Gallium indium oxide film and preparation method thereof

Abstract

The invention provides a gallium indium oxide thin film and a preparation method thereof, the gallium indium oxide thin film is prepared based on a substrate through a pulse laser deposition method and comprises a main epitaxial layer and a buffer layer, the buffer layer is connected between the substrate and the main epitaxial layer, the chemical formula of the main epitaxial layer and the chemical formula of the buffer layer are (Ga1-xInx) 2O3, and x is larger than or equal to 0.1 and smaller than or equal to 0.5. The preparation method comprises the following steps: providing a substrate; depositing a gallium indium oxide buffer layer on the substrate through a pulse laser deposition method to obtain an intermediate product; and depositing a main epitaxial layer of the gallium-indium oxide on the buffer layer through a pulse laser deposition method to prepare the gallium-indium oxide thin film. The thin buffer layer is prepared before the main epitaxial layer is prepared, so that the crystallization quality of the thin film can be improved, the problems of high defect density and the like of the thin film are solved, the defects of the gallium-indium oxide thin film are reduced, and the high-quality gallium-indium oxide thin film is obtained.

Description

Technical Field

[0001] The present application relates to the technical field of semiconductor materials, and in particular to a gallium indium oxide film and a preparation method thereof. Background Art

[0002] The fourth-generation semiconductor material gallium oxide (Ga2O3) is an ultra-wide bandgap semiconductor. Due to its large bandgap (≈5eV) and high critical breakdown field (≈8MV / cm), gallium oxide has become an attractive and important research hotspot. The absorption cutoff edge corresponding to the gallium oxide material is located in the solar-blind ultraviolet region (200-280nm), and it is a natural ultraviolet detection material. The detection range of undoped gallium oxide in the solar-blind ultraviolet band is relatively limited. In order to expand the application range of the material, indium (In) can be added to form gallium indium oxide to adjust the bandgap width and expand the spectral response range of the photodetector.

[0003] Pulse Laser Deposition (PLD) is a common physical vapor deposition technology for inorganic thin films. The surface of the thin film material prepared by this technology is relatively flat, and the film thickness can be precisely controlled. In addition, PLD uses high-energy laser pulses to quickly heat the surface of the target material, so that the atoms in the material vaporize and re-condense on the substrate in a very short time. This rapid non-equilibrium process helps to achieve high solid solubility. However, the current PLD deposition of gallium indium oxide thin films all adopts a single growth method, that is, the same process parameters are used during the growth process, including oxygen pressure, laser energy, substrate temperature, etc., resulting in the gallium indium oxide thin film obtained by epitaxy on the substrate using PLD technology. There are problems such as poor crystal quality and high film defect density. Summary of the invention

[0004] In view of this, the present application provides a gallium indium oxide film and a preparation method thereof, aiming to effectively solve the problem that the existing pulsed laser deposition method adopts a single growth method, resulting in poor crystal quality and many film defects in the gallium indium oxide film obtained by epitaxial growth on a substrate.

[0005] The present application provides a gallium indium oxide film, which is prepared on a substrate by a pulsed laser deposition method. The gallium indium oxide film includes a main epitaxial layer and a buffer layer, wherein the buffer layer is connected between the substrate and the main epitaxial layer, and the chemical formulas of the main epitaxial layer and the buffer layer are (Ga 1-x In x )2O3, where 0.1≤x≤0.5.

[0006] In one embodiment, x=0.3; and / or, the thickness of the buffer layer is 40nm-80nm; and / or, the thickness of the main epitaxial layer is 220nm-250nm.

[0007] In one embodiment, the substrate is a flexible mica substrate, and the chemical formula is KAl2(Si3Al)O 10 (OH)2.

[0008] The present application also provides a method for preparing a gallium indium oxide thin film, the preparation method comprising:

[0009] S1: providing a substrate;

[0010] S2: depositing a buffer layer of gallium indium oxide on the substrate by pulsed laser deposition to obtain an intermediate product;

[0011] S3: depositing a main epitaxial layer of gallium indium oxide on the buffer layer by pulsed laser deposition to obtain a gallium indium oxide thin film.

[0012] In one embodiment, the step S2 includes:

[0013] First, control the gas pressure in the growth chamber of the pulsed laser deposition device to be lower than 4*10 -6 Pa, then placing the substrate into the growth chamber, heating the substrate with a heating device at a heating rate of 7 to 10° C. / min, and turning on the laser to preheat the substrate;

[0014] When the temperature of the substrate reaches 300-700° C., an oxygen pressure of 0.01-10 Pa is introduced, the target spacing is adjusted to 30-60 mm, the target position is rotated to the gallium indium oxide target, the laser is set to 1-10 Hz, 200-300 mJ, the gallium indium oxide target is set to self-rotation and swing mode, the laser is started until the laser hits the gallium indium oxide target for a corresponding number of pulses, and then the laser is turned off, the buffer layer is grown on the substrate, and the heating device is controlled to perform in-situ annealing at a cooling rate of 7-10° C. / min under an oxygen pressure of 0.01-10 Pa, and the temperature is cooled to room temperature to obtain the intermediate product.

[0015] In one embodiment, the growth time of the buffer layer is 4 to 8 minutes; and / or the number of pulses of the laser hitting the gallium indium oxide target is 720 to 1440.

[0016] In one embodiment, the heating rate of the heating device is 10°C / min; and / or the heating temperature of the substrate is 500°C; and / or the target spacing is adjusted to 40mm; and / or the laser is set to 3Hz, 250mJ; and / or the cooling rate of the heating device is 7°C / min; and / or the oxygen pressure is 10Pa.

[0017] In one embodiment, step S3 includes:

[0018] Control the gas pressure in the growth chamber of the pulsed laser deposition device to be less than 4*10 -6 Pa, placing the intermediate product into the growth chamber, and turning on the laser to preheat it;

[0019] At room temperature, an oxygen pressure of 0.01 to 10 Pa is introduced, the target spacing is adjusted to 30 to 60 mm, the target position is rotated to the gallium indium oxide target, the laser is set to 1 to 10 Hz, 200 to 300 mJ, the gallium indium oxide target is set to self-rotation and swing mode, the laser is started until the laser hits the gallium indium oxide target for a corresponding number of pulses, and then the laser is turned off, the main epitaxial layer is grown on the buffer layer to obtain a sample, the sample is placed in a high-temperature annealing furnace and post-annealed in an air atmosphere, the post-annealing temperature is set to 800 to 1000° C., and the post-annealing time is set to 0.5 to 2 h to obtain the gallium indium oxide film.

[0020] In one embodiment, the growth time of the main epitaxial layer is 20 to 25 minutes; and / or the number of pulses of the laser hitting the gallium indium oxide target is 3600 to 4500.

[0021] In one embodiment, the oxygen pressure is 10Pa; and / or the target spacing is adjusted to 40mm; and / or the laser is set to 3Hz, 250mJ; and / or the post-annealing temperature is set to 1000°C; and / or the post-annealing time is set to 1h.

[0022] In summary, the present application provides a gallium indium oxide thin film and a preparation method thereof. The gallium indium oxide thin film is prepared on a substrate by a pulsed laser deposition method and includes a main epitaxial layer and a buffer layer, wherein the buffer layer is connected between the substrate and the main epitaxial layer, and the chemical formulas of the main epitaxial layer and the buffer layer are both (Ga 1-x In x )2O3, wherein 0.1≤x≤0.5. The preparation method comprises: providing a substrate; depositing a buffer layer of gallium indium oxide on the substrate by a pulsed laser deposition method to obtain an intermediate product; and depositing a main epitaxial layer of gallium indium oxide on the buffer layer by a pulsed laser deposition method to obtain a gallium indium oxide thin film. The present application prepares a thin buffer layer before preparing the main epitaxial layer. The thin film material of the buffer layer has the same or similar lattice structure as the thin film material of the main epitaxial layer, so that the main epitaxial layer can have no abrupt transition in the lattice structure, thereby reducing crystal defects such as dislocations, and the addition of the buffer layer can maintain the stability of the main epitaxial layer during the growth process, avoiding the decrease in the crystal quality of the thin film due to interface mismatch or stress accumulation, thereby obtaining a high-quality gallium indium oxide thin film. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1This is a schematic diagram of the structure of the gallium indium oxide film and substrate of the present application.

[0024] Figure 2 This is a schematic diagram of the process of preparing the gallium indium oxide thin film of the present application.

[0025] Figure 3 This is a comparison chart of the light transmittance of a gallium indium oxide film (including a 40nm buffer layer and a 250nm main epitaxial layer) and a gallium indium oxide film without a buffer layer (including only a 250nm main epitaxial layer) in an embodiment of the present application.

[0026] Figure 4 This is a comparison chart of X-ray diffraction of a gallium indium oxide film (including a 40nm buffer layer and a 250nm main epitaxial layer) and a gallium indium oxide film without a buffer layer (including only a 250nm main epitaxial layer) and β-Ga2O3 in one embodiment of the present application. DETAILED DESCRIPTION

[0027] Before describing the embodiments in detail, it should be understood that the present application is not limited to the detailed structure or component arrangement described below or in the drawings in the present application. The present application may be an embodiment implemented in other ways. Moreover, it should be understood that the words and terms used herein are only used for descriptive purposes and should not be interpreted restrictively. The words "including", "comprising", "having" and the like used herein are meant to include the items listed thereafter, their equivalents and other additional items. In particular, when describing "a certain element", the present application does not limit the number of the element to one, but may also include multiple elements.

[0028] Please refer to Figure 1 As shown, the present application provides a gallium indium oxide film, which is grown on a substrate 1, and includes a main epitaxial layer 3 and a buffer layer 2, wherein the buffer layer 2 is connected between the substrate 1 and the main epitaxial layer 3, and the chemical formulas of the main epitaxial layer 3 and the buffer layer 2 are both (Ga 1-x In x )2O3, wherein 0.1≤x≤0.5, preferably, x=0.3, therefore, the chemical formula of the main epitaxial layer 3 and the buffer layer 2 are both (Ga 0.7 In 0.3 )2O3. The gallium indium oxide film can be prepared based on the substrate 1 by pulsed laser deposition. In other embodiments, the gallium indium oxide film can also be prepared by other methods. It should be noted that in the present application, the main epitaxial layer 3 and the buffer layer 2 are both β-(Ga 1-x In x)2O3. The present application prepares a thin buffer layer 2 before preparing the main epitaxial layer 3, which can improve the crystallization quality of the film, improve the high density of film defects, and reduce defects in the gallium indium oxide film, thereby obtaining a high-quality gallium indium oxide film, which can be used to make semiconductor devices such as photodetectors.

[0029] The thickness of the buffer layer 2 is set to be 40 nm to 80 nm; the thickness of the main epitaxial layer 3 is set to be 220 nm to 250 nm.

[0030] Traditional optoelectronic devices usually use rigid materials as substrates. Although these rigid materials have excellent performance, they lack flexibility, which limits their application in emerging fields such as wearable devices and flexible displays. Mica has significant advantages as a semiconductor film substrate in flexible optoelectronic devices. It has good flexibility and thermal stability, as well as high optical transparency and chemical inertness. In addition, the cost of mica is relatively low, which can further enhance its application value in the manufacture of flexible optoelectronic devices. In this application, substrate 1 uses a flexible mica substrate with a chemical formula of KAl2(Si3Al)O 10 (OH)2.

[0031] Please refer to Figure 2 As shown, the present application also provides a method for preparing a gallium indium oxide thin film, and the above-mentioned gallium indium oxide thin film can be prepared by the preparation method. Specifically, the preparation method comprises:

[0032] S1: providing a substrate;

[0033] S2: depositing a buffer layer of gallium indium oxide on the substrate by pulsed laser deposition to obtain an intermediate product;

[0034] S3: depositing a main epitaxial layer of gallium indium oxide on the buffer layer by a pulsed laser deposition method to obtain a gallium indium oxide thin film.

[0035] Preferably, the substrate is a flexible mica substrate.

[0036] Furthermore, step S1 includes: preparing a flexible mica substrate, ultrasonically cleaning the mica substrate with acetone, ethanol, and deionized water for 10 minutes in sequence, and then drying it with a nitrogen gun to achieve a cleaning process for the mica substrate to remove impurities such as oil, dust, etc. on the mica substrate.

[0037] Step S2 includes: placing the cleaned mica substrate into a growth chamber of a pulsed laser deposition device, setting growth parameters so that a layer of gallium indium oxide with a thickness of 40nm to 80nm is grown on the mica substrate, and performing in-situ annealing so that the gallium indium oxide grown on the mica substrate forms a buffer layer to obtain an intermediate product, which includes a substrate and a buffer layer.

[0038] Step S3 includes: placing the intermediate product after in-situ annealing into a growth chamber of a pulsed laser deposition device, setting growth parameters so that a layer of gallium indium oxide with a thickness of 220nm to 250nm is grown on the buffer layer, performing post-annealing in an air atmosphere in a high-temperature annealing furnace so that the gallium indium oxide grown on the buffer layer forms a main epitaxial layer, and obtaining a final product gallium indium oxide film on a substrate, wherein the gallium indium oxide film includes a buffer layer and a main epitaxial layer.

[0039] More specifically, step S2 includes: first controlling the gas pressure in the growth chamber of the pulsed laser deposition device to be lower than 4*10 - 6 Pa, then put the mica substrate into the growth chamber, use a heating device to heat the mica substrate at a heating rate of 7-10°C / min, turn on the laser to preheat it; when the temperature of the mica substrate reaches 300-700°C, introduce an oxygen pressure of 0.01-10Pa, adjust the target distance to 30-60mm, rotate the target to the gallium indium oxide target, set the laser to 1-10Hz, 200-300mJ, set the gallium indium oxide target to self-rotation and swing mode, start the laser, and turn off the laser after the laser hits the gallium indium oxide target for a corresponding number of pulses, grow a buffer layer (gallium indium oxide) on the substrate, control the heating device to perform in-situ annealing at a cooling rate of 7-10°C / min under an oxygen pressure of 0.01-10Pa, and cool to room temperature to obtain an intermediate product.

[0040] The growth time of the buffer layer is 4 to 8 minutes, the number of pulses of the laser hitting the gallium indium oxide target is 720 to 1440, and the gallium indium oxide target includes Ga2O3 and In2O3, and Ga2O3:In2O3=30:70at.%.

[0041] Preferably, the heating rate of the heating device is 10°C / min, the heating temperature of the substrate is 500°C, the target spacing is adjusted to 40mm, the laser is set to 3Hz, 250mJ, the cooling rate of the heating device is 7°C / min, and the oxygen pressure is 10Pa.

[0042] Step S3 includes: controlling the gas pressure in the growth chamber of the pulsed laser deposition device to be lower than 4*10 -6Pa, put the intermediate product into the growth chamber, turn on the laser to preheat it; at room temperature, introduce an oxygen pressure of 0.01-10Pa, adjust the target distance to 30-60mm, rotate the target to the gallium indium oxide target, set the laser to 1-10Hz, 200-300mJ, set the gallium indium oxide target to self-rotation and swing mode, start the laser, and turn off the laser after the laser hits the gallium indium oxide target for a corresponding number of pulses, grow a main epitaxial layer (gallium indium oxide) on the buffer layer, and obtain a sample, put the sample into a high-temperature annealing furnace for post-annealing treatment in an air atmosphere, set the post-annealing temperature to 800-1000°C, and set the post-annealing time to 0.5-2h to obtain a gallium indium oxide thin film.

[0043] The growth time of the main epitaxial layer is 20 to 25 minutes, the number of pulses of the laser hitting the gallium indium oxide target is 3600 to 4500, and the gallium indium oxide target includes Ga2O3 and In2O3, and Ga2O3:In2O3=30:70at.%.

[0044] Preferably, the oxygen pressure is 10 Pa, the target spacing is adjusted to 40 mm, the laser is set to 3 Hz, 250 mJ, the post-annealing temperature is set to 1000° C., and the post-annealing time is set to 1 h.

[0045] The present application prepares a thin buffer layer before preparing the main epitaxial layer. The thin film material of the buffer layer has the same or similar lattice structure as the thin film material of the main epitaxial layer, so that the main epitaxial layer can have no abrupt transition in the lattice structure, thereby reducing crystal defects such as dislocations, improving the crystallization quality of the film, improving problems such as high film defect density, and reducing gallium indium oxide film defects; and the addition of the buffer layer can maintain the stability of the main epitaxial layer film during growth, avoid the decrease in the crystallization quality of the film due to interface mismatch or stress accumulation, thereby obtaining a high-quality gallium indium oxide film.

[0046] Three specific embodiments of the preparation method of the present application are described in detail below.

[0047] Embodiment 1:

[0048] (1) A flexible mica substrate is provided and the mica substrate is cleaned.

[0049] The mica substrate was ultrasonically cleaned with acetone, ethanol and deionized water for 10 minutes in sequence, and then dried with a nitrogen gun to achieve a cleaning process for the mica substrate to remove impurities such as oil, dust and the like on the mica substrate.

[0050] (2) Growth of 40nm thick β-(Ga 0.7 In 0.3 )2O3 buffer layer film.

[0051] First, control the gas pressure in the growth chamber of the pulsed laser deposition device to be lower than 4*10 -6 Pa, then put the mica substrate into the growth chamber, use a heating device to heat the mica substrate at a heating rate of 10°C / min, turn on the laser to preheat it; when the temperature of the mica substrate reaches 500°C, introduce 10Pa of oxygen pressure, adjust the target distance to 40mm, rotate the target to the gallium indium oxide target, the gallium indium oxide target includes Ga2O3 and In2O3, Ga2O3:In2O3=30:70at.%, set the laser to 3Hz, 250mJ, set the gallium indium oxide target to self-rotation and swing mode, start the laser until the number of pulses of the laser hitting the gallium indium oxide target is 720, turn off the laser, and grow a buffer layer (β-(Ga) with a thickness of 40nm on the substrate 0.7 In 0.3 )2O3), control the heating device to perform in-situ annealing at a cooling rate of 7°C / min under an oxygen pressure of 10Pa, and cool it to room temperature to obtain an intermediate product.

[0052] (3) Growth of 250nm thick β-(Ga 0.7 In 0.3 )2O3 main epitaxial layer thin film.

[0053] Control the gas pressure in the growth chamber of the pulsed laser deposition device to be less than 4*10 -6 Pa, put the intermediate product into the growth chamber, turn on the laser to preheat it; at room temperature, introduce 10Pa of oxygen pressure, adjust the target distance to 40mm, rotate the target to the gallium indium oxide target, set the laser to 3Hz, 250mJ, set the gallium indium oxide target to self-rotation and swing mode, start the laser until the number of pulses on the gallium indium oxide target is 4500, turn off the laser, and grow a main epitaxial layer (β-(Ga 0.7 In 0.3 )2O3), to obtain a sample; take out the sample and then put the sample into a high-temperature annealing furnace for post-annealing treatment in an air atmosphere, the post-annealing temperature is set to 1000°C, the post-annealing time is set to 1h, and a gallium indium oxide film is obtained.

[0054] The performance of the prepared gallium indium oxide film was compared with that of the gallium indium oxide film without a buffer layer. Figure 3 and Figure 4 As shown, Figure 3This is a comparison chart of the light transmittance of a gallium indium oxide film (including a 40nm buffer layer and a 250nm main epitaxial layer) and a gallium indium oxide film without a buffer layer (including only a 250nm main epitaxial layer). It can be seen from the figure that the absorption edge of the film prepared without a buffer layer is wider than the absorption edge of the film prepared with a buffer layer, indicating that the film prepared without a buffer layer has more defect states and impurities, which will introduce additional energy levels in the band gap, causing the distribution of light absorption to become wider, that is, the gallium indium oxide film prepared with a buffer layer has fewer defect states and impurities than the film prepared without a buffer layer, indicating that the addition of a buffer layer can improve problems such as high film defect density and reduce defects in the gallium indium oxide film. Figure 4 The X-ray diffraction comparison diagram of the gallium indium oxide film (including a 40nm buffer layer and a 250nm main epitaxial layer) and the gallium indium oxide film without a buffer layer (including only a 250nm main epitaxial layer) and β-Ga2O3 can be seen from the figure that the β-(Ga2O3) prepared in this application 1-x In x )2O3's (-201) peak is shifted to the left by 0.9° compared with the (-201) peak of β-Ga2O3. By comparing the XRD results, it can be seen that the film prepared with the addition of a buffer layer has a higher diffraction peak intensity and a narrower half-peak width than the film prepared without a buffer layer, indicating that the film prepared with the addition of a buffer layer has a better crystallization quality.

[0055] Embodiment 2:

[0056] (1) A flexible mica substrate is provided and the mica substrate is cleaned.

[0057] The mica substrate was ultrasonically cleaned with acetone, ethanol and deionized water for 10 minutes in sequence, and then dried with a nitrogen gun to achieve a cleaning process for the mica substrate to remove impurities such as oil, dust and the like on the mica substrate.

[0058] (2) Growth of 60nm thick β-(Ga 0.7 In 0.3 )2O3 buffer layer film.

[0059] First, control the gas pressure in the growth chamber of the pulsed laser deposition device to be lower than 4*10 -6Pa, then put the mica substrate into the growth chamber, use a heating device to heat the mica substrate at a heating rate of 10°C / min, turn on the laser to preheat it; when the temperature of the mica substrate reaches 500°C, introduce 10Pa of oxygen pressure, adjust the target distance to 40mm, rotate the target to the gallium indium oxide target, the gallium indium oxide target includes Ga2O3 and In2O3, Ga2O3:In2O3=30:70at.%, set the laser to 3Hz, 250mJ, set the gallium indium oxide target to self-rotation and swing mode, start the laser until the number of pulses of the laser hitting the gallium indium oxide target is 1080, turn off the laser, and grow a buffer layer (β-(Ga) with a thickness of 60nm) on the substrate 0.7 In 0.3 )2O3), control the heating device to perform in-situ annealing at a cooling rate of 7°C / min under an oxygen pressure of 10Pa, and cool it to room temperature to obtain an intermediate product.

[0060] (3) Growth of 250nm thick β-(Ga 0.7 In 0.3 )2O3 main epitaxial layer thin film.

[0061] Control the gas pressure in the growth chamber of the pulsed laser deposition device to be less than 4*10 -6 Pa, put the intermediate product into the growth chamber, turn on the laser to preheat it; at room temperature, introduce 10Pa of oxygen pressure, adjust the target distance to 40mm, rotate the target to the gallium indium oxide target, set the laser to 3Hz, 250mJ, set the gallium indium oxide target to self-rotation and swing mode, start the laser until the number of pulses on the gallium indium oxide target is 4500, turn off the laser, and grow a main epitaxial layer (β-(Ga 0.7 In 0.3 )2O3), to obtain a sample; take out the sample and then put the sample into a high-temperature annealing furnace for post-annealing treatment in an air atmosphere, the post-annealing temperature is set to 1000°C, the post-annealing time is set to 1h, and a gallium indium oxide film is obtained.

[0062] Embodiment three:

[0063] (1) A flexible mica substrate is provided and the mica substrate is cleaned.

[0064] The mica substrate was ultrasonically cleaned with acetone, ethanol and deionized water for 10 minutes in sequence, and then dried with a nitrogen gun to achieve a cleaning process for the mica substrate to remove impurities such as oil, dust and the like on the mica substrate.

[0065] (2) Growth of 80nm thick β-(Ga 0.7 In 0.3 )2O3 buffer layer film.

[0066] First, control the gas pressure in the growth chamber of the pulsed laser deposition device to be lower than 4*10 -6 Pa, then put the mica substrate into the growth chamber, use a heating device to heat the mica substrate at a heating rate of 10°C / min, turn on the laser to preheat it; when the temperature of the mica substrate reaches 500°C, introduce 10Pa of oxygen pressure, adjust the target distance to 40mm, rotate the target to the gallium indium oxide target, the gallium indium oxide target includes Ga2O3 and In2O3, Ga2O3:In2O3=30:70at.%, set the laser to 3Hz, 250mJ, set the gallium indium oxide target to self-rotation and swing mode, start the laser until the number of pulses of the laser hitting the gallium indium oxide target is 1440, turn off the laser, and grow a buffer layer (β-(Ga) with a thickness of 80nm) on the substrate. 0.7 In 0.3 )2O3), control the heating device to perform in-situ annealing at a cooling rate of 7°C / min under an oxygen pressure of 10Pa, and cool it to room temperature to obtain an intermediate product.

[0067] (3) Growth of 250nm thick β-(Ga 0.7 In 0.3 )2O3 main epitaxial layer thin film.

[0068] Control the gas pressure in the growth chamber of the pulsed laser deposition device to be less than 4*10 -6 Pa, put the intermediate product into the growth chamber, turn on the laser to preheat it; at room temperature, introduce 10Pa of oxygen pressure, adjust the target distance to 40mm, rotate the target to the gallium indium oxide target, set the laser to 3Hz, 250mJ, set the gallium indium oxide target to self-rotation and swing mode, start the laser until the number of pulses on the gallium indium oxide target is 4500, turn off the laser, and grow a main epitaxial layer (β-(Ga 0.7 In 0.3 )2O3), to obtain a sample; take out the sample and then put the sample into a high-temperature annealing furnace for post-annealing treatment in an air atmosphere, the post-annealing temperature is set to 1000°C, the post-annealing time is set to 1h, and a gallium indium oxide film is obtained.

[0069] In summary, the present application provides a gallium indium oxide thin film and a preparation method thereof. The gallium indium oxide thin film is prepared on a substrate by a pulsed laser deposition method and includes a main epitaxial layer and a buffer layer, wherein the buffer layer is connected between the substrate and the main epitaxial layer, and the chemical formulas of the main epitaxial layer and the buffer layer are both (Ga 1-x In x)2O3, wherein 0.1≤x≤0.5. The preparation method comprises: providing a substrate; depositing a buffer layer of gallium indium oxide on the substrate by a pulsed laser deposition method to obtain an intermediate product; and depositing a main epitaxial layer of gallium indium oxide on the buffer layer by a pulsed laser deposition method to obtain a gallium indium oxide thin film. The present application prepares a thin buffer layer before preparing the main epitaxial layer. The thin film material of the buffer layer has the same or similar lattice structure as the thin film material of the main epitaxial layer, so that the main epitaxial layer can have no abrupt transition in the lattice structure, thereby reducing crystal defects such as dislocations, and the addition of the buffer layer can maintain the stability of the main epitaxial layer during the growth process, avoiding the decrease in the crystal quality of the thin film due to interface mismatch or stress accumulation, thereby obtaining a high-quality gallium indium oxide thin film.

[0070] The concepts described herein may be implemented in other forms without departing from their spirit and characteristics. The specific embodiments disclosed should be considered illustrative rather than restrictive. Therefore, the scope of this application is determined by the appended claims rather than by the preceding description. Any changes within the literal meaning and equivalent scope of the claims should fall within the scope of these claims.

Claims

1. A gallium indium oxide thin film, characterized in that: The gallium indium oxide film is prepared based on a substrate by a pulsed laser deposition method. The gallium indium oxide film includes a main epitaxial layer and a buffer layer. The buffer layer is connected between the substrate and the main epitaxial layer. The chemical formulas of the main epitaxial layer and the buffer layer are (Ga 1-x In x )2O3, where 0.1≤x≤0.

5.

2. The gallium indium oxide thin film according to claim 1, characterized in that The x=0.3; and / or the thickness of the buffer layer is 40nm-80nm; and / or the thickness of the main epitaxial layer is 220nm-250nm.

3. The gallium indium oxide thin film according to claim 1, characterized in that The substrate is a flexible mica substrate, and the chemical formula is KAl2(Si3Al)O 10 (OH)2.

4. A method for preparing a gallium indium oxide thin film, characterized in that: The preparation method comprises: S1: providing a substrate; S2: depositing a buffer layer of gallium indium oxide on the substrate by pulsed laser deposition to obtain an intermediate product; S3: depositing a main epitaxial layer of gallium indium oxide on the buffer layer by pulsed laser deposition to obtain a gallium indium oxide thin film.

5. The method for preparing a gallium indium oxide thin film according to claim 4, characterized in that: The step S2 comprises: First, control the gas pressure in the growth chamber of the pulsed laser deposition device to be lower than 4*10 -6 Pa, then placing the substrate into the growth chamber, heating the substrate with a heating device at a heating rate of 7 to 10° C. / min, and turning on the laser to preheat the substrate; When the temperature of the substrate reaches 300-700° C., an oxygen pressure of 0.01-10 Pa is introduced, the target spacing is adjusted to 30-60 mm, the target position is rotated to the gallium indium oxide target, the laser is set to 1-10 Hz, 200-300 mJ, the gallium indium oxide target is set to self-rotation and swing mode, the laser is started until the laser hits the gallium indium oxide target for a corresponding number of pulses, and then the laser is turned off, the buffer layer is grown on the substrate, and the heating device is controlled to perform in-situ annealing at a cooling rate of 7-10° C. / min under an oxygen pressure of 0.01-10 Pa, and the temperature is cooled to room temperature to obtain the intermediate product.

6. The method for preparing a gallium indium oxide thin film according to claim 5, characterized in that: The growth time of the buffer layer is 4 to 8 minutes; and / or the number of pulses of the laser hitting the gallium indium oxide target is 720 to 1440.

7. The method for preparing a gallium indium oxide thin film according to claim 5, characterized in that: The heating rate of the heating device is 10°C / min; and / or the heating temperature of the substrate is 500°C; and / or the target spacing is adjusted to 40mm; and / or the laser is set to 3Hz, 250mJ; and / or the cooling rate of the heating device is 7°C / min; and / or the oxygen pressure is 10Pa.

8. The method for preparing a gallium indium oxide thin film according to claim 4, characterized in that: The step S3 comprises: Control the gas pressure in the growth chamber of the pulsed laser deposition device to be less than 4*10 -6 Pa, placing the intermediate product into the growth chamber, and turning on the laser to preheat it; At room temperature, an oxygen pressure of 0.01 to 10 Pa is introduced, the target spacing is adjusted to 30 to 60 mm, the target position is rotated to the gallium indium oxide target, the laser is set to 1 to 10 Hz, 200 to 300 mJ, the gallium indium oxide target is set to self-rotation and swing mode, the laser is started until the laser hits the gallium indium oxide target for a corresponding number of pulses, and then the laser is turned off, the main epitaxial layer is grown on the buffer layer to obtain a sample, the sample is placed in a high-temperature annealing furnace and post-annealed in an air atmosphere, the post-annealing temperature is set to 800 to 1000° C., and the post-annealing time is set to 0.5 to 2 h to obtain the gallium indium oxide film.

9. The method for preparing a gallium indium oxide thin film according to claim 8, characterized in that: The growth time of the main epitaxial layer is 20 to 25 minutes; and / or the number of pulses of the laser hitting the gallium indium oxide target is 3600 to 4500.

10. The method for preparing a gallium indium oxide thin film according to claim 8, characterized in that: The oxygen pressure is 10Pa; and / or, the target spacing is adjusted to 40mm; and / or, the laser is set to 3Hz, 250mJ; and / or, the post-annealing temperature is set to 1000°C; and / or, the post-annealing time is set to 1h.

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