A reflector and its preparation method and application

Abstract

The present invention belongs to the field of optical thin film technology, and specifically relates to a reflector, a preparation method thereof, and an application thereof. The present invention provides a reflector comprising a substrate and a plurality of reflective film units and an aluminum oxide layer sequentially stacked on the surface of the substrate; each reflective film unit comprises a silicon-containing material layer, a metal aluminum layer, and a carbon layer sequentially stacked from bottom to top; the carbon layer and the aluminum oxide layer in the reflective film unit are in contact. The present invention can further improve the energy bandwidth of the composite film by adding a metal aluminum layer to the silicon / carbon composite film system; at an angle close to normal incidence, the reflector obtained by the present invention maintains a relatively high reflectivity within the energy range of 20eV to 40eV, forming a high reflection plateau, which greatly improves the application range of the reflector.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical films, and in particular relates to a reflector and a preparation method and application thereof. Background Art

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

[0003] Currently, the main spectral lines used for observation are helium and highly ionized iron. Mo / Si multilayers are the most commonly used composite film systems on reflectors. Mo / Si multilayers are primarily used in the 13.1nm wavelength band and offer high reflection efficiency and resolution, but their narrow energy bandwidth limits their use in space exploration. Summary of the Invention

[0004] The purpose of the present invention is to provide a reflector and a preparation method and application thereof. The reflector provided by the present invention has a wide energy bandwidth.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

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

[0007] Each reflective film unit comprises a silicon-containing material layer, a metal aluminum layer and a carbon layer stacked in sequence from bottom to top;

[0008] The carbon layer and the aluminum oxide layer in the reflective film unit are in contact with each other.

[0009] Preferably, the number of repetition periods of the reflective film unit is 50-100.

[0010] Preferably, the material of the silicon-containing material layer includes elemental silicon, silicon dioxide or silicon carbide.

[0011] Preferably, in each reflective film unit, the thickness of the silicon-containing material layer is 7-9 nm, the thickness of the metal aluminum layer is 2-3 nm, and the thickness of the carbon layer is 8-10 nm.

[0012] Preferably, the thickness of the aluminum oxide layer is 4 to 6 nm.

[0013] The present invention also provides a method for preparing the reflector described in the above technical solution, comprising the following steps:

[0014] Periodically growing reflective film units on the surface of a substrate to obtain a reflective substrate;

[0015] An aluminum oxide layer is grown on the surface of the carbon layer of the reflective substrate, and is subjected to annealing treatment to obtain the reflective mirror.

[0016] Preferably, the reflective film growing unit is a magnetron sputtering reflective film growing unit;

[0017] The magnetron sputtering conditions of the silicon-containing material layer of each reflective film unit include: sputtering power of 100-120W, sputtering voltage of 400V-430V, sputtering pressure of 0.27Pa, vacuum degree of 2*10 -4 Pa, time is 8 to 10 seconds;

[0018] The magnetron sputtering conditions of the metal aluminum layer of each reflective film unit include: sputtering power of 50-80W, sputtering voltage of 278-286V, sputtering pressure of 0.27Pa, vacuum degree of 2*10 -4 Pa, time is 2 to 3 seconds;

[0019] The magnetron sputtering conditions of the carbon layer of each reflective film unit include: sputtering power of 60-90W, sputtering voltage of 345-367V, sputtering pressure of 0.27Pa, vacuum degree of 2*10 -4 Pa, time is 8 to 10s.

[0020] Preferably, the grown aluminum oxide layer is a magnetron sputtering grown aluminum oxide layer;

[0021] The conditions for growing the aluminum oxide layer by magnetron sputtering include: sputtering power of 60 to 80 W, sputtering voltage of 266 to 273 V, sputtering pressure of 0.27 Pa, and vacuum of 2*10 -4 Pa, time is 4 to 6s.

[0022] Preferably, the annealing treatment temperature is 200-300° C., and the holding time is 18-22 minutes.

[0023] The present invention also provides the use of the reflector described in the above technical solution or the reflector prepared by the preparation method described in the above technical solution in a space telescope or a space probe.

[0024] The present invention provides a reflector comprising a substrate and a plurality of reflective film units and an aluminum oxide layer sequentially stacked on the substrate surface. Each reflective film unit comprises a silicon-containing material layer, a metallic aluminum layer, and a carbon layer stacked sequentially from bottom to top. The carbon layer and the aluminum oxide layer in the reflective film unit are in contact. By adding a metallic aluminum layer to the silicon / carbon composite film system, the present invention further broadens the energy bandwidth of the composite film. At angles of near-normal incidence (grazing incidence angle of 85°), the reflector obtained by the present invention maintains a relatively high reflectivity within the energy range of 20eV to 40eV, forming a high-reflectivity plateau, significantly expanding the reflector's applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is the XRD pattern of the reflector obtained in Example 1. DETAILED DESCRIPTION

[0026] The present invention provides a reflector, comprising a substrate and a plurality of reflective film units and an aluminum oxide layer sequentially stacked on the surface of the substrate;

[0027] Each reflective film unit comprises a silicon-containing material layer, a metal aluminum layer and a carbon layer stacked in sequence from bottom to top;

[0028] The carbon layer and the aluminum oxide layer in the reflective film unit are in contact with each other.

[0029] In the present invention, the substrate preferably includes single crystal silicon, single crystal quartz, fused silica glass or K9 glass. The present invention has no particular limitation on the thickness of the substrate, and any thickness known to those skilled in the art can be used.

[0030] In the present invention, the number of repetition periods of the reflective film unit is preferably 50 to 100, more preferably 60 to 90, and even more preferably 70 to 80.

[0031] In the present invention, the material of the silicon-containing material layer preferably includes elemental silicon, silicon dioxide, or silicon carbide. In the present invention, in each reflective film unit, the thickness of the silicon-containing material layer is preferably 7 to 9 nm, the thickness of the metal aluminum layer is preferably 2 to 3 nm, and the thickness of the carbon layer is preferably 8 to 10 nm.

[0032] In the present invention, the thickness of the aluminum oxide layer is preferably 4 to 6 nm, more preferably 4 to 5 nm. In the present invention, the aluminum oxide layer has a dense structure, which can protect the reflective film unit from damage and corrosion and improve the reflectivity.

[0033] The present invention also provides a method for preparing the reflector described in the above technical solution, comprising the following steps:

[0034] Periodically growing reflective film units on the surface of a substrate to obtain a reflective substrate;

[0035] An aluminum oxide layer is grown on the surface of the carbon layer of the reflective substrate, and is subjected to annealing treatment to obtain the reflective mirror.

[0036] In the present invention, unless otherwise specified, all raw materials are commercially available products well known to those skilled in the art.

[0037] The present invention periodically grows reflective film units on the surface of a substrate to obtain a reflective substrate.

[0038] Before growing the reflective film unit, the present invention preferably further includes performing a pretreatment of the substrate to remove impurities; the pretreatment of the substrate to remove impurities preferably includes sequentially performing ultrasonic treatment in the cleaning solution and water.

[0039] In the present invention, the cleaning solution is preferably an RCA solution; the RCA solution preferably includes ammonia water and hydrogen peroxide. The present invention has no particular limitation on the concentration of the RCA solution, and a process well known to those skilled in the art can be used.

[0040] The present invention does not specifically limit the process of ultrasonic treatment in the cleaning solution and water, and can be performed using a process well known to those skilled in the art. In the present invention, ultrasonic treatment in the RCA solution can remove particles and dust from the substrate surface, while cleaning in water can remove residual cleaning solution from the substrate surface.

[0041] In the present invention, the reflective film growing unit is a magnetron sputtering reflective film growing unit. In the present invention, the magnetron sputtering is preferably performed in an argon atmosphere.

[0042] In the present invention, the magnetron sputtering conditions of the silicon-containing material layer of each reflective film unit preferably include: sputtering power of 100-120W, sputtering voltage of 400V-430V, sputtering pressure of 0.27Pa, vacuum degree of 2*10 -4 Pa, time is 8 to 10s.

[0043] In the present invention, the magnetron sputtering conditions of the metal aluminum layer of each reflective film unit preferably include: sputtering power of 50 to 80 W, sputtering voltage of 278 to 286 V, sputtering pressure of 0.27 Pa, vacuum degree of 2*10 -4 Pa, time is 2 to 3s.

[0044] In the present invention, the magnetron sputtering conditions of the carbon layer of each reflective film unit preferably include: sputtering power of 60 to 90 W, sputtering voltage of 345 to 367 V, sputtering pressure of 0.27 Pa, and vacuum degree of 2*10 -4 Pa, time is 8 to 10s.

[0045] The present invention has no special limitation on the magnetron sputtering process, and the process well known to those skilled in the art can be used.

[0046] After obtaining the reflective substrate, the present invention grows an aluminum oxide layer on the surface of the carbon layer of the reflective substrate, and performs annealing treatment to obtain the reflective mirror.

[0047] In the present invention, the aluminum oxide layer is preferably grown by magnetron sputtering. In the present invention, the magnetron sputtering is preferably performed in an argon atmosphere.

[0048] In the present invention, the conditions for the magnetron sputtering growth of the aluminum oxide layer preferably include: sputtering power of 60 to 80 W, sputtering voltage of 266 to 273 V, sputtering pressure of 0.27 Pa, and vacuum of 2*10 -4 Pa, time is 4 to 6s.

[0049] After the growth of the aluminum oxide layer is completed, the present invention preferably further comprises naturally cooling the obtained substrate to room temperature.

[0050] In the present 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 18-22 minutes. In the present invention, the annealing is preferably performed under vacuum conditions. In the present invention, the annealing can eliminate stress in the coating layer.

[0051] After the annealing treatment, the present invention preferably further comprises naturally cooling the obtained substrate to room temperature.

[0052] The present invention also provides the use of the reflector described in the above technical solution or the reflector produced by the production method described in the above technical solution in a space telescope or space probe. The present invention does not particularly limit the specific implementation of the application, and the application can be carried out using a process well known to those skilled in the art.

[0053] In order to further illustrate the present invention, a reflector provided by the present invention, its preparation method and application are described in detail below with reference to the accompanying drawings and embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0054] Example 1

[0055] The single crystal silicon substrate was ultrasonically treated in RCA solution and water in turn. The ultrasonically treated substrate was placed in a vacuum magnetron coating machine. Under an argon atmosphere, a single silicon layer with a thickness of 8 nm was grown on the surface of the substrate by magnetron sputtering using single silicon as the target material. The magnetron sputtering conditions were as follows: sputtering power of 110 W, sputtering voltage of 415 V, sputtering pressure of 0.27 Pa, and vacuum degree of 2*10-4 Pa, time is 8s;

[0056] In an argon atmosphere, a 2 nm thick aluminum layer was grown on the surface of the silicon layer by magnetron sputtering using aluminum as the target. The conditions for magnetron sputtering were as follows: sputtering power 65 W, sputtering voltage 278 V, sputtering pressure 0.27 Pa, and vacuum degree 2*10 -4 Pa, time is 2 to 3 seconds;

[0057] In an argon atmosphere, a carbon layer with a thickness of 10 nm was grown on the surface of the metal aluminum layer by magnetron sputtering using a pure carbon cathode target as a carbon source. The magnetron sputtering conditions were as follows: sputtering power 75 W, sputtering voltage 345 V, sputtering pressure 0.27 Pa, and vacuum degree 2*10 -4 Pa, the time is 8 to 10 s; the repetition period of the reflective film unit is 50, and a reflective substrate is obtained;

[0058] In an argon atmosphere, a 6 nm thick aluminum oxide layer was grown on the surface of the carbon layer by magnetron sputtering. The conditions of magnetron sputtering were: sputtering power 70 W, sputtering voltage 266 V, sputtering pressure 0.27 Pa, and vacuum degree 2*10 -4 After the plating is completed, it is naturally cooled to room temperature; then, it is heated to 200° C. under vacuum conditions for annealing, the heat preservation time is 20 minutes, and it is cooled to room temperature to obtain the reflecting mirror.

[0059] Comparative Example 1

[0060] A reflecting mirror was prepared in the same manner as in Example 1, except that the reflecting film unit did not include a metal aluminum layer.

[0061] Comparative Example 2

[0062] A reflector was prepared in the same manner as in Example 1, except that the aluminum oxide layer was not included.

[0063] Performance Testing

[0064] Test Example 1

[0065] The reflector obtained in Example 1 was subjected to an X-ray diffraction test, and the obtained XRD pattern was as follows: Figure 1 As shown by Figure 1 It can be seen that the reflector provided by the present invention increases the bandwidth of a diffraction peak and has a broadband diffraction effect.

[0066] Test Example 2

[0067] The reflectivity of the reflectors obtained in Example 1 and Comparative Examples 1-2 was tested, and the test results are shown in Table 1.

[0068] Table 1 Reflectivity test results of the reflectors obtained in Example 1 and Comparative Examples 1-2

[0069] Example 1 Comparative Example 1 Comparative Example 2 Test wavelength range 20eV~40eV 20eV~40eV 20eV~40eV Reflectivity 20％～62％ 3％～8.3％ 18％～33％ Highest reflectivity 62％ 8.3％ 33％

[0070] As can be seen from Table 1, the reflector obtained by the present invention maintains a relatively high reflectivity in the energy range of 20 eV to 40 eV, forming a high reflection plateau area, which greatly improves the applicable range of the reflector.

[0071] Although the above embodiment provides a detailed description of the present invention, it is only a part of the embodiments of the present invention, not all of the embodiments. Other embodiments can be obtained based on this embodiment without creativity, and these embodiments all fall within the scope of protection of the present invention.

Claims

1. A reflector, characterized in that: It consists of a substrate and a plurality of reflective film units and an aluminum oxide layer stacked in sequence on the surface of the substrate; Each reflective film unit comprises a silicon-containing material layer, a metal aluminum layer and a carbon layer stacked in sequence from bottom to top; The carbon layer and the aluminum oxide layer in the reflective film unit are in contact; The reflectivity of the reflector in the wavelength range of 20 to 40 eV is 20 to 62%.

2. The reflector according to claim 1, wherein: The number of repetition periods of the reflective film unit is 50 to 100.

3. The reflector according to claim 1, wherein: The material of the silicon-containing material layer includes elemental silicon, silicon dioxide or silicon carbide.

4. The reflecting mirror according to any one of claims 1 to 3, wherein In each reflective film unit, the thickness of the silicon-containing material layer is 7-9 nm, the thickness of the metal aluminum layer is 2-3 nm, and the thickness of the carbon layer is 8-10 nm.

5. The reflector according to claim 1, wherein: The thickness of the aluminum oxide layer is 4-6 nm.

6. The method for preparing a reflector according to any one of claims 1 to 5, characterized in that: The following steps are involved: Periodically growing reflective film units on the surface of a substrate to obtain a reflective substrate; An aluminum oxide layer is grown on the surface of the carbon layer of the reflective substrate, and is annealed to obtain the reflective mirror.

7. The preparation method according to claim 6, characterized in that The reflective film growing unit is a magnetron sputtering reflective film growing unit; The magnetron sputtering conditions of the silicon-containing material layer of each reflective film unit include: sputtering power of 100-120W, sputtering voltage of 400-430V, sputtering pressure of 0.27Pa, vacuum degree of 2*10 -4 Pa, time is 8 to 10 seconds; The magnetron sputtering conditions of the metal aluminum layer of each reflective film unit include: sputtering power of 50-80W, sputtering voltage of 278-286V, sputtering pressure of 0.27Pa, vacuum degree of 2*10 -4 Pa, time is 2 to 3 seconds; The magnetron sputtering conditions of the carbon layer of each reflective film unit include: sputtering power of 60-90W, sputtering voltage of 345-367V, sputtering pressure of 0.27Pa, vacuum degree of 2*10 -4 Pa, time is 8 to 10s.

8. The preparation method according to claim 6, characterized in that The grown aluminum oxide layer is a magnetron sputtering grown aluminum oxide layer; The conditions for magnetron sputtering to grow the aluminum oxide layer include: sputtering power of 60 to 80 W, sputtering voltage of 266 to 273 V, sputtering pressure of 0.27 Pa, and vacuum of 2*10 -4 Pa, time is 4 to 6s.

9. The preparation method according to claim 6, characterized in that The annealing treatment temperature is 200-300° C., and the holding time is 18-22 minutes.

10. Use of the reflector according to any one of claims 1 to 5 or the reflector prepared by the preparation method according to any one of claims 6 to 9 in a space telescope or a space probe.

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