed substrate to form a new film formation region, the nozzle and the seed substrate are moved in the long side direction. The film forming process is performed by relatively scanning and using the region adjacent to the new film-formed region as the new film-forming execution region, and the previously formed film adjacent to the new film-formed region. The crystal manufacturing method according to any one of claims 1 to 6, wherein a process of executing the heat treatment is performed repeatedly using a finished region as the heating execution region. In the film formation and crystallization step, the film formation process is performed by an aerosol deposition method in which the raw material powder is sprayed onto the seed substrate in an atmosphere at a pressure lower than atmospheric pressure.
The crystal manufacturing method according to claim 1.   In the film formation crystallization step, the film formation process is performed by a powder jet deposition method in which the raw material powder is injected onto the seed substrate in an atmosphere of atmospheric pressure or atmospheric pressure. 8. The method for producing a crystal according to any one of 7 above.