WO2021131966A1

WO2021131966A1 - Aln laminate board

Info

Publication number: WO2021131966A1
Application number: PCT/JP2020/046971
Authority: WO
Inventors: 博久小川; 義政小林; 和希飯田; 宏之柴田
Original assignee: 日本碍子株式会社
Priority date: 2019-12-23
Filing date: 2020-12-16
Publication date: 2021-07-01
Also published as: JPWO2021131966A1; JP7620571B2

Abstract

This laminate board is provided with an AlN polycrystalline layer, an AlN single-crystal layer formed on the AlN polycrystalline layer, and a metal component-containing region which contacts the area of interface between the AlN polycrystalline layer and the AlN single-crystal layer and in which multiple metal components are introduced in a dispersed manner.

Description

AlN laminated board

The technique disclosed in the present specification relates to a laminated plate in which an AlN single crystal layer and an AlN polycrystalline layer are laminated.

An AlN single crystal plate may be used as a substrate for an ultraviolet light emitting device. For example, Non-Patent Document 1 discloses a method for manufacturing an ultraviolet light emitting device manufactured on an AlN single crystal plate. In Non-Patent Document 1, a functional layer of an ultraviolet light emitting device is formed on an AlN single crystal plate. After the functional layer is formed on the AlN single crystal plate, the AlN single crystal plate is thinned by mechanical polishing in order to improve the ultraviolet light transmittance.

The ultraviolet light emitting device described in Non-Patent Document 1 uses an AlN single crystal plate as a substrate. In the process of forming the functional layer of the ultraviolet light emitting device, a thick substrate is used to prevent damage to the substrate. However, since a thick AlN single crystal plate is expensive, an AlN polycrystalline plate is used as a support substrate on the AlN single crystal plate. A laminated board in which the boards are laminated may be used as a handling substrate for manufacturing an ultraviolet light emitting device. Therefore, after forming a functional layer on the surface of the laminated plate on the AlN single crystal plate side, the AlN polycrystalline plate is removed by mechanical polishing. However, if the AlN polycrystalline plate is thinned by mechanical polishing, the functional layer may be affected during mechanical polishing. Therefore, conventionally, when thinning an AlN polycrystalline plate by mechanical polishing, it is necessary to carefully perform mechanical polishing in order to suppress the influence on the functional layer. As a result, the time required to manufacture the ultraviolet light emitting device increases. Therefore, there is a need for a laminated plate that can be easily thinned.

This specification discloses a technique for easily thinning a laminated plate in a laminated plate in which an AlN single crystal layer and an AlN polycrystalline layer are laminated.

The laminate disclosed in the present specification is in contact with the AlN polycrystalline layer, the AlN single crystal layer formed on the AlN polycrystalline layer, and the interface portion between the AlN single crystal layer and the AlN polycrystalline layer. It includes a metal component-containing region in which a plurality of metal components are dispersed and introduced.

In the above-mentioned laminated board, a plurality of metal components are dispersed and introduced at the interface portion between the AlN single crystal layer and the AlN polycrystalline layer. Therefore, for example, by irradiating the laminated board with a laser to sublimate (vaporize) the metal component-containing region, fine cracks can be generated in the metal component-containing region and the laminated board can be thinned. That is, the AlN polycrystalline layer can be removed from the laminated plate by a method other than mechanical polishing such as laser lift-off. Therefore, the AlN polycrystalline layer can be easily removed, and the influence on the functional layer of the ultraviolet light emitting device or the like when the AlN polycrystalline layer is removed can be reduced.

The schematic diagram of the ultraviolet light emitting device produced using the laminated board which concerns on Examples 1 to 3. The schematic diagram of the laminated board which concerns on Example 1. FIG. The schematic diagram of the laminated board which concerns on Example 2. The schematic diagram of the laminated board which concerns on Example 3. FIG.

The main features of the examples described below are listed. It should be noted that the technical elements described below are independent technical elements and exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Absent.

The laminate disclosed in the present specification is a laminate of an AlN single crystal layer and an AlN polycrystalline layer. Single crystal AlN, for example, compared to sapphire _is a _{Al x Ga y N (0 ≦} x ≦ 1,0 <y ≦ 1) or the same close nitride semiconductor and the lattice constant of such. Therefore, the AlN single crystal layer of the laminated plate disclosed in the present specification is useful as a growth substrate for an ultraviolet light emitting device (UV LED) having a nitride semiconductor as a functional layer. Further, AlN single crystal plate, for example as compared to _{_{sapphire, Al x Ga y N (0}} ≦ x ≦ 1,0 <y ≦ 1) nitride semiconductor and thermal expansion coefficient, such as are close or the same. Therefore, it is useful as a handling substrate when manufacturing an ultraviolet light emitting device. When only an AlN single crystal plate is used as a handling substrate when manufacturing an ultraviolet light emitting device, it is necessary to use a thick AlN single crystal plate in order to secure strength, but a thick AlN single crystal plate is used. It is expensive. The laminate disclosed in the present specification is provided with an AlN polycrystalline layer on the back surface side of the AlN single crystal layer (the side on which the functional layer of the ultraviolet light emitting device is not provided). The AlN polycrystalline layer can be obtained (or manufactured) at a relatively low cost. Therefore, by laminating the AlN single crystal layer and the AlN polycrystalline layer, a high-strength growth substrate having a relatively close lattice constant to that of the nitride semiconductor can be realized without using an expensive thick AlN single crystal plate. be able to.

Further, the laminated board disclosed in the present specification has a metal component-containing region in which the metal component is dispersed and introduced at the interface portion between the AlN single crystal layer and the AlN polycrystalline layer. Therefore, for example, after the ultraviolet light emitting device is formed on the AlN single crystal layer of the laminated plate, the laminated plate is irradiated with a laser from the AlN polycrystalline layer side so that the metal component in the metal component-containing region absorbs the laser. , The back surface side (the AlN polycrystalline layer side on which the functional layer of the ultraviolet light emitting device is not provided) can be lifted off from the metal component-containing region. Since the laminated board can be thinned in a short time regardless of the thickness of the laminated board that is lifted off (removed), the manufacturing time of the ultraviolet light emitting device can be shortened. That is, even when the ultraviolet light emitting device is manufactured using the thick laminated plate, it is possible to suppress an increase in the time required for manufacturing the ultraviolet light emitting device. Further, the thinning of the laminated plate by laser lift-off can reduce the force (vibration) applied to the functional layer of the ultraviolet light emitting device as compared with the thinning by mechanical polishing, and the influence on the functional layer can be reduced. Can be done. The metal component-containing region can be distinguished from the portion other than the metal component-containing region by observing the laminated board using an SEM or the like. The laminated board disclosed in the present specification is not particularly limited, but may have a thickness (distance between the front and back surfaces including the AlN single crystal layer and the AlN polycrystalline layer) of 0.5 to 10.0 mm. The metal component-containing region may be provided at a portion in contact with the interface between the AlN single crystal layer and the AlN polycrystalline layer. That is, the metal component-containing region may be provided in the AlN single crystal layer, may be provided in the AlN polycrystalline layer, or may be provided across both the AlN single crystal layer and the AlN polycrystalline layer. It may be provided.

In the laminated board disclosed in the present specification, the thickness of the metal component-containing region may be, for example, 0.1 μm or more and 5.0 μm or less. That is, the metal component-containing region is locally provided in the thickness direction from the front surface to the back surface of the laminated board. When the thickness of the metal component-containing region is 0.1 μm or more, when the laminated plate is irradiated with the laser, the metal component sufficiently absorbs the laser, the metal component is sublimated, and fine particles are contained in the metal component-containing region. Cracks can be generated and the AlN polycrystalline layer can be lifted off. Further, if it is 5.0 μm or less, it is possible to suppress the cracks generated in the metal component-containing region from extending to a portion other than the metal component-containing region (the cracks can be easily contained in the metal component-containing region). ), The laminated plate can be suitably laser lifted off without adversely affecting the ultraviolet light emitting device. The thickness of the metal component-containing region may be 0.2 μm or more, 0.3 μm or more, 0.5 μm or more, 0.7 μm or more, and 1.0 μm. It may be the above, and may be 1.5 μm or more. The thickness of the metal component-containing region may be 4.5 μm or less, 4.0 μm or less, 3.5 μm or less, or 3.0 μm or less.

In the laminated board disclosed in the present specification, the distance between adjacent metal components in the metal component-containing region may be 1 μm or more and 300 μm or less. In other words, the gap between the metal components may be 1 μm or more and 300 μm or less. According to such a configuration, if it is 1 μm or more, it is possible to suppress an adverse effect on the ultraviolet light emitting device due to cracks generated in the metal component-containing region. Further, if the thickness is 300 μm or less, cracks generated in the metal component-containing region are connected, and the back surface side of the AlN single crystal plate can be reliably separated by laser lift-off. The "adjacent metal components" mean metal components adjacent to each other in a direction (substantially parallel) along the end face in the thickness direction of the AlN polycrystalline layer. The distance between adjacent metal components may be 2 μm or more, 5 μm or more, 10 μm or more, 20 μm or more, and 25 μm or more. Further, the distance between the metal components in the metal component-containing region may be 275 μm or less, 250 μm or less, 200 μm or less, 150 μm or less, or 100 μm or less. ..

In the laminated board disclosed in the present specification, the metal component-containing region may contain at least one metal component selected from Al, Ga, Cu, Fe, Mo, Ni, Ta, and Ti, and the metal component may be contained. At least one of the above may be contained as a main component. Further, "a main component containing at least one of the metal components" means that the metal component-containing region contains 50% by weight or more of the metal component. These elements have a high ability to absorb light having a wavelength in a predetermined range, specifically, light having a wavelength of 245 to 1200 nm, and are easily absorbed by laser light. Therefore, according to such a configuration, the laminated board can be suitably laser lifted off. The metal component in the metal component-containing region may be, for example, a simple substance metal, an alloy containing the metal component, an oxide containing the metal component, a composite oxide, or a nitride. , Composite nitride, and composite oxynitride.

In the laminated board disclosed in the present specification, the metal component-containing region may particularly contain at least one metal component selected from Al, Ga, Cu, and Ni. The above-mentioned metal component material is relatively easily available, and in particular, it easily absorbs laser light, so that it can be suitably laser lifted off.

In the laminated board disclosed in the present specification, the metal component may be in the form of particles. In this case, the metal component (particles containing the metal component) may have an aspect ratio of more than 1 and 10 or less. In this case, the metal component may exist in the metal component-containing region so that the long side is along the first surface (or the first surface and the second surface) (substantially parallel). Specifically, the long side of the metal component may be arranged so as to form an angle of less than 20 degrees with respect to the first surface. When the aspect ratio of the metal component is larger than 1, the area of the surface along the first surface becomes sufficiently large, the absorption efficiency of the laser is improved, the laser lift-off can be performed efficiently, and the metal component-containing region is formed. Since the cracks that are generated are likely to occur along substantially parallel to the first surface (or the first surface and the second surface), the adverse effect on the ultraviolet light emitting device can be suppressed. Further, when the aspect ratio is 10 or less, the metal component can be easily introduced into the AlN single crystal plate. The aspect ratio may be 0.5 or more, 1.0 or more, 1.5 or more, or 2.0 or more. Further, the aspect ratio may be 8 or less, 7 or less, 5 or less, or 3 or less.

Further, when the material containing the metal component is introduced into the metal component-containing region, the Young's modulus of the metal component-containing region becomes smaller than the Young's modulus of the AlN single crystal layer and the AlN polycrystalline layer. Therefore, if a metal component-containing region is provided at the interface between the AlN single crystal layer and the AlN polycrystalline layer, the strain caused by the difference in thermal expansion coefficient between the AlN single crystal layer and the AlN polycrystalline layer can be alleviated. Can be done. Therefore, during heat treatment or the like, the force applied from the AlN polycrystalline layer to the AlN single crystal layer can be reduced based on the difference in the coefficient of thermal expansion between the AlN single crystal layer and the AlN polycrystalline layer. As a result, it is possible to reduce the occurrence of warpage and cracks in the AlN single crystal layer.

(Example 1)
Hereinafter, the laminated board 10 according to the embodiment will be described. The laminated board 10 is used as a handling substrate for manufacturing the ultraviolet light emitting device 1. Therefore, before explaining the laminated plate 10 in detail, the ultraviolet light emitting device 1 using the laminated plate 10 as a handling substrate will be briefly described.

The ultraviolet light emitting device 1 is an ultraviolet light emitting diode (UV LED), and includes an AlN single crystal layer 12, an n-type nitride semiconductor layer 2, a p-type nitride semiconductor layer 3, and a light emitting layer 4. The n-type nitride semiconductor layer 2 is provided on the surface of the AlN single crystal layer 12. The light emitting layer 4 is provided on a part of the surface of the n-type nitride semiconductor layer 2 (on the right side in FIG. 1). Therefore, the surface of the n-type nitride semiconductor layer 2 is partially provided with the light emitting layer 4, and the other parts are exposed. A p-type nitride semiconductor layer 3 is provided on the surface of the light emitting layer 4. That is, the light emitting layer 4 is provided between the n-type nitride semiconductor layer 2 and the p-type nitride semiconductor layer 3. Electrodes (not shown) are provided on the surface of the p-type nitride semiconductor layer 3 and the exposed portion of the surface of the n-type nitride semiconductor layer 2, respectively. Although not shown, the n-type nitride semiconductor layer 2 may actually be formed of a plurality of layers, and the p-type nitride semiconductor layer 3 may be formed of a plurality of layers. Often, the light emitting layer 4 may be formed of a plurality of layers. The material and the number of each layer of the n-type nitride semiconductor layer 2, each layer of the p-type nitride semiconductor layer 3, and each layer of the light emitting layer 4 can be appropriately selected according to the application of the ultraviolet light emitting device 1.

When producing the ultraviolet light emitting device 1, first, the n-type nitride semiconductor layer 2 is formed on the surface of the laminated plate 10 of this embodiment (specifically, the surface of the AlN single crystal layer 12). Next, the light emitting layer 4 is formed on the surface of the formed n-type nitride semiconductor layer 2, and the p-type nitride semiconductor layer 3 is formed on the surface of the formed light emitting layer 4. After that, a part of the light emitting layer 4 and the p-type nitride semiconductor layer 3 is removed to expose a part of the surface of the n-type nitride semiconductor layer 2. In order to form high-quality

nitride semiconductor layers

2, 3 and 4, the

nitride semiconductor layers

2, 3 and 4 are formed on the surface of the laminated plate 10 (the surface of the AlN single crystal layer 12). Further, in order to facilitate the film formation and processing of the n-type nitride semiconductor layer 2, the p-type nitride semiconductor layer 3, and the light emitting layer 4, a thick laminate is used as a handling substrate when manufacturing the ultraviolet light emitting device 1. The plate 10 is used. On the other hand, since the AlN single crystal layer 12 and the AlN polycrystalline layer 14 are laminated on the laminated plate 10, if the laminated plate 10 is used as it is as the substrate of the ultraviolet light emitting device 1, the AlN polycrystalline layer 14 emits light ( Ultraviolet light) becomes difficult to pass through the laminated plate 10. Therefore, after the n-type nitride semiconductor layer 2, the p-type nitride semiconductor layer 3, and the light emitting layer 4 are formed, the laminated plate 10 is thinned to a required thickness. That is, the AlN polycrystalline layer 14 which is an unnecessary portion is removed from the laminated plate 10 so that only the AlN single crystal layer 12 required as a substrate is left. Hereinafter, the n-type nitride semiconductor layer 2, the p-type nitride semiconductor layer 3, and the light emitting layer 4 may be collectively referred to as a “functional layer”.

As shown in FIG. 2, the laminated board 10 includes an AlN single crystal layer 12 and an AlN polycrystalline layer 14. The AlN single crystal layer 12 is composed of the single crystal AlN. The AlN polycrystalline layer 14 is composed of polycrystalline AlN. In this embodiment, for example, single crystal AlN and polycrystalline AlN are defined as follows. Counting time under the conditions of voltage 40 kV, current 40 mA, collimator diameter 0.5 mm, anti-scattering slit 3 mm, ω step width 0.01 ° using XRD device (D8-DISCOVER manufactured by Bruker-AXS) using CuKα wire. The XRC profile of the (002) plane of the AlN single crystal layer is measured in 1 second. Then, the measurement is performed using the half-value width based on the obtained XRC profile, and the measured value of less than 10,000 arcsec is referred to as single crystal AlN, and the measured value of 10,000 arcsec or more is referred to as polycrystalline AlN. Both the AlN single crystal layer 12 and the AlN polycrystalline layer 14 can be formed by, for example, a sublimation method. The method for forming the AlN single crystal layer 12 and the AlN polycrystal layer 14 is not particularly limited, and the AlN single crystal layer 12 and the AlN polycrystal layer 14 are, for example, a CVD method, an HVPE method, an MBE method, or sputtering. Use other methods such as vapor phase film formation method such as method, liquid phase film formation method such as hydrothermal method and Na flux method, and room temperature bonding in which single crystal AlN and multicrystal AlN are bonded by surface activation method. Can also be formed.

Further, the laminated board 10 includes a metal component-containing region 16 provided between the front surface 20 and the back surface 22. Specifically, the metal component-containing region 16 is arranged at the interface portion between the AlN single crystal layer 12 and the AlN polycrystalline layer 14 (hereinafter, also simply referred to as “intersection portion”), and in this embodiment, the metal component-containing region 16 is arranged. The metal component-containing region 16 is arranged so as to straddle both the AlN single crystal layer 12 and the AlN polycrystalline layer 14 in the interface portion. In this embodiment, when the ultraviolet light emitting device 1 is manufactured by using the laminated plate 10 as the handling substrate in the laminated plate 10, the surface on which the functional layer is formed (that is, the AlN single crystal layer 12 in the thickness direction) is formed. The exposed surface) is referred to as the front surface 20, and the surface on the opposite side thereof (that is, the exposed surface of the AlN polycrystalline layer 14 in the thickness direction) is referred to as the back surface 22. The metal component-containing region 16 is locally provided in the thickness direction of the laminated plate 10, and is provided substantially parallel to the back surface 14.

The metal component-containing region 16 is arranged across both the AlN single crystal layer 12 and the AlN polycrystalline layer 14 at the interface between the AlN single crystal layer 12 and the AlN polycrystalline layer 14. In the metal component-containing region 16, a plurality of metal particles are dispersed and introduced in the AlN single crystal layer 12 and the AlN polycrystalline layer 14. Specifically, the metal particles in the metal component-containing region 16 have an aspect ratio of more than 1 and adjusted to 10 or less, and their long sides are arranged along the front surface 12 and the back surface 14. Further, the metal particles are arranged at intervals so that the distance between the adjacent metal components is 1 μm to 300 μm. The method of introducing metal particles (metal components) is not particularly limited. For example, the metal component-containing region 16 can be formed by mixing a raw material containing a metal component with a raw material (solid raw material or raw material gas) forming the AlN single crystal layer 12. Alternatively, by adhering a raw material containing a metal component to the surface of the AlN polycrystalline layer 14 and forming the AlN single crystal layer 12 on the surface of the AlN polycrystalline layer 14, the metal components are made into the AlN single crystal layer 12 and the AlN polycrystalline layer 14. The metal component-containing region 16 can also be formed by diffusing the layer 14 in the vicinity of the interface portion. The metal particles are simple substances selected from Al, Ga, Cu, Fe, Mo, Ni, Ta, and Ti. The metal component-containing region 16 contains at least one of the above metal components as a main component. The metal particles may be an alloy containing the metal element, an oxide or a composite oxide containing the metal element, or a nitride or a composite nitride containing the metal component. It may be a composite oxynitride containing the above-mentioned metal component.

The impurity metal component-containing region 16 prevents the laser light from passing from the front surface 20 to the back surface 22 (or from the back surface 22 to the front surface 20) of the laminated plate 10 due to the introduction of the metal component. That is, specifically, when the ultraviolet laser beam is irradiated from the back surface 22 of the laminated plate 10, the metal particles in the metal component-containing region 16 absorb the ultraviolet laser beam. As a result, the metal component of the metal component-containing region 16 is sublimated (vaporized), fine cracks are generated in the metal component-containing region 16, and the AlN polycrystalline layer 14 can be removed (lifted off). As the metal particles introduced into the metal component-containing region 16, those that easily absorb the laser beam are selected. Specifically, metal particles having a wavelength of 245 nm to 1200 nm, which are easily absorbed, are introduced into the metal component-containing region 16.

Table 1 below shows an example of a metal that easily absorbs light having a wavelength of 245 nm to 1200 nm. The metals shown in Table 1 (Al, Ga, Cu, Fe, Mo, Ni, Ta, Ti) preferably absorb laser light having a wavelength of 245 nm to 1200 nm. Table 1 shows the absorbance of the metal with respect to light having wavelengths of 400 nm and 800 nm. The metals shown in Table 1 (Al, Ga, Cr, Cu, Fe, Mo, Ni, Ta, Ti) absorb light having a wavelength of 245 nm to 1200 nm well. Therefore, the metal particles containing these elements absorb and vaporize the laser beam when irradiated with the laser beam having a wavelength of 245 nm to 1200 nm. Since the metal component-containing region 16 is provided substantially parallel to the back surface 22 of the laminated plate 10, the laminated plate 10 is separated at a portion (that is, an interface portion) in which metal particles containing the above elements are introduced. .. Therefore, the laminated plate 10 in which the metal particles containing at least one of the above elements are introduced into the interface portion is thinned in the metal component-containing region 16 (that is, the interface portion) by laser lift-off. Thereby, the AlN polycrystalline layer 14 can be separated from the laminated board 10. Further, since the metal component-containing region 16 is arranged in both the AlN single crystal layer 12 and the AlN polycrystalline layer 14 at the interface portion, the laminated plate 10 separates substantially the entire AlN polycrystalline layer 14. Therefore, the time for mechanical polishing after the laser lift-off can be shortened.

Further, when the above element is introduced into the metal component-containing region 16, the metal component-containing region 16 alleviates the strain caused by the difference in the coefficient of thermal expansion between the AlN single crystal layer 12 and the AlN polycrystalline layer 14 at the interface portion. can do. The single crystal AlN constituting the AlN single crystal layer 12 and the polycrystalline AlN constituting the AlN polycrystalline layer 14 have relatively close coefficients of thermal expansion, but are slightly different from each other. Therefore, in the heat treatment step when manufacturing the ultraviolet light emitting device 1, the AlN single crystal layer 12 (the portion where the metal component-containing region 16 is not provided) and the AlN polycrystalline layer 14 (the portion where the metal component-containing region 16 is not provided) are not provided. There is a difference in the amount of deformation (elongation amount) of the part). When the metal component-containing region 16 is not provided, the interface portion between the AlN single crystal layer 12 and the AlN polycrystalline layer 14 may be distorted, and the AlN single crystal layer 12 may be warped or deteriorated such as cracks. The laminated board 10 of this embodiment includes a metal component-containing region 16 at an interface portion. The Young's modulus of the metal component-containing region 16 is smaller than the Young's modulus of the AlN single crystal layer 12 and the AlN polycrystalline layer 14. Therefore, the metal component-containing region 16 can alleviate the strain caused by the difference in the coefficient of thermal expansion between the AlN single crystal layer 12 and the AlN polycrystalline layer 14 at the interface portion. Since the deterioration of the AlN single crystal layer 12 can be suppressed and the ultraviolet light emitting device 1 can be formed on the surface of the high quality AlN single crystal layer 12, the adverse effect on the functional layer of the ultraviolet light emitting device 1 can be reduced. Can be done.

In this embodiment, for example, the thickness L1 of the laminated board 10 is adjusted to 0.5 mm to 10.0 mm, and the thickness L2 of the metal component-containing region 16 is adjusted to 0.1 μm to 5.0 μm. ing. The thickness L1 of the laminated plate 10 is the length between the front surface 20 and the back surface 22, and indicates the length in the direction perpendicular to the front surface 20 and the back surface 22. In other words, the thickness L1 of the laminated plate 10 is the length from the exposed surface of the AlN single crystal layer 12 to the exposed surface of the AlN polycrystalline layer 14 via the interface portion. Further, the thickness L2 of the metal component-containing region 16 also indicates the length in the direction perpendicular to the front surface 20 and the back surface 22. By setting the thickness L2 of the metal component-containing region 16 to 0.1 μm or more, the metal particles (metal component) reliably absorb the laser beam (the laser beam does not pass through the metal component-containing region 16), and the metal component. The effect of generating fine cracks in the content region 16 can be obtained. That is, the laser lift-off can be performed in the metal component-containing region 16. Further, by setting the thickness L2 to 0.1 μm or more, the effect of reducing the defect (deterioration of the AlN single crystal layer 12) caused by the difference in the coefficient of thermal expansion between the AlN single crystal layer 12 and the AlN polycrystalline layer 14 can be further reduced. You can definitely get it. Further, by setting the thickness L2 to 5.0 μm or less, the generation of cracks due to the irradiation of the laser beam can be contained within the metal component-containing region 16. Therefore, it is possible to suppress an adverse effect on the ultraviolet light emitting device.

(Example 2)
In Example 1 above, the metal component-containing region 16 is arranged in both the AlN single crystal layer 12 and the AlN polycrystalline layer 14, but is not limited to such a configuration. The metal component-containing region may be arranged at the interface between the AlN single crystal layer 12 and the AlN polycrystalline layer 14. For example, as shown in FIG. 3, the impurity region 116 is arranged in the AlN single crystal layer 12. It may have been done. In this example, the metal component-containing region 116 is different from the metal component-containing region 16 of Example 1, and the other configurations are substantially the same. Therefore, the description of the same configuration as that of the laminated board 10 of the first embodiment will be omitted.

As shown in FIG. 3, the metal component-containing region 116 of the laminated board 110 is arranged in the AlN single crystal layer 12. That is, the metal component is introduced into the AlN single crystal layer 12 at the interface portion between the AlN single crystal layer 12 and the AlN polycrystalline layer 14. Since the type of the metal component introduced into the metal component-containing region 116 and the thickness L2 of the metal component-containing region 116 are the same as those of the metal component-containing region 16 of Example 1, detailed description thereof will be omitted. ..

Also in this embodiment, the laminated plate 110 is separated in the metal component-containing region 116 by laser lift-off. That is, since the metal component-containing region 116 is arranged in the AlN single crystal layer 12 at the interface portion, the entire AlN polycrystalline layer 14 is separated from the laminated plate 110 by laser lift-off. Therefore, the AlN polycrystalline layer 14 can be suitably separated from the laminated plate 10 by laser lift-off. Further, the metal component-containing region 116 reduces the defect (deterioration of the AlN single crystal layer 12) caused by the difference in the coefficient of thermal expansion between the AlN single crystal layer 12 and the AlN polycrystalline layer 14.

(Example 3)
Further, the metal component-containing region may be arranged at the interface between the AlN single crystal layer 12 and the AlN polycrystalline layer 14. For example, as shown in FIG. 4, the metal component-containing region 216 is the AlN polycrystalline layer. It may be arranged in 14. In this example, the metal component-containing region 216 is different from the metal component-containing region 16 of Example 1, and the other configurations are substantially the same. Therefore, the description of the same configuration as that of the laminated board 10 of the first embodiment will be omitted.

As shown in FIG. 4, the metal component-containing region 216 of the laminated board 210 is arranged in the AlN polycrystalline layer 14. That is, the metal component is introduced into the AlN polycrystalline layer 14 at the interface between the AlN single crystal layer 12 and the AlN polycrystalline layer 14. Since the type of the metal component introduced into the metal component-containing region 216 and the thickness L2 of the metal component-containing region 116 are the same as those of the metal component-containing region 16 of Example 1, detailed description thereof will be omitted. ..

Also in this embodiment, it is possible to reduce the problem that the metal component-containing region 216 is caused by the difference in the coefficient of thermal expansion between the AlN single crystal layer 12 and the AlN polycrystalline layer 14. Further, the laminated plate 210 is separated in the metal component-containing region 216 by laser lift-off. That is, even if the metal component-containing region 216 is provided in the AlN polycrystalline layer 14, the metal component-containing region 216 is arranged in contact with the interface portion between the AlN single crystal layer 12 and the AlN polycrystalline layer 14. The laminated plate 110 is separated at the interface portion by laser lift-off. Therefore, since the AlN polycrystalline layer 14 is substantially removed by the laser lift-off, the mechanical polishing time can be significantly shortened as compared with the conventional method of thinning only by mechanical polishing.

The specific examples of the disclosed technology have been described in detail in the present specification, but these are merely examples and do not limit the scope of claims. The techniques described in the claims include various modifications and modifications of the specific examples illustrated above. In addition, the technical elements described in the present specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing.

Claims

AlN polycrystalline layer and
The AlN single crystal layer formed on the AlN polycrystalline layer and
A laminated board including a metal component-containing region which is in contact with an interface portion between the AlN single crystal layer and the AlN polycrystalline layer and in which a plurality of metal components are dispersed and introduced.
The laminated board according to claim 1, wherein the thickness of the metal component-containing region is 0.1 μm or more and 5.0 μm or less.
The laminated board according to claim 1 or 2, wherein the distance between adjacent metal components in the metal component-containing region is 1 μm or more and 300 μm or less.
Any one of claims 1 to 3, wherein the metal component has an aspect ratio of more than 1, 10 or less, and a long side existing along the end face in the thickness direction of the AlN polycrystalline layer. Laminated plate according to the item.
The laminate according to any one of claims 1 to 4, wherein the metal component-containing region contains at least one metal component selected from Al, Ga, Cu, Fe, Mo, Ni, Ta, and Ti. ..
The laminated board according to claim 5, wherein the metal component-containing region contains at least one metal component selected from Al, Ga, Cu, and Ni.