Rare earth doped gallium oxide thin film material and preparation method and application thereof

Abstract

The invention provides a rare earth doped gallium oxide thin film material and a preparation method and application thereof. The preparation method comprises the following steps: in a vacuum chamber, depositing a thin film on the surface of a cleaned substrate by using a rare earth oxide doped gallium oxide target material through a single-target radio frequency sputtering method to obtain the rare earth doped gallium oxide thin film material. Rare earth elements are doped in gallium oxide through a single-target radio frequency magnetron sputtering method, physical properties such as forbidden bandwidth of the gallium oxide material are regulated and controlled, application of the gallium oxide material in the field of photoelectric detection or semiconductor light-emitting devices is widened, and the obtained rare earth doped gallium oxide thin film material is uniform in surface film formation and high in yield. The average transmittance at the wavelength of 350-800 nm is greater than 90%, and the doping concentration of rare earth elements in the gallium oxide thin film material can be adjusted by directly replacing target materials with different doping proportions; the preparation method disclosed by the invention is simple, does not need expensive equipment, has obvious cost advantage and is suitable for large-scale production.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor materials and relates to a rare earth doped gallium oxide thin film material and a preparation method and application thereof. Background Art

[0002] Gallium oxide (Ga2O3) material is an emerging ultra-wide bandgap semiconductor material. Since its bandgap is in the range of 4.4eV-5.2eV and the corresponding cutoff wavelength is in the solar-blind band (200nm-280nm), Ga2O3 material has natural spectral selectivity for solar-blind ultraviolet rays and has good application prospects in the field of photoelectric detection. At the same time, its breakdown voltage of up to 8MV / cm has also made it a focus of attention in the field of power devices. In addition, Ga2O3 material is one of the suitable matrix materials for the preparation of light-emitting devices, and its radiation resistance, high temperature resistance, and high voltage resistance have certain advantages in the field of light-emitting devices. However, even though Ga2O3 has a wide direct bandgap, its bandgap still needs to be further regulated to broaden its application in the field of optoelectronic devices at different wavelengths.

[0003] As a traditional effective luminescent material, rare earth ions have been widely used in the fields of lighting and display due to their high luminescence intensity and constant emission wavelength. Doping rare earth elements into Ga2O3 materials can regulate the physical properties of gallium oxide materials such as the band gap width, and broaden the application of Ga2O3 materials in the field of optoelectronic devices.

[0004] CN112707433A discloses a method for preparing rare earth cerium doped gallium oxide nanomaterials. A gallium oxide film is grown on a substrate by a carbon thermal reduction method. By doping the rare earth element cerium into gallium oxide, the light absorption of the gallium oxide matrix is ​​enhanced. The method is expected to be used in solar cells to improve the photoelectric conversion efficiency.

[0005] CN109852381A discloses a Yb and Er co-doped gallium oxide film and a preparation method thereof. On a substrate, a laser pulse deposition method is used to grow a gallium oxide film, rare earth Yb is used as a sensitizer, and rare earth Er is used as a near-infrared luminescence center. By co-doping the sensitizer and the luminescence center, an enhanced near-infrared photoluminescence film material is prepared, and the band gap width of the material is widened. The obtained Yb and Er co-doped gallium oxide film has a strong luminescence signal in the near-infrared band and a high conversion efficiency.

[0006] CN117144293A discloses a selenium-doped gallium oxide film and its preparation method and application. On a substrate, a gallium oxide film is grown by laser pulse deposition. Se is doped into Ga2O3 to adjust its band gap. 2- Replace O 2- Due to the antibonding interaction between the local Se energy level and the Ga2O3 valence band, Ga2(O1-x Se x )3 film has a significantly reduced band gap, and Ga2(O 1-x Se x )3 The band gap width of the film can be freely adjusted with the Se content. The prepared film has high transmittance to visible light and even ultraviolet light, and can be used in optoelectronic devices such as photodetectors.

[0007] However, among the above-mentioned preparation methods, whether it is the carbon thermal reduction method or the pulsed laser deposition method, although it can adjust the bandgap width by rare earth doping, the preparation process is complicated and requires high costs, which is not conducive to large-scale production.

[0008] Therefore, how to achieve the regulation of the bandgap width of gallium oxide materials while reducing the preparation cost of rare earth-doped gallium oxide thin film materials and broadening the application of gallium oxide materials in the field of light-emitting devices is a technical problem that needs to be solved urgently. Summary of the invention

[0009] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a rare earth doped gallium oxide thin film material and its preparation method and application. The present invention dopes rare earth elements into gallium oxide by single-target radio frequency magnetron sputtering, regulates the physical properties of gallium oxide materials such as the band gap width, broadens the application of gallium oxide materials in the field of photoelectric detection or semiconductor light-emitting devices, and the obtained rare earth doped gallium oxide thin film material has an average transmittance of more than 90% at a wavelength of 350nm-800nm; and the preparation method of the present invention is simple and does not require expensive equipment. Compared with the existing methods such as chemical vapor deposition and laser pulse deposition, the process is simpler, the cost advantage is obvious, and it is suitable for large-scale production.

[0010] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0011] In a first aspect, the present invention provides a method for preparing a rare earth-doped gallium oxide thin film material, the preparation method comprising:

[0012] In a vacuum chamber, a rare earth oxide-doped gallium oxide target material is used to deposit a thin film on the surface of a cleaned substrate by a single-target radio frequency sputtering method to obtain the rare earth-doped gallium oxide thin film material.

[0013] The present invention effectively adjusts the bandgap width of the gallium oxide material by doping rare earth oxides into gallium oxide, thereby broadening its application in different wavelength ranges in the field of optoelectronic devices.

[0014] The present invention uses a single-target radio frequency sputtering method. On the one hand, compared with the chemical vapor deposition method and pulsed laser deposition method mainly used to prepare rare earth-doped gallium oxide materials, magnetron sputtering equipment is cheaper, the process is simpler, and the cost is lower; further, the traditional use of magnetron sputtering to grow doped materials usually uses a dual-target sputtering method, that is, a target material with good conductivity is installed on a DC target gun, and a target material with poor conductivity is installed on an RF target gun, but this method requires adjusting the DC power and RF power to grow the doped material, and its process flow and equipment are relatively complex. The single-target radio frequency magnetron sputtering method used in the present invention only requires a piece of target material and a target gun to complete the material growth, optimizes the process flow, and has lower requirements for equipment. On the other hand, the present invention uses a single-target radio frequency magnetron sputtering method, which can directly replace the target material with different doping ratios to achieve the adjustment of the rare earth element doping concentration in the gallium oxide thin film material. Compared with the dual-target sputtering method, its deposition process is not affected by the DC sputtering process, and the doping concentration of the grown film is more stable, with better process robustness.

[0015] Preferably, the rare earth element in the rare earth oxide includes any one of Yb, Lu or Gd, or a combination of at least two of them.

[0016] In the present invention, the degree of adjustment of the bandgap width of the gallium oxide film can be controlled by changing the type of doped rare earth elements; and when any one of Yb, Lu or Gd or a combination of at least two of them is selected as the rare earth doping element, the doping concentration of the doped target material can be adjusted within a larger concentration range, and the doped target material is not prone to cracking during hot pressing and sintering.

[0017] The present application does not specifically limit the cleaning method of the substrate. Exemplarily, the present invention provides a cleaning method, comprising: performing ultrasonic cleaning in acetone, ethanol and deionized water in sequence.

[0018] Optionally, the ultrasonic cleaning time is 5 min-15 min.

[0019] Preferably, in the target material, the molar ratio of the rare earth oxide to the gallium oxide is (0.5-7):(93-99.5), such as 0.5:99.5, 3:97, 5:95 or 7:93, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0020] In the present invention, by adjusting the molar ratio of rare earth oxide to gallium oxide, the doping concentration of the grown rare earth-doped gallium oxide film can be regulated, and then the degree of adjustment of the band gap width of the gallium oxide film can be controlled, so the selection of the molar ratio of rare earth oxide to gallium oxide in the target material is particularly important.

[0021] Preferably, the substrate is placed on a substrate table surface.

[0022] Preferably, the temperature of the substrate table is 25°C-600°C, preferably 80°C-600°C, for example 25°C, 50°C, 80°C, 100°C, 200°C, 300°C, 400°C, 500°C or 600°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0023] Preferably, the rotation speed of the substrate table is 5 rpm-20 rpm, such as 5 rpm, 10 rpm, 15 rpm or 20 rpm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0024] Preferably, the vertical distance between the substrate and the target is 5 cm-12 cm, for example, 5 cm, 6 cm, 7 cm, 8 cm, 9 cm, 10 cm, 11 cm or 12 cm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0025] Optionally, the vertical distance between the substrate and the target material can be adjusted by raising the substrate.

[0026] Preferably, before the deposition begins, the vacuum chamber pressure is reduced to 10 -3 Pa and pre-sputtering was performed.

[0027] Preferably, the pre-sputtering method comprises: turning on the radio frequency power supply but not turning on the baffle.

[0028] In the present invention, pre-sputtering is performed before deposition begins, and the radio frequency power supply is turned on, but the baffle is not turned on, so that pollutants on the target material can be removed, making the prepared rare earth-doped gallium oxide thin film material purer.

[0029] Preferably, the pre-sputtering time is 10 min-20 min, for example, 10 min, 12 min, 14 min, 16 min, 18 min or 20 min, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0030] Preferably, during the deposition process, a protective gas is introduced, and the protective gas includes argon.

[0031] Preferably, during the deposition process, the flow rate of the argon gas is 40sccm-50sccm, for example, 40sccm, 42sccm, 44sccm, 46sccm, 48sccm or 50sccm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0032] Preferably, the gas pressure during the deposition process is 0.5Pa-2.5Pa, such as 0.5Pa, 1.0Pa, 1.5Pa, 2.0Pa or 2.5Pa, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0033] In the present invention, the gas pressure during the deposition process is regulated to be 0.5 Pa to 2.5 Pa, which is more conducive to the uniformity of the deposited film.

[0034] Preferably, during the deposition process, the sputtering power of single-target RF sputtering is 70W-200W, for example, 70W, 90W, 110W, 130W, 150W, 170W or 200W, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0035] Preferably, the deposition time of the deposition is 0.5h-4h, for example 0.5h, 1.0h, 1.5h, 2.0h, 2.5h, 3.0h, 3.5h or 4h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0036] Preferably, the deposited thin film is subjected to annealing treatment.

[0037] In the present invention, an annealing process is performed after the thin film is deposited, so as to further improve the crystal quality of the thin film material.

[0038] Preferably, the annealing treatment is performed in a protective atmosphere.

[0039] Preferably, the protective atmosphere comprises a nitrogen atmosphere and / or an inert gas atmosphere.

[0040] Preferably, the heating rate of the annealing treatment is 5°C / min-15°C / min, for example, 5°C / min, 7°C / min, 9°C / min, 11°C / min, 13°C / min or 15°C / min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0041] Preferably, the annealing temperature is 500°C-900°C, such as 500°C, 600°C, 700°C, 800°C or 900°C, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0042] Preferably, the annealing treatment time is 0.5h-2.5h, such as 0.5h, 1.0h, 1.5h, 2.0h or 2.5h, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0043] As a preferred technical solution, the preparation method comprises:

[0044] Clean the substrate, select the target material according to the molar ratio of rare earth oxide to gallium oxide (0.5-7): (93-99.5); before the film deposition begins, reduce the vacuum chamber pressure to 10 -3 Pa or less, and pre-sputtering for 10min-20min; in the process of depositing the thin film, using argon atmosphere as the deposition atmosphere, and setting its flow rate to 40sccm-50sccm, the gas pressure to 0.5Pa-2.5Pa, setting the temperature of the substrate stage to between 25°C-600°C, the rotation speed to between 5rpm-20rpm, and the distance between the substrate stage and the target material to 5cm-12cm; turning on the RF power supply, setting the RF power supply power to 70W-200W, and using RF magnetron sputtering single target sputtering to perform deposition for 0.5h-4h to obtain the rare earth doped gallium oxide thin film material;

[0045] The rare earth element in the rare earth oxide includes any one of Yb, Lu or Gd or a combination of at least two of them.

[0046] In a second aspect, the present invention provides a rare earth-doped gallium oxide thin film material, wherein the rare earth-doped gallium oxide thin film material is prepared by the method for preparing the rare earth-doped gallium oxide thin film material described in the first aspect.

[0047] The average transmittance of the film material at a wavelength of 350nm-800nm ​​is greater than 90%.

[0048] In a third aspect, the present invention further provides an application of the rare earth-doped gallium oxide thin film material as described in the second aspect, wherein the rare earth-doped gallium oxide thin film material is applied to the field of photoelectric detection or semiconductor light-emitting devices.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] 1. The present invention uses a single-target radio frequency sputtering method to dope rare earth elements into gallium oxide, which effectively adjusts the band gap width of the gallium oxide material, broadens the application of gallium oxide materials in the field of photoelectric detection or semiconductor light-emitting devices, and is expected to prepare semiconductor light-emitting devices with different wavelengths.

[0051] 2. The present invention uses a single-target radio frequency magnetron sputtering method, which can adjust the doping concentration of rare earth elements in the gallium oxide thin film material by directly replacing the target material with different doping ratios. In addition, since the deposition process is not affected by the DC sputtering process, the doping concentration of the grown film is more stable and has better process robustness.

[0052] 3. The present invention uses a single-target radio frequency magnetron sputtering method, the required equipment is relatively low in price, the process is simple, and large-scale production can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 Schematic diagram of the preparation process of Example 1.

[0054] Figure 2 These are the SEM and EDS images of the Yb-doped Ga2O3 film prepared in Example 1.

[0055] Figure 3 These are the SEM and EDS images of the Lu-doped Ga2O3 thin film prepared in Example 2.

[0056] Figure 4 These are the SEM and EDS images of the Gd-doped Ga2O3 thin film prepared in Example 3.

[0057] Figure 5 is the (Ahv) of the Yb-doped Ga2O3 film prepared in Example 1 2 Relationship diagram with hv.

[0058] Figure 6 is the Lu-doped Ga2O3 film (Ahv) prepared in Example 2 2 Relationship diagram with hv.

[0059] Figure 7 is the (Ahv) of the Gd-doped Ga2O3 film prepared in Example 3 2 Relationship diagram with hv.

[0060] Figure 8 is the (Ahv) of the pure Ga2O3 film prepared in Comparative Example 1 2 Relationship diagram with hv.

[0061] Fig. 9 The graph is a relationship graph of the optical band gap of the thin films prepared in Examples 1-3 and Comparative Example 1 as the types of doped rare earth elements vary.

[0062] Fig.10 The transmission spectra of the thin film materials prepared in Examples 1-3 and Comparative Example 1 are shown. DETAILED DESCRIPTION

[0063] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0064] Example 1

[0065] This embodiment provides a rare earth-doped gallium oxide thin film material, wherein the rare earth-doped gallium oxide thin film material is a Yb-doped Ga2O3 thin film.

[0066] The preparation method of the rare earth doped gallium oxide thin film material is as follows Figure 1 As shown, the details are as follows:

[0067] (1) Substrate cleaning: <0001> The Al2O3 substrate with a size of 10 mm × 10 mm was ultrasonically cleaned in acetone, ethanol, and deionized water for 10 min, then rinsed with flowing deionized water and dried with a nitrogen gun. Finally, it was placed in a magnetron sputtering vacuum chamber for deposition.

[0068] (2) Installing the target material: The target material here is a mixed target material of Yb2O3:Ga2O3=5:95 (molar ratio), in which the purity of Yb2O3 and Ga2O3 is above 99.99%.

[0069] (3) Thin film deposition: The thin film is deposited by single-target RF magnetron sputtering. Before the deposition begins, the pressure in the vacuum chamber is reduced to 10 -3 Pa, the substrate stage temperature was set to 100°C, the substrate stage rotation speed was 10rpm, the distance from the substrate to the target was 7cm, the deposition atmosphere was 99.99% pure argon, the gas flow rate was 40sccm, the gas pressure was 1.5Pa, the RF power was 150W, and the deposition time was 2h.

[0070] from Figure 2 From the SEM image of the Yb-doped gallium oxide thin film prepared in Example 1, it can be seen that the Yb-doped gallium oxide thin film is formed uniformly.

[0071] from Figure 2 It can be seen from the EDS graph that in the Yb-doped Ga2O3 film prepared in Example 1, Yb, Ga and O elements are evenly distributed in the material.

[0072] exist Figure 5 Yb-doped Ga2O3 thin films (Ahv) 2 In the relationship diagram with hv, after linear fitting, the intercept of the linear equation on the x-axis is the required bandgap width. It can be obtained that the bandgap width Eg≈5.11eV of the Yb-doped gallium oxide film prepared in Example 1.

[0073] Example 2

[0074] This embodiment provides a rare earth-doped gallium oxide thin film material, wherein the rare earth-doped gallium oxide thin film material is a Lu-doped Ga2O3 thin film.

[0075] The preparation method of the rare earth doped gallium oxide thin film material is as follows:

[0076] (1) Substrate cleaning: <0001> The Al2O3 substrate with a size of 10 mm × 10 mm was ultrasonically cleaned in acetone, ethanol, and deionized water for 10 min, then rinsed with flowing deionized water and dried with a nitrogen gun. Finally, it was placed in a magnetron sputtering vacuum chamber for deposition.

[0077] (2) Installing the target material: The target material here is a mixed target material of Lu2O3:Ga2O3=5:95 (molar ratio), in which the purity of Lu2O3 and Ga2O3 is above 99.99%.

[0078] (3) Thin film deposition: The thin film is deposited by single-target RF magnetron sputtering. Before the deposition begins, the pressure in the vacuum chamber is reduced to 10 -3 Pa, the substrate stage temperature was set to 25°C, the substrate stage rotation speed was 5rpm, the distance from the substrate to the target was 5cm, the deposition atmosphere was 99.99% pure argon, the gas flow rate was 45sccm, the gas pressure was 0.5Pa, the RF power was 70W, and the deposition time was 0.5h.

[0079] from Figure 3 From the SEM image of the Lu-doped Ga2O3 thin film prepared in Example 2 provided, it can be seen that the Lu-doped gallium oxide thin film is formed uniformly.

[0080] from Figure 3 It can be seen from the EDS graph that in the Lu-doped gallium oxide thin film prepared in Example 2, Lu, Ga and O elements are evenly distributed in the material.

[0081] from Figure 6 Lu-doped Ga2O3 thin films (Ahv) 2 It can be seen from the relationship diagram with hv that the Lu-doped Ga2O3 film prepared in Example 2 has a band gap width Eg≈5.26eV.

[0082] Example 3

[0083] This embodiment provides a rare earth doped gallium oxide thin film material, wherein the rare earth doped gallium oxide thin film material is a Gd doped Ga2O3 thin film.

[0084] The preparation method of the rare earth doped gallium oxide thin film material is as follows:

[0085] (1) Substrate cleaning: <0001> The Al2O3 substrate with a size of 10 mm × 10 mm was ultrasonically cleaned in acetone, ethanol, and deionized water for 10 min, then rinsed with flowing deionized water and dried with a nitrogen gun. Finally, it was placed in a magnetron sputtering vacuum chamber for deposition.

[0086] (2) Installing the target material: The target material here is a mixed target material of Gd2O3:Ga2O3=5:95 (molar ratio), in which the purity of Gd2O3 and Ga2O3 is above 99.99%.

[0087] (3) Thin film deposition: The thin film is deposited by single-target RF magnetron sputtering. Before the deposition begins, the pressure in the vacuum chamber is reduced to 10 -3 Pa, the substrate stage temperature was set to 600°C, the substrate stage rotation speed was 20rpm, the distance from the substrate to the target was 12cm, the deposition atmosphere was 99.99% pure argon, the gas flow rate was 50sccm, the gas pressure was 2.5Pa, the RF power was 200W, and the deposition time was 4h.

[0088] from Figure 4 From the SEM image of the Gd-doped gallium oxide thin film prepared in Example 3, it can be seen that the Gd-doped gallium oxide thin film is formed uniformly.

[0089] from Figure 4 It can be seen from the EDS graph that in the Gd-doped Ga2O3 film prepared in Example 3, Gd, Ga and O elements are evenly distributed in the material.

[0090] from Figure 7 Gd doped Ga2O3 thin film (Ahv) 2 It can be seen from the relationship diagram with hv that the band gap width Eg≈5.21eV of the Gd-doped gallium oxide film prepared in Example 3.

[0091] Example 4

[0092] The difference between this embodiment and embodiment 1 is that the target material used in step (2) of this embodiment is a mixed target material of Tb4O7:Ga2O3=5:95 (molar ratio), wherein the purity of Ga2O3 and Tb4O7 is both above 99.99%.

[0093] The rest of the preparation methods and parameters were the same as those in Example 1.

[0094] Example 5

[0095] The difference between this embodiment and embodiment 1 is that the target material in step (2) of this embodiment is a mixed target material of Yb2O3:Ga2O3=0.2:99.8 (molar ratio).

[0096] The rest of the preparation methods and parameters were the same as those in Example 1.

[0097] Example 6

[0098] The difference between this embodiment and embodiment 1 is that the target material in step (2) of this embodiment is a mixed target material of Yb2O3:Ga2O3=10:90 (molar ratio).

[0099] The rest of the preparation methods and parameters were the same as those in Example 1.

[0100] Example 7

[0101] The difference between this embodiment and embodiment 1 is that the target material in step (2) of this embodiment is a mixed target material of Yb2O3:Ga2O3=0.5:99.5 (molar ratio).

[0102] The rest of the preparation methods and parameters were the same as those in Example 1.

[0103] Example 8

[0104] The difference between this embodiment and embodiment 1 is that the target material in step (2) of this embodiment is a mixed target material of Yb2O3:Ga2O3=7:93 (molar ratio).

[0105] The rest of the preparation methods and parameters were the same as those in Example 1.

[0106] Example 9

[0107] The difference between this embodiment and embodiment 1 is that the gas pressure of the deposition process in step (3) of this embodiment is 5Pa.

[0108] The rest of the preparation methods and parameters were the same as those in Example 1.

[0109] Example 10

[0110] The difference between this embodiment and embodiment 1 is that this embodiment adds an annealing process after step (3), and the method of the annealing process is as follows:

[0111] The film was placed in a tubular furnace, evacuated, and then introduced with argon gas. The heating rate of the tubular furnace was 10°C / min, and the film was kept at 700°C for 1 hour, and then cooled with the furnace to complete the annealing.

[0112] The rest of the preparation methods and parameters were the same as those in Example 1.

[0113] Comparative Example 1

[0114] This embodiment provides a rare earth doped gallium oxide thin film material, wherein the rare earth doped gallium oxide thin film material is a pure Ga2O3 thin film.

[0115] The difference between this comparative example and Example 1 is that the target material used in this comparative example is a pure gallium oxide target material, wherein the purity of Ga2O3 is above 99.99%.

[0116] The rest of the preparation methods and parameters were the same as those in Example 1.

[0117] from Figure 8 Pure Ga2O3 thin film (Ahv) 2 From the relationship diagram with hv, it can be seen that the band gap width Eg≈5.06eV of the pure gallium oxide film prepared in Comparative Example 1.

[0118] Comparative Example 2

[0119] This embodiment provides a rare earth-doped gallium oxide thin film material, wherein the rare earth-doped gallium oxide thin film material is a Yb-doped Ga2O3 thin film.

[0120] The difference between this comparative example and Example 1 is that this comparative example adopts a dual-target magnetron sputtering method and adds a DC target gun.

[0121] The preparation method of the dual-target magnetron sputtering is as follows:

[0122] (1) Substrate cleaning: <0001> The Al2O3 substrate with a size of 10 mm × 10 mm was ultrasonically cleaned in acetone, ethanol, and deionized water for 10 min, then rinsed with flowing deionized water and dried with a nitrogen gun. Finally, it was placed in a magnetron sputtering vacuum chamber for deposition.

[0123] (2) Installing the target material: Install a Yb target material with a purity of 99.99% on the DC target gun, and install a Ga2O3 target material with a purity of 99.99% on the RF target gun.

[0124] (3) Thin film deposition: The thin film is deposited by using RF magnetron sputtering and dual-target sputtering. Before starting the deposition, the pressure in the vacuum chamber is reduced to 10 -3 Pa, the substrate stage temperature was set to 100°C, the substrate stage rotation speed was 10rpm, the distance from the substrate to the target was 7cm, the deposition atmosphere was 99.99% argon, the gas flow rate was 40sccm, the gas pressure was 1.5Pa, the DC power was 20W, the RF power was 150W, and the deposition time was 2h.

[0125] Performance Testing

[0126] The gallium oxide films prepared in Examples 1-10 and Comparative Examples 1-2 were tested by SEM, EDS and UV-visible spectrophotometer, and their (Ahv) 2 The relationship between hv is tested and calculated, and the test results are as follows Figure 1-10 And as shown in Table 1.

[0127] Table 1

[0128]

[0129]

[0130] Three repetitive experiments were carried out according to the preparation parameters of Example 1 and Comparative Example 2, and the obtained gallium oxide film was subjected to EDS test to analyze its element content. The test and analysis results are shown in Table 2 and Table 3, respectively.

[0131] Table 2

[0132] Example 1-1 Example 1-2 Examples 1-3 Molar ratio of gallium atoms to rare earth atoms 14.39:1 14.63:1 14.75:1

[0133] Table 3

[0134] Comparative Example 2-1 Comparative Example 2-2 Comparative Examples 2-3 Molar ratio of gallium atoms to rare earth atoms 16.43:1 9.23:1 13.21:1

[0135] like Figure 5-8 As shown in Table 1, the band gap widths of the rare earth-doped gallium oxide thin film materials prepared in Examples 1-3 are approximately 5.11 eV, 5.26 eV and 5.21 eV, respectively, while the band gap width of the pure gallium oxide thin film material prepared in Comparative Example 1 is approximately 5.06 eV, which indicates that the present invention successfully adjusts the band gap width of the gallium oxide material by doping rare earth elements into gallium oxide by single-target radio frequency magnetron sputtering, thereby broadening its application in the field of photoelectric detection or semiconductor light-emitting devices.

[0136] From the comparison between Example 1 and Example 4 in Table 1, it can be seen that when Tb element is doped, the target material will produce slight cracks during the hot pressing sintering process, affecting the uniformity of the product film. From the comparison between Example 1 and Examples 5-6 in Table 1, it can be seen that during the preparation process, the molar ratio of rare earth oxide to gallium oxide is too low, and the regulating effect on the band gap width of the gallium oxide material is not obvious; while the molar ratio of rare earth oxide to gallium oxide is too high, it will affect the uniformity of the product film.

[0137] like Fig. 9 As shown in Example 1, Example 7 and Example 8 in Table 1, it can be seen that the band gap width of the gallium oxide-based thin film material can be freely adjusted by adjusting the type and concentration of the doped rare earth element, so that it can meet the needs of optoelectronic device applications with different spectral response requirements.

[0138] As shown in Table 2 and Table 3, through EDS element analysis, it can be seen that according to the preparation parameters of Example 1, three repetitive experiments were carried out, and the rare earth element doping concentration ratio of the thin film prepared each time was close, with good repeatability; but the rare earth element doping ratio of the doped thin film prepared in Comparative Example 2 and its repeated experiments showed a large deviation. This shows that the single-target RF magnetron sputtering method used in the present invention, because the doping ratio is only related to the original target material, sputtering based on the target material with the same element doping and the same doping ratio to obtain the thin film, the element doping concentration ratio is close, and it has good process robustness.

[0139] like Fig.10 As shown in Table 1, the average transmittance of the films prepared in Examples 1-10 and Comparative Example 1 at wavelengths of 350nm-800nm ​​is greater than 90%, which indicates that the films prepared by the single-target RF magnetron sputtering method of the present invention have high transmittance in the visible light and UVA bands.

[0140] In summary, the present invention uses a single-target radio frequency sputtering method to deposit a thin film on the surface of a cleaned substrate by using a rare earth oxide-doped gallium oxide target in a vacuum chamber, thereby obtaining a rare earth-doped gallium oxide thin film material, effectively adjusting the bandgap width of the gallium oxide material, and the obtained thin film material surface is uniformly formed, and the average transmittance at a wavelength of 350nm-800nm ​​is greater than 90%; and the degree of adjustment of its bandgap width can be controlled by the type and concentration of the doped rare earth element, which broadens its application in the field of photoelectric detection or semiconductor light-emitting devices. In addition, the present invention does not need to use expensive equipment by using a single-target radio frequency sputtering method, and the process is simpler and has obvious cost advantages; and the present invention uses a single-target radio frequency magnetron sputtering method, which can directly replace the target material with different doping ratios to achieve the adjustment of the rare earth element doping concentration in the gallium oxide thin film material, and because it is not affected by the DC sputtering process during the deposition process, the doping concentration of the grown film is more stable and has better process robustness.

[0141] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing a rare earth-doped gallium oxide thin film material, characterized in that: The preparation method comprises: In a vacuum chamber, a rare earth oxide-doped gallium oxide target material is used to deposit a thin film on the surface of a cleaned substrate by a single-target radio frequency sputtering method to obtain the rare earth-doped gallium oxide thin film material.

2. The method for preparing a rare earth-doped gallium oxide thin film material according to claim 1, characterized in that: The rare earth element in the rare earth oxide includes any one of Yb, Lu or Gd or a combination of at least two thereof; Preferably, in the target material, the molar ratio of the rare earth oxide to the gallium oxide is (0.5-7):(93-99.5).

3. The method for preparing the rare earth-doped gallium oxide thin film material according to claim 1 or 2, characterized in that: The substrate is placed on the surface of the substrate table; Preferably, the temperature of the substrate stage is 25°C-600°C, preferably 80°C-600°C; Preferably, the rotation speed of the substrate table is 5 rpm-20 rpm; Preferably, the vertical distance between the substrate and the target is 5 cm-12 cm.

4. The method for preparing a rare earth-doped gallium oxide thin film material according to any one of claims 1 to 3, characterized in that: Before the deposition begins, the vacuum chamber pressure is reduced to 10 -3 pa or less and pre-sputtering is performed; Preferably, the pre-sputtering method comprises: turning on the radio frequency power supply but not turning on the baffle; Preferably, the pre-sputtering time is 10 min-20 min.

5. The method for preparing a rare earth-doped gallium oxide thin film material according to any one of claims 1 to 4, characterized in that: During the deposition process, a protective gas is introduced, wherein the protective gas includes argon gas; Preferably, during the deposition process, the flow rate of the argon gas is 40 sccm-50 sccm; Preferably, the gas pressure during the deposition process is 0.5Pa-2.5Pa; Preferably, during the deposition process, the sputtering power of the single-target radio frequency sputtering is 70W-200W; Preferably, the deposition time of the deposition is 0.5h-4h.

6. The method for preparing a rare earth-doped gallium oxide thin film material according to any one of claims 1 to 5, characterized in that: performing annealing treatment on the deposited thin film; Preferably, the annealing treatment is carried out in a protective atmosphere; Preferably, the protective atmosphere comprises a nitrogen atmosphere and / or an inert gas atmosphere; Preferably, the heating rate of the annealing treatment is 5°C / min-15°C / min; Preferably, the annealing temperature is 500°C-900°C; Preferably, the annealing treatment time is 0.5h-2.5h.

7. The method for preparing a rare earth-doped gallium oxide thin film material according to claim 1, characterized in that: The preparation method comprises: Clean the substrate, select the target material according to the molar ratio of rare earth oxide to gallium oxide (0.5-7): (93-99.5); before the film deposition begins, reduce the vacuum chamber pressure to 10 -3 Pa or less, and pre-sputtering for 10min-20min; in the process of depositing the thin film, using argon atmosphere as the deposition atmosphere, and setting its flow rate to 40sccm-50sccm, the gas pressure to 0.5Pa-2.5Pa, setting the temperature of the substrate stage to between 25°C-600°C, the rotation speed to between 5rpm-20rpm, and the distance between the substrate stage and the target material to 5cm-12cm; turning on the RF power supply, setting the RF power supply power to 70W-200W, and using RF magnetron sputtering single target sputtering to perform deposition for 0.5h-4h to obtain the rare earth doped gallium oxide thin film material; The rare earth element in the rare earth oxide includes any one of Yb, Lu or Gd or a combination of at least two of them.

8. A rare earth doped gallium oxide thin film material, characterized in that: The rare earth-doped gallium oxide thin film material is prepared by the method for preparing the rare earth-doped gallium oxide thin film material according to any one of claims 1 to 7.

9. The rare earth doped gallium oxide thin film material according to claim 8, characterized in that: The average transmittance of the film material at a wavelength of 350nm-800nm ​​is greater than 90%.

10. An application of the rare earth doped gallium oxide thin film material as claimed in claim 8 or 9, characterized in that: The rare earth doped gallium oxide thin film material is applied in the field of photoelectric detection or semiconductor light emitting devices.

Images