A method for preparing AR+AF films using etching and graphite bombardment processes

Abstract

This invention discloses a method for preparing an AR+AF film using etching and graphite bombardment processes. First, etching is performed on the AR film. An inert gas, an etching gas, and O2 are introduced into an ion source region. A substrate coated with the AR film is then placed into the ion source region, where the ionized gas etches the AR surface. Next, graphite bombardment is performed while inert gas and O2 are simultaneously introduced. Finally, an AF film is deposited on the AR film surface. This invention achieves a high-wear-resistance, long-life, and strong adhesion between the AR and AF layers through micro-etching and graphite bombardment treatment on the AR film surface, without affecting the product's optical performance. This method is applicable to AR films of various materials and thicknesses with SiO2 as the outermost layer on different substrates.

Description

Technical Field

[0001] This invention belongs to the field of coating technology, specifically a method for preparing AR+AF films using etching and graphite bombardment processes. Background Technology

[0002] Due to various demands for energy conservation and anti-reflection, there are diverse requirements for coating various AR (Anti-Reflective) films onto various substrates, including glass, PC, PET, PMMA, metals, and ceramics. The demand for AR anti-reflective films is increasing. For example, to reduce energy consumption and minimize outdoor reflections on mobile phone cover glass, many mobile phone front cover windows require AR coatings. The demand for AR coatings on automotive center console screens is also growing. Currently, AR films on mobile phone cover glass and automotive center console screens are generally used in conjunction with AF (Anti-Frequency) films, forming an AR+AF film. This achieves simultaneous anti-reflection and anti-reflection effects, while also providing fingerprint resistance, stain resistance, and easy cleaning.

[0003] To meet various anti-reflection and optical requirements, the thickness and number of AR (Anti-reflective) films vary accordingly, becoming thicker and more layered. As the AR film thickness changes, the surface roughness and morphology become more complex. Generally, the thicker the film and the more layers, the greater the surface roughness, and the more uncontrollable the surface morphology becomes, exhibiting various abnormal sharp points. This uncontrollability of AR surface morphology and roughness further complicates the subsequent AF (Anti-aft) process, significantly impacting AR+AF surface properties such as abrasion resistance and lifespan. Therefore, post-AR processing is necessary on the AR surface.

[0004] Conventional AR post-treatments include PLASMA, linear ion source treatment, RF ion source treatment, Hall ion source treatment, and ICP treatment. However, these treatments are essentially superficial, only providing a slight surface impact and resulting in poor treatment effects. Currently, the overall abrasion resistance level of AR+AF in the industry is as follows: under normal conditions (abrasion resistance conditions: 1 kg 0000# steel wool, frequency 60 times / min, stroke 50mm), after 2000 abrasion cycles, the water droplet angle is generally less than 100 degrees, mostly remaining at the level of 70-90 degrees. Currently, attempts to use various commonly used post-treatment processes have also shown that it is difficult to maintain a water droplet angle greater than 100 degrees after 2000 abrasion cycles, generally remaining at a level of 80-100 degrees. Summary of the Invention

[0005] To address the aforementioned problems in existing technologies, the purpose of this invention is to provide a method for preparing AR+AF films using etching and graphite bombardment processes. By superimposing micro-etching and graphite bombardment treatment on the AR film surface, a high-wear-resistance, long-life AR+AF film with strong adhesion between AR and AF is obtained, without affecting the product's optical performance. Micro-etching transforms the inconsistent surface roughness of the AR film into a uniform pattern. Graphite bombardment treatment increases the number of hydroxyl groups after micro-etching and removes residual macromolecular clusters and other residues left after micro-etching, achieving a cleaning effect. This method is applicable to AR films of various materials and thicknesses with SiO2 as the outermost layer on different substrates.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] An AR+AF film preparation method with etching and graphite bombardment processes is disclosed. First, etching is performed on the AR film. Inert gas, etching gas and O2 are introduced into the ion source region. The substrate coated with AR film is sent into the ion source region. The ionized gas etches the AR surface. Then, graphite bombardment is performed while inert gas and O2 are introduced. Finally, an AF film is deposited on the AR film surface.

[0008] As a further improvement to the above technical solution:

[0009] The inert gas is Ar, the ion source is an ICP ion source, and the power supply for the ICP is an RF power supply.

[0010] The etching gas is one of CF4, SF6, CHF3, NF3, C2F6, and BCl3.

[0011] During etching, different thicknesses of the AR film surface are etched by controlling the gas flow rate, RF power, and etching time. The etching is completed when the spectral reflectance and water droplet angle of the etched AR film reach the set range. During graphite bombardment, different degrees of treatment of the AR film surface are achieved by controlling the gas flow rate, power supply, and processing time. The graphite bombardment is completed when the water droplet angle reaches the set value.

[0012] During graphite bombardment, different degrees of treatment on the AR film surface are achieved by controlling the flow ratio of Ar and O2, power supply and processing time. Graphite bombardment is completed when the water droplet angle reaches below 10°.

[0013] The etching is complete when the water droplet angle of the etched AR film is greater than 100 degrees.

[0014] The thickness of the AR film before etching is equal to the sum of the target thickness and the etched thickness.

[0015] During etching, the RF power is 1–10 kW, the Ar gas flow rate is 20–1000 sccm, the etching gas flow rate is 50–5000 sccm, the O2 flow rate is 10–2000 sccm, and the etching time is 30–300 s.

[0016] During graphite bombardment, the power supply is 1–20 kW, the Ar flow rate is 20–2000 sccm, the O2 flow rate is 10–2000 sccm, and the processing time is 1–30 min.

[0017] The outermost layer of the AR film on the substrate is SiO2.

[0018] The beneficial effects of this invention are: by micro-etching and graphite bombardment treatment on the surface of the AR film, an AR+AF film with high wear resistance, long life, and strong adhesion between AR and AF is obtained, and the optical performance of the product is not affected. The micro-etching treatment makes the surface roughness of the AR film change from inconsistent to regular and consistent. The graphite bombardment treatment increases the hydroxyl groups after micro-etching treatment on the one hand, and reacts away the residual macromolecular clusters and other residues left after micro-etching treatment on the other hand, achieving a cleaning effect. The method is applicable to AR films of various materials and thicknesses with SiO2 as the outermost layer of different substrates. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the preparation method of the AR+AF membrane of the present invention.

[0020] Figure 2 This is a spectral variation diagram of the products obtained by etching the second AR film layer (unetched) and the second AR film layer under five etching processes according to the present invention.

[0021] Figure 3 This is a spectral variation diagram of the first AR film layer without etching and the products obtained by etching the first AR film layer under five different etching processes.

[0022] Figure 4 This is the first unetched AR film surface roughness microscopic AFM image of this invention.

[0023] Figure 5 This is the first AR film surface roughness microscopic AFM image etched by etching process 3 in this invention.

[0024] Figure 6 This is a graph showing the spectral transmittance of the substrate and the same AR film etched under the same etching process parameters, and then processed with graphite under six sets of process parameters.

[0025] Figure 7This is an average spectral transmittance diagram in the range of 380nm to 780nm for products etched with the substrate and the same AR film under the same etching process parameters, after graphite treatment under six sets of process parameters.

[0026] Figure 8 This is a graph showing the spectral reflectance of the substrate and the same AR film etched under the same etching process parameters, after being processed with graphite under six sets of process parameters.

[0027] Figure 9 The average spectral reflectance of the substrate and the same AR film etched under the same etching process parameters of this invention, after graphite treatment under six sets of process parameters, is within the range of 380nm to 780nm.

[0028] Figure 10 This is a graph showing the spectral absorption rate of the substrate and the same AR film etched under the same etching process parameters, and then processed with graphite under six sets of process parameters.

[0029] Figure 11 This is a graph showing the average spectral absorption rate of the substrate and the same AR film etched under the same etching process parameters, after graphite treatment under six sets of process parameters, within the range of 380nm to 780nm. Detailed Implementation

[0030] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0031] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0032] A method for preparing an AR+AF film using etching and graphite bombardment processes is disclosed. First, micro-etching is performed on the AR film. Ar gas, etching gas, and O2 are introduced into an ICP ion source region. A substrate coated with the AR film is then introduced into the ion source region. The ionized gas etches the AR surface. The etching process parameters are: RF power range 1–10 kW, Ar gas flow rate range 20–1000 sccm, etching gas flow rate range 50–5000 sccm, and O2 gas flow rate... The etching process ranges from 10 to 2000 sccm, with an etching time of 30 to 300 seconds. Then, the AR surface is bombarded with graphite. Ar and O2 gases are introduced into the graphite bombardment target area. The power supply for graphite bombardment is set to 1 to 20 kilowatts, with Ar as the working gas and a flow rate of 20 to 2000 sccm, and O2 as the reactive gas with a flow rate of 10 to 2000 sccm. The processing time is 1 to 30 minutes. Finally, an AF coating is applied to the AR film surface.

[0033] The etching process is complete when the spectral reflectance and water droplet angle of the etched AR film reach the set range.

[0034] The graphite bombardment treatment is complete when the water droplet angle after graphite bombardment reaches a set value. The water droplet angle is measured on the AR surface. The level of the water droplet angle after treatment can be used to assess the hydroxyl level of the AR surface, i.e., the level of dehydration condensation. Generally, the water droplet angle of the AR film surface after graphite bombardment treatment can reach below 10 degrees. The smaller the water droplet angle, the higher the hydroxyl level, and the greater the adhesion between the AR film and the AF film during subsequent deposition. Preferably, in this scheme, the requirement is met when the water droplet angle of the AR film surface after graphite bombardment treatment reaches below 10 degrees.

[0035] During graphite bombardment, graphite deposits a layer of carbon (C) on the substrate without oxygen. When appropriate amounts of O2 are added during C deposition, a process called C + O2 = CO2 occurs, reacting the potentially deposited C film into CO2, which is then released. Therefore, adding O2 during graphite bombardment allows the C and O2 on the AR film to react during the bombardment process. Simultaneously, particles in the atmosphere react with some organic matter on the substrate, thus achieving a cleaning effect. It also increases the -OH groups on the AR film surface, promoting dehydration and condensation during subsequent AF (aluminum oxide) film formation, increasing the adhesion and contact area of ​​the AF on the AR surface. In summary, graphite post-treatment increases the number of hydroxyl groups (-OH) after micro-etching and reacts to remove residual macromolecular clusters and other residues left after micro-etching, achieving a cleaning effect.

[0036] The ICP is inductively coupled plasma, which is the ion source, and RF is the power source for the ICP.

[0037] After micro-etching, the droplet angle of the AR surface needs to be measured. The level of the droplet angle after processing can be used to evaluate the roughness level of the AR surface. When the droplet angle of the AR surface is greater than 90 degrees, the micro-etched surface is effectively treated, indicating that the surface roughness of the AR gradually becomes uniform. Ideally, the droplet angle of the AR surface after micro-etching should be greater than 100 degrees.

[0038] Preferably, the outermost layer of the AR film on the substrate is SiO2.

[0039] In this embodiment, the etching gas is CF4. During etching, Ar, CF4, and O2 gases are introduced into the ICP ion source region, and the power supply to each device in the ion source region is turned on, with the plasma excited by radio frequency. During the electron collision ionization process, various ions are generated, such as CF4. 3+ CF 2+ O 2+ O - and F - The electron collision decomposition process generates free radicals such as CF3, CF2, O, and F. Chemical reactions occurring in the gas phase and on the SiO2 surface of the AR film produce other molecules, such as CO, CO2, SiF2, and SiF4, achieving the effect of etching the SiO2 surface of the AR film. The concentration and energy distribution of these particles affect the performance indicators of the entire AR surface treatment process, such as the etching rate and the etched thickness. Therefore, the etch thickness can be controlled by adjusting the gas flow rate, RF power, and etching time.

[0040] The preparation method of the AR+AF film is as follows: Figure 1 As shown, it is:

[0041] Step S1: Substrate pretreatment. The pretreatment mainly refers to cleaning and heating.

[0042] Step S2: AR deposition.

[0043] Step S3: AR surface micro-etching treatment.

[0044] Step S4: The AR surface is bombarded with graphite.

[0045] Step S5: Apply AF coating to the AR surface.

[0046] In step S2, the outermost layer of the deposited AR film structure is SiO2. Table 1 shows a film structure applicable to the above process method, where the film layer directly in contact with the substrate is the first layer, and the topmost film layer is the last layer. The last layer of the AR film is generally a low-refractive-index material, SiO2, which also forms the basis for the special treatments in steps S3 and S4, allowing for etching and graphite bombardment of the SiO2 film layer. The first layer uses the low-refractive-index material SiO2 as the bonding layer between the AR and the substrate, increasing the adhesion between them. Nb2O5, Si3N4, and TiO2 are high-refractive-index materials for AR. The AR is based on a HL film stack consisting of Nb2O5, Si3N4, TiO2, and SiO2. An HL film stack refers to a stack of high-refractive-index and low-refractive-index materials, as shown in Table 1 where the first and second layers form an HL film stack.

[0047] Table 1 shows a membrane structure applicable to this scheme.

[0048] number of floors Material Last layer <![CDATA[SiO2]]> Second to last floor <![CDATA[Nb2O5 / Si3N4 / TiO2, etc.]]> Multiple membrane stacks ........ Fifth floor <![CDATA[SiO2]]> Fourth floor <![CDATA[Nb2O5 / Si3N4 / TiO2, etc.]]> Third layer <![CDATA[SiO2]]> Second floor <![CDATA[Nb2O5 / Si3N4 / TiO2, etc.]]> First layer <![CDATA[SiO2]]> substrate Glass / (organic substrates such as PC, PET, PMMA, etc.) / Metal / Ceramic, etc.

[0049] Based on the above membrane structure, in this embodiment, two AR membranes are prepared. The structure of the first AR membrane is shown in Table 2, and the structure of the second AR membrane is shown in Table 3.

[0050] Table 2. First AR film structure

[0051] number of floors Material Film thickness(nm) Seventh floor <![CDATA[SiO2]]> 90.2 Sixth floor <![CDATA[Nb2O5]]> 36.01 Fifth floor <![CDATA[SiO2]]> 5.09 Fourth floor <![CDATA[Nb2O5]]> 71.4 Third layer <![CDATA[SiO2]]> 31.65 Second floor <![CDATA[Nb2O5]]> 14.94 First layer <![CDATA[SiO2]]> 20 substrate Glass

[0052] Table 3. Second type of AR film structure

[0053] number of floors Material Film thickness(nm) Fifth floor <![CDATA[SiO2]]> 89.1 Fourth floor <![CDATA[Si3N4]]> 137.28 Third layer <![CDATA[SiO2]]> 37.1 Second floor <![CDATA[Si3N4]]> 15.64 First layer <![CDATA[SiO2]]> 20 substrate Glass

[0054] In this embodiment, step S3, namely etching, is performed on the two AR film layers mentioned above. Each AR film layer is etched under one of the five processes listed in Table 4.

[0055] Table 4. Five Etching Process Parameters

[0056] ICP-RF-P(KW) Ar(SCCM) CF4(SCCM) O2(SCCM) Etching time Etching process 1 1~10KW 20～1000 50～5000 10～2000 30 Etching process 2 1~10KW 20～1000 50～5000 10～2000 60 Etching process 3 1~10KW 20～1000 50～5000 10～2000 90 Etching process 4 1~10KW 20～1000 50～5000 10～2000 120 Etching process 5 1~10KW 20～1000 50～5000 10～2000 150

[0057] Based on Table 4, five sets of process parameters were selected, with each set differing only in etching time. The first and second AR films were etched under these five sets of process parameters. The spectral changes of the un-etched first AR film and the products etched under the five etching processes are shown below. Figure 3 As shown, the spectral changes of the products obtained by etching the unetched second AR film layer and the second AR film layer under five etching processes are as follows: Figure 2As shown. At this time, the thicknesses of the first type of AR film layer etched under etching processes 1, 2, 3, 4, and 5 are 3nm, 6nm, 9nm, 12nm, and 15nm, respectively; the thicknesses of the second type of AR film layer etched under etching processes 1, 2, 3, 4, and 5 are 3nm, 6nm, 9nm, 12nm, and 15nm, respectively. Figure 2 and Figure 3 The horizontal axis represents wavelength (nm), and the vertical axis represents reflectivity (%).

[0058] Depend on Figure 2 and Figure 3 It can be seen that as the etching time increases, the reflectivity of the products obtained by etching the first AR film layer and the products obtained by etching the second AR film layer gradually increases in the wavelength range of 500nm to 780nm. This indicates that the thickness of the AR film layer changes as the etching proceeds, meaning that this solution achieves the etching effect.

[0059] As can be seen from the above, different etching times result in different etching amounts or etching thicknesses. In order to ensure that the thickness of the AR film after etching is the design value and to obtain the required optical performance of the AR film, the thickness of the AR film before etching should be greater than the design value to reserve or compensate for the thickness to be etched. For example, for the first type of AR film layer structure, the thickness of the last SiO2 layer needs to be 90.2 nm. The thickness of the AR film prepared before etching for AR films that do not require etching and those that need to be etched under the five sets of process parameters mentioned above is shown in Table 5. The unit of thickness of each layer in the table is nm.

[0060] Table 5. Thickness of each AR film layer before etching, including those requiring no etching process and those requiring the above five etching processes.

[0061] Membrane system 1 Membrane System 2 Membrane system 3 Membrane system 4 Membrane system 5 Membrane system 6 Level 1 20 20 20 20 20 20 2nd floor 14.94 14.94 14.94 14.94 14.94 14.94 3rd floor 31.65 31.65 31.65 31.65 31.65 31.65 4th floor 71.4 71.4 71.4 71.4 71.4 71.4 5th floor 5.09 5.09 5.09 5.09 5.09 5.09 6th floor 36.01 36.01 36.01 36.01 36.01 36.01 7th floor 90.2 93.2 96.2 99.2 102.2 105.2 Etching No etching required Etching process 1 Etching process 2 Etching process 3 Etching process 4 Etching process 5

[0062] Based on Table 5, the thickness of the AR film layer after etching through each process is the design value.

[0063] The first AR film structure exhibited water droplet angles of 34.616°, 55°, 75°, 104.522°, 104.201°, and 101.828° under the five sets of process parameters (correlation processes 1, 2, 3, 4, and 5) without etching. It can be seen that the water droplet angle changes significantly with increasing etching time or etching amount, gradually increasing in size. This indicates a significant improvement in the AR surface roughness, suggesting that the AR surface roughness gradually becomes more uniform. When the water droplet angle on the AR surface exceeds 90 degrees, the micro-etched surface is effectively treated.

[0064] The surface roughness microscopic AFM images of the first AR film structure before etching and after etching process 3 are shown below. Figure 4 and 5 As shown, the untreated AR surface exhibits many irregular protrusions and peaks. After micro-etching, the irregular protrusions and peaks are preferentially etched away, and the remaining AR surface particles tend to be regular and uniform.

[0065] Etching in the semiconductor field is a completely destructive process; for example, etching Si and SiO2 completely etches a designated area. In this solution, during etching, the SiO2 layer on the AR surface is etched layer-by-layer while ensuring that the original AR optical performance is not affected. The spikes on the AR surface are most active when in contact with the etching plasma; these are removed first. After the spikes and other protrusions are removed, the AR surface is etched uniformly, but the thickness is controlled accordingly—this is called micro-etching. In other words, the etching of the AR surface is micro-etching, meaning that the optical performance of the AR itself must not be damaged or affected, while effectively etching the AR surface to make it suitable for further processes or to give it better optical performance due to the etching process.

[0066] After the AR film etching was completed, the product was subjected to graphite bombardment. In order to verify the effect of graphite bombardment on the optical performance of the product, the product with the same AR film etched under the same process parameters was subjected to graphite bombardment under the six processes in Table 6.

[0067] Table 6. Parameters of Six Graphite Bombardment Processes

[0068] power Argon oxygen time Oxygen / Argon Ratio Process 1 1~20KW 50~1000sccm 0~2000sccm 0~30min 25％ Process 2 1~20KW 50~1000sccm 0~2000sccm 0~30min 50％ Process 3 1~20KW 50~1000sccm 0~2000sccm 0~30min 75％ Process 4 1~20KW 50~1000sccm 0~2000sccm 0~30min 100％ Process 5 1~20KW 50~1000sccm 0~2000sccm 0~30min 125％ Process 6 1~20KW 50~1000sccm 0~2000sccm 0~30min 150％

[0069] Based on Table 6, six sets of process parameters were selected for the experiment. The only difference between the two sets of process parameters was the oxygen / argon flow ratio, while the power and time were the same. Figure 6 The graph shows the spectral transmittance of a product etched with the same substrate and AR film under the same etching process parameters, and then treated with graphite under six different sets of process parameters. Figure 7 For substrate and Figure 6 The corresponding processed products show the average spectral transmittance of the products within the 380nm–780nm range under six different processes. From... Figure 6 and Figure 7 The results show that when the oxygen-argon ratio is greater than 75%, the C coating is basically reacted into CO2, which will not affect the transmittance of the treated product.

[0070] Figure 8 The graph shows the spectral reflectance curves of the substrate and the same AR film etched under the same etching process parameters, after being treated with graphite under six sets of process parameters. Figure 9 For substrate and Figure 8 The corresponding processed products show the average reflectance curves within the 380nm–780nm range under six different processes. From... Figure 8 and Figure 9 The results show that when the oxygen-argon ratio is greater than 75%, the C coating is basically reacted into CO2, which will not affect the reflectivity of the treated product.

[0071] Figure 10 The images show the spectral absorption curves of products etched with the same AR film as the substrate under the same etching process parameters, after being treated with graphite under six sets of process parameters. Figure 10 For substrate and Figure 11 The corresponding processed products show the average absorbance curves within the 380nm–780nm range under six different processes. From... Figure 10 and Figure 11 The results show that when the oxygen-argon ratio is greater than 75%, the C coating is basically reacted into CO2, which will not affect the absorption rate of the treated product.

[0072] As can be seen from the above, when the oxygen-argon ratio is greater than 75%, graphite bombardment will not affect the optical performance of the processed products.

[0073] To verify the effect of graphite bombardment on the water droplet angle of the product, the substrate and the product after etching with the same AR film under the same process parameters were subjected to graphite bombardment under the six processes in Table 7, and the resulting water droplet angles are shown in Table 7.

[0074] Table 7 shows six graphite bombardment parameters and water droplet angles of the etched products of the substrate and the same AR film under the same process parameters.

[0075] Oxygen / Argon Ratio Test water droplet angle substrate 39 Process 1 25％ 38 Process 2 50％ 35 Process 3 75％ 24 Process 4 100％ 8 Process 5 125％ 7 Process 6 150％ 7

[0076] As shown in Table 7, when the oxygen-argon ratio of graphite bombardment is ≥100%, the water droplet angle is below 10°, indicating that the treatment effect on the substrate reaches a relatively ideal state at this time.

[0077] In step S5, the deposition method of AF can be vapor deposition, spraying, spin coating, etc.

[0078] The process and preparation method are carried out in a coating equipment. In this embodiment, the coating equipment includes three chambers arranged sequentially: a first chamber, a second chamber, and a third chamber. Valves isolate the first and second chambers, and the second and third chambers. The second chamber is the coating chamber. In this embodiment, the coating equipment used is the Hongda HD-SCK1600-ICP vacuum dual-chamber coating equipment.

[0079] Step S1 described above is performed in the first chamber, which is equipped with a reactive ion source and a heater to achieve cleaning and heating of the substrate. The coating chamber is equipped with a target area and an ion source area. The target area is equipped with multiple target materials, and an ICP ionization gas, namely inductively coupled plasma, is passed through the ion source area.

[0080] The coating chamber contains a substrate holder, which is a cylindrical drum. The substrate is fixed to the side of the cylindrical drum, and the drum rotates around the central axis of the drum, meaning the substrate revolves around the central axis. As the substrate rotates, it sequentially passes through the target area and the ion source area. When the substrate passes through the target area, multiple target materials are sequentially sputtered and deposited on the substrate to form the desired AR film layer. Controlling the number of rotations of the substrate allows for the determination of the required film layer and thickness. When the substrate passes through the ion source area, the gas introduced into the ion source area is ionized and reacts with the AR film layer to achieve an etching effect. Graphite bombardment is achieved through a C-target and is also completed in the coating chamber; that is, steps S2, S3, and S4 are all completed in the second chamber. Step S5 is completed in the third chamber.

[0081] It should be noted that the parameter control of the above coating process can adopt the existing technology, and will not be elaborated here.

[0082] After AR surface micro-etching superimposed graphite bombardment treatment, the wear resistance level of AR+AF is improved to 20,000 cycles greater than 100 degrees, and can be repeatedly stabilized at 5,000 cycles greater than 105 degrees in subsequent production.

[0083] Table 8 compares the wear resistance of AR+AF, AR+graphite treatment+AF, and AR+micro-etching+graphite treatment+AF. The wear resistance conditions were 1 kg of 0000# steel wool, a frequency of 60 cycles / min, and a stroke of 50 mm. The wear resistance was based on 2000 cycles as a baseline, followed by 5000, 10000, 15000, and 20000 cycles. The data in the table represent the water droplet angle values ​​in degrees.

[0084] Table 8 shows the wear resistance test results for AR+AF, AR+graphite-treated+AF, and AR+micro-etching+graphite-treated+AF.

[0085]

[0086] As shown in Table 8, the AR+AF film that has undergone AR surface micro-etching and graphite treatment in sequence has better wear resistance than the untreated film and the film that has only undergone graphite treatment.

[0087] Finally, it is necessary to state that the above embodiments are only used to further illustrate the technical solution of the present invention in detail, and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A method for preparing an AR+AF film using etching and graphite bombardment processes, characterized in that, First, etching is performed on the AR film. Inert gas, etching gas, and O2 are introduced into the ion source region. The substrate coated with the AR film is then fed into the ion source region. The ionized gas etches the AR surface, followed by graphite bombardment while inert gas and O2 are introduced simultaneously. Finally, an AF film is deposited on the AR film surface. The outermost layer of the AR film on the substrate is SiO2. During etching, different thicknesses of the AR film surface are etched by controlling the gas flow rate, the power of the ion source, and the etching time. Etching is completed when the spectral reflectance of the etched AR film reaches a set range and the water droplet angle is greater than 100 degrees. During graphite bombardment, different degrees of treatment of the AR film surface are achieved by controlling the flow ratio of Ar and O2, the power of the source, and the processing time. The flow ratio of Ar and O2 is greater than 75%, and graphite bombardment is completed when the water droplet angle reaches less than 10 degrees.

2. The preparation method according to claim 1, characterized in that: The inert gas is Ar, the ion source is an ICP ion source, and the power supply for the ICP is an RF power supply.

3. The preparation method according to claim 2, characterized in that: The etching gas is one of CF4, SF6, CHF3, NF3, C2F6, and BCl3.

4. The preparation method according to claim 1, wherein: The thickness of the AR film before etching is equal to the sum of the target thickness and the etched thickness.

5. The preparation method according to claim 3, characterized in that: During etching, the RF power is 1~10 kW, the Ar gas flow rate is 20~1000 sccm, the etching gas flow rate ranges from 50~5000 sccm, the O2 flow rate is 10~2000 sccm, and the etching processing time is 30~300 s.

6. The preparation method according to claim 3, characterized in that: During graphite bombardment, the power supply is 1~20kw, the Ar flow rate is 20~2000sccm, the O2 flow rate is 10~2000sccm, and the processing time is 1~30min.

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