Preparation method of gallium oxide arc light monitor

Abstract

The invention provides a preparation method of a gallium oxide arc light monitor, which belongs to the technical field of photoelectric detection and comprises the following steps: sequentially depositing a gallium oxide low-oxygen layer and a gallium oxide thin film on the surface of a cleaned silicon substrate by adopting a magnetron sputtering method; sequentially carrying out cleaning, photoresist spin-coating and drying on the gallium oxide thin film, then pasting a mask plate of the interdigital electrode on the surface of the thin film, and exposing and developing by using a photoetching machine; removing redundant photoresist on the surface of the film by using an etching machine to expose the gallium oxide surface; and sequentially depositing Ti and Au electrodes in the mask region on the surface of the gallium oxide thin film by using the magnetron sputtering instrument again. As the arc light signal has the characteristic wavelength in the solar-blind ultraviolet band, the gallium oxide material is selected, the wide band gap characteristic (about 4.9 eV) of the gallium oxide material is utilized to efficiently detect the signal in the band, and the interference of clutters such as visible light is effectively avoided, so that the monitoring accuracy and sensitivity are remarkably improved, and the false alarm rate is reduced.

Description

A method for fabricating a gallium oxide arc light monitor Technical Field

[0001] This invention belongs to the field of photoelectric detection technology, specifically relating to a method for preparing a gallium oxide arc light monitor, which is suitable for the safety monitoring and protection of electrical equipment. Background Technology

[0002] Arc flash monitoring is an important means of monitoring and early warning of electrical equipment faults. In high-voltage and complex environments, arc flash phenomena can cause equipment damage or even safety hazards. Therefore, a technical means to quickly and accurately monitor arc flash is needed.

[0003] Currently, most arc flash monitoring devices on the market rely on optical or electronic sensors. However, optical sensors are easily interfered with in strong background light environments (such as sunlight), especially in the ultraviolet band; while electronic sensors are difficult to detect effectively in the early stages of arc flash generation and have a slow response speed. The solar-blind ultraviolet band (200-280 nm) is unaffected by sunlight and is an ideal band for arc flash monitoring, but traditional ultraviolet detectors, such as silicon-based optoelectronic devices, have weak or no response in this band.

[0004] Gallium oxide (Ga2O3) exhibits excellent wide bandgap characteristics (approximately 4.9 eV), demonstrating remarkable detection performance in the solar-blind ultraviolet band, and possesses good high-temperature and strong radiation stability, making it an ideal material for next-generation solar-blind ultraviolet detectors. However, effective solutions for applying gallium oxide detectors to the field of arc light monitoring are currently lacking. Summary of the Invention

[0005] This invention aims to provide a method for fabricating a gallium oxide arc flash monitor, solving the problems of existing detectors being susceptible to background light interference, having slow response speeds, and being insensitive to weak light. The arc flash monitor fabricated using this method can achieve highly sensitive monitoring of arc flash phenomena in electrical equipment, significantly reducing false alarm rates and providing reliable protection for the safe operation of power systems.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A method for fabricating a gallium oxide arc detector includes the following steps:

[0008] S1. Clean the silicon substrate to remove surface oxides;

[0009] S2. A gallium oxide low-oxygen layer and a gallium oxide thin film are sequentially deposited on the cleaned silicon substrate using magnetron sputtering.

[0010] S3. The gallium oxide thin film obtained in S2 is cleaned, spin-coated with photoresist and dried in sequence. Then, the mask of the interdigitated electrode is attached to the surface of the thin film and exposed by a photolithography machine. It is placed in the developing solution to complete the development, leaving the pattern of the interdigitated electrode on the surface of the gallium oxide thin film.

[0011] S4. Use an etching machine to remove excess photoresist from the surface of the thin film obtained in S3, exposing the surface of the gallium oxide thin film, which facilitates the subsequent growth of metal electrodes.

[0012] S5. Using the magnetron sputtering instrument again, Ti and Au electrodes are sequentially deposited on the mask area of ​​the gallium oxide thin film surface obtained in S4. Ti is used to increase the adhesion of the Au electrode.

[0013] S6. Soak the product obtained in S5 in acetone to remove the gum, and then ultrasonically clean it in anhydrous ethanol to remove excess Ti and Au, leaving a regular electrode pattern.

[0014] Optionally, in step S1, the silicon substrate is a Si (100) oriented substrate.

[0015] Optionally, in step S2, a gallium oxide low-oxygen layer is first deposited under an argon atmosphere to prevent the silicon substrate from being oxidized to SiO2, and then a gallium oxide thin film is deposited under an argon-oxygen mixed atmosphere. In embodiments of the present invention, the argon flow rate is 8 sccm and the oxygen flow rate is 2 sccm. The gallium oxide thin film may contain metal dopants, such as Mg, Al, Bi, etc., and has a total thickness of 200 nm.

[0016] Optionally, in step S3, the number of interdigitated electrodes is 5-20 pairs, and the finger width and finger spacing are 5-20 μm. The purpose of preparing interdigitated electrodes on the thin film surface is to allow the subsequently deposited titanium and gold to form the shape of interdigitated electrodes, rather than depositing a large area of ​​metal layer on the gallium oxide thin film surface.

[0017] Optionally, in step S3, the gallium oxide film obtained in S2 is cleaned sequentially using the following reagents: ultrasonic cleaning with acetone at 40-60 W power for 15 min, ultrasonic cleaning with anhydrous ethanol at 40-60 W power for 15 min, ultrasonic cleaning with deionized water at 40-60 W power for 15 min, and finally dried with a nitrogen gun.

[0018] Optionally, in step S3, after spin-coating the gallium oxide thin film with photoresist, it needs to be hardened in a 100°C constant temperature drying oven for 20-30 minutes to dry the photoresist. A mercury lamp is used for exposure in the photolithography machine, with an exposure time of 20-30 seconds. Ultrasonic development in the developing solution takes 10-30 seconds. After development, it is ultrasonically cleaned in deionized water for 1-2 minutes, and then dried in a 100°C constant temperature drying oven for 10-20 minutes.

[0019] Optionally, in step S5, when depositing Ti and Au in the mask region on the surface of the gallium oxide thin film, the magnetron sputtering process parameters include: the atmosphere is argon, the argon flow rate is 20 sccm; the target material is a Ti metal target and an Au metal target; the sputtering power is 100-150 W; the substrate temperature is room temperature; and the sputtering time is 200-1000 s.

[0020] Optionally, in step S6, the film is immersed in acetone for 24 h and ultrasonically cleaned with anhydrous ethanol at a power of 40 W for 30-120 s.

[0021] Optionally, the product obtained in step S6 is cut and packaged to obtain a gallium oxide arc monitor that can be integrated and used. The gallium oxide arc monitor is finger-shaped or comb-shaped, with a length of 2-5 mm, a width of 1-3 mm, and a height of 0.1-0.6 mm.

[0022] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0023] (1) Using gallium oxide material for arc monitoring can significantly reduce the impact of interference light such as visible light on signal detection;

[0024] (2) Gallium oxide materials have a faster response speed and higher sensitivity, and are more sensitive to capturing weak signals in the early stage of arc generation;

[0025] (3) This invention integrates gallium oxide semiconductor detector with high-performance signal detection circuit. Through optimized interface circuit and signal processing module, a photoelectric detection system with high integration and high stability is constructed, realizing the full-link integrated processing from optical signal detection to electrical signal output.

[0026] (4) The intelligent detection circuit adopted significantly improves the key performance indicators of the detector, such as signal-to-noise ratio and response speed, through a real-time feedback mechanism. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 is a side view schematic diagram of the sensitive element portion of the gallium oxide arc light monitor of the present invention;

[0029] Figure 2 is a top view of the sensitive element portion of the gallium oxide arc monitor of the present invention;

[0030] Figure 3 shows the structure of the detection circuit of the present invention;

[0031] Figure 4 is a photograph of the gallium oxide arc monitor according to an embodiment of the present invention;

[0032] Figure 5 shows the photo-dark current test results of the gallium oxide arc monitor according to an embodiment of the present invention. Detailed Implementation

[0033] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0034] Example

[0035] A method for fabricating a gallium oxide arc detector includes the following steps:

[0036] (1) Polish and clean the silicon substrate on one or both sides to remove the surface oxide layer and obtain a clean surface for depositing gallium oxide thin film. The specific cleaning method is as follows: ultrasonically clean the substrate in acetone for 15 min, ultrasonically clean it in anhydrous ethanol for 15 min, ultrasonically clean it in deionized water for 10-30 min, blow it dry with a nitrogen gun, and immediately send it into the magnetron sputtering vacuum chamber.

[0037] (2) A gallium oxide thin film with a total thickness of 200 nm was deposited on a silicon substrate using magnetron sputtering. The background vacuum was better than 3 × 10⁻⁶. -7 Following the torsion process, a 10 nm thick gallium oxide low-oxygen layer was first deposited under an argon atmosphere at 20 sccm to prevent oxidation of the silicon substrate in an oxygen atmosphere. Next, a 190 nm thick gallium oxide film was deposited in an argon-oxygen mixed gas atmosphere, with an oxygen flow rate of 2 sccm and an argon flow rate of 18 sccm. The target was a 99.99% pure Ga₂O₃ ceramic target, the sputtering power was 120 W, the substrate temperature was 25 °C, and the total sputtering time was 5100 s.

[0038] (3) Photolithography was performed on the surface of the top gallium oxide film to define the electrode pattern. The gallium oxide film obtained in step (2) was cleaned sequentially using the following reagents: ultrasonic cleaning with acetone at 40-60 W power for 15 min, ultrasonic cleaning with anhydrous ethanol at 40-60 W power for 15 min, and ultrasonic cleaning with deionized water at 40-60 W power for 15 min, and finally dried with a nitrogen gun. After cleaning the gallium oxide film, photoresist was spin-coated, and then the film was hardened in a 100℃ constant temperature drying oven for 20 min to dry. Then, the mask of the interdigitated electrode was attached to the surface of the film and exposed with a photolithography machine for 25 s. After exposure, ultrasonic development was performed in the developer for 25 s, ultrasonic cleaning was performed in deionized water for 1 min, and drying was performed in a 100℃ constant temperature drying oven for 10 min. The film was then removed and cooled for later use.

[0039] (4) Deposit metallic Ti on the sample obtained in step (3). Use a magnetron sputtering system with a background vacuum better than 3 × 10⁻⁶. -7 Torr, argon flow rate 20 sccm, temperature 25℃, target material 99.99% pure Ti metal target, depositing metallic Ti with a thickness of 20 nm in the mask area on the sample surface, sputtering power 120 W, sputtering time 339 s.

[0040] (5) Deposit Au metal on the sample obtained in step (4). Using a magnetron sputtering instrument, with a background vacuum better than 3×10-7 Torr, an argon flow rate of 20 sccm, a temperature of 25℃, and a target material of 99.99% pure Au metal target, deposit Au metal on the mask area of ​​the sample surface with a thickness of 50 nm, a sputtering power of 80 W, and a sputtering time of 428 s.

[0041] (6) Remove the adhesive from the sample obtained in step (5) and remove excess metal at the same time. Place the sample in a beaker, soak it in acetone solution for 1 hour, and ultrasonically clean it for 30 seconds until the excess metal is completely removed.

[0042] (7) Clean the sample obtained in step (6). Sonicate in anhydrous ethanol for 30 s to remove excess acetone. Centrifuge at 3000 r / min for 30 s to remove excess moisture. Transfer to a 100℃ constant temperature drying oven and dry for 10 min. Remove and cool for later use.

[0043] (8) The sample obtained in step (7) is tested. The morphology is observed under a microscope, and the device performance is measured using a semiconductor analyzer.

[0044] (9) Cut and package the high-performance sample from step (8) to obtain a gallium oxide arc monitor that can be integrated and used.

[0045] Figure 1 is a side view of the sensitive element portion of the gallium oxide arc monitor of the present invention. The sensitive element portion includes a gallium oxide thin film and deposited electrodes. The gallium oxide thin film is deposited on the surface of a silicon substrate, along with an interdigitated electrode pattern formed of gold and titanium. Figure 2 is a top view of the sensitive element portion of the gallium oxide arc monitor of the present invention, showing the shape of the interdigitated electrodes.

[0046] (10) The gallium oxide arc monitor packaged in step (9) is fitted with a detection circuit, as shown in Figure 3. The detection circuit includes an adjustable transimpedance amplifier circuit, a voltage conversion circuit, a microcontroller control system, and an OLED screen display module. The adjustable transimpedance amplifier circuit is directly connected to the sensor via a precision impedance matching network, converting the weak input current signal into a voltage signal. The voltage conversion circuit performs secondary conditioning and level conversion on the signal. The processed signal is transmitted to the microcontroller control system for digital processing and analysis. Finally, the measurement data is displayed in real time on the OLED screen. Figure 4 is a photograph of the gallium oxide arc monitor according to an embodiment of the present invention.

[0047] To verify the amplification performance and linearity of the weak current detection circuit, a high-precision current source (Keysight B2912A) was used to conduct multi-range calibration experiments on the gallium oxide arc monitor prepared in this embodiment. The calibration experiments covered 100kΩ and 400kΩ feedback resistor ranges, with input current ranging from 1μA to 20μA. The output voltage values ​​under different input currents were collected. The test results are shown in Table 1, indicating that the device has a current-voltage response.

[0048] Table 1

[0049]

[0050] Figure 5 shows the dark current test results of the gallium oxide arc monitor according to an embodiment of the present invention. The horizontal axis represents the applied bias voltage, from -10 to 10 V; the vertical axis represents the current magnitude; and the test wavelength is 254 nm. As can be seen from the figure, under a 10 V bias voltage, the dark current is 10 V. -12 The order of magnitude is A, and the photocurrent is 10. -6 On the order of A. Since the arc light signal has a characteristic wavelength in the solar-blind ultraviolet band, this invention uses gallium oxide material, which utilizes its wide bandgap characteristics (approximately 4.9 eV) to efficiently detect signals in this band, effectively avoiding interference from clutter such as visible light, thereby significantly improving the accuracy and sensitivity of monitoring and reducing the false alarm rate.

[0051] Comparative Example 1

[0052] In step (2), no gallium oxide low oxygen layer was prepared; instead, a gallium oxide thin film was directly deposited on the silicon precipitate surface. The other steps were the same as in the example.

[0053] After being packaged into a device, the photocurrent and dark current ratio were tested, and the ratio was on the order of 100. This indicates that the gallium oxide low-oxygen layer can prevent the formation of silicon oxide on the silicon substrate surface, which is conducive to the lattice growth of gallium oxide, resulting in better crystal quality of subsequently deposited gallium oxide and better device performance.

[0054] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for fabricating a gallium oxide arc light monitor, characterized in that, Includes the following steps: S1. Clean the silicon substrate to remove surface oxides; S2. Deposit a gallium oxide low-oxygen layer and a gallium oxide thin film sequentially on the cleaned silicon substrate using magnetron sputtering; S3. Clean, spin-coate photoresist, and dry the gallium oxide thin film obtained in S2. Then, attach the mask of the interdigitated electrodes to the surface of the thin film and expose it with a photolithography machine. Place it in a developing solution to complete the development, leaving the pattern of interdigitated electrodes on the surface of the gallium oxide thin film; S4. Remove excess photoresist from the surface of the thin film obtained in S3 using an etching machine to expose the surface of the gallium oxide thin film; S5. Deposit Ti and Au electrodes sequentially in the mask area on the surface of the gallium oxide thin film obtained in S4 using a magnetron sputtering machine again; S6. Clean the product obtained in S5 to remove excess Ti and Au, leaving a regular electrode pattern.

2. The method for fabricating a gallium oxide arc detector according to claim 1, characterized in that, In step S1, the silicon substrate is a Si (100) oriented substrate.

3. The method for fabricating a gallium oxide arc detector according to claim 1, characterized in that, In step S2, a gallium oxide low-oxygen layer is first deposited in an argon atmosphere, and then a gallium oxide thin film is deposited in an argon-oxygen mixed atmosphere; preferably, in the argon-oxygen mixed atmosphere, the argon flow rate is 8 sccm and the oxygen flow rate is 2 sccm.

4. The method for fabricating a gallium oxide arc detector according to claim 1, characterized in that, In step S3, the number of interdigital electrodes is 5-20 pairs, and the finger width and finger spacing is 5-20 μm.

5. The method for fabricating a gallium oxide arc detector according to claim 1, characterized in that, In step S3, the gallium oxide film obtained in S2 is cleaned sequentially using the following reagents: ultrasonic cleaning with acetone at 40-60 W power for 15 min, ultrasonic cleaning with anhydrous ethanol at 40-60 W power for 15 min, ultrasonic cleaning with deionized water at 40-60 W power for 15 min, and finally dried with a nitrogen gun.

6. The method for fabricating a gallium oxide arc detector according to claim 1, characterized in that, In step S3, after spin-coating the gallium oxide thin film with photoresist, the film is hardened in a 100°C constant temperature drying oven for 20-30 minutes to dry the photoresist; a mercury lamp is used for exposure in the photolithography machine, and the exposure time is 20-30 seconds; the ultrasonic development time in the developing solution is 10-30 seconds. After development, ultrasonically clean in deionized water for 1-2 minutes, and then dry in a 100℃ constant temperature drying oven for 10-20 minutes.

7. The method for fabricating a gallium oxide arc detector according to claim 1, characterized in that, In step S5, when depositing Ti and Au in the mask area on the surface of the gallium oxide thin film, the magnetron sputtering process parameters include: the atmosphere is argon, the argon flow rate is 20 sccm; the target material is a Ti metal target and an Au metal target; the sputtering power is 100-150 W; the substrate temperature is room temperature; and the sputtering time is 200-1000 s.

8. The method for fabricating a gallium oxide arc detector according to claim 1, characterized in that, In step S6, the film is immersed in acetone for 24 h and ultrasonically cleaned with anhydrous ethanol at a power of 40 W for 30-120 s.

9. The method for fabricating a gallium oxide arc detector according to any one of claims 1 to 8, characterized in that, The product obtained in step S6 is cut and packaged to obtain the gallium oxide arc monitor.

10. A gallium oxide arc light monitor, characterized in that, The gallium oxide arc monitor is prepared by the method described in claim 9. The gallium oxide arc monitor is finger-shaped or comb-shaped, with a length of 2-5 mm, a width of 1-3 mm, and a height of 0.1-0.6 mm.

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