A method for producing a crystalline thin film made of an oxide or nitride of a group 13 element, and a laminate in which the crystalline thin film is stacked.

Abstract

This invention provides a method for producing a crystalline thin film made of a uniform, large-area oxide or nitride of a group 13 element, and a laminate formed by stacking these crystalline thin films, using a low-temperature, highly efficient, and environmentally friendly process. [Solution] An amorphous thin film made of an oxide or nitride of a group 13 element is deposited on an oriented or non-oriented substrate by a reactive film deposition method using a group 13 element as a raw material and introducing an oxidizing or nitriding gas. Next, a crystalline thin film made of an oxide or nitride of a group 13 element is synthesized by irradiating the surface of the amorphous thin film with a laser to cause epitaxial or non-epitaxial growth.

Description

[Technical Field]

[0001] This invention relates to a method for manufacturing a uniform, large-area crystalline thin film made of an oxide or nitride of a group 13 element, which is efficient at low temperatures and has a low environmental impact. It also relates to a laminate in which such crystalline thin films are stacked, which is suitable for the manufacture of medium- and high-voltage power devices and optical devices. [Background technology]

[0002] Wide-bandgap semiconductor materials possess high voltage resistance and high transmittance in the ultraviolet and visible light regions, and have been put into practical use as power devices, transparent conductive thin films, and light-emitting devices. For the past several decades, materials such as GaN and SiC have had bandgap (E) of about 3 eV. g Research and development have been conducted, from fundamental physics to implementation, focusing on the materials of ).

[0003] In recent years, in order to realize higher-performance electronic devices, E g Research into semiconductor materials with E is actively underway. For example, gallium oxide (Ga2O3) is E g The temperature exceeds 4 eV, and aluminum nitride (AlN) is E g It is attracting attention as a wide-bandgap semiconductor with a voltage of approximately 6 eV.

[0004] Taking Ga2O3-based semiconductor devices as an example, depositing large-area crystalline Ga2O3 thin films is crucial for significantly reducing manufacturing costs. While oxide semiconductor thin films have conventionally been deposited using various physical or chemical vapor deposition methods, there are few reports on the uniform and stable deposition of large-area Ga2O3 thin films using low-temperature processes.

[0005] Furthermore, in Ga2O3-based semiconductor devices, controlling crystallinity and orientation is just as important as controlling semiconductor properties through impurity doping. Among the crystalline polymorphs of Ga2O3, the thermodynamically most stable β phase and the metastable α phase have been fabricated under high-temperature conditions of 500°C or higher in each film deposition process, but there are few reports on crystal growth in the low-temperature range below 500°C.

[0006] For example, Patent Document 1 discloses a method for manufacturing a gallium oxide semiconductor film by mist CVD, which includes a flow straightening step to straighten the flow of mist and carrier gas so that it flows along the surface of the substrate. According to this method, it is possible to improve the in-plane uniformity of the film thickness and the film deposition rate using a simple apparatus and method, and a high effect can be obtained when depositing films on large-area substrates. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2022-016426 [Non-patent literature]

[0008] [Non-Patent Document 1] Taishi Shiojiri, Satoshi Kaneko, et al., "Room-temperature laser annealing for solid-phase epitaxial crystallization of β-Ga2O3 thin films," Applied Physics Express, Volume 9, Number 10, 2016.10, 105502-1-105502-4 [Overview of the project] [Problems that the invention aims to solve]

[0009] However, while the method for manufacturing a gallium oxide semiconductor film described in Patent Document 1 does not require reduced pressure and allows for the deposition of large-area films at relatively low temperatures, it is necessary to continuously heat the substrate to promote crystal growth. In the example, the substrate is heated to 500°C to promote gallium oxide crystal growth. This requires a significant amount of time and energy for heating and cooling the production equipment, which is undesirable from the standpoint of manufacturing efficiency, energy conservation, and environmental impact.

[0010] As described above, in the formation of a gallium oxide thin film by the conventional vapor deposition method, it was not always sufficient from the viewpoint of forming a uniform and stable large-area film. Further, in order to crystallize gallium oxide and synthesize a crystalline thin film of gallium oxide, a high-temperature heating process was required, resulting in low production efficiency and a large environmental burden. At present, there is still no method that can solve these problems and manufacture a uniform and large-area crystalline gallium oxide thin film by a process with high production efficiency at low temperature and a small environmental burden.

[0011] The present invention has been made in view of the above problems, and an object thereof is to provide a method capable of producing an amorphous thin film composed of an oxide or nitride of a group 13 element by a film formation process at room temperature, and then crystallizing the amorphous oxide or nitride of the group 13 element by laser irradiation to produce a uniform and large-area crystalline thin film composed of an oxide or nitride of the group 13 element. Another object is to provide a laminate in which a crystalline thin film composed of a uniform and large-area oxide or nitride of a group 13 element, which is suitable for the manufacture of medium and high voltage power devices and optical devices, is laminated.

[0012] As disclosed in Non-Patent Document 1, the present inventors have repeatedly studied a technique for synthesizing a highly oriented β-Ga2O3 thin film from an amorphous Ga2O3 thin film deposited on an α-Al2O3 substrate using an excimer laser annealing (ELA) method. By using this technique, a β-Ga2O3 thin film having excellent characteristics as a wide-gap semiconductor material can be synthesized by a process at room temperature.

[0013] The present inventors have found that in a physical vapor deposition method capable of forming a uniform and large-area film with high throughput, a stable and large-area amorphous thin film of gallium oxide can be formed by a reactive film formation using metallic gallium as a raw material and introducing an oxidizing gas at room temperature. Further, by applying the above laser annealing technique, it has been found that an amorphous thin film of gallium oxide can be crystallized by a process at room temperature to form a uniform and large-area crystalline thin film of gallium oxide. As a result of further research, the present invention has been completed.

[0014] That is, the present invention is a method for manufacturing a crystalline thin film composed of a Group 13 element oxide, including the following steps. (a1) A step of depositing a Group 13 element oxide by a physical vapor deposition method in which a Group 13 element single substance or alloy is used as a raw material and an oxidizing gas is introduced onto the surface of a single crystal or oriented polycrystal of a substrate to form an amorphous thin film thereof. (b1) A step of irradiating the surface of the amorphous thin film with a laser to epitaxially grow the amorphous oxide of the Group 13 element in a solid phase or a liquid phase, synthesizing a crystalline oxide of the Group 13 element, and forming a crystalline thin film thereof, and / or (c1) When the substrate is transparent to the laser, irradiating the laser through the substrate from the opposite surface of the surface of the substrate on which the amorphous thin film is formed to the interface between the substrate and the amorphous thin film, epitaxially growing the amorphous oxide of the Group 13 element in a solid phase or a liquid phase in the laser-irradiated portion, synthesizing a crystalline oxide of the Group 13 element, and forming a crystalline thin film thereof.

[0015] Further, the present invention is a method for manufacturing a crystalline thin film composed of a Group 13 element oxide, including the following steps. (a′1) A step of depositing a Group 13 element oxide by a physical vapor deposition method in which a Group 13 element single substance or alloy is used as a raw material and an oxidizing gas is introduced onto the surface of an unoriented polycrystal or amorphous of a substrate to form an amorphous thin film thereof. (b′1) A step of irradiating the surface of the amorphous thin film with a laser to non-epitaxially grow the amorphous oxide of the Group 13 element in a solid phase or a liquid phase, synthesizing a crystalline oxide of the Group 13 element, and forming a crystalline thin film thereof, and / or (c′1) When the substrate is transparent to the laser, irradiating the laser through the substrate from the opposite surface of the surface of the substrate on which the amorphous thin film is formed to the interface between the substrate and the amorphous thin film, non-epitaxially growing the amorphous oxide of the Group 13 element in a solid phase or a liquid phase in the laser-irradiated portion, synthesizing a crystalline oxide of the Group 13 element, and forming a crystalline thin film thereof.

[0016] Furthermore, the present invention is a method for manufacturing a crystalline thin film composed of a Group 13 element nitride, including the following steps. (a2) A process of depositing nitrides of group 13 elements onto the surface of a single crystal or oriented polycrystalline substrate by a physical vapor phase growth method using elemental or alloyed group 13 elements as raw materials and introducing a nitriding gas, thereby forming an amorphous thin film. (b2) A step of irradiating the surface of the amorphous thin film with a laser to epitaxially grow amorphous nitride of a group 13 element in the laser-irradiated portion in a solid or liquid phase, synthesizing a crystalline nitride of a group 13 element to form a crystalline thin film thereof, and / or (c2) If the substrate is transparent to the laser, the laser is irradiated from the opposite side of the surface of the substrate on which the amorphous thin film is formed, through the substrate, to the interface between the substrate and the amorphous thin film, thereby causing the amorphous nitride of the group 13 element in the laser-irradiated portion to grow epitaxially in the solid or liquid phase, and synthesizing a crystalline nitride of the group 13 element to form a crystalline thin film thereof.

[0017] Furthermore, the present invention provides a method for producing a crystalline thin film made of a nitride of a group 13 element, comprising the following steps. (a2') A process of depositing nitrides of Group 13 elements onto the unoriented polycrystalline or amorphous surface of a substrate by a physical vapor phase growth method using elemental or alloyed Group 13 elements as raw materials and introducing a nitriding gas, thereby forming an amorphous thin film. (b2') A step of irradiating the surface of the amorphous thin film with a laser to non-epitaxially grow amorphous nitride of a group 13 element in the laser-irradiated portion in a solid or liquid phase, synthesizing a crystalline nitride of a group 13 element to form a crystalline thin film thereof, and / or (c2') If the substrate is transparent to the laser, the laser is irradiated from the opposite side of the surface of the substrate on which the amorphous thin film is formed, through the substrate, to the interface between the substrate and the amorphous thin film, thereby causing the amorphous nitride of the group 13 element in the laser-irradiated portion to grow non-epitaxially in solid or liquid phase, synthesizing a crystalline nitride of the group 13 element and forming a crystalline thin film thereof.

[0018] The manufacturing method of the present invention, in a high-throughput physical vapor deposition method such as vacuum deposition or sputtering that enables uniform and large-area film deposition, involves ionizing, atomizing, or clustering high-purity raw materials of Group 13 elements or alloys, and then reacting them with an oxidizing or nitriding gas such as plasma-generated oxygen or nitrogen, or a reactive gas such as ozone, to deposit them on a substrate. This allows for the efficient and stable deposition of large-area amorphous thin films made of oxides or nitrides of Group 13 elements through a process at room temperature.

[0019] Next, by sequentially irradiating the surface of an amorphous thin film deposited on an oriented or non-oriented substrate with a laser, the amorphous oxide or nitride in the laser-irradiated area is crystallized in a solid or liquid phase to synthesize a crystalline oxide or nitride. This process at room temperature allows for the efficient production of a large-area, uniform crystalline thin film made of a group 13 element oxide or nitride.

[0020] Furthermore, the present invention comprises a substrate and a crystalline thin film made of an oxide or nitride of a group 13 element laminated on its surface, wherein the group 13 element is one or more selected from the group consisting of gallium, aluminum, and indium, and the area of ​​the crystalline thin film is 150 mm². 2 The above describes a laminate in which crystalline thin films made of oxides or nitrides of group 13 elements are stacked, with an average film thickness of 100 nm or more and a band gap of 4.0 eV or more.

[0021] The laminate of the present invention comprises a uniform, large-area crystalline thin film made of a gallium, aluminum, or indium oxide or nitride, or a mixed crystal crystalline thin film made of oxides or nitrides of two or more of these elements. It is expected to offer excellent properties as a wide-bandgap semiconductor material and a significant reduction in manufacturing costs, making it suitable for applications such as the manufacture of medium-voltage or high-voltage power devices and optical devices. [Effects of the Invention]

[0022] The present invention provides a method for manufacturing crystalline thin films that allows for the production of uniform, large-area crystalline thin films made of oxides or nitrides of Group 13 elements at low temperatures using a highly efficient and environmentally friendly process. Furthermore, a laminate in which the crystalline thin films of the present invention are stacked comprises uniform, large-area crystalline thin films made of oxides or nitrides of Group 13 elements, and is expected to exhibit excellent properties as a wide-bandgap semiconductor material and significantly reduce manufacturing costs. [Brief explanation of the drawing]

[0023] [Figure 1] This is an explanatory diagram of the reactive deposition of amorphous gallium oxide thin films by reactive ion plating (IP) in the method for manufacturing crystalline thin films of the present invention. [Figure 2] This is an explanatory diagram of the crystallization of an amorphous gallium oxide thin film by the excimer laser annealing (ELA) method in the manufacturing method of the crystalline thin film of the present invention. [Figure 3] This is an image of the appearance of an amorphous gallium oxide thin film, etc., deposited by the reactive IP method of Example 1. [Figure 4] This is the electron probe microanalyzer (EPMA) analysis spectrum of an amorphous gallium oxide thin film deposited by the reactive IP method of Example 1. [Figure 5] This graph shows the relationship between the inductively coupled plasma (ICP) output during film deposition and the thin film composition, based on X-ray photoelectron spectroscopy (XPS) analysis of amorphous gallium oxide thin films deposited by the reactive IP method of Example 2. [Figure 6] This graph shows the relationship between the oxygen gas flow rate during film formation and the film thickness of an amorphous gallium oxide thin film deposited by the reactive IP method of Example 2. [Figure 7] This graph shows the relationship between the oxygen gas flow rate during film formation and the thin film composition, based on EPMA analysis of an amorphous gallium oxide thin film formed by the reactive IP method in Example 2. [Figure 8] This is a correlation diagram showing the relationship between the oxygen gas flow rate during film formation, the laser fluence during ELA, and the crystalline state of the crystalline gauze thin film, based on X-ray diffraction (XRD) analysis of the crystalline gauze thin film prepared in Example 2. [Figure 9] This is a correlation diagram showing the relationship between the oxygen gas flow rate during film formation, the laser fluence during ELA, and the crystalline state of the crystalline gauze thin film, based on XRD analysis of the crystalline gauze thin film prepared in Example 3. [Figure 10] This is a correlation diagram showing the relationship between the ICP output during film formation, the laser fluence during ELA, and the crystalline state of the crystalline gauze thin film, based on XRD analysis of the crystalline gauze thin film prepared in Example 3. [Modes for carrying out the invention]

[0024] The following describes in detail the method for producing a crystalline thin film made of an oxide or nitride of a Group 13 element according to the present invention, and a laminate in which such crystalline thin films are stacked. Note that material compositions, shapes, structures, manufacturing methods, etc., that are not described here may be the same as or substantially the same as those known to those skilled in the art.

[0025] In this specification, "consisting of" means essentially or substantially consisting of the element or compound in question, and allows for the inclusion of trace amounts of other elements or compounds. For example, it may include dopants (impurities) intentionally added to impart semiconductor properties.

[0026] Furthermore, "abbreviated" is not limited to cases where the product is strictly identical, but rather includes errors or modifications that do not result in a loss of identity. For example, "abbreviated whole" is not limited to cases where the product is strictly whole, but includes forms that can be considered equivalent to the whole from the perspective of their effects and benefits.

[0027] The present invention relates to a method for producing a crystalline thin film made of an oxide or nitride of an element belonging to Group 13 of the periodic table. Gallium oxide (Ga2O3), aluminum oxide (Al2O3), and indium oxide (In2O3) are preferred examples of oxides, and gallium nitride (GaN) and aluminum nitride (AlN) are preferred examples of nitrides. First, in steps (a1), (a1'), (a2), and (a2'), an oxide or nitride of a Group 13 element is deposited on the surface of a substrate that will serve as a support by physical vapor deposition to form an amorphous thin film made of an oxide or nitride of a Group 13 element.

[0028] In steps (a1) and (a2), the substrate surface (deposited surface) must be composed of a single crystal with aligned crystal orientations, or an oriented polycrystalline material in which one or more axes are oriented perpendicular to the plane or in the in-plane direction, in order to epitaxially grow amorphous oxides or nitrides of group 13 elements by the laser annealing method described later. It is preferable that it be composed of a single crystal or a highly oriented polycrystalline material in which one or more axes are oriented perpendicular to the plane and in the in-plane direction. The deposition surface of the substrate may be planarized to prevent orientation growth in unintended or random directions, thereby forming a step-terrace structure.

[0029] The material forming the above-mentioned oriented substrate surface must have a lattice constant and crystal structure similar to the crystalline oxide or nitride of the group 13 element being synthesized, and must be capable of epitaxial growth. It is an inorganic material exhibiting a single crystal, oriented, or highly oriented polycrystalline crystal structure, and preferably examples include oxides or nitrides of silicon or group 13 elements, such as single-crystal silicon, single-crystal alumina (sapphire), and single-crystal gallium oxide.

[0030] Furthermore, in the embodiments described later, crystallization of the amorphous thin film deposited on an amorphous substrate has been observed depending on the deposition conditions for the amorphous thin film and the laser irradiation conditions. In steps (a1') and (a2'), the surface (deposited surface) of the substrate may be composed of unoriented polycrystalline or amorphous material.

[0031] The material constituting the above-mentioned non-oriented substrate surface is an inorganic material exhibiting a non-oriented polycrystalline or amorphous structure, and preferably examples include oxides or nitrides of silicon or group 13 elements, such as soda-lime glass, quartz glass, alumina, and polycrystalline gallium oxide.

[0032] The substrate may have a single-layer or multi-layer structure, as long as the uppermost layer forming its surface (deposited surface) has the above-mentioned characteristics. The shape and thickness of the substrate are not limited as long as it has sufficient strength, heat resistance, etc. as a support and exhibits the desired characteristics for the application of the crystalline thin film of the present invention.

[0033] For physical vapor deposition (PVD) to deposit oxides or nitrides of group 13 elements on the surface of a substrate, a method that can deposit smooth, uniformly thick, large-area amorphous thin films at high throughput and low cost is desirable. Vacuum deposition is preferred from the viewpoint of deposition rate and room temperature deposition, and sputtering is preferred from the viewpoint of uniform, large-area deposition and room temperature deposition. Among vacuum deposition methods, methods that allow independent control of the reactivity of the oxidizing or nitriding gas and the supply rate of the group 13 element raw materials, such as ion plating, are more preferable.

[0034] The PVD method used in this invention uses high-purity elemental or alloyed Group 13 elements as raw materials and deposits an amorphous thin film consisting of oxides or nitrides of Group 13 elements by a reactive film deposition method that introduces an oxidizing or nitriding gas. This makes it possible to deposit a film with a desired material composition while minimizing impurities, and to deposit a large-area film with a uniform thickness.

[0035] To prevent contamination with impurities, it is desirable that the purity of the Group 13 element raw materials be as high as possible. Specifically, for metallic Ga and In, a purity of 6N (99.9999%) or higher is preferred, and for metallic Al, a purity of 5N (99.999%) or higher is preferred. Since the melting point of metallic Ga is 29.76°C, in typical film deposition equipment, metallic Ga is placed in an alumina crucible or similar container to serve as an evaporation source or target.

[0036] In the PVD method used in the present invention, multiple individual Group 13 elements may be used as raw materials simultaneously. Specifically, two or more evaporation sources or targets selected from Ga, Al, and In are installed in the film deposition apparatus to perform reactive film deposition. By controlling the supply rate of each raw material, an amorphous thin film of a desired composition consisting of two or more oxides or nitrides selected from Ga, Al, and In can be deposited, and a mixed crystal crystalline thin film of a desired composition can be synthesized by laser annealing.

[0037] Furthermore, an alloy consisting of multiple Group 13 elements may be used as a raw material. By using an alloy raw material, an amorphous thin film of a desired composition consisting of two or more oxides or nitrides can be formed by simply setting up one evaporation source or target during film formation, and a mixed crystal crystalline thin film of a desired composition can be synthesized.

[0038] Examples of alloys consisting of Group 13 elements include alloys composed of two or more elements selected from Ga (gallium), Al (aluminum), and In (indium). Specifically, GaIn alloys and InAlGa alloys are examples. The Group 13 element alloy raw materials only need to be mixed fairly uniformly in a molten state, and their composition ratio can be set to any ratio so that a crystalline thin film of the desired composition can be synthesized. Similarly, it is desirable that the purity of the Group 13 element alloy raw materials be as high as possible, and specifically, a high purity of 4N (99.99%) or higher is preferred.

[0039] Oxidizing gases used in reactive film deposition include O2 gas, plasma-treated O2 gas, and ozone (O3) gas. Nitriding gases include N2 gas and plasma-treated N2 gas. By plasma-treating O2 or N2 gas introduced into the film deposition apparatus using a plasma coil placed between the evaporation source or target and the substrate, highly reactive radicals are generated. Atoms, ions, or clusters of Group 13 elements supplied from the evaporation source or target are oxidized or nitrided by passing through these oxidizing or nitriding gases, generating oxides or nitrides of Group 13 elements which are deposited on the substrate surface. The supply amount (partial pressure) of the oxidizing or nitriding gas is not limited as long as an amorphous thin film consisting of oxides or nitrides of Group 13 elements of a desired composition can be efficiently deposited at a desired deposition rate.

[0040] The shape and size of the amorphous thin film are not limited as long as the crystalline thin film of the present invention can be manufactured uniformly and stably. Vacuum deposition and sputtering methods allow for the industrial deposition of large areas, and it is considered possible to deposit amorphous thin films with a diameter of 4 to 6 inches or more. A larger area of ​​the amorphous thin film is preferable because it reduces the manufacturing cost of semiconductor devices. For a rectangular substrate, 150 mm is preferred. 2 Preferably, the above (10 x 15 mm square or larger) is preferred, and for a roughly circular substrate, 20 cm 2 A diameter of 2 inches or more is preferable.

[0041] The thickness of the amorphous thin film is not limited as long as the crystalline thin film of the present invention can be manufactured uniformly and stably. In our research, we observed that the particle size and crystalline state of in-plane grains in epitaxially grown crystalline Ga2O3 thin films changed depending on the thickness of the amorphous Ga2O3 thin film and the laser irradiation intensity. The thickness of the amorphous thin film is set considering irradiation conditions such as laser irradiation intensity, the crystalline structure and morphology of the crystalline thin film, and the application of the crystalline thin film. Examples of amorphous thin film thickness deposited in one cycle include a range of several tens of nanometers to 1 μm. Specifically, the range of 10 to 750 nm is preferred, and the range of 20 to 500 nm is more preferred.

[0042] Next, in steps (b1) and (b2), a laser is irradiated onto the surface of an amorphous thin film made of an oxide or nitride of a group 13 element deposited on an oriented substrate to epitaxially grow the amorphous oxide or nitride of the group 13 element in the laser-irradiated area, thereby synthesizing a crystalline oxide or nitride of the group 13 element.

[0043] Furthermore, in steps (b1') and (b2'), a laser is irradiated onto the surface of an amorphous thin film consisting of an oxide or nitride of a group 13 element deposited on a non-oriented substrate to cause non-epitaxial growth of the amorphous oxide or nitride of the group 13 element in the laser-irradiated area, thereby synthesizing a crystalline oxide or nitride of the group 13 element.

[0044] The medium, wavelength, and pulse width of the laser used for irradiation are not limited as long as sufficient energy is applied to efficiently crystallize the amorphous thin film at low energy. Both pulsed lasers and continuous-wave (CW) lasers are acceptable. Examples of suitable mediums include solids, gases, and semiconductors; wavelengths include visible light, ultraviolet light, and X-rays; and pulse widths include nanoseconds, picoseconds, and phetoseconds.

[0045] From the viewpoint of microfabrication and irradiation costs, visible light lasers (wavelengths 380-780 nm) and ultraviolet lasers (wavelengths less than 380 nm) are preferred. Examples of visible light lasers include semiconductor lasers, helium-neon (HeNe) lasers, and lasers obtained by wavelength conversion of infrared solid-state lasers such as YAG and YLF, while examples of ultraviolet lasers include excimer lasers, semiconductor lasers, and lasers obtained by wavelength conversion of infrared solid-state lasers such as YAG and YLF.

[0046] Among these, excimer lasers are more preferred because irradiation devices are widely available and they have a proven track record in laser annealing in the semiconductor field. The medium can be any of argon-fluorine (ArF, wavelength 193 nm), krypton-fluorine (KrF, wavelength 248 nm), xenon-chlorine (XeCl, wavelength 308 nm), or xenon-fluorine (XeF, wavelength 351 nm). ArF and KrF are preferred because they have short oscillation wavelengths and enable microfabrication, and KrF is more preferred because it has low irradiation costs.

[0047] A semiconductor laser that is small, lightweight, has low power consumption, and can be directly modulated may also be used. Oscillation at a shorter wavelength is advantageous in terms of laser fluence because it reduces the number of nonlinear optical elements sandwiched to shorten the wavelength. Also, an infrared solid-state laser that is small, lightweight, low-cost, and can provide high output may be used. The fundamental wave in the infrared region is wavelength-converted to 1 / 2 to 1 / 4 by a nonlinear optical element and then irradiated.

[0048] In the laser annealing of an amorphous thin film, irradiation conditions such as pulse energy (mJ), pulse width, repetition frequency (Hz), number of shots, and fluence of energy density (mJ / cm 2 ) are set in consideration of the balance between the characteristics of the obtained group 13 element crystalline oxide or nitride and the manufacturing cost. Also, as described above, the laser irradiation conditions are adjusted in consideration of the film thickness of the amorphous thin film, the crystal structure and morphology of the synthesized crystalline oxide or nitride, and the use of the crystalline thin film to be manufactured. The laser fluence is exemplified in the range of 100 to 500 mJ / cm 2 . If it is less than 300 mJ / cm 2 , crystal growth in the solid phase proceeds, and if it is 300 mJ / cm 2 or more, the irradiated portion tends to melt and crystal growth in the liquid phase proceeds.

[0049] Epitaxial growth or non-epitaxial growth by laser annealing of an amorphous thin film may be in the solid phase or the liquid phase, but crystal growth in the solid phase is preferred from the viewpoints of manufacturing stability and cost. The laser fluence in the case of solid-phase crystal growth is preferably in the range of 10 to 300 mJ / cm 2 , and more preferably in the range of 20 to 200 mJ / cm 2 .

[0050] According to the research of the present inventors, a relationship has been recognized between the laser fluence and the film thickness of the amorphous Ga2O3 thin film and the average grain size and crystal morphology of the crystal grains. By adjusting the laser fluence and the film thickness of the amorphous Ga2O3 thin film, it has been shown that the average grain size and crystal morphology of the crystal grains can be controlled within a suitable range in epitaxial growth or non-epitaxial growth by ELA.

[0051] The area irradiated with the laser is the majority or nearly the entire surface of the amorphous thin film in a planar view. "Majority" means 50% or more of the surface area. To maximize substrate utilization, the laser is irradiated to nearly the entire surface of a rectangular substrate, and to an area that allows for as many chips as possible to be obtained from a roughly circular substrate. By moving the laser light source or the substrate, or by scanning the laser using a carvano mirror and irradiating sequentially, it is considered possible to crystallize large-area amorphous thin films with diameters of 4 to 6 inches or more.

[0052] The laser irradiation direction may be directly above or below the substrate, or it may be irradiated at an angle. Lasers with the same or different irradiation conditions may be superimposed. The spot shape of the laser beam is set considering the energy application required for crystallization and production efficiency, and examples include rectangles with sides of several hundred μm to 20 mm or circles with a diameter of several hundred μm to 20 mm. Examples of shot counts include 250 to 20,000 shots, and examples of repetition frequency include 1 Hz to 300 Hz. A line-shaped laser (line laser) may be irradiated continuously.

[0053] The crystal structure of the crystalline thin film of the present invention is not limited as long as it can exhibit the desired properties for its application and can be stably synthesized. For example, gallium oxide (Ga2O3) is known to have five different crystalline polymorphisms: α, β, γ, δ, and ε, each with a different crystal structure. For applications requiring high performance as a power semiconductor material, the thermodynamically most stable β phase (monoclinic) and the metastable α phase (rhombohedral) are preferred. The crystal morphology is preferably a highly oriented polycrystalline film (epitaxial film) epitaxially grown on an oriented substrate surface.

[0054] The epitaxial growth method may be a solid-phase method in which a thin film is grown while maintaining its solid state, or a liquid-phase method in which the laser-irradiated area is melted and grown. Furthermore, it may be a heteroepitaxial method in which the crystalline oxide or nitride of the group 13 element to be synthesized is grown on a crystal plane of a substrate with a different lattice constant, crystal orientation, or material composition, or a homoepitaxial method in which it is grown on a crystal plane of a substrate with the same lattice constant, crystal orientation, and material composition.

[0055] For heteroepitaxial structures using single-layer substrates, examples of substrate types include α-Al2O3 (sapphire) plane orientation (0001) single crystal substrates and Si plane orientation (100) single crystal substrates. From the viewpoint of similarity of atomic arrangement, ease of availability, and cost, α-Al2O3 (sapphire) plane orientation (0001) single crystal substrates are preferred. For homoepitaxial structures using single-layer substrates, the substrate is a single crystal substrate of an oxide or nitride of a group 13 element to be epitaxially grown. For example, in the case of gallium oxide, an example of a β-Ga2O3 plane orientation (001) single crystal substrate is used.

[0056] In heteroepitaxial systems using multilayer substrates, the uppermost layer (deposited surface) of the substrate may be a highly oriented polycrystalline surface composed of silicon, alumina, or oxides or nitrides of different Group 13 elements. In homoepitaxial systems using multilayer substrates, the uppermost layer (deposited surface) of the substrate may be a highly oriented polycrystalline surface composed of oxides or nitrides of the same Group 13 element.

[0057] In heteroepitaxial growth, a buffer layer may be provided between the substrate and the crystalline thin film to mitigate defects such as misfit dislocations caused by in-plane lattice mismatch between the substrate crystal surface and the epitaxially grown crystalline thin film. Examples of buffer layers include NiO(111) layers laminated on the substrate crystal surface by a physical vapor phase growth method similar to that used for amorphous thin films.

[0058] In the embodiments described later, crystal growth of amorphous thin films deposited on amorphous substrates is observed depending on the deposition conditions and laser irradiation conditions for the amorphous thin films. In this specification, in crystal growth of amorphous thin films deposited on a substrate by laser annealing, crystal growth on a non-oriented substrate is referred to as non-epitaxial growth. In this non-epitaxial growth, the uppermost layer (deposited surface) of the substrate may be an amorphous surface made of silicon or an oxide or nitride of a group 13 element. Examples include soda-lime glass substrates, quartz substrates, alumina substrates, etc.

[0059] In the manufacturing method of the present invention, steps (c1) and (c2) may be performed, in which a laser is irradiated from the surface opposite to the surface of the oriented substrate on which the amorphous thin film is deposited, through the substrate, to the interface between the substrate and the amorphous thin film, thereby crystallizing the amorphous oxide or nitride of a group 13 element in the laser-irradiated area and synthesizing a crystalline oxide or nitride. Epitaxial growth progresses from the interface between the substrate and the amorphous thin film, and the transparency increases as the crystallization of the amorphous thin film progresses, so the amorphous thin film can be crystallized even when the laser is irradiated from the opposite side.

[0060] For similar reasons, steps (c1') and (c2') may be performed, in which a laser is irradiated through the substrate to the interface between the substrate and the amorphous thin film from the surface opposite to the surface of the non-oriented substrate on which the amorphous thin film is deposited. It is presumed that non-epitaxial growth will proceed from the interface between the substrate and the amorphous thin film, and as the crystallization of the amorphous thin film progresses, its transparency will increase, so the amorphous thin film can be crystallized even if the laser is irradiated from the opposite side.

[0061] In this case, the substrate must be transparent to the laser. Transparency means it must be approximately transparent, and sufficient energy can be applied to the substrate by irradiating it with a laser to crystallize the amorphous oxide or nitride of a group 13 element in the laser-irradiated area. Specifically, an example is when a laser is incident on a substrate formed from a predetermined material and having a predetermined thickness, and the transmittance T(I / I0) of the transmitted light I relative to the incident light I0 is in the range of 75-95%.

[0062] The steps (a1), (b1) and / or (c1), (a2), (b2) and / or (c2), (a1'), (b1') and / or (c1'), (a2'), (b2') and / or (c2') constitute one cycle, and these cycles may be repeated multiple times. This makes it possible to manufacture thicker crystalline thin films with an average thickness of 5 to 10 μm or more, without being limited by irradiation conditions such as laser penetration depth and laser irradiation intensity. Furthermore, the type of individual or alloy raw material of group 13 elements and the type of reactive gas introduced may be changed with each cycle. This makes it possible to construct a laminated structure of various types of crystalline thin films, and to impart diverse semiconductor properties to the laminated crystalline thin films.

[0063] The larger the area of ​​the crystalline thin film produced by the manufacturing method of the present invention, and the larger the area of ​​the crystalline thin film in the laminate of the present invention, the lower the manufacturing cost of the semiconductor device produced by processing it, which is therefore preferable. For a rectangular substrate, 150 mm² is preferable. 2 Preferably, the above (10 x 15 mm square or larger) is preferred, and for a roughly circular substrate, 20 cm 2 A diameter of 2 inches or more is preferable.

[0064] The film thickness is not limited as long as it can perform the desired function in the semiconductor device material application. An average film thickness of 100 nm or more is exemplified. Furthermore, the more uniform the film thickness, the better. The in-plane uniformity of the film thickness is evaluated by the average film thickness and its standard deviation, the Max-Min method, etc. For example, using a spectroscopic interferometry film thickness meter, etc., measurements are taken at 5 to 15 equally spaced points in the long axis or diametrical direction of the substrate, and the evaluation is calculated as (maximum value - minimum value) / (maximum value + minimum value) or (average value × 2) × 100. In-plane uniformity of less than 10% is preferable, and less than 5% is more preferable.

[0065] Applications for the laminate of the present invention include medium-voltage or high-voltage power devices or optical devices. The band gap of the crystalline thin film is preferably 4.0 eV or higher, and more preferably 4.7 eV or higher. Doping of impurities to impart semiconductor properties to the crystalline thin film can be done by incorporating impurities into the amorphous oxide or nitride at the stage of deposition of the amorphous thin film by physical vapor deposition in steps (a1), (a2), (a1'), and (a2') above, or by incorporating impurities into the amorphous or crystalline oxide or nitride before or after steps (b1) and / or (c1), (b2) and / or (c2), (b1') and / or (c1'), (b2') and / or (c2') above by ion diffusion, ion implantation, etc. [Examples]

[0066] The method for producing a crystalline thin film made of an oxide or nitride of a Group 13 element according to the present invention will be described in detail below with reference to examples. However, the present invention is not limited to these examples, and various modifications are possible without departing from the technical spirit of the invention.

[0067] [Example 1] (Film formation by reactive ion plating method) Amorphous Ga2O3 thin films were deposited on an ultraplanar sapphire (α-Al2O3) substrate for thin film deposition using reactive ion plating (IP) with introduced O2 gas. The surface of liquid metallic Ga in an alumina crucible was evaporated by irradiating it with an electron beam from an electron gun. The substrate temperature was kept at room temperature (below 20°C, unheated). A schematic diagram of the apparatus is shown in Figure 1, and the detailed deposition conditions are shown below. Note that the electron gun output was suppressed to ensure complete oxidation of the Ga, and the deposition rate is considered to be close to the minimum value.

[0068] ·Deposition vacuum degree: 1×10 -5 Pa (base pressure) • Evaporation source: Metallic Ga, purity 7N (99.99999%) • Electron beam output: 900W (90mA × 10kV) • Oxidizing gas: Plasma-induced O2 gas, 1 × 10⁻⁶ -3~10 -2 Pa (pressure after introduction) • Substrate: α-Al2O3(0001) substrate, 20×20×0.5mm • Deposition rate: 3 nm / min (deposition time 90 minutes, film thickness 270 nm) • IP device: Manufactured by Showa Vacuum Co., Ltd., model number SIP-700

[0069] (Evaluation and analysis of amorphous gallium oxide thin films) Figure 3 shows the appearance of amorphous Ga2O3 thin films deposited by the reactive IP method described above. Sample (1) is a pure Ga thin film deposited without the introduction of O2 gas, (2) is a thin film deposited after the first introduction of O2 gas, and (3) is a thin film deposited after the second introduction of O2 gas. A transparent thin film, presumably an amorphous Ga2O3 thin film, was obtained after the second introduction of O2 gas.

[0070] This transparent thin film was subjected to elemental analysis using an electron probe microanalyzer (EPMA) (JEOL Ltd., model JXA-iHP200F). The analysis spectrum is shown in Figure 4. No impurities were detected, confirming the deposition of a high-purity Ga2O3 thin film. Furthermore, analysis of the crystal structure by X-ray diffraction (XRD) revealed no diffraction attributed to Ga2O3, confirming that it is amorphous.

[0071] [Example 2] (Film formation by reactive ion plating method) An amorphous Ga2O3 thin film was deposited on an ultraplanarized sapphire (α-Al2O3) step substrate for thin film deposition using the same reactive IP method as in Example 1. The substrate temperature was kept at room temperature (below 20°C, unheated). Detailed deposition conditions are shown below. Atomic force microscopy (AFM) observation of the amorphous Ga2O3 thin film immediately after deposition revealed a root mean square (RMS) surface roughness of 1.13 nm.

[0072] ·Deposition vacuum degree: 1×10 -5 Pa (base pressure) • Evaporation source: Metallic Ga, purity 7N (99.99999%) • Electron beam output: 900W (90mA × 10kV) • ICP output: 4 or 6 levels (10, 20, 30, 50, 70, 90W) • Oxidizing gas: Plasma-induced O2 gas, 1 × 10⁻⁶ -3 ~10 -2 Pa (pressure after introduction) • Oxidizing gas flow rate: O2 gas flow rate, 4 levels: 2, 3, 5, 7 sccm • Substrate: α-Al2O3(0001) step substrate, φ2 inch (1 / 4 division) • IP device: Manufactured by Showa Vacuum Co., Ltd., model number SIP-700

[0073] Amorphous Ga2O3 thin films were deposited using an O2 gas flow rate of 7 sccm and inductively coupled plasma (ICP) power varied to 30, 50, 70, and 90 W. Film thickness monitoring using a quartz crystal film thickness gauge showed a film thickness of approximately 250-400 nm. The composition was analyzed elementally using an X-ray photoelectron spectroscopy (XPS) analyzer (ULVAC-PHIE, model Quantera SXM). Figure 5 shows the variation in the atomic composition ratio of oxygen in the amorphous Ga2O3 thin film with respect to ICP power. No significant change in the atomic composition ratio of oxygen in the amorphous Ga2O3 thin film was observed depending on the ICP power, indicating that the thin film composition is relatively stable.

[0074] Furthermore, amorphous Ga2O3 thin films were deposited using an ICP output of 30W and varying O2 gas flow rates of 2, 3, 5, and 7 sccm. The film thickness was approximately 30-80 nm. Figure 6 shows the variation in the film thickness of the amorphous Ga2O3 thin film with respect to the O2 gas flow rate. A tendency for the film thickness of the amorphous Ga2O3 thin film to increase almost proportionally to the O2 gas flow rate was observed.

[0075] The composition of amorphous Ga2O3 thin films deposited under identical conditions was analyzed using EPMA with two-element (Ga, O) specified analysis. Figure 7 shows the variation in the atomic composition ratio of oxygen in amorphous Ga2O3 thin films with respect to O2 gas flow rate. A tendency for the atomic composition ratio of oxygen in amorphous Ga2O3 thin films to increase with O2 gas flow rate was observed, but above 3 sccm, the oxygen atomic composition ratio remained almost constant. Since the change in film thickness was larger than the change in film composition, it is presumed that increasing the O2 gas flow rate during deposition reduces the density of the amorphous Ga2O3 thin film and changes the film quality.

[0076] (Crystallization by excimer laser annealing) Amorphous Ga2O3 thin films deposited on an α-Al2O3(0001) step substrate by the reactive IP method described above were epitaxially grown by excimer laser annealing (ELA) to synthesize crystalline Ga2O3 and form a crystalline thin film. Under atmospheric conditions at room temperature, an excimer laser was sequentially irradiated over the entire surface of the amorphous Ga2O3 thin film while moving the irradiation source. A schematic of the laser annealing is shown in Figure 2, and the detailed irradiation conditions are shown below. AFM observation of the crystalline Ga2O3 thin film after ELA showed a surface RMS of 1.10 nm.

[0077] • Irradiation laser: KrF excimer laser, wavelength 248nm • Laser pulse width: 20 nsec Laser fluence: 50, 80, 110 mJ / cm² 2 These are the three stages. Non-focused light incidence onto the thin film surface • Number of pulses: 1000-3000 pulses • Repetition frequency: 10-20Hz • Laser spot shape: 15 x 15 mm square • Excimer laser light source: Coherent, model number COMPexPro

[0078] (Evaluation and analysis of crystalline gallium oxide thin films) The crystalline state of a crystalline Ga2O3 thin film formed by epitaxial growth using ELA was analyzed using an X-ray diffractometer (XRD) (Rigaku Corporation, model SmartLab). Figure 8 shows the relationship between the O2 gas flow rate during film formation, the laser fluence during ELA, and the crystalline state. As shown above, it was observed that the thickness of the amorphous Ga2O3 thin film increased almost proportionally to the O2 gas flow rate. However, by increasing the laser fluence in accordance with the film thickness, it is possible to form a crystalline Ga2O3 thin film by epitaxial growth of an amorphous Ga2O3 thin film at room temperature in an atmospheric environment.

[0079] [Example 3] (Film formation by reactive ion plating method) An amorphous Ga2O3 thin film was deposited using the same reactive IP method as in Example 2, except that the substrate was an n-type silicon single crystal (n-type Si(111)) substrate. On the surface of the n-type Si(111) substrate was SiO X An amorphous native oxide film (thickness 1 nm or less, Eg 9 eV or less, softening point 1400°C or less) is formed on top of it, and amorphous GaO X This means that thin films (thickness 30-400 nm, Eg 4 eV or less, melting point 1700-1900°C) are stacked on top of each other.

[0080] In this example, the distance between the target and the substrate was set to be relatively short in order to achieve film deposition with as uniform a thickness as possible. Dark brown interference colors were observed across the entire substrate mounting surface of the substrate and the apparatus, suggesting that an amorphous Ga2O3 thin film was deposited with uniform thickness over an area exceeding φ4 inches. Based on the principles of the IP method, it is thought that uniform large-area film deposition on larger substrates, such as φ6 inches, is possible by scaling up the size of the vacuum chamber and other factors.

[0081] (Crystallization by excimer laser annealing) Except for using an n-type Si(111) substrate with a native oxide film, crystal growth was carried out using the same ELA method as in Example 2 to synthesize crystalline Ga2O3 and form a crystalline thin film.

[0082] (Evaluation and analysis of crystalline gallium oxide thin films) The crystalline state of crystalline Ga2O3 thin films formed by ELA was analyzed by X-ray diffraction (XRD). Figure 9 shows the relationship between the O2 gas flow rate during film formation, the laser fluence during ELA, and the crystalline state, while Figure 10 shows the relationship between the ICP output during film formation, the laser fluence during ELA, and the crystalline state.

[0083] From the results in Figures 9 and 10, amorphous SiO X Amorphous GaO film deposited on top X It was confirmed that the thin film could be crystallized by ELA under an atmospheric environment at room temperature. Figure 9 shows the amorphous GaO film thickness increasing depending on the O2 gas flow rate. X In thin films (film thickness 30-80 nm) using ELA, crystallization was observed in regions with thicker film thickness and higher laser fluence. Figure 10 shows amorphous GaO with increased film thickness depending on ICP output. X Crystallization was observed over a wide area in thin films (film thickness approximately 250-400 nm) of ELA.

[0084] This amorphous SiO X Amorphous GaO film deposited on a substrate X The mechanism of non-epitaxial growth of thin films by ELA is not entirely clear, but it is believed that the application of energy by ELA triggers the growth of air-amorphous GaO X Thin film interface, amorphous GaO X Thin film - amorphous SiO X Substrate interface, or amorphous GaO X It is possible that homogeneous or heterogeneous nucleation occurred somewhere within the thin film, leading to solid-phase crystal growth.

[0085] Furthermore, one method for evaluating the band gap of thin film samples is to calculate the optical band gap using a Tauc plot. According to the inventors' research, an optical band gap of approximately 4.8 to 4.9 eV was obtained in β-Ga2O3 thin films after ELA. This value is equivalent to that of single-crystal β-Ga2O3 and β-Ga2O3 thin films epitaxially grown at high temperatures of 500°C or higher. [Industrial applicability]

[0086] The manufacturing method of the present invention enables the efficient production of uniform, large-area crystalline thin films made of oxides or nitrides of Group 13 elements by a low-temperature process. Furthermore, the laminates of the present invention are expected to exhibit excellent properties and significant cost reductions as wide-bandgap semiconductors and optical device materials.

[0087] Therefore, the method for producing a crystalline thin film made of an oxide or nitride of a group 13 element according to the present invention, and the laminate in which the crystalline thin film is stacked, are particularly important in the fields of power electronics such as field-effect transistors (FETs) and optoelectronics such as optical elements equipped with microlens arrays, and are expected to be applied to high-voltage, high-power devices and light-emitting and absorbing devices in the deep ultraviolet region.

Claims

1. A method for producing a crystalline thin film made of an oxide of a group 13 element, including the following steps: (a1) A process of depositing an amorphous thin film of an oxide of a group 13 element on the surface of a single crystal or oriented polycrystalline substrate by a physical vapor phase growth method using a group 13 element as a raw material and introducing an oxidizing gas, (b1) A step of irradiating the surface of the amorphous thin film with a laser to epitaxially grow amorphous oxides of Group 13 elements in the laser-irradiated portion in a solid or liquid phase, synthesizing crystalline oxides of Group 13 elements and forming a crystalline thin film thereof, and / or (c1) If the substrate is transparent to the laser, the laser is irradiated from the opposite side of the surface of the substrate on which the amorphous thin film is formed, through the substrate, to the interface between the substrate and the amorphous thin film, thereby causing the amorphous oxide of the group 13 element in the laser-irradiated portion to grow epitaxially in solid or liquid phase, synthesizing a crystalline oxide of the group 13 element and forming a crystalline thin film thereof.

2. A method for producing a crystalline thin film made of an oxide of a group 13 element, including the following steps: (a1') A process of depositing an amorphous thin film of an oxide of a group 13 element on the unoriented polycrystalline or amorphous surface of a substrate by a physical vapor phase growth method using a group 13 element as a raw material and introducing an oxidizing gas. (b1') A step of irradiating the surface of the amorphous thin film with a laser to non-epitaxially grow amorphous oxides of group 13 elements in the laser-irradiated portion in a solid or liquid phase, synthesizing crystalline oxides of group 13 elements and forming a crystalline thin film thereof, and / or (c1') If the substrate is transparent to the laser, the laser is irradiated from the opposite side of the surface of the substrate on which the amorphous thin film is formed, through the substrate, to the interface between the substrate and the amorphous thin film, thereby causing the amorphous oxide of the group 13 element in the laser-irradiated portion to grow non-epitaxially in solid or liquid phase, synthesizing a crystalline oxide of the group 13 element and forming a crystalline thin film thereof.

3. A method for producing a crystalline thin film made of a nitride of a group 13 element, including the following steps: (a2) A process of depositing nitrides of group 13 elements onto the surface of a single crystal or oriented polycrystalline substrate by a physical vapor phase growth method using elemental or alloyed group 13 elements as raw materials and introducing a nitriding gas, thereby forming an amorphous thin film. (b2) A step of irradiating the surface of the amorphous thin film with a laser to epitaxially grow amorphous nitride of a group 13 element in the laser-irradiated portion in a solid or liquid phase, synthesizing a crystalline nitride of a group 13 element to form a crystalline thin film thereof, and / or (c2) If the substrate is transparent to the laser, the laser is irradiated from the opposite side of the surface of the substrate on which the amorphous thin film is formed, through the substrate, to the interface between the substrate and the amorphous thin film, thereby causing the amorphous nitride of the group 13 element in the laser-irradiated portion to grow epitaxially in solid or liquid phase, synthesizing a crystalline nitride of the group 13 element and forming a crystalline thin film thereof.

4. A method for producing a crystalline thin film made of a nitride of a group 13 element, including the following steps: (a2') A process of depositing nitrides of group 13 elements onto the unoriented polycrystalline or amorphous surface of a substrate by a physical vapor phase growth method using elemental or alloyed group 13 elements as raw materials and introducing a nitriding gas, thereby forming an amorphous thin film. (b2') A step of irradiating the surface of the amorphous thin film with a laser to non-epitaxially grow amorphous nitride of a group 13 element in the laser-irradiated portion in a solid or liquid phase, synthesizing a crystalline nitride of a group 13 element to form a crystalline thin film thereof, and / or (c2') If the substrate is transparent to the laser, the laser is irradiated from the opposite side of the surface of the substrate on which the amorphous thin film is formed, through the substrate, to the interface between the substrate and the amorphous thin film, thereby causing the amorphous nitride of the group 13 element in the laser-irradiated portion to grow non-epitaxially in solid or liquid phase, synthesizing a crystalline nitride of the group 13 element and forming a crystalline thin film thereof.

5. A method for producing a crystalline thin film according to any one of claims 1 to 4, wherein the group 13 element is one or more selected from the group consisting of gallium, aluminum, and indium.

6. A method for producing a crystalline thin film according to any one of claims 1 to 4, wherein the process from the step of forming the amorphous thin film to the step of forming the crystalline thin film constitutes one cycle, and this cycle is repeated multiple times.

7. A method for producing a crystalline thin film according to any one of claims 1 to 4, wherein the physical vapor phase growth method is a vacuum deposition method or a sputtering method.

8. The method for manufacturing a crystalline thin film according to any one of claims 1 to 4, wherein the laser is a visible light laser or an ultraviolet laser.

9. The method for producing a crystalline thin film according to claim 1, wherein the oxide of the group 13 element is gallium oxide, and the epitaxial growth is homoepitaxial growth.

10. The method for producing a crystalline thin film according to claim 1, wherein the oxide of the group 13 element is gallium oxide, and the epitaxial growth is heteroepitaxial growth.

11. The method for producing a crystalline thin film according to claim 9 or 10, wherein the crystalline oxide of the group 13 element is β-type gallium oxide.

12. The device comprises a substrate and a crystalline thin film made of an oxide or nitride of a group 13 element laminated on its surface, The aforementioned Group 13 element is one or more elements selected from the group consisting of gallium, aluminum, and indium. The area of ​​the crystalline thin film is 150 mm². ２ The above conditions are met, and the average film thickness is 100 nm or more, and the band gap is 4.0 eV or more. A laminate comprising crystalline thin films made of oxides or nitrides of Group 13 elements.

13. A laminate comprising crystalline thin films according to claim 12, wherein its application is to medium-voltage or high-voltage power devices and optical devices.

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