An (Al x Ga 1-x )2O3 thin film in-situ annealing apparatus and method

Abstract

The application relates to the technical field of semiconductor thin film material manufacturing, and particularly relates to an in-situ annealing device and method for (Al x Ga 1‑x )2O3 thin film. The in-situ annealing device comprises a deposition chamber and an annealing assembly; a target table and a bottom support are arranged in the deposition chamber, and a set gap is arranged between the target table and the bottom support; the annealing assembly comprises a rotating shaft, a front heating disc and a baffle, the rotating shaft is rotatably arranged on the deposition chamber, the front heating disc and the baffle are arranged on different circumferential angles of the inner end of the rotating shaft, the front heating disc and the baffle are located between the target table and the bottom support, the rotating shaft is a hollow pipe, gas outlets are arranged on the front heating disc, and the hollow pipe is communicated with the gas outlets and used for introducing inert gas into the deposition chamber. According to the application, in-situ annealing is realized, pollution in the thin film transfer process is avoided, and the heating uniformity during annealing is improved, so that the thin film defects are reduced and the thin film quality is improved.

Description

Technical Field

[0001] This invention relates to the field of electronic special material manufacturing technology, and particularly to a (Al) x Ga 1-x Apparatus and method for in-situ annealing of 2O3 thin films. Background Technology

[0002] Currently, the preparation technology of electronic special materials is developing towards high purity and multifunctionality. For example, high-purity cobalt targets and nickel-platinum alloy targets are widely used in the manufacture of high-end electronic devices such as integrated circuits and memory due to their excellent conductivity and corrosion resistance. However, these traditional metal targets have limitations in emerging fields such as wide-bandgap semiconductors and ultraviolet optoelectronic devices; their bandgap width is difficult to control flexibly, and their stability at high temperatures is insufficient. In contrast, (Al) x Ga 1-x )2O3 thin films can achieve continuous variation of bandgap by adjusting the composition, while also possessing high breakdown field strength and thermal stability, making them an ideal candidate material for next-generation power electronics and deep ultraviolet optoelectronic devices.

[0003] (Al x Ga 1-x Gallium oxide (Al₂O₃) is a ternary alloy composed of gallium oxide and aluminum oxide. Since aluminum and gallium belong to the same group and their crystal structures are somewhat similar, they can form a solid solution in any proportion. Its band gap can be changed according to the aluminum composition value x. As x gradually increases from 0 to 1, (Al₂O₃)₂O₃… x Ga 1-x The bandgap of gallium oxide (Ga₂O₃) can be tuned from 4.8 eV to 7.2 eV. Therefore, by doping gallium oxide with aluminum oxide, the absorption edge of gallium oxide can be extended from the solar blind band to the vacuum ultraviolet band. At the same time, the breakdown field strength of gallium oxide is further improved, making this material valuable for applications in optoelectronic detection, power electronic devices and other fields.

[0004] (Al x Ga 1-x Methods for preparing gallium oxyacetylene (Ga₂O₃) thin films include pulsed laser deposition (PLD), magnetron sputtering deposition (MSD), and atomized chemical vapor deposition (CVD). PLD and MSD are physical vapor deposition methods. Their principle involves using lasers or particles to ablate or bombard a ternary alloy target of gallium oxyacetylene and aluminum oxyacetylene, generating elemental particles necessary for film growth. These particles then undergo collision, adsorption, nucleation, diffusion, and growth processes on the substrate to ultimately form a film. Atomized CVD is a chemical vapor deposition method. Specifically, gallium oxyacetylene and aluminum oxyacetylene solutions undergo a chemical reaction after atomization. Organic groups are converted into smaller molecules such as water and carbon dioxide and leave, while metal atoms remain on the substrate to form a film.

[0005] However, both physical vapor deposition and chemical vapor deposition methods inevitably have limitations in (Al) x Ga 1-x One reason for defects in gallium oxide (GaO) films is the difference in radii between aluminum and gallium ions. When aluminum partially replaces gallium in the gallium oxide lattice, lattice distortion occurs. When this lattice distortion accumulates to a certain extent, it generates stress in the film, which is one source of defects. Currently, the most common method to address defects caused by lattice distortion is to anneal the sample. High temperatures alter the atomic positions, causing the atoms to rearrange and relax within the lattice, releasing stress and thus eliminating or minimizing defects.

[0006] However, the commonly used annealing method involves removing the film from the growth chamber and transferring it to an annealing apparatus after the film has cooled to room temperature following growth. This process is cumbersome and time-consuming, and the film is easily contaminated during the transfer, affecting its quality. Furthermore, commonly used annealing equipment includes box furnaces and tube furnaces, where the heating area is relatively large compared to the sample, potentially leading to uneven heating depending on the sample's placement.

[0007] Therefore, the existing technology has the following technical problems:

[0008] ① Cumbersome process and risk of contamination: The film needs to go through multiple steps of “growth → cooling → transfer → annealing”, which is time-consuming and increases the probability of sample contamination. In particular, impurities may be adsorbed or surface oxidation may occur during the transfer process.

[0009] ② Poor heating uniformity: The heating area of ​​traditional annealing equipment is much larger than the sample size, and the sample placement affects the thermal field distribution, resulting in a significant temperature gradient, which easily generates thermal stress and exacerbates film defects.

[0010] ③ Insufficient equipment compatibility: Existing annealing equipment is separate from thin film growth equipment, making in-situ annealing impossible. Repeated vacuuming and heating operations are required, resulting in low efficiency and high energy consumption. Summary of the Invention

[0011] This invention aims to solve the existing (Al) x Ga 1-x The annealing process for O2 thin films is cumbersome, susceptible to contamination, and suffers from uneven heating. By improving the heating system of the pulsed laser deposition equipment and introducing a preheating plate, in-situ annealing is achieved, avoiding contamination during film transfer and improving heating uniformity during annealing. This reduces film defects and improves film quality.

[0012] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0013] A kind (Al)x Ga 1-x A 2O3 thin film in-situ annealing apparatus includes: a deposition chamber and an annealing assembly; the deposition chamber is provided with a target stage and a base, and a set gap exists between the target stage and the base; the annealing assembly includes a rotating shaft, a front heating plate, and a baffle; the rotating shaft is rotatably mounted on the deposition chamber; the front heating plate and the baffle are mounted at different circumferential angles at the inner end of the rotating shaft, and the front heating plate and the baffle are located between the target stage and the base; the rotating shaft is a hollow tube; the front heating plate has an outlet hole, and a gas dispersion mesh is provided in the outlet hole; the hollow tube communicates with the outlet hole for introducing inert gas into the deposition chamber.

[0014] Optionally, an electric heating wire is installed on the front heating plate, and the electric heating wire is wound around the end face of the front heating plate that is provided with an air vent.

[0015] Optionally, the annealing assembly also includes a handle, which is attached to the rotating shaft and fixed with a fixing screw, and the outer end of the rotating shaft is provided with a gas valve for switching on and off the inert gas.

[0016] Optionally, the target platform is provided with a target material on the side facing the base, and the base is provided with a substrate on the side facing the target platform.

[0017] Optionally, the front heating plate has a diameter of 75mm, and when the front heating plate is lowered, it is parallel to the base and the distance between them is 5mm.

[0018] The present invention also provides a (Al) as described above. x Ga 1-x The annealing method of the 2O3 thin film in-situ annealing apparatus includes the following steps:

[0019] After thin film deposition is completed in the pulsed laser deposition equipment, the sample is held on the bottom of the deposition chamber;

[0020] Rotating the pivot lowers the front heating plate to a position parallel to the base, and the front heating plate is connected to the inert gas supply system through a hollow tube;

[0021] The heating elements of the base and the front heating plate are activated to form a double-sided heating structure. The heating temperature range is set and the inert gas delivery is started to perform in-situ annealing of the film.

[0022] After maintaining the predetermined annealing time, turn off the heating system and gas supply, and remove the annealed film after the cavity has cooled naturally.

[0023] Optionally, the heating temperature range is 700-800℃.

[0024] Optionally, the annealing time is 30-60 minutes.

[0025] Optionally, the inert gas is nitrogen.

[0026] Optionally, thin film deposition in a pulsed laser deposition apparatus includes:

[0027] Prepare the sapphire substrate;

[0028] Place the target and substrate on the target stage and base respectively, tighten them with screws, and then place them into the deposition chamber. The distance between the target and substrate is 4.7-10cm.

[0029] The chamber was evacuated to 7×10-5 Pa using mechanical and molecular pumps, the substrate heating temperature was set to 600-680℃, and high-purity oxygen was introduced to control the oxygen pressure in the deposition chamber at 1 Pa.

[0030] After the environment inside the chamber stabilizes, pre-targeting is first performed to remove contaminants from the surface of the target material. Then, pulsed laser is used to ablate the target material for deposition. The laser wavelength is 248nm, the energy of a single pulse laser is 150-450mJ, the frequency is 3-10Hz, and the number of pulses is 10800-36000.

[0031] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0032] 1. This in-situ annealing apparatus includes a deposition chamber and an annealing assembly. The deposition chamber contains a target stage and a base, with a specific gap between them to accommodate film growth space. The annealing assembly includes a rotating shaft, a front heating plate, and a baffle. The rotating shaft rotates to switch the positions of the front heating plate and the baffle between the target stage and the base. The front heating plate and the baffle are fixed at different circumferential angles on the rotating shaft. When the shaft rotates, the front heating plate can descend to the vicinity of the base to form an annealing heating zone. The rotating shaft is designed as a hollow tube, connected to a vent on the front heating plate, through which inert gas is supplied to the chamber. This apparatus achieves double-sided heating of the film and inert gas protection during the annealing process, avoiding the contamination problems caused by sample transfer in traditional annealing processes. Simultaneously, the compact heating plate layout improves temperature uniformity.

[0033] 2. This in-situ annealing method simplifies the annealing process: By improving the heating system of the thin film growth equipment, annealing is completed directly in the deposition chamber, eliminating the sample transfer step, avoiding contamination, and improving efficiency; it enhances heating uniformity: the double-sided heating design (with the base and front heating plate working together) reduces the distance between the heating area and the sample (e.g., 5mm), achieving a uniform thermal field distribution and reducing thermal stress; it enhances film quality: by introducing an in-situ inert gas (e.g., nitrogen), film oxidation during annealing is suppressed, and the oxygen vacancy concentration is controlled, improving the film's electrical properties. Through these improvements, this invention solves the technical bottlenecks of complex processes, uneven heating, and high contamination risks in traditional annealing processes.

[0034] Advantages of additional aspects of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In addition, the spacing or dimensions between components are exaggerated to show the position of each component, and the schematic diagrams are for illustrative purposes only.

[0036] Figure 1 This is a schematic diagram of the annealing assembly provided in an embodiment of the present invention;

[0037] Figure 2 This is an enlarged schematic diagram of the front heating plate provided in an embodiment of the present invention;

[0038] Figure 3 This is a schematic diagram of the interior of the deposition chamber provided in an embodiment of the present invention;

[0039] Figure 4 This is a schematic diagram of the annealing assembly provided in an embodiment of the present invention installed on the deposition chamber;

[0040] In the diagram: 1. Heating wire; 2. Front heating plate; 3. Gas outlet; 4. Rotating shaft; 5. Baffle; 6. Handle; 7. Fixing screw; 8. Gas valve; 9. Pulsed laser; 10. Target stage; 11. Target material; 12. Plasma; 13. Substrate; 14. Base support; 15. Growth gas tube; 16. Inlet valve; 17. Gas dispersion mesh. Detailed Implementation

[0041] 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. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0042] like Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, this embodiment proposes a (Al) x Ga 1-xA 2O3 thin film in-situ annealing apparatus includes: a deposition chamber and an annealing assembly; the deposition chamber is provided with a target stage 10 and a base 14, and there is a set gap between the target stage 10 and the base 14; the annealing assembly includes a rotating shaft 4, a front heating plate 2 and a baffle 5, the rotating shaft 4 is rotatably mounted on the deposition chamber, the front heating plate 2 and the baffle 5 are mounted at different circumferential angles at the inner end of the rotating shaft 4, and the front heating plate 2 and the baffle 5 are located between the target stage 10 and the base 14, the rotating shaft 4 is a hollow tube, the front heating plate 2 is provided with a gas outlet 3, and the hollow tube is connected to the gas outlet 3 for introducing inert gas into the deposition chamber.

[0043] This in-situ annealing device eliminates the need to wait for the chamber to cool after film growth, then remove the film, transfer it to the annealing furnace, and re-evacuate, purge, and heat it. This greatly simplifies the annealing process and prevents unnecessary contamination during film transfer. Furthermore, the introduction of inert gas through the hollow tube and vent 3 further protects the film and improves annealing quality.

[0044] like Figure 2 As shown, the eight radial vents on the front heating plate ensure uniform gas distribution within the columnar heating area between the heating plate and the substrate. Additionally, a metal gas dispersion mesh 17 is added to all vents. The function of the gas dispersion mesh 17 is twofold: first, to disperse the columnar gas flow from the vents, facilitating gas diffusion within the columnar heating area and quickly forming an inert gas protection layer; second, to appropriately reduce the gas flow rate by blocking the gas flow through the gas dispersion mesh 17, preventing the gas from carrying away heat during the initial annealing heating phase, thus avoiding problems such as reduced heating rate and uneven heating.

[0045] like Figure 1 As shown, an electric heating wire 1 is installed on the front heating plate 2, and the electric heating wire 1 is coiled around the end face of the front heating plate 2 where the air outlet 3 is provided.

[0046] The heating wire 1 is made of iron-chromium-aluminum alloy and is coiled on the surface of the front heating plate 2. The coiling path unfolds around the center of the heating plate to ensure uniform heat distribution. The coiling method of the heating wire is matched with the position of the vent 3, which not only avoids blocking the gas passage, but also minimizes the temperature gradient on the heated surface of the thin film through radiative heat transfer, significantly improving the heating uniformity of the thin film during annealing and effectively reducing lattice stress caused by local overheating or temperature difference.

[0047] like Figure 4 As shown, the annealing assembly also includes a handle 6, which is sleeved on the rotating shaft 4 and fixed with a fixing screw 7. The outer end of the rotating shaft 4 is provided with a gas valve 8 for switching on and off the inert gas. The deposition chamber is also provided with a growth gas pipe 15, and an inlet valve 16 is provided at the end of the growth gas pipe 15.

[0048] A handle 6 is installed at the outer end of the rotating shaft 4, and the rotation angle of the rotating shaft 4 is locked by a fixing screw 7. The gas valve 8 at the end of the rotating shaft 4 is used to open and close the inert gas supply. The operator can adjust the position of the heating plate and control the gas flow simultaneously through the external handle 6. This design simplifies the annealing operation process, realizes integrated control of heating and gas protection, and improves process repeatability.

[0049] The target stage 10 has a target 11 facing the base 14, and the base 14 has a substrate 13 facing the target stage 10, with a distance of 4.7-10 cm between them. This distance range ensures that when the pulsed laser 9 ablates the target 11, the plasma plume 12 can be effectively transmitted to the surface of the substrate 13, while avoiding excessively high particle energy that could lead to thin film defects. The corresponding positions of the substrate 13 and the target 11 provide an optimized deposition environment for thin film growth.

[0050] The front heating plate 2 has a diameter of 75mm. When lowered, the front heating plate 2 is parallel to the base 14 with a spacing of 5mm. This size design ensures that the heating area matches the sample size, preventing excessive heat diffusion into the surrounding cavity. The narrow 5mm spacing forms a compact heating cavity, enabling the film to quickly reach the annealing temperature through double-sided radiant heating, while reducing heat loss and improving energy utilization efficiency.

[0051] The relationship between annealing temperature T and film composition x, film thickness d, and inert gas flow rate Q:

[0052] T = T0 + ax + bln d + cQ (1);

[0053] Where T0 is the reference temperature, which was determined to be 700℃ through experiments; x is between 0.1 and 0.9; the film thickness d depends on different growth rates and growth times depending on the process parameters; the flow rate Q is in sccm (standard cubic centimeters per minute); and a, b, and c are coefficients.

[0054] The relationship between annealing time t and gas flow rate Q, temperature T, and pressure P is as follows:

[0055]

[0056] Where t is the annealing time in seconds; A is the annealing factor, determined by the working density, molar mass of the gas, and the volume of the heating region, and is taken as 0.022 here; R is the gas constant, taken as 8.314 Jmol. -1 K -1 T and P are the annealing temperature and pressure, respectively, in °C and Pa, where T is determined by Formula 1; Q is the gas flow rate, in sccm.

[0057] In summary, the improvement to the pulsed laser deposition heating system of this invention is low-cost and simple. The use of double-sided in-situ annealing, with a distance of only 5mm between the front heating plate 2 and the base 14, promotes more uniform heating of the thin film and avoids thermal stress caused by temperature gradients. Inert gas is supplied through gas pipelines within the front heating plate 2 to further protect the thin film and simultaneously increase oxygen vacancies, improving conductivity.

[0058] The annealing method based on the above-mentioned annealing apparatus includes the following steps:

[0059] After thin film deposition is completed in the pulsed laser 9 deposition apparatus, the sample is held on the base 14 of the deposition chamber;

[0060] Rotate the shaft 4 to lower the front heating plate 2 to form a parallel structure with the base 14. The front heating plate 2 is connected to the inert gas supply system through a hollow tube.

[0061] The heating elements of the base tray 14 and the front heating plate 2 are activated to form a double-sided heating structure. The heating temperature range is set and the inert gas delivery is started to perform in-situ annealing of the film.

[0062] After maintaining the predetermined annealing time, turn off the heating system and gas supply, and remove the annealed film after the cavity has cooled naturally.

[0063] After thin film deposition, the front heating plate 2 is lowered to the vicinity of the base 14 by rotating the shaft 4, forming a double-sided structure. The heating elements of the base 14 and the front heating plate 2 are activated simultaneously, and an annealing temperature of 700-800℃ is set. An inert gas (such as nitrogen) is introduced through the hollow pipe of the shaft 4. Double-sided heating ensures uniform heating of the thin film in the thickness direction, eliminating the stress gradient caused by unilateral heating. Inert gas protection prevents film oxidation at high temperatures, and the annealing atmosphere is controlled by adjusting the gas flow rate, further reducing oxygen vacancy defects.

[0064] This method improves the heating system of existing pulsed laser deposition equipment by adding a preheating plate 2 with gas input function to achieve in-situ annealing of the film. This avoids the problem of possible contamination when the film is removed for annealing and also improves the uniformity of heating during film annealing. Introducing inert gas can further protect the film, reduce film defects, and improve film quality.

[0065] The heating temperature range is 700-800℃, which is selected based on the lattice relaxation characteristics of the thin film: below 700℃, atomic migration ability is insufficient, and defect repair is incomplete; above 800℃, it may lead to decomposition of the thin film composition or damage to the substrate. Within this temperature range, aluminum and gallium ions can fully rearrange, releasing lattice distortion stress while maintaining the chemical stability of the thin film.

[0066] The annealing time is 30-60 minutes, which balances annealing efficiency and energy consumption: less than 30 minutes results in insufficient defect elimination; more than 60 minutes may cause excessive grain growth, affecting the surface roughness of the film. Experiments have verified that this time window can reduce the film stress to an acceptable level and significantly improve electrical properties (such as a 20%-30% increase in carrier mobility).

[0067] The inert gas is nitrogen. Nitrogen's chemical inertness effectively isolates oxygen, preventing oxidation of the film during high-temperature annealing. Furthermore, nitrogen has a small molecular weight and diffuses rapidly within the chamber, quickly forming a uniform protective atmosphere. Compared to heavy inert gases such as argon, nitrogen is cheaper and more readily available, making it suitable for industrial applications.

[0068] Thin film deposition in a pulsed laser 9 deposition apparatus includes:

[0069] Prepare a sapphire substrate 13;

[0070] Place the target 11 and substrate 13 on the target stage 10 and the base 14 respectively, tighten them with screws, and then place them into the deposition chamber. The distance between the target 11 and substrate 13 is 4.7-10cm.

[0071] The chamber was evacuated to 7×10-5 Pa using mechanical and molecular pumps, the substrate 13 heating temperature was set to 600-680℃, and high-purity oxygen was introduced to control the oxygen pressure in the deposition chamber at 1 Pa.

[0072] After the environment inside the chamber stabilizes, pre-targeting is first performed to remove contaminants from the surface of the target material 11. Then, the target material 11 is ablated by a pulsed laser 9 for deposition. The laser wavelength is 248nm, the energy of a single pulse of the laser 9 is 150-450mJ, the frequency is 3-10Hz, and the number of pulses is 10800-36000.

[0073] Example 1

[0074] First, the target stage is removed from the deposition chamber, the target material is placed and tightened with screws, and then the target stage is put back into the chamber. The atomic ratio of aluminum to gallium in the target material is 1:2.

[0075] Then, remove the base from the deposition chamber, place the prepared sapphire substrate on the base and press it firmly with a metal sheet, then put the base back into the chamber and adjust the distance between the target and the substrate to 5 cm.

[0076] Subsequently, the chamber door was closed, and a low vacuum was first drawn using a mechanical pump, followed by a high vacuum using a molecular pump, until the background pressure of the chamber reached 7×10-5 Pa.

[0077] After reaching the predetermined vacuum level, turn on the substrate heating device, set the temperature to 600℃, and the heating rate to 20℃ / min.

[0078] After heating to the set temperature, growth gas needs to be introduced; in this embodiment, high-purity oxygen is used. The inlet valve is opened to introduce oxygen, and a molecular pump is used to control the pressure and stabilize the chamber pressure at 1 Pa.

[0079] After the pressure stabilizes, we prepare to pre-penetrate the target to remove contaminants from the surface of the target. First, we control the rotating shaft to place the metal baffle between the target and the substrate to prevent contaminants from depositing on the substrate. Then, we set the laser parameters to 300mJ per pulse, 5Hz frequency, 3000 pulses, and 10min target time to fully remove contaminants.

[0080] Then, the metal baffle was opened, and the laser parameters were set to 150mJ per pulse, 5Hz frequency, and 18000 pulses. Deposition began and lasted for 1 hour.

[0081] After deposition, the laser is turned off, and in-situ annealing begins. The control shaft is used to place the front heating plate between the substrate and the target, and the position is fixed with fixing screws. The heating power supply of the front heating plate is turned on, and the temperature of the front heating plate and the bottom heating wire is set to 800°C, the heating rate is 10°C / min, and the annealing time is 30min. The inert gas valve is opened, and inert gas is introduced. In this embodiment, nitrogen is used.

[0082] After annealing, turn off the heating power, nitrogen gas, mechanical pump and molecular pump, and wait for the sample to cool to room temperature before taking it out.

[0083] Comparative Example 1

[0084] First, the target stage is removed from the deposition chamber, the target material is placed and tightened with screws, and then the target stage is put back into the chamber. The atomic ratio of aluminum to gallium in the target material is 1:2.

[0085] Then, remove the base from the deposition chamber, place the prepared sapphire substrate on the base and press it firmly with a metal sheet, then put the base back into the chamber and adjust the distance between the target and the substrate to 5 cm.

[0086] Subsequently, the chamber door was closed, and a low vacuum was first drawn using a mechanical pump, followed by a high vacuum using a molecular pump, until the background pressure of the chamber reached 7×10-5 Pa.

[0087] After reaching the predetermined vacuum level, turn on the substrate heating device, set the temperature to 600℃, and the heating rate to 20℃ / min.

[0088] After heating to the set temperature, growth gas needs to be introduced; in this embodiment, high-purity oxygen is used. The inlet valve is opened to introduce oxygen, and a molecular pump is used to control the pressure and stabilize the chamber pressure at 1 Pa.

[0089] After the pressure stabilizes, we prepare to pre-penetrate the target to remove contaminants from the surface of the target. First, we control the rotating shaft to place the metal baffle between the target and the substrate to prevent contaminants from depositing on the substrate. Then, we set the laser parameters to 300mJ per pulse, 5Hz frequency, 3000 pulses, and 10min target time to fully remove contaminants.

[0090] Then, the metal baffle was opened, and the laser parameters were set to 150mJ per pulse, 5Hz frequency, and 18000 pulses. Deposition began and lasted for 1 hour. After deposition, the heating, oxygen, mechanical pump, and molecular pump were turned off, and the sample was removed after cooling to room temperature.

[0091] Annealing is performed using a tubular annealing furnace. First, the film is rinsed sequentially with deionized water and anhydrous ethanol to remove surface dust and other contaminants. Then, it is dried with a nitrogen gun. The sample is placed in a quartz annealing box, which is then pushed to the heating zone in the middle of the quartz tube of the annealing furnace. The furnace is then closed and the stopper is plugged. A mechanical pump is used to draw the quartz tube to a negative pressure. Then, the oxygen valve is opened to fill the quartz tube with oxygen. Once the tube is full of oxygen and the pressure is equal to atmospheric pressure, the heating power is turned on. The heating program is set as follows: from room temperature to 800℃ at a heating rate of 10℃ / min, then held at 800℃ for 30 minutes. After 30 minutes, the program is stopped and the sample is cooled to room temperature with the furnace before being removed.

[0092] As can be seen from the above Example 1 and Comparative Example 1, compared with the general annealing process of taking the film out of the cavity and then transferring it into the annealing furnace, in-situ annealing greatly simplifies the operation process and can also prevent the sample from being exposed to the air and contaminated with pollutants.

[0093] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A kind of (Al) x Ga 1-x The 2O3 thin film in-situ annealing apparatus is characterized in that, include: Deposition chamber and annealing assembly; The deposition chamber is provided with a target platform and a base, and there is a set gap between the target platform and the base; The base is equipped with a heating element; The annealing assembly includes a rotating shaft, a front heating plate, and a baffle. The rotating shaft is rotatably mounted on the deposition chamber. The front heating plate and the baffle are mounted at different circumferential angles at the inner end of the rotating shaft, and the front heating plate and the baffle are located between the target stage and the base. The rotating shaft is a hollow tube. The front heating plate has an air outlet, and a gas dispersion mesh is provided in the air outlet. The hollow tube is connected to the air outlet for introducing inert gas into the deposition chamber. The deposition chamber is also equipped with a growth gas pipe; An electric heating wire is installed on the front heating plate, and the electric heating wire is wound around the end face of the front heating plate that is provided with an air vent. The front heating plate has a diameter of 75 mm, and when it is lowered, it is parallel to the base and the distance between them is 5 mm.

2. As described in claim 1 (Al) x Ga 1-x The 2O3 thin film in-situ annealing apparatus is characterized in that, The annealing assembly also includes a handle, which is attached to the rotating shaft and fixed with a fixing screw. The outer end of the rotating shaft is provided with a gas valve for switching on and off inert gas.

3. As described in claim 1 (Al) x Ga 1-x The 2O3 thin film in-situ annealing apparatus is characterized in that, The target platform is provided with a target material on the side facing the base, and the base is provided with a substrate on the side facing the target platform.

4. A method as described in any one of claims 1-3 (A1) x Ga 1-x The annealing method of the 2O3 thin film in-situ annealing apparatus is characterized by, Includes the following steps: After thin film deposition is completed in the pulsed laser deposition equipment, the sample is held on the bottom of the deposition chamber; Rotating the pivot lowers the front heating plate to a position parallel to the base, and the front heating plate is connected to the inert gas supply system through a hollow tube; The heating elements of the base and the front heating plate are activated to form a double-sided heating structure. The heating temperature range is set and the inert gas delivery is started to perform in-situ annealing of the film. After maintaining the predetermined annealing time, turn off the heating system and gas supply, and remove the annealed film after the cavity has cooled naturally.

5. The annealing method as described in claim 4, characterized in that, The heating temperature range is 700-800℃.

6. The annealing method as described in claim 4, characterized in that, The annealing time is 30-60 minutes.

7. The annealing method as described in claim 4, characterized in that, The inert gas is nitrogen.

8. The annealing method as described in claim 4, characterized in that, Thin film deposition in a pulsed laser deposition apparatus includes: Prepare the sapphire substrate; Place the target and substrate on the target stage and base respectively, tighten them with screws, and then place them into the deposition chamber. The distance between the target and substrate is 4.7-10 cm. The chamber was evacuated to 7 × 10⁻⁶ using a mechanical pump and a molecular pump. -5 Pa, set the substrate heating temperature to 600-680 ℃, introduce high-purity oxygen, and control the oxygen pressure in the deposition chamber at 1 Pa; After the environment inside the chamber stabilizes, pre-targeting is performed to remove contaminants from the target surface. Then, pulsed laser is used to ablate the target for deposition. The laser wavelength is 248 nm, the energy of a single pulse is 150-450 mJ, the frequency is 3-10 Hz, and the number of pulses is 10800-36000.

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