Tantalum oxide film with high laser damage threshold under near-infrared long wave and preparation method of tantalum oxide film

Abstract

The invention relates to the technical field of optical films with high damage thresholds, in particular to a tantalum oxide film with a high laser damage threshold under near-infrared long waves and a preparation method thereof, and the preparation method comprises the following steps: cleaning a substrate material by using a strong oxidation inorganic solvent, cleaning by using an organic solvent after cleaning by using deionized water, drying by blowing nitrogen, and drying to obtain the tantalum oxide film with the high laser damage threshold under near-infrared long waves. A clean substrate is obtained; depositing tantalum oxide on a clean substrate to obtain a tantalum oxide deposited substrate; and carrying out rapid annealing on the substrate deposited with tantalum oxide to obtain a substrate plated with tantalum oxide. According to the tantalum oxide thin film with the high laser damage threshold value under the near-infrared long wave and the preparation method of the tantalum oxide thin film, the laser damage threshold value of the tantalum oxide thin film at the near-infrared long wave is effectively improved through rapid annealing, the laser damage threshold value is improved by about 190% compared with an unannealed film layer, and the preparation time is greatly shortened.

Description

Technical Field

[0001] The invention relates to the technical field of high damage threshold optical films, in particular to a tantalum oxide film with high laser damage threshold under near infrared long wave and a preparation method thereof. Background Art

[0002] With the widespread application of high-power laser systems, such as laser processing, laser communications, laser weapons, and high-energy physics research, the performance requirements for optical components are becoming increasingly stringent, especially in terms of the ability to withstand high-energy laser radiation without being damaged, that is, the laser damage threshold, which has become a key indicator for measuring the applicability of materials. The research on the preparation of tantalum oxide films with high laser damage threshold is not only a positive response to the challenges of existing laser technology, but also an important direction for promoting innovation in optical material science and technology. It is of great significance to promote the performance improvement of high-power laser systems and expand their application scope.

[0003] Tantalum oxide (Ta2O5), as a high-performance dielectric material, has become one of the ideal candidate materials for preparing high laser damage threshold films due to its excellent chemical stability, high refractive index, good light transmittance and low absorption characteristics under high-energy radiation. However, the original or unoptimized tantalum oxide film is often difficult to directly meet the stringent requirements of high-power laser systems for laser damage threshold. Therefore, how to improve the laser damage threshold of tantalum oxide films through effective preparation and modification methods has become a research hotspot in the current fields of materials science and laser technology.

[0004] At present, there are studies on the laser damage threshold of preparation methods, such as optimization of preparation methods such as electron beam evaporation deposition, magnetron sputtering deposition, sol-gel method, pulsed laser deposition, etc. There are also studies on improving the laser damage threshold of tantalum oxide film by conventional annealing. Conventional annealing usually takes 12 hours. Under the optimized process temperature conditions, the highest laser damage threshold is 7.5J / cm 2 The laser damage threshold is increased by 75% (4.3 J / cm without annealing). 2 ) (Optics & Laser Technology 41, 2009). There are also studies on the effect of different laser pulses on the damage threshold, and the highest laser damage threshold of tantalum oxide and silicon oxide film on quartz substrate is 21.57 J / cm 2 (Infrared and Laser Engineering, 52, 3, 2023).

[0005] However, current research is basically focused on the damage threshold of tantalum oxide under near-infrared shortwave (780~1100nm), and there is almost no research on the laser damage threshold in the near-infrared long-wave (1100~2526nm) segment, and there is almost no research on the effect of annealing method on laser damage threshold. Summary of the invention

[0006] The purpose of the present invention is to provide a tantalum oxide film with a high laser damage threshold under near-infrared long waves and a preparation method thereof. Rapid annealing is used to effectively improve the laser damage threshold of the tantalum oxide film at near-infrared long waves. Compared with the unannealed film layer, the laser damage threshold is increased by about 190%, and the preparation time is greatly shortened.

[0007] To achieve the above object, the present invention provides a method for preparing a tantalum oxide film with a high laser damage threshold under near-infrared long-wave, comprising the following steps: S1. Clean the substrate material with a strong oxidizing inorganic solvent, wash with deionized water, then use an organic solvent to clean it, blow dry with nitrogen, and then dry it to obtain a clean substrate; S2, depositing tantalum oxide on the clean substrate in S1 to obtain a substrate on which tantalum oxide is deposited; S3, performing rapid annealing on the substrate on which tantalum oxide is deposited in S2 to obtain a tantalum oxide-plated substrate.

[0008] Preferably, in S1, the substrate material includes but is not limited to one or more of quartz, single crystal silicon, sapphire, and zinc sulfide.

[0009] Preferably, in S1, the cleaning time using a strong oxidizing inorganic solvent is 0.2-1 h, and the strong oxidizing inorganic solvent includes one or more of concentrated sulfuric acid, ammonia water and hydrogen peroxide.

[0010] Preferably, in S1, the cleaning time using the organic solvent is 0.2-0.5 h, and the organic solvent includes one or more of alcohol and acetone.

[0011] Preferably, in S1, the drying is carried out in an oven or a hot plate, the drying temperature is 100-200° C., and the drying time is 0.5-1 h.

[0012] Preferably, in S2, the deposition method includes but is not limited to one or more of electron beam evaporation, magnetron sputtering, and ion beam sputtering.

[0013] Preferably, in S2, the temperature for depositing tantalum oxide is 20-400° C., the rate for depositing tantalum oxide is 0.5-10 nm / min, and the thickness of the deposited tantalum oxide is 10-600 nm.

[0014] Preferably, in S3, the temperature of the rapid annealing is 200-900° C., the heating rate of the rapid annealing is 200-300° C. / min, and the holding time is 1-10 min.

[0015] Preferably, in S3, the rapid annealing atmosphere includes but is not limited to one or more of air, nitrogen, and argon.

[0016] The above method for preparing a tantalum oxide film with a high laser damage threshold under near-infrared long waves prepares a substrate coated with a tantalum oxide film.

[0017] Preferably, the laser induced damage threshold of the tantalum oxide-plated substrate is tested according to the ISO11254 standard S-on-1 test method, and lasers with different energy densities are irradiated 10 times at a single point, with a laser energy step of 0.1-1 J / cm 2 Each laser irradiation lasts 1 to 10 minutes, and the energy density value at which the film is damaged is the laser damage threshold of the film. Test laser wavelength range: 1100 to 2526 nm; test laser frequency range: 1 to 30 KHz.

[0018] Therefore, the present invention adopts the above steps to prepare a tantalum oxide film with high laser damage threshold under near-infrared long wave, including substrate cleaning, film preparation, rapid annealing process, to damage threshold testing, which can be used to improve the laser damage threshold of optical films.

[0019] The present invention adopts rapid annealing to effectively improve the laser damage threshold of the tantalum oxide film at the near-infrared long wave (1100~2526nm). Compared with the unannealed film layer, the laser damage threshold is improved by about 190%. Moreover, compared with conventional thermal annealing, rapid thermal annealing takes less time and has better effect, which has significant advantages in improving production efficiency.

[0020] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The present invention is a schematic flow chart of a method for preparing a tantalum oxide film with a high laser damage threshold under near-infrared long waves. DETAILED DESCRIPTION

[0022] The present invention is further described below in conjunction with the accompanying drawings and embodiments. Unless otherwise defined, the technical terms or scientific terms used in the present invention should be the usual meanings understood by people with ordinary skills in the field to which the present invention belongs. The above-mentioned features mentioned in the present invention or the features mentioned in the specific examples can be combined arbitrarily, and these specific embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of this application.

[0023] Example 1 like Figure 1 As shown, the present invention provides a method for preparing a tantalum oxide film with a high laser damage threshold under near-infrared long-wave, comprising the following steps: S1. Use concentrated sulfuric acid to heat and clean the double-polished quartz for 0.5 h, rinse with deionized water and then use alcohol to clean for 0.2 h, blow dry with nitrogen and then dry on a hot plate at 120°C for 0.5 h to obtain clean quartz.

[0024] S2, depositing tantalum oxide on the clean substrate in S1 by magnetron sputtering, the temperature of depositing tantalum oxide is 200°C, the rate of depositing tantalum oxide is 5nm / min, the thickness of deposited tantalum oxide is 350nm, and the background vacuum of depositing tantalum oxide is 5.0×10 -4 Pa, and a substrate for depositing tantalum oxide is obtained.

[0025] S3. The substrate on which tantalum oxide is deposited in S2 is rapidly annealed in an air atmosphere, wherein the rapid annealing temperature is 500-900°C, the annealing temperature step is 100°C, the rapid annealing heating rate is 200°C / min, and the holding time is 5min, thereby obtaining a tantalum oxide-plated substrate.

[0026] Comparative Example 1 S1. Use concentrated sulfuric acid to heat and clean the double-polished quartz for 0.5 h, rinse with deionized water and then use alcohol to clean for 0.2 h, blow dry with nitrogen and then dry on a hot plate at 120°C for 0.5 h to obtain clean quartz.

[0027] S2, depositing tantalum oxide on the clean substrate in S1 by magnetron sputtering, the temperature of depositing tantalum oxide is 200°C, the rate of depositing tantalum oxide is 5nm / min, the thickness of deposited tantalum oxide is 350nm, and the background vacuum of depositing tantalum oxide is 5.0×10 -4 Pa, the resulting substrate on which tantalum oxide was deposited.

[0028] S3. Perform conventional annealing on the substrate on which tantalum oxide is deposited in S2 in an air atmosphere. The conventional annealing temperature is 500-900°C, the annealing temperature is stepped by 100°C, the conventional annealing heating rate is 5°C / min, and the holding time is 1h, to obtain a tantalum oxide-plated substrate.

[0029] Test Example 1 The laser-induced damage threshold of the sample was tested according to the ISO11254 standard S-on-1 test method. Lasers with different energy densities were irradiated 10 times at a single point, with a laser energy step of 0.1 J / cm 2 Each laser irradiation lasts for 1 minute, and the energy density value at which the film is damaged is the laser damage threshold of the film.

[0030] Test laser wavelength: 2050nm; Test laser frequency: 200Hz.

[0031] Tantalum oxide-plated substrates obtained at different annealing temperatures in Example 1 and Comparative Example 1 were tested respectively, and the results are shown in Table 1.

[0032] Table 1. Laser damage threshold data of Example 1 and Comparative Example 1 at different annealing temperatures

[0033] It can be seen from Table 1 that both Example 1 and Comparative Example 1 obtain the best laser damage threshold when annealed at 600°C. Compared with the unannealed film layer, the laser damage threshold in Example 1 is increased by about 190%, and the laser damage threshold in Comparative Example 1 is increased by about 129%. The laser damage threshold in Example 1 is significantly greater than the laser damage threshold in Comparative Example 1.

[0034] In addition, in terms of time consumption, conventional annealing at 600°C, holding temperature for 1 hour, heating and cooling time, the total time required is about 10 hours in Comparative Example 1; while rapid thermal annealing is adopted in Example 1, annealing at 600°C, holding temperature for 5 minutes, and heating and cooling time for a total of about 20 minutes. It can be seen that the rapid annealing method adopted in Example 1 only takes 1 / 30 of the time in Comparative Example 1, while reducing the film contamination caused by the conventional annealing process and the defects caused by the film contamination, saving time cost, greatly shortening the process time, and having significant advantages in improving production efficiency.

[0035] Therefore, the present invention adopts the above steps to provide a tantalum oxide film with high laser damage threshold under near-infrared long wave and a preparation method thereof, and adopts rapid annealing to effectively improve the laser damage threshold of the tantalum oxide film at near-infrared long wave (1100~2526nm). Compared with the unannealed film layer, the laser damage threshold is improved by about 190%, and compared with conventional thermal annealing, the rapid thermal annealing has better effect, which has significant advantages in improving production efficiency.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for preparing a tantalum oxide film with high laser damage threshold under near-infrared long-wave, characterized in that: The following steps are included: S1. Clean the substrate material with a strong oxidizing inorganic solvent, wash with deionized water, then use an organic solvent to clean it, blow dry with nitrogen, and then dry it to obtain a clean substrate; S2, depositing tantalum oxide on the clean substrate in S1 to obtain a substrate on which tantalum oxide is deposited; S3, performing rapid annealing on the substrate on which tantalum oxide is deposited in S2 to obtain a tantalum oxide-plated substrate.

2. The method for preparing a tantalum oxide thin film with high laser damage threshold under near-infrared long-wave according to claim 1, characterized in that: In S1, the substrate material includes but is not limited to one or more of quartz, single crystal silicon, sapphire, and zinc sulfide.

3. The method for preparing a tantalum oxide thin film with high laser damage threshold under near-infrared long-wave according to claim 1, characterized in that: In S1, the cleaning time using a strong oxidizing inorganic solvent is 0.2-1h, and the strong oxidizing inorganic solvent includes one or more of concentrated sulfuric acid, ammonia water and hydrogen peroxide.

4. The method for preparing a tantalum oxide thin film with high laser damage threshold under near-infrared long-wave according to claim 1, characterized in that: In S1, the cleaning time using the organic solvent is 0.2-0.5h, and the organic solvent includes one or more of alcohol and acetone.

5. The method for preparing a tantalum oxide thin film with high laser damage threshold under near-infrared long-wave according to claim 1, characterized in that: In S1, drying is performed in an oven or a hot plate, the drying temperature is 100-200°C, and the drying time is 0.5-1h.

6. The method for preparing a tantalum oxide thin film with high laser damage threshold under near-infrared long-wave according to claim 1, characterized in that: In S2, the deposition method includes but is not limited to one or more of electron beam evaporation, magnetron sputtering, and ion beam sputtering.

7. The method for preparing a tantalum oxide thin film with high laser damage threshold under near-infrared long-wave according to claim 1, characterized in that: In S2, the temperature for depositing tantalum oxide is 20-400° C., the rate for depositing tantalum oxide is 0.5-10 nm / min, and the thickness of deposited tantalum oxide is 10-600 nm.

8. The method for preparing a tantalum oxide thin film with high laser damage threshold under near-infrared long-wave according to claim 1, characterized in that: In S3, the temperature of rapid annealing is 200~900°C, the heating rate of rapid annealing is 200~300°C / min, and the holding time is 1~10min.

9. The method for preparing a tantalum oxide thin film with high laser damage threshold under near-infrared long-wave according to claim 1, characterized in that: In S3, the rapid annealing atmosphere includes but is not limited to one or more of air, nitrogen, and argon.

10. A method for preparing a tantalum oxide thin film with a high laser damage threshold under near-infrared long-wavelength according to any one of claims 1 to 9, and a substrate coated with a tantalum oxide thin film.

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