Epsilon-Ga2O3 thin film, metastable-phase gallium oxide ultraviolet detector and preparation method of epsilon-Ga2O3 thin film

Abstract

The invention belongs to the technical field of wide bandgap semiconductor technology preparation, and discloses an epsilon-Ga2O3 film, a metastable-phase gallium oxide ultraviolet detector and a preparation method thereof, and the preparation method comprises the following steps: heating a clean and pretreated substrate to 550-610 DEG C, introducing a mixed gas of a carrier gas and a diluent gas into the substrate, setting time, and carrying out the epitaxy of a low-doped epsilon-Ga2O3 film; after growth is finished, the temperature in the reaction cavity is increased to 620-700 DEG C, and an epsilon-Ga2O3 highly-doped film is formed in an epitaxial mode. The double-layer structure is combined with doping, so that lattice mismatch is relieved, and formation of epsilon-Ga2O3 is promoted. In the Ge doping process, Ga < 3 + > is successfully replaced by Ge < 4 + >, so that the lattice constant is reduced, the pressure stress of the film is relieved, and the crystal quality of the epsilon-Ga2O3 epitaxial film is improved.

Description

Technical Field

[0001] This invention relates to the field of wide bandgap semiconductor fabrication technology, specifically to a... e -Ga2O3 thin film, metastable gallium oxide ultraviolet detector and its preparation method. Background Technology

[0002] The statements herein provide only background information in relation to this invention and do not necessarily constitute prior art.

[0003] Deep ultraviolet (DUV) detectors operate in the 200-280 nm wavelength range and possess advantages such as resistance to environmental interference, high signal-to-noise ratio, and high precision. They are widely used in fields such as flame detection, missile tracking, solar blind imaging, and ultraviolet communication. Ga2O3, a semiconductor material, is an ideal material for DUV detectors due to its ultra-wide bandgap, high breakdown electric field strength, and high Barley figure of merit. e Ga2O3, with its higher symmetry, strong polarization effect, and deeper intrinsic ultraviolet response, offers more possibilities for novel detector structures.

[0004] However, currently due to e -Ga₂O₃ heteroepitaxial growth exhibits significant lattice mismatch, leading to a rotating domain structure in the film and significantly reducing its crystallinity. Furthermore, traditional UIDs... e Ga2O3-based photodetectors exhibit low photocurrent and slow response speed, which severely limits their application. e The ability of Ga2O3-based photodetectors to monitor weak signals hinders the realization of multifunctional applications and makes it difficult to meet the stringent performance requirements of high-performance electronic devices.

[0005] Although there are methods for preparing n-type doped materials... e While there has been research on Ga2O3 thin films, the doping technology is not mature, and the performance of the prepared semiconductor devices is difficult to meet the requirements. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide a... e -Ga2O3 thin film, metastable gallium oxide ultraviolet detector and its preparation method.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solution: In a first aspect, the present invention provides e The method for preparing Ga2O3 thin films includes the following steps: heating a cleaned and pretreated substrate to 550-610℃, introducing a mixture of carrier gas and dilution gas into the substrate for a set time, then atomizing and adding a low-doped gallium oxide precursor solution with a Ge doping concentration of 1-5%, and epitaxially... e-Ga2O3 thin film; After growth, the temperature inside the reaction chamber is heated to 620-700℃, and the atmosphere is kept constant. A highly doped gallium oxide precursor solution with a Ge doping concentration of 5-8% is then atomized and added. The highly doped epitaxial growth is then carried out. e -Ga2O3 thin film.

[0008] Secondly, the present invention provides e -Ga2O3 thin film, prepared by the preparation method described above.

[0009] Thirdly, the present invention provides a metastable gallium oxide ultraviolet detector, comprising a C-plane sapphire substrate and a low-doped substrate attached to the surface of the C-plane sapphire substrate. e -Ga2O3 thin film and attached to low-doped e High doping on the surface of Ga2O3 thin film e -Ga2O3 thin film, highly doped e - An electrode is attached to the surface of the Ga2O3 thin film.

[0010] The beneficial effects achieved by one or more embodiments of the present invention described above are as follows: e Ga2O3 is a semiconductor wafer, currently e The presence of rotating domains in Ga2O3 heteroepitaxial layer results in poor film quality and immature epitaxial doping, leading to poor performance, long response time, and low photo-dark current ratio in the fabricated solar-blind detector. This severely limits the possibility of detecting weak signals and realizing multifunctional applications.

[0011] This invention is the first to propose a method combining bilayer structures with doping engineering to alleviate lattice mismatch and promote... e - The formation of Ga2O3. During the Ge doping process, Ge... 4+ Successfully replaced Ga 3+ This leads to a decrease in the lattice constant, thereby relieving the compressive stress on the thin film, making... e The crystal quality of Ga2O3 epitaxial films has been improved, and the reduction of film defects is conducive to the improvement of device performance.

[0012] Furthermore, by alternating low-temperature, low-doping and high-temperature, high-doping epitaxy, efficient Ge doping was achieved, increasing the carrier concentration in the thin film and improving the photocurrent of the device. This resulted in the fabrication of a solar-blind photodetector with low dark current and high detectivity.

[0013] The preparation method of the present invention has the advantages of simple preparation process, flexible operation and low cost, and has great application prospects. Attached Figure Description

[0014] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0015] Figure 1 The double-layer Ge-doped material prepared in Example 3 of this invention e - XRD rocking curve of Ga2O3 thin film (002) surface; Figure 2 The double-layer Ge-doped material prepared in Example 3 of this invention e SEM image of a Ga2O3 thin film; Figure 3 The double-layer Ge-doped material prepared in Example 3 of this invention e XPS Ge3d image of Ga2O3 thin film; Figure 4 This is a schematic diagram of the structure of an ultraviolet detector provided in an embodiment of the present invention; Figure 5 This is an IV test pattern of the device prepared in Example 1 of the present invention; Figure 6 The image shows the IV test pattern of the device prepared in Example 2 of this invention; Figure 7 This is an IV test pattern of the device prepared in Example 3 of the present invention; Figure 8 This is an IV test pattern of the device prepared in Comparative Example 1 of the present invention; Figure 9 This is an IV test pattern of the device prepared in Comparative Example 2 of the present invention; Figure 10 This is an IV test pattern of the device prepared in Comparative Example 3 of the present invention. Detailed Implementation

[0016] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0017] In a first aspect, the present invention provides e The method for preparing Ga2O3 thin films includes the following steps: The cleaned and pretreated substrate is heated to 550-610℃, and a mixture of carrier gas and dilution gas is introduced into it for a set time. Then, a lightly doped gallium oxide precursor solution with a Ge doping concentration of 1-5% is atomized and added, and the low-doped precursor is epitaxially grown. e -Ga2O3 thin film; After growth, the temperature inside the reaction chamber is heated to 620-700℃, and the atmosphere is kept constant. A highly doped gallium oxide precursor solution with a Ge doping concentration of 5-8% is then atomized and added. The highly doped epitaxial growth is then carried out. e -Ga2O3 thin film.

[0018] The doping concentration of Ge is the ratio of germanium to gallium.

[0019] The substrate can be a C-plane sapphire substrate, an aluminum nitride substrate, or a gallium nitride substrate, etc.

[0020] Gallium oxide n-type doping often uses elements such as Si and Sn, but the doping effect is not good. By comparing the densities of the two donor levels Nd1 and Nd2 for each dopant, it was found that Ge doping resulted in a higher donor level density, further indicating that for similar doping concentrations of Ge and Si, Ge doping is more effective.

[0021] Ge-doped solutions with low and high doping concentrations were prepared, and Ge-doped sapphires were epitaxially grown on C-plane sapphire using the Mist-CVD method. e -Ga2O3 thin films. Compared with traditional doping, this method not only significantly reduces the preparation cost, but also utilizes suitable dopants to prepare highly efficient n-type doped thin films, providing a solution for fabricating high-performance solar-blind detectors.

[0022] Under normal pressure, using argon as the carrier gas and oxygen as the diluent gas, the solution is ultrasonically atomized and then transported to the surface of a pretreated substrate. First, a low-temperature, low-doped layer is formed by holding the solution at 550-610℃, then the temperature is raised to 620-700℃ to epitaxially form a high-temperature, high-doped layer, resulting in a bilayer Ge. e - Doping with Ga2O3 thin films not only alleviates lattice stress and improves film quality, but also enhances device performance through effective doping.

[0023] In some embodiments, the cleaning pretreatment method is as follows: the substrate is ultrasonically cleaned sequentially with isopropanol, ethanol and deionized water, and then dried with nitrogen.

[0024] In some embodiments, the concentration of gallium acetylacetonate in the low-doped gallium oxide precursor solution and / or the high-doped gallium oxide precursor solution is 0.01-0.1 mol / L.

[0025] Preferably, the concentration of gallium acetylacetonate is 0.03-0.07 mol / L, and more preferably 0.05 mol / L.

[0026] In some embodiments, the Ge dopant is germanium iodide.

[0027] In some embodiments, epitaxial low-doping e The curing time for Ga2O3 thin films is 1.5-2.5 h; epitaxial high-doping e The curing time for the Ga2O3 thin film is 1.5-2.5 h.

[0028] Preferred, low-doped epitaxial layer e The temperature for Ga2O3 thin films is 580-610℃; epitaxial high-doping e - The temperature range for Ga2O3 thin films is 630-660℃.

[0029] In some embodiments, the carrier gas is argon and the diluent gas is oxygen.

[0030] Secondly, the present invention provides e -Ga2O3 thin film, prepared by the preparation method described above.

[0031] In some embodiments, the e The thickness of the Ga2O3 film is 3-7 μm, and the half-width at half-maximum of the rocking curve is 0.53°.

[0032] Thirdly, the present invention provides a metastable gallium oxide ultraviolet detector, comprising a substrate and a low-doped [material] attached to the surface of the substrate. e -Ga2O3 thin film and attached to low-doped e High doping on the surface of Ga2O3 thin film e -Ga2O3 thin film, highly doped e - An electrode is attached to the surface of the Ga2O3 thin film.

[0033] The substrate can be a C-plane sapphire substrate, an aluminum nitride substrate, or a gallium nitride substrate, etc.

[0034] In some embodiments, the electrode is a titanium-gold electrode, with a titanium layer thickness of 15-25 nm and a gold layer thickness of 20-40 nm.

[0035] Preferably, the titanium electrode is an interdigitated electrode.

[0036] The interdigital electrode device has 13 pairs of interdigital electrodes, each 500 μm in length, with a finger spacing of 10 μm, and an effective irradiation area of ​​1.25 × 10⁻⁶. -3 cm 2 .

[0037] The method achieves 60%-80% high-efficiency Ge doping. e -Ga2O3 thin film, and the film quality is high, with a rocking curve as low as 0.35°.

[0038] The present invention will be further described below with reference to the embodiments.

[0039] Example 1 s1: Substrate pretreatment The C-side sapphire substrate was ultrasonically cleaned sequentially with isopropanol, ethanol, and deionized water for 2 minutes each time to remove any impurities. After each chemical cleaning, the substrate was dried using high-purity nitrogen gas (purity ≥ 99.999%) to ensure the substrate surface was dry and free of watermarks.

[0040] s2: Precursor solution preparation First, prepare a 1% Ge-doped precursor solution. This requires accurately weighing 1.85 g of 99.99% pure gallium acetylacetonate and 0.029 g of 99.99% pure germanium iodide (the doping concentration refers to the ratio of germanium to gallium; the gallium solution ratio is 0.05 mol / L, so to prepare 1% germanium iodide relative to gallium acetylacetonate, the molar concentration of germanium iodide is 0.0005 mol / L, and its molecular weight is 580.26. To prepare 100 mL of solution, the calculated value is m = 0.0005 × 0.1 × 580.26, which is 0.029 g; the same applies below). Dissolve these powders in 100 mL of deionized water and add 1.52 mL of 36% concentrated hydrochloric acid to promote the dissolution of gallium acetylacetonate. Next, prepare a 5% Ge-doped precursor solution. Accurately weigh 1.85 g of 99.99% pure gallium acetylacetonate and 0.145 g of 99.99% pure germanium iodide, respectively. Dissolve these powders in 100 mL of deionized water, and add 1.52 mL of 36 wt% concentrated hydrochloric acid to promote the dissolution of gallium acetylacetonate. Stir the beaker with a magnetic stirrer at room temperature for 6 hours to ensure all powders are completely dissolved. After stirring, allow the solution to stand for at least 2 hours to allow insoluble impurities to settle for later use.

[0041] s3: CVD epitaxial growth Secure the sapphire crystal in the upper connecting rod and adjust its height to ensure the distance between the substrate and the reaction source is precisely controlled at 15mm. Set the reaction chamber heating temperature to 600℃. Once the target temperature is reached, set the argon flow rate to 2L / min and the oxygen flow rate to 0.3L / min, precisely controlled by a mass flow controller. Before starting atomization, maintain the carrier gas path for at least 1 hour to ensure the gas fills the entire reaction chamber.

[0042] Subsequently, a precursor solution with a 1% Ge doping concentration was added to an ultrasonic atomizing vessel and atomization was started. The gas transported the atomized liquid to the reaction chamber for deposition and growth for 2 hours.

[0043] Next, the temperature was raised to 640℃ and held for 1 hour to ensure stability within the reaction chamber. Then, a precursor solution with a 5% Ge doping concentration was introduced, and atomization was initiated for 2 hours to obtain a bilayer Ge-doped product. e -Ga2O3 thin film.

[0044] s4: Device fabrication process After spin-coating photoresist onto the epitaxial wafer, a mask with a specific pattern was placed on it for photolithography of the MSM structure electrode pattern, with an exposure time set to 7 s. After exposure, the wafer was placed in a developer solution and shaken for 30 s for development. The sample was then rinsed and dried with a nitrogen gun. Subsequently, titanium / gold electrodes were once evaporated onto the thin film with the photolithographic pattern using electron beam evaporation technology. The titanium layer thickness was 20 nm, and the gold layer thickness was 30 nm, with a deposition rate of 2 Å / s. Finally, the colloidal mask was removed by ultrasonication. The fabricated device was annealed at 500 °C in a nitrogen atmosphere for 3 min to promote ohmic contact between the thin film and the electrodes. IV testing was performed using a DC probe station.

[0045] Example 2 The difference from Example 1 is in steps s2 and s3, while the rest are the same as in Example 1.

[0046] s2: Precursor solution preparation First, prepare a 2% Ge-doped precursor solution by accurately weighing 1.85 g of 99.99% pure gallium acetylacetonate and 0.058 g of 99.99% pure germanium iodide. Dissolve these powders in 100 mL of deionized water, and add 1.52 mL of 36 wt% concentrated hydrochloric acid to promote the dissolution of gallium acetylacetonate. Next, prepare a 5% Ge-doped precursor solution by accurately weighing 1.85 g of 99.99% pure gallium acetylacetonate and 0.145 g of 99.99% pure germanium iodide. Dissolve these powders in 100 mL of deionized water, and add 1.52 mL of 36% concentrated hydrochloric acid to promote the dissolution of gallium acetylacetonate. Stir both beakers with a magnetic stirrer at room temperature for 6 hours to ensure complete dissolution of all powders. After stirring, allow the solution to stand for at least 2 hours to allow insoluble impurities to settle for later use.

[0047] s3: CVD epitaxial growth Secure the sapphire crystal in the upper connecting rod and adjust its height to ensure the distance between the substrate and the reaction source is precisely controlled at 15mm. Set the reaction chamber heating temperature to 600℃. Once the target temperature is reached, set the argon flow rate to 2L / min and the oxygen flow rate to 0.3L / min, precisely controlled by a mass flow controller. Before starting atomization, maintain the carrier gas path for at least 1 hour to ensure the gas fills the entire reaction chamber.

[0048] Subsequently, the prepared precursor solution with a 2% Ge doping concentration was added to the ultrasonic atomizing tank and atomization was started. The gas transported the atomized liquid to the reaction chamber for deposition and growth for 2 hours.

[0049] Next, the temperature was raised to 640℃ and held for 1 hour to ensure stability within the reaction chamber. Then, a precursor solution with a 5% Ge doping concentration was introduced, and atomization was initiated for 2 hours to obtain a bilayer Ge-doped product. e -Ga2O3 thin film.

[0050] Example 3 The difference from Example 1 is in steps s2 and s3, while the rest are the same as in Example 1.

[0051] s2: Precursor solution preparation First, prepare a 5% Ge-doped precursor solution by accurately weighing 1.85 g of 99.99% pure gallium acetylacetonate and 0.145 g of 99.99% pure germanium iodide. Dissolve these powders in 100 mL of deionized water, and add 1.52 mL of 36 wt% concentrated hydrochloric acid to promote the dissolution of gallium acetylacetonate. Then, prepare another 5% Ge-doped precursor solution by accurately weighing 1.85 g of 99.99% pure gallium acetylacetonate and 0.145 g of 99.99% pure germanium iodide. Dissolve these powders in 100 mL of deionized water, and add 1.52 mL of 36% concentrated hydrochloric acid to promote the dissolution of gallium acetylacetonate. Stir both beakers at room temperature using a magnetic stirrer for 6 hours to ensure complete dissolution of all powders. After stirring, allow the solution to stand for at least 2 hours to allow insoluble impurities to settle for later use.

[0052] s3: CVD epitaxial growth Secure the sapphire crystal in the upper connecting rod and adjust its height to ensure the distance between the substrate and the reaction source is precisely controlled at 15mm. Set the reaction chamber heating temperature to 600℃. Once the target temperature is reached, set the argon flow rate to 2L / min and the oxygen flow rate to 0.3L / min, precisely controlled by a mass flow controller. Before starting atomization, maintain the carrier gas path for at least 1 hour to ensure the gas fills the entire reaction chamber.

[0053] Subsequently, the prepared precursor solution with a 5% Ge doping concentration was added to the ultrasonic atomizing tank and atomization was started. The gas transported the atomized liquid to the reaction chamber for deposition and growth for 2 hours.

[0054] Next, the temperature was raised to 640℃ and held for 1 hour to ensure stability within the reaction chamber. Then, a precursor solution with a 5% Ge doping concentration was introduced, and atomization was initiated for 2 hours to obtain a bilayer Ge-doped product. e -Ga2O3 thin film.

[0055] Comparative Example 1 s1: Substrate pretreatment The C-side sapphire substrate was ultrasonically cleaned sequentially with isopropanol, ethanol, and deionized water for 2 minutes each time to remove any impurities. After each chemical cleaning, the substrate was dried using high-purity nitrogen gas (purity ≥ 99.999%) to ensure the substrate surface was dry and free of watermarks.

[0056] s2: Precursor solution preparation First, prepare the precursor solution by accurately weighing 1.85 g of 99.99% pure gallium acetylacetonate and dissolving it in 100 mL of deionized water. Add 1.52 mL of 36 wt% concentrated hydrochloric acid to promote the dissolution of gallium acetylacetonate. Stir the mixture in each beaker at room temperature for 6 hours using a magnetic stirrer to ensure complete dissolution of all powder. After stirring, allow the solution to stand for at least 2 hours to allow insoluble impurities to settle for later use.

[0057] s3: CVD epitaxial growth Secure the sapphire crystal in the upper connecting rod and adjust its height to ensure the distance between the substrate and the reaction source is precisely controlled at 15mm. Set the reaction chamber heating temperature to 600℃. Once the target temperature is reached, set the argon flow rate to 2L / min and the oxygen flow rate to 0.2L / min, precisely controlled by a mass flow controller. Before starting atomization, maintain the carrier gas path for at least 1 hour to ensure the gas fills the entire reaction chamber.

[0058] Subsequently, the prepared precursor solution was added to the ultrasonic atomizing chamber and atomization was started. The gas transported the atomized liquid to the reaction chamber for deposition and growth for 2 hours, resulting in unintentionally doped material. e -Ga2O3 thin film.

[0059] s4: Device fabrication process After spin-coating the epitaxial wafer with photoresist, a mask with a specific pattern is placed on it to perform photolithography of the MSM structure electrode pattern, with an exposure time of 7 seconds. After the exposure time, the wafer is placed in the developer and shaken for 30 seconds for development. The sample is then rinsed and dried with a nitrogen gun. Next, titanium / gold electrodes are evaporated once on the thin film with the photolithographic pattern using electron beam evaporation technology, with a deposition rate of 2 Å / s. Finally, the colloidal mask is removed by ultrasonication.

[0060] The prepared device was annealed at 500°C in a nitrogen atmosphere for 3 min to promote ohmic contact between the thin film and the electrode; IV testing was performed using a DC probe station.

[0061] Comparative Example 2 s1: Substrate pretreatment The C-side sapphire substrate was ultrasonically cleaned sequentially with isopropanol, ethanol, and deionized water for 2 minutes each time to remove any impurities. After each chemical cleaning, the substrate was dried using high-purity nitrogen gas (purity ≥ 99.999%) to ensure the substrate surface was dry and free of watermarks.

[0062] s2: Precursor solution preparation First, prepare a 5% Ge-doped precursor solution. Accurately weigh 3.7 g of 99.99% pure gallium acetylacetonate and 0.29 g of 99.99% pure germanium iodide, and dissolve these powders in 200 mL of deionized water. Add 3.04 mL of 36 wt% concentrated hydrochloric acid to promote the dissolution of gallium acetylacetonate. Stir the solution in each beaker using a magnetic stirrer at room temperature for 6 hours to ensure complete dissolution of all powders. After stirring, allow the solution to stand for at least 2 hours to allow insoluble impurities to settle for later use.

[0063] s3: CVD epitaxial growth The sapphire crystal was fixed in the upper connecting rod, and the height of the upper connecting rod was adjusted to ensure that the distance between the substrate and the reaction source was precisely controlled at 15 mm. The heating temperature of the reaction chamber was set to 640℃. After reaching the target temperature, the argon flow rate was set to 2 L / min and the oxygen flow rate to 0.3 L / min, precisely controlled by a mass flow controller. Before starting atomization, the carrier gas path was kept ventilated for at least 1 hour to ensure that the gas filled the entire reaction chamber.

[0064] Subsequently, a precursor solution with a 5% Ge doping concentration was added to an ultrasonic atomizing vessel and atomization was initiated. Gas transported the atomized liquid to the reaction chamber for deposition and growth for 4 hours, resulting in a monolayer of Ge-doped material. e -Ga2O3 thin film.

[0065] s4: Device fabrication process After spin-coating photoresist onto the epitaxial wafer, a mask with a specific pattern was placed on it for photolithography of the MSM structure electrode pattern, with an exposure time set to 7 s. After exposure, the sample was placed in a developer solution and shaken for 30 s for development. The sample was then rinsed and dried with a nitrogen gun. Subsequently, titanium / gold electrodes were evaporated onto the thin film with the photolithographic pattern using electron beam evaporation at a deposition rate of 2 Å / s. Finally, the colloidal mask was removed by ultrasonication. The fabricated device was annealed at 500 °C in a nitrogen atmosphere for 3 min to promote ohmic contact between the thin film and the electrodes. IV testing was performed using a DC probe station.

[0066] Comparative Example 3 The difference from Example 1 is in steps s2 and s3, while the rest are the same as in Example 1.

[0067] s2: Precursor solution preparation First, prepare a 1% Ge-doped precursor solution by accurately weighing 3.7 g of 99.99% pure gallium acetylacetonate and 0.058 g of 99.99% pure germanium iodide. Dissolve these powders in 200 mL of deionized water and add 3.04 mL of 36 wt% concentrated hydrochloric acid to promote the dissolution of gallium acetylacetonate.

[0068] Stir each beaker with a magnetic stirrer at room temperature for 6 hours to ensure all powders are completely dissolved. After stirring, allow the solution to stand for at least 2 hours to allow insoluble impurities to settle for later use.

[0069] s3: CVD epitaxial growth The sapphire crystal was fixed in the upper connecting rod, and the height of the upper connecting rod was adjusted to ensure that the distance between the substrate and the reaction source was precisely controlled at 15 mm. The heating temperature of the reaction chamber was set to 600℃. After reaching the target temperature, the argon flow rate was set to 2 L / min and the oxygen flow rate to 0.3 L / min, which were precisely controlled by a mass flow controller.

[0070] Before starting atomization, the carrier gas path was kept ventilated for at least 1 hour to ensure that the gas filled the entire reaction chamber. Subsequently, a precursor solution with a 1% Ge doping concentration was added to the ultrasonic atomization vessel and atomization was started. The gas transported the atomized liquid into the reaction chamber for deposition and growth for 4 hours.

[0071] Figure 1 The double-layer Ge-doped material prepared in Example 3 e The XRD rocking curve of the (002) plane of the Ga2O3 thin film shows a film quality of 0.35°, which is at a relatively low level, confirming the acquisition of high-quality film. e -Ga2O3 thin film.

[0072] Figure 2 The double-layer Ge-doped material prepared in Example 3 e SEM image of the Ga2O3 thin film. The image shows a clear boundary between the substrate and the film, and the film is uniform with a thickness of 5 μm, indicating a relatively fast growth rate of 1.25 μm / h.

[0073] Figure 3 This is for the preparation of bilayer Ge doped material in Example 3. e XPS Ge3d images of Ga2O3 thin films, from Figure 3 The presence of Ge elements is clearly visible, and analysis reveals double-layered Ge doping. e The Ge content on the surface of the Ga2O3 thin film is 4%, which proves that 80% efficient doping has been achieved.

[0074] Figure 4 The diagram below shows the structure of the ultraviolet detector provided in Embodiment 1 of the present invention. The device has 13 pairs of interdigitated electrodes, each 500 μm in length, with a spacing of 10 μm between the electrodes, and an effective irradiation area of ​​1.25 × 10⁻⁶. -3 cm 2 .

[0075] Figure 5 , Figure 6 , Figure 7 , Figure 8, Figure 9 , Figure 10 The images show the IV test patterns of the devices prepared in Examples 1-3 and Comparative Examples 1-3, respectively. It can be seen that the bilayer Ge-doped devices prepared in Examples 1-3... e Ga2O3 thin films exhibit higher photocurrent, with a photo-dark current ratio reaching 10. 7 Meanwhile, Examples 1, 2, and 3 exhibit responsivity as high as 132.4, 407.2, and 508 A / W, respectively, and a response time of 2.62 × 10⁻⁶. 16 9.59×10 16 1.77×10 16 Jones's detectivity. In comparison, the detectivity of Comparative Examples 1-3 were 4.53, 38.68, and 0.59 A / W, respectively, and the responsivity was 8.73 × 10⁻⁶. 13 4.89×10 12 7.26×10 12 Jones.

[0076] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A kind ε The method for preparing Ga2O3 thin films is characterized by: Includes the following steps: The cleaned and pretreated substrate is heated to 550-610℃, and a mixture of carrier gas and dilution gas is introduced into it for a set time. Then, a lightly doped gallium oxide precursor solution with a Ge doping concentration of 1-5% is atomized and added, and the low-doped precursor is epitaxially grown. ε -Ga2O3 thin film; After growth, the temperature inside the reaction chamber is heated to 620-700℃, and the atmosphere is kept constant. A highly doped gallium oxide precursor solution with a Ge doping concentration of 5-8% is then atomized and added. The highly doped precursor is then epitaxially grown. ε -Ga2O3 thin film.

2. As described in claim 1 ε The method for preparing Ga2O3 thin films is characterized by: The cleaning pretreatment method is as follows: the substrate is ultrasonically cleaned sequentially with isopropanol, ethanol and deionized water, and then dried with nitrogen.

3. As described in claim 1 ε The method for preparing Ga2O3 thin films is characterized by: In the low-doped gallium oxide precursor solution and / or the high-doped gallium oxide precursor solution, the concentration of gallium acetylacetonate is 0.01-0.1 mol / L.

4. As described in claim 1 ε The method for preparing Ga2O3 thin films is characterized by: The Ge dopant is germanium iodide.

5. The method according to claim 1 ε The method for preparing Ga2O3 thin films is characterized by: Epitaxial low doping ε The curing time for Ga2O3 thin films is 1.5-2.5 h; epitaxial high-doping ε The curing time for the Ga2O3 thin film is 1.5-2.5 h; Epitaxial low doping ε The temperature for Ga2O3 thin films is 580-610℃; epitaxial high-doping ε - The temperature range for Ga2O3 thin films is 630-660℃.

6. The method according to claim 1 ε The method for preparing Ga2O3 thin films is characterized by: The carrier gas is argon, and the diluent gas is oxygen.

7. A kind ε -Ga2O3 thin film, characterized in that: It is prepared by any one of the preparation methods described in claims 1-6.

8. The method according to claim 7 ε -Ga2O3 thin film, characterized in that: ε The thickness of the Ga2O3 film is 3-7 μm, and the half-width at half-maximum of the rocking curve is 0.53°.

9. A metastable gallium oxide ultraviolet detector, characterized in that: Including the substrate and the low-doped material of claim 1 attached to the surface of the substrate. ε -Ga2O3 thin film and attached to low-doped ε -The highly doped Ga2O3 thin film surface as described in claim 1 ε -Ga2O3 thin film, highly doped ε - An electrode is attached to the surface of the Ga2O3 thin film.

10. The metastable gallium oxide ultraviolet detector according to claim 9, characterized in that: The electrode is a titanium-gold electrode, with a titanium layer thickness of 15-25nm and a gold layer thickness of 20-40nm.

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