A reflector, its preparation method and application

Abstract

This invention belongs to the field of optical thin film technology, specifically relating to a reflector, its fabrication method, and its application. The invention provides a reflector comprising a substrate and a plurality of reflective film units and a tungsten layer sequentially stacked on the surface of the substrate. Each reflective film unit comprises, from bottom to top, a single-element silicon layer, a high atomic number metal layer, and a silicon carbide layer sequentially stacked. The silicon carbide layer and the tungsten layer of the reflective film unit are in contact. The high atomic number metal layer is made of Rh, Au, or Pt. By adding a high atomic number metal layer to the SiC / Si composite film system, this invention can further improve the energy bandwidth of the composite film. At near-normal incidence angles, the reflector obtained by this invention maintains a relatively high reflectivity in the energy range of 40 eV to 80 eV, forming a high-reflectivity plateau region, greatly expanding the applicability of the reflector.

Description

Technical Field

[0001] This invention belongs to the field of optical thin film technology, specifically relating to a reflector, its preparation method, and its application. Background Technology

[0002] Exploring the impact of solar energy activity on Earth's space weather and climate is an important topic in modern scientific research. Solar flares, coronal mass ejections, and other activities are significant factors influencing Earth's space weather and climate. Therefore, extensive imaging studies have been conducted on the extreme ultraviolet light in the solar radiation spectrum.

[0003] Currently, the main spectral lines used for observation are helium spectra and highly ionized iron element spectra. The composite film system commonly used on the reflectors is mainly Mo / Si multilayer film. The application band of Mo / Si multilayer film is mainly 13.1 nm. It has the advantages of high reflection efficiency and high resolution, but its energy bandwidth is relatively narrow, which limits the application of reflectors in space exploration. Summary of the Invention

[0004] The purpose of this invention is to provide a reflector, its preparation method, and its application. The reflector provided by this invention has a wide energy bandwidth.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] The present invention provides a reflector, comprising a substrate and a plurality of reflective film units and a tungsten metal layer sequentially stacked on the surface of the substrate;

[0007] Each reflective film unit comprises a single-element silicon layer, a high atomic number metal layer, and a silicon carbide layer stacked sequentially from bottom to top;

[0008] The silicon carbide layer and the tungsten metal layer of the reflective film unit are in contact;

[0009] The high atomic number metal layer is made of materials including Rh, Au, or Pt.

[0010] Preferably, the number of repetition cycles of the reflective film unit is 30 to 50.

[0011] Preferably, in each reflective film unit, the thickness of the elemental silicon layer is 7-9 nm, the thickness of the high atomic number metal layer is 1-3 nm, and the thickness of the silicon carbide layer is 7-9 nm;

[0012] The thickness of the tungsten metal layer is 4–6 nm.

[0013] Preferably, the substrate material includes single-crystal silicon, single-crystal quartz, fused silica glass, or K9 glass.

[0014] The present invention also provides a method for preparing the reflector described in the above technical solution, comprising the following steps:

[0015] A reflective substrate is obtained by periodically growing reflective film units on the substrate surface.

[0016] A tungsten metal layer is grown on the surface of the silicon carbide layer of the reflective substrate, and then annealed to obtain the reflector.

[0017] Preferably, the reflective film growth unit is a magnetron sputtering reflective film growth unit;

[0018] The magnetron sputtering conditions for the single-element silicon layer of each reflective film unit include: sputtering power of 100-120W, sputtering voltage of 400-430V, sputtering pressure of 0.27-0.29Pa, vacuum degree of 2E-4Pa, and time of 7-9 seconds.

[0019] The magnetron sputtering conditions for the high atomic number metal layer of each reflective film unit include: sputtering power of 150-160W, sputtering voltage of 345-355V, sputtering pressure of 0.27-0.29Pa, vacuum degree of 2E-4Pa, and time of 2-3 seconds.

[0020] The magnetron sputtering parameters for the silicon carbide layer of each reflective film unit include: sputtering power of 120–140 W, sputtering voltage of 366 V–378 V, sputtering pressure of 0.27–0.29 Pa, vacuum degree of 2E–4 Pa, and time of 7–9 seconds.

[0021] Preferably, the tungsten metal layer is grown by magnetron sputtering;

[0022] The conditions for growing a tungsten metal layer by magnetron sputtering include: sputtering power of 70-80W, sputtering voltage of 286-297V, sputtering pressure of 0.27-0.29Pa, vacuum degree of 2E-4Pa, and time of 3-5 seconds.

[0023] Preferably, the annealing temperature is 200–300°C and the holding time is 110–130 min.

[0024] Preferably, before growing the reflective film unit, the substrate is further subjected to a pretreatment to remove impurities.

[0025] The present invention also provides the application of the reflector described in the above technical solution or the reflector prepared by the preparation method described in the above technical solution in space telescopes or space probes.

[0026] This invention provides a reflector comprising a substrate and a plurality of reflective film units and a tungsten layer sequentially stacked on the surface of the substrate. Each reflective film unit comprises, from bottom to top, a single-element silicon layer, a high atomic number metal layer, and a silicon carbide layer. The silicon carbide layer and the tungsten layer of the reflective film unit are in contact. The high atomic number metal layer is made of Rh, Au, or Pt. By adding a high atomic number metal layer to the SiC / Si composite film system, this invention can further broaden the energy bandwidth of the composite film. At a near-normal incidence angle (75° grazing incidence angle), the reflector obtained by this invention maintains a relatively high reflectivity in the energy range of 40 eV to 80 eV, forming a high-reflectivity plateau region, which greatly improves the adaptability of the reflector. Attached Figure Description

[0027] Figure 1 The XRD pattern of the mirror obtained in Example 1;

[0028] Figure 2 The image shows the XRD pattern of the mirror obtained in Comparative Example 1. Detailed Implementation

[0029] The present invention provides a reflector, comprising a substrate and a plurality of reflective film units and a tungsten metal layer sequentially stacked on the surface of the substrate;

[0030] Each reflective film unit comprises a single-element silicon layer, a high atomic number metal layer, and a silicon carbide layer stacked sequentially from bottom to top;

[0031] The silicon carbide layer and the tungsten metal layer of the reflective film unit are in contact;

[0032] The high atomic number metal layer is made of materials including Rh, Au, or Pt.

[0033] In this invention, the substrate preferably comprises monocrystalline silicon, single crystal quartz, fused silica glass, or K9 glass. This invention does not impose any particular limitation on the thickness of the substrate; any material well-known to those skilled in the art can be used.

[0034] In this invention, the number of repetition cycles of the reflective film unit is preferably 30 to 50, more preferably 32 to 45, and even more preferably 35 to 40.

[0035] In this invention, in each reflective film unit, the thickness of the elemental silicon layer is preferably 7-9 nm, the thickness of the high atomic number metal layer is preferably 1-3 nm, and the thickness of the silicon carbide layer is preferably 7-9 nm.

[0036] In this invention, the thickness of the tungsten metal layer is preferably 4–6 nm. In this invention, the tungsten metal layer serves as a protective layer and also improves reflection efficiency.

[0037] The present invention also provides a method for preparing the reflector described in the above technical solution, comprising the following steps:

[0038] A reflective substrate is obtained by periodically growing reflective film units on the substrate surface.

[0039] A tungsten metal layer is grown on the surface of the silicon carbide layer of the reflective substrate, and then annealed to obtain the reflector.

[0040] In this invention, unless otherwise specified, all raw materials are commercially available products well known to those skilled in the art.

[0041] The present invention periodically grows reflective film units on the surface of a substrate to obtain a reflective substrate.

[0042] Before growing the reflective film unit, the present invention preferably includes a pretreatment to remove impurities from the substrate; the pretreatment preferably includes ultrasonic treatment in the cleaning solution and water in sequence.

[0043] In this invention, the cleaning solution is preferably an RCA solution; the RCA solution preferably includes ammonia and hydrogen peroxide. This invention does not impose any particular limitation on the concentration of the RCA solution; any process well-known to those skilled in the art can be used.

[0044] This invention does not specifically limit the ultrasonic treatment process in the cleaning solution and water; any process well-known to those skilled in the art can be used. In this invention, ultrasonic treatment in the RCA solution can remove particles and dust from the substrate surface; rinsing in water can remove residual cleaning solution from the substrate surface.

[0045] In this invention, the reflective film growth unit is a magnetron sputtering reflective film growth unit. Preferably, the magnetron sputtering is performed in an argon atmosphere.

[0046] In this invention, the preferred conditions for magnetron sputtering of the single-element silicon layer of each reflective film unit include: sputtering power of 100-120W, sputtering voltage of 400-430V, sputtering pressure of 0.27-0.29Pa, vacuum degree of 2E-4Pa, and time of 7-9 seconds.

[0047] In this invention, the preferred conditions for magnetron sputtering of the high atomic number metal layer of each reflective film unit include: sputtering power of 150-160W, sputtering voltage of 345-355V, sputtering pressure of 0.27-0.29Pa, vacuum degree of 2E-4Pa, and time of 2-3 seconds.

[0048] In this invention, the preferred conditions for magnetron sputtering of the silicon carbide layer of each reflective film unit include: sputtering power of 120-140W, sputtering voltage of 366V-378V, sputtering pressure of 0.27-0.29Pa, vacuum degree of 2E-4Pa, and time of 7-9 seconds.

[0049] The present invention does not impose any special limitations on the magnetron sputtering process; any process well known to those skilled in the art can be used.

[0050] After obtaining the reflective substrate, the present invention grows a tungsten metal layer on the silicon carbide layer surface of the reflective substrate, and after annealing, obtains the reflector.

[0051] In this invention, the tungsten metal layer is grown by magnetron sputtering. Preferably, the magnetron sputtering is performed in an argon atmosphere.

[0052] In this invention, the preferred conditions for magnetron sputtering growth of the tungsten metal layer include: sputtering power of 70-80W, sputtering voltage of 286-297V, sputtering pressure of 0.27-0.29Pa, vacuum degree of 2E-4Pa, and time of 3-5 seconds.

[0053] After the tungsten metal layer is grown, the present invention preferably includes naturally cooling the obtained substrate to room temperature.

[0054] In this invention, the annealing temperature is preferably 200–300°C, more preferably 220–280°C, and even more preferably 230–250°C; the holding time is preferably 110–130 min, and even more preferably 120 min. In this invention, the annealing treatment is preferably performed in a vacuum environment. In this invention, the stress in the coating layer can be eliminated through annealing.

[0055] After the annealing process, the present invention preferably further includes naturally cooling the obtained substrate to room temperature.

[0056] This invention also provides the application of the reflector described in the above-described technical solution or the reflector prepared by the preparation method described in the above-described technical solution in space telescopes or space probes. This invention does not impose any special limitations on the specific implementation of the application; any process well-known to those skilled in the art can be used.

[0057] To further illustrate the present invention, a reflector, its preparation method, and its application are described in detail below with reference to the accompanying drawings and embodiments. However, these descriptions should not be construed as limiting the scope of protection of the present invention.

[0058] Example 1

[0059] The single-crystal silicon substrate was ultrasonically treated sequentially in RCA solution and water. The ultrasonically treated substrate was then placed in a vacuum magnetron sputtering machine. Under an argon atmosphere, using elemental silicon as the target material, an 8 nm thick silicon layer was grown on the surface of the substrate by magnetron sputtering. The magnetron sputtering conditions were: sputtering power of 110 W, sputtering voltage of 415 V, sputtering pressure of 0.28 Pa, vacuum degree of 2E-4 Pa, and time of 8 seconds.

[0060] A 2 nm thick metallic rhodium layer was grown on the surface of a single silicon layer by magnetron sputtering under an argon atmosphere using elemental rhodium as the target material. The magnetron sputtering conditions were: sputtering power of 155 W, sputtering voltage of 350 V, sputtering pressure of 0.28 Pa, vacuum degree of 2E-4 Pa, and time of 2.5 seconds.

[0061] Under an argon atmosphere, using silicon carbide as the target, an 8 nm thick silicon carbide layer was grown on the surface of a rhodium layer by magnetron sputtering. The magnetron sputtering parameters were: sputtering power of 130 W, sputtering voltage of 372 V, sputtering pressure of 0.28 Pa, vacuum degree of 2E-4 Pa, and time of 8 seconds. The repetition period of the reflective film unit was 30, resulting in a reflective substrate.

[0062] A 5 nm thick tungsten metal layer was grown on the surface of a silicon carbide layer by magnetron sputtering under an argon atmosphere using tungsten metal as the target material. The magnetron sputtering conditions were: sputtering power of 75 W, sputtering voltage of 292 V, sputtering pressure of 0.28 Pa, vacuum degree of 2E-4 Pa, and time of 4 seconds. After deposition, the layer was allowed to cool naturally to room temperature. Then, it was heated to 250 °C in a vacuum environment for annealing, held at that temperature for 2 hours, and cooled to room temperature to obtain the reflector.

[0063] Comparative Example 1

[0064] The mirror was prepared according to the method of Example 1, except that the reflective film unit of Comparative Example 1 did not include a rhodium layer.

[0065] Performance testing

[0066] Test Example 1

[0067] X-ray diffraction tests were performed on the mirrors obtained in Example 1 and Comparative Example 1, and the resulting XRD patterns are shown below. Figures 1-2 As shown, where Figure 1 Example 1, Figure 2 For Comparative Example 1, by Figures 1-2 As can be seen, the reflector provided by the present invention has an increased bandwidth of one diffraction peak compared to Comparative Example 1, and has a broadband diffraction effect.

[0068] Test Example 2

[0069] The reflectivity of the mirrors obtained in Example 1 and Comparative Example 1 was tested, and the test results are shown in Table 1.

[0070] Table 1. Reflectivity test results of the mirrors obtained in Example 1 and Comparative Example 1.

[0071] Example 1 Comparative Example 1 Test wavelength range 40eV~75eV 45eV~70eV reflectivity 3.8％～8.2％ 1.5％～1.2％

[0072] As can be seen from Table 1, the reflector obtained by the present invention maintains a relatively high reflectivity in the energy range of 40eV to 75eV, forming a high reflectivity plateau area, which greatly improves the adaptability of the reflector.

[0073] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. Other embodiments can be obtained based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A reflector, characterized in that, It consists of a substrate and a plurality of reflective film units and a tungsten metal layer sequentially stacked on the surface of the substrate; Each reflective film unit consists of a single-element silicon layer, a high atomic number metal layer, and a silicon carbide layer stacked sequentially from bottom to top; The number of repetition cycles of the reflective film unit is 30-50; in each reflective film unit, the thickness of the elemental silicon layer is 7-9 nm, the thickness of the high atomic number metal layer is 1-3 nm, the thickness of the silicon carbide layer is 7-9 nm, and the thickness of the tungsten metal layer is 4-6 nm; The silicon carbide layer and the tungsten metal layer of the reflective film unit are in contact; The high atomic number metal layer is made of Rh, Au, or Pt. The reflectivity of the mirror is 3.8-8.2% in the wavelength range of 40-75 eV.

2. The reflector according to claim 1, characterized in that, The substrate material includes monocrystalline silicon, quartz monocrystalline, fused silica glass, or K9 glass.

3. The method for preparing the reflector according to claim 1 or 2, characterized in that, Includes the following steps: A reflective substrate is obtained by periodically growing reflective film units on the substrate surface. A tungsten metal layer is grown on the surface of the silicon carbide layer of the reflective substrate, and then annealed to obtain the reflector.

4. The preparation method according to claim 3, characterized in that, The reflective film growth unit is a magnetron sputtering reflective film growth unit; The magnetron sputtering conditions for the single silicon layer of each reflective film unit include: sputtering power of 100~120W, sputtering voltage of 400~430V, sputtering pressure of 0.27~0.29Pa, vacuum degree of 2E-4Pa, and time of 7~9 seconds. The magnetron sputtering conditions for the high atomic number metal layer of each reflective film unit include: sputtering power of 150~160W, sputtering voltage of 345~355V, sputtering pressure of 0.27~0.29Pa, vacuum degree of 2E-4Pa, and time of 2~3 seconds. The magnetron sputtering conditions for the silicon carbide layer of each reflective film unit include: sputtering power of 120~140W, sputtering voltage of 366V~378V, sputtering pressure of 0.27~0.29Pa, vacuum degree of 2E-4Pa, and time of 7~9 seconds.

5. The preparation method according to claim 3, characterized in that, The grown tungsten metal layer is grown by magnetron sputtering. The conditions for growing a tungsten metal layer by magnetron sputtering include: sputtering power of 70~80W, sputtering voltage of 286~297V, sputtering pressure of 0.27~0.29Pa, vacuum degree of 2E-4Pa, and time of 3~5 seconds.

6. The preparation method according to claim 3, characterized in that, The annealing process is performed at a temperature of 200-300℃ for 110-130 minutes.

7. The preparation method according to any one of claims 3 to 6, characterized in that, Before growing the reflective film unit, the substrate is further subjected to a pretreatment to remove impurities.

8. The application of the reflector according to claim 1 or 2 or the reflector prepared by the preparation method according to any one of claims 3 to 7 in a space telescope or space probe.

Images