A high-hardness hydrophobic modified DLC film and its preparation method

Abstract

This invention relates to the field of functional thin films and surface engineering technology, specifically to a high-hardness hydrophobic modified DLC thin film and its preparation method, comprising the following steps: S1: Pre-treating the substrate surface to remove oxide layers, scratches, and contaminants; S2: Etching and activating the substrate surface using an ion beam; S3: Depositing a metal transition layer on the activated substrate surface; S4: Depositing a high sp3 content DLC host layer on the metal transition layer surface; S5: Fluorinizing the DLC surface to form a surface-penetrating fluorinated layer, ultimately obtaining the high-hardness hydrophobic modified DLC thin film. This invention significantly improves the surface hydrophobic properties and enhances tribological wear behavior while maintaining the high hardness and structural integrity of the DLC thin film, achieving synergistic optimization of mechanical properties and surface functionalization.

Description

Technical Field

[0001] This invention relates to the field of functional thin films and surface engineering technology, and in particular to a high-hardness hydrophobic modified DLC thin film and its preparation method. Background Technology

[0002] Diamond-like carbon (DLC) films, due to their high hardness, low coefficient of friction, excellent wear resistance, and good chemical stability, have broad application prospects in the surface protection of semiconductor equipment, precision machinery, and vacuum environment components. Especially for critical moving parts, guiding parts, and protective parts in semiconductor manufacturing equipment, whose service environments often involve complex plasma, vacuum, and frictional coupling, coatings are required to possess not only high hardness and good mechanical properties but also low surface energy and weak interfacial adsorption capacity to reduce contaminant adhesion and liquid spreading, thereby improving service reliability and service life. However, traditional high-SPF coatings... 3 DLC films with high content have high surface energy and exhibit hydrophilic or weakly hydrophobic properties. Their water contact angle is usually below 80°, which makes it difficult to meet the requirements of surface hydrophobicity for special working conditions such as anti-fouling and self-cleaning.

[0003] To improve the hydrophobic properties of DLC films, existing technologies mainly employ two methods: one is to introduce fluorine-containing precursors during the DLC deposition process to form fluorine-containing DLC ​​films through co-deposition; the other is to use fluorine-containing plasma for post-treatment of the deposited DLC films. However, both methods have significant drawbacks; the former introduces fluorine-containing components during deposition, which easily leads to disordered carbon structure in the DLC matrix, resulting in... 3 The decrease in bond content leads to a significant reduction in hardness and mechanical properties; the latter, when treated with direct plasma, involves high-energy ions and electrons in the system, accompanied by a strong ion bombardment effect, which not only causes rearrangement of the carbon structure on the surface of DLC, but also results in sp... 3 Key to sp 2 Graphitization occurs through bond transformation and may also lead to surface etching, increasing roughness and affecting the structural continuity and interfacial bonding performance of the film. Therefore, how to effectively improve the surface hydrophobicity of DLC films while maintaining their high hardness and structural integrity has become a pressing technical challenge in the field of surface engineering. Summary of the Invention

[0004] To achieve the above objectives, the present invention provides a high-hardness hydrophobic modified DLC film and its preparation method.

[0005] A high-hardness hydrophobic modified DLC film includes a substrate, a metal transition layer disposed on the surface of the substrate, and a high-sp... 3 DLC main layer with high content and formed in high sp 3The DLC substrate has an infiltrated fluorinated layer on its surface.

[0006] Optionally, the substrate is one of 316L stainless steel, cemented carbide, or monocrystalline silicon wafer.

[0007] Optionally, the metal transition layer is a Ti layer, a Cr layer, or a TiCr alloy layer, with a thickness of 300–400 nm.

[0008] A method for preparing a high-hardness hydrophobic modified DLC film includes the following steps: S1: Perform surface pretreatment on the substrate to remove oxide layers, scratches, and contaminants, and then clean and dry it; S2: The pretreated substrate is placed in a vacuum chamber, argon gas is introduced, and the substrate surface is etched and activated by an ion beam to remove the residual oxide layer and increase surface activity. S3: A metal transition layer is deposited on the activated substrate surface using magnetron sputtering technology; S4: High sp2 deposits are made on the surface of the metal transition layer using filtered cathode vacuum arc technology. 3 DLC main layer; S5: The substrate with the deposited DLC main layer is placed in the remote plasma processing chamber, and a mixture of fluorine source gas and inert gas is introduced. Low-energy neutral fluorine-containing active groups are generated by the remote plasma source to fluorinate the DLC surface, forming a surface-penetrating fluorinated layer, and finally the high-hardness hydrophobic modified DLC film is obtained.

[0009] Optionally, S1 specifically includes: S11: Place the substrate in the cleaning agent aqueous solution and perform ultrasonic cleaning for 5-15 minutes; S12: Remove the substrate and rinse it with deionized water 1 to 3 times; S13: Place the rinsed substrate in anhydrous ethanol and ultrasonically clean for 5-15 minutes. S14: Remove the substrate and dry it at 60-80℃ for 10-30 minutes.

[0010] Optionally, S2 specifically includes: S21: Place the pretreated matrix in a vacuum chamber and evacuate the chamber to a pressure below 4 × 10⁻⁶. -3 Pa; S22: Introduce argon gas into the chamber, control the argon gas flow rate to 400-600 sccm, and adjust the chamber pressure to 0.3-0.8 Pa; S23: Set the substrate bias voltage to -400 to -600V, the duty cycle to 50% to 70%, turn on the ion source, and set the ion source current to 80 to 120A; S24: Perform ion beam etching on the substrate surface for 20–40 min.

[0011] Optionally, S3 specifically includes: S31: Place the ion-beam etched and activated substrate into the magnetron sputtering deposition chamber, and evacuate the chamber to a pressure below 5 × 10⁻⁶. -3 Pa; S32: Introduce argon gas into the chamber, control the argon gas flow rate to 100-300 sccm, and adjust the working pressure of the chamber to 0.2-0.8 Pa; S33: Turn on the power supply for the metal target, wherein the metal target is a Ti target, a Cr target, or a TiCr alloy target, with a purity of 99.99% or higher; S34: Set the substrate bias voltage to -50 to -150V and the duty cycle to 40% to 80%; S35: Employs a high-power pulsed magnetron sputtering mode, setting the peak power density of the target material to 500–1500 W / cm³. 2 The pulse frequency is 100–1000 Hz, and the pulse width is 50–200 μs; S36: Deposit a metal transition layer on the substrate surface for 5 to 20 minutes, and control the thickness of the metal transition layer to be 300 to 400 nm.

[0012] Optionally, S4 specifically includes: S41: Place the substrate with the deposited metal transition layer in the filter cathode vacuum arc deposition chamber, and evacuate the chamber to a pressure below 4 × 10⁻⁶. -3 Pa; S42: Set the magnetic field parameters of the filter bend and control the magnetic field current to 1-5A to guide the arc spot to operate stably and filter large particles. S43: Turn on the high-purity graphite target arc power supply and set the arc current to 60-80A; S44: Set the substrate bias voltage to -50 to -200V and the duty cycle to 50% to 80%; S45: Depositing high sp on the surface of the metal transition layer 3 The DLC substrate layer was deposited at a concentration of 10–30 min for a time of 500–800 nm. 3 The bond content is greater than 65%.

[0013] Optionally, S5 specifically includes: S51: Place the substrate with the deposited DLC host layer in the remote plasma processing chamber, and evacuate the chamber to a pressure below 5 × 10⁻⁶. -3 Pa; S52: Introduce a mixture of Ar and NF3 into the chamber, wherein the flow rate of Ar is 1500-2500 sccm and the flow rate of NF3 is 300-700 sccm, and adjust the working pressure of the chamber to 150-250 Pa. S53: Turn on the remote plasma source, set the radio frequency power to 2500-4000W, and do not apply the substrate bias voltage; S54: Low-energy neutral fluorine-containing active groups are generated by a remote plasma source to fluorinate the DLC surface. The treatment time is 1 to 10 minutes, forming a surface-penetrating fluorinated layer with a thickness of 20 to 50 nm. S55: After the process is complete, stop the gas supply, turn off the plasma source, and evacuate the chamber to a pressure below 5 × 10⁻⁶. -3 After maintaining the pressure at 5-10 min, nitrogen gas is introduced to backfill to atmospheric pressure. The substrate is then removed to obtain the high-hardness hydrophobic modified DLC film.

[0014] The beneficial effects of this invention are: This invention maintains a high sp 3 Based on the dense carbon skeleton structure of the DLC host layer, CF is introduced through a surface-penetrating fluorination layer. x The functional groups significantly reduce the surface polarity and surface energy of the film, greatly increasing the water contact angle to over 100°, achieving a synergistic optimization of high hardness and excellent hydrophobicity. At the same time, the fluorinated layer and the underlying DLC ​​host layer have a continuous transition without interface discontinuity, ensuring good film-substrate adhesion and structural stability, and avoiding performance degradation caused by surface peeling or interface weakening in traditional fluorination treatment.

[0015] This invention employs a step-by-step strategy of deposition followed by fluorination. The core of this strategy lies in utilizing a remote plasma source to generate low-energy, neutral fluorine-containing active groups, enabling chemical modification of the DLC surface under conditions of no ion bombardment and no applied substrate bias. This method effectively avoids the sp-induced degradation caused by high-energy ion bombardment in traditional fluorine-containing plasma treatments. 3 →sp 2 Structural transformation and surface etching damage are used to enhance hydrophobic properties while maximizing the preservation of the hardness and mechanical integrity of the DLC host layer. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only for this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1This is a schematic diagram of the DLC thin film preparation method according to an embodiment of the present invention; Figure 2 This is a schematic diagram illustrating the working principle of the remote plasma source in an embodiment of the present invention. Detailed Implementation

[0018] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. It should also be noted that, to make the embodiments more comprehensive, the following embodiments are the best and preferred embodiments, and those skilled in the art can use other alternative methods to implement some well-known technologies; moreover, the accompanying drawings are only for more specific description of the embodiments and are not intended to specifically limit the present invention.

[0019] It should be noted that the use of terms such as "an embodiment," "an embodiment," "an exemplary embodiment," and "some embodiments" in the specification indicates that the described embodiment may include a specific feature, structure, or characteristic, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments (whether explicitly described or not) should be within the knowledge of those skilled in the art.

[0020] Generally, terms can be understood at least partly from their use in context. For example, depending at least partly on the context, the term "one or more" as used herein can be used to describe any feature, structure, or characteristic in a singular sense, or a combination of features, structures, or characteristics in a plural sense. Additionally, the term "based on" can be understood not necessarily to convey an exclusive set of factors, but rather, alternatively, depending at least partly on the context, to allow for the presence of other factors that are not necessarily explicitly described.

[0021] Example 1 A high-hardness hydrophobic modified DLC film includes a substrate, a metal transition layer disposed on the surface of the substrate, and a high-sp... 3 DLC main layer with high content and formed in high sp 3 The DLC substrate has an infiltrated fluorinated layer on its surface.

[0022] High SP 3 The DLC host layer has a dense carbon skeleton structure, and its sp... 2 The carbon regions are distributed in a continuous network, serving as preferential diffusion channels for fluorine-containing active groups.

[0023] Surface-penetrated fluorinated layers are formed by fluorine elements entering high-sp levels through chemical adsorption and spontaneous diffusion. 3 The gradient doping structure is formed inside the surface of the DLC host layer, and there is no interface discontinuity between the fluorinated layer and the lower DLC host layer, presenting a continuous transition.

[0024] The base material is 316L stainless steel.

[0025] The metal transition layer is a Ti layer with a thickness of 350 nm.

[0026] like Figure 1 As shown, a method for preparing a high-hardness hydrophobic modified DLC film includes the following steps: S1: Perform surface pretreatment on the substrate to remove oxide layers, scratches, and contaminants, and then clean and dry it; S2: The pretreated substrate is placed in a vacuum chamber, argon gas is introduced, and the substrate surface is etched and activated by an ion beam to remove the residual oxide layer and increase surface activity. S3: A metal transition layer is deposited on the activated substrate surface using magnetron sputtering technology; S4: High sp2 deposits are made on the surface of the metal transition layer using filtered cathode vacuum arc technology. 3 DLC main layer; S5: The substrate with the deposited DLC main layer is placed in the remote plasma processing chamber, and a mixture of fluorine source gas and inert gas is introduced. Low-energy neutral fluorine-containing active groups are generated by the remote plasma source to fluorinate the DLC surface, forming a surface-penetrating fluorinated layer, and finally a high-hardness hydrophobic modified DLC film is obtained.

[0027] S1 specifically includes: S11: Place the substrate in the cleaning agent aqueous solution and perform ultrasonic cleaning for 10 minutes; S12: Remove the substrate and rinse twice with deionized water; S13: Place the rinsed substrate in anhydrous ethanol and ultrasonically clean for 10 min; S14: Remove the substrate and dry it at 70℃ for 20 minutes.

[0028] S2 specifically includes: S21: Place the pretreated matrix in a vacuum chamber and evacuate the chamber to a vacuum level of 3.5 × 10⁻⁶. -3 Pa; S22: Introduce argon gas into the chamber, control the argon gas flow rate to 500 sccm, and adjust the chamber pressure to 0.5 Pa; S23: Set the substrate bias voltage to -500V, the duty cycle to 60%, turn on the ion source, and set the ion source current to 100A; S24: Perform ion beam etching on the substrate surface for 30 minutes.

[0029] S3 specifically includes: S31: Place the substrate, activated by ion beam etching, into the magnetron sputtering deposition chamber, and evacuate the chamber to 4×10⁻⁶. -3 Pa; S32: Introduce argon gas into the chamber, control the argon gas flow rate to 200 sccm, and adjust the working gas pressure of the chamber to 0.5 Pa; S33: Turn on the power supply for the metal target. The metal target is a Ti target with a purity of 99.99% or higher. S34: Set the substrate bias voltage to -100V and the duty cycle to 60%; S35: Employs a high-power pulsed magnetron sputtering mode, setting the peak power density of the target material to 1000 W / cm³. 2 The pulse frequency is 500Hz and the pulse width is 100μs; S36: Deposit a metal transition layer on the substrate surface for 12 minutes, and control the thickness of the metal transition layer to be 350 nm.

[0030] S4 specifically includes: S41: Place the substrate with the deposited metal transition layer in the filter cathode vacuum arc deposition chamber, and evacuate the chamber to 3.5 × 10⁻⁶. -3 Pa; S42: Set the magnetic field parameters of the filter bend and control the magnetic field current to 3A to guide the arc spot to operate stably and filter large particles. S43: Turn on the high-purity graphite target arc power supply and set the arc current to 70A; S44: Set the substrate bias voltage to -120V and the duty cycle to 65%; S45: Depositing high sp on the surface of the metal transition layer 3 The DLC substrate layer was deposited for 20 minutes, with a thickness of 650 nm. 3 The bond content is 76%.

[0031] S5 specifically includes: S51: Place the substrate with the deposited DLC host layer in the remote plasma processing chamber, and evacuate the chamber to 4.0 × 10⁻⁶. -3 Pa; S52: Introduce a mixture of Ar and NF3 into the chamber, with an Ar flow rate of 2000 sccm and an NF3 flow rate of 500 sccm, and adjust the working pressure of the chamber to 200 Pa. S53: Turn on the remote plasma source, set the radio frequency power to 3200W, and do not apply the substrate bias voltage; S54: Low-energy neutral fluorine-containing active groups are generated by a remote plasma source to fluorinate the DLC surface for 5 minutes, forming a surface-penetrating fluorinated layer with a thickness of 35 nm. S55: After the process is complete, stop the gas supply, turn off the plasma source, and evacuate the chamber to 4×10⁻⁶. -3 After maintaining the pressure at 8 Pa for 8 minutes, nitrogen gas was introduced to backfill to atmospheric pressure. The substrate was then removed, yielding a high-hardness hydrophobic modified DLC film.

[0032] Example 2 In this embodiment, cemented carbide is used as the substrate, and a Cr metal transition layer and a high sp2 layer are sequentially deposited on the substrate surface. 3 The composition includes a DLC main layer and a surface-infiltrated fluorinated layer; wherein, the Cr metal transition layer has a thickness of 300 nm, the DLC main layer has a thickness of 500 nm, and the DLC main layer has a sp... 3 The bond content is 76%, and the thickness of the surface-infiltrated fluorinated layer is 20 nm. S1: Place the substrate in the cleaning agent aqueous solution and ultrasonically clean for 5 min. After removing it, rinse it once with deionized water. Then place the substrate in anhydrous ethanol and ultrasonically clean for 5 min. Finally, dry it at 60℃ for 10 min to obtain the pretreated substrate. S2: Place the pretreated cemented carbide substrate in a vacuum chamber and evacuate the chamber to a vacuum level of 3.8 × 10⁻⁶. -3 Pa; then argon gas was introduced, the argon gas flow rate was controlled at 400 sccm, and the chamber pressure was adjusted to 0.3 Pa; the substrate bias voltage was set to -400 V, the duty cycle was 50%, the ion source was turned on and the ion source current was set to 80 A, and the substrate surface was etched for 20 min to remove the residual oxide layer and improve the surface activity. S3: Place the etched and activated hard alloy substrate in the magnetron sputtering deposition chamber, and evacuate the chamber to 4.5 × 10⁻⁶. -3 Pa; Argon gas is introduced and the flow rate is controlled at 100 sccm, and the working pressure in the chamber is adjusted to 0.2 Pa; The Cr target power supply with a purity of 99.99% is turned on, the substrate bias voltage is set to -50V, and the duty cycle is 40%; High-power pulsed magnetron sputtering mode is adopted, and the peak power density of the target is set to 500 W / cm³. 2 The pulse frequency was 100Hz, the pulse width was 50μs, and the deposition time was 5min to form a Cr metal transition layer with a thickness of 300nm on the substrate surface. S4: Place the substrate with the deposited Cr metal transition layer in the filtered cathode vacuum arc deposition chamber, and evacuate the chamber to 3.8 × 10⁻⁶. -3 Pa; set the filter bend magnetic field current to 1A, turn on the high-purity graphite target arc power supply, and set the arc current to 60A; simultaneously set the substrate bias voltage to -50V, the duty cycle to 50%, and deposit for 10 minutes to form a 500nm thick sp... 3 The DLC host layer has a bond content of 68%; S5: Place the substrate with the deposited DLC host layer in the remote plasma processing chamber, and evacuate the chamber to 4.5 × 10⁻⁶. -3 Pa; then, a mixture of Ar and NF3 gas was introduced, with an Ar flow rate of 1500 sccm and an NF3 flow rate of 300 sccm, and the working pressure of the chamber was adjusted to 150 Pa; the remote plasma source was turned on, the radio frequency power was set to 2500 W, and no substrate bias was applied, and the DLC surface was fluorinated for 1 min to form a surface-infiltrated fluorinated layer with a thickness of 20 nm; after the treatment, the gas supply was stopped, the plasma source was turned off, and the chamber was evacuated to 4.5 × 10⁻⁶ Pa. -3 Pa and hold for 5 minutes, then introduce nitrogen gas to backfill to atmospheric pressure, remove the substrate, and obtain a high-hardness hydrophobic modified DLC film.

[0033] Example 3 In this embodiment, a single-crystal silicon wafer is used as the substrate, and a TiCr alloy transition layer and a high sp2 layer are sequentially deposited on the substrate surface. 3 The composition includes a DLC main layer and a surface-infiltrated fluorinated layer; wherein, the TiCr alloy transition layer has a thickness of 400 nm, the DLC main layer has a thickness of 800 nm, and the DLC main layer has a sp... 3 The bond content is 76%, and the thickness of the surface-infiltrated fluorinated layer is 50 nm. S1: The substrate was ultrasonically cleaned in an aqueous cleaning solution for 15 minutes, then rinsed three times with deionized water; the substrate was then ultrasonically cleaned in anhydrous ethanol for 15 minutes, and finally dried at 80°C for 30 minutes to obtain the pretreated substrate. S2: Place the pretreated single-crystal silicon wafer substrate in a vacuum chamber and evacuate the chamber to 3.0 × 10⁻⁶. -3 Pa; then argon gas was introduced, the argon gas flow rate was controlled at 600 sccm, and the chamber pressure was adjusted to 0.8 Pa; the substrate bias voltage was set to -600 V, the duty cycle was 70%, the ion source was turned on and the ion source current was set to 120 A, and the substrate surface was etched for 40 min to remove the residual oxide layer and improve the surface activity. S3: Place the etched and activated single-crystal silicon wafer substrate into the magnetron sputtering deposition chamber, and evacuate the chamber to 4.0 × 10⁻⁶. -3 Pa; Argon gas is introduced and the flow rate is controlled at 300 sccm, and the working pressure in the chamber is adjusted to 0.8 Pa; The TiCr alloy target power supply with a purity of 99.99% is turned on, the substrate bias voltage is set to -150V, and the duty cycle is 80%; High-power pulsed magnetron sputtering mode is adopted, and the peak power density of the target material is set to 1500 W / cm³. 2 The pulse frequency was 1000Hz, the pulse width was 200μs, and the deposition time was 20min, forming a TiCr alloy transition layer with a thickness of 400nm on the substrate surface. S4: Place the substrate with the deposited TiCr alloy transition layer in the filtered cathode vacuum arc deposition chamber, and evacuate the chamber to 3.0 × 10⁻⁶. -3 Pa; set the filter bend magnetic field current to 5A, turn on the high-purity graphite target arc power supply, and set the arc current to 80A; simultaneously set the substrate bias voltage to -200V, the duty cycle to 80%, and deposit for 30 minutes to form a layer with a thickness of 800nm ​​on the TiCr alloy transition layer surface. 3 The DLC host layer has a bond content of 76%; S5: Place the substrate with the deposited DLC host layer in the remote plasma processing chamber, and evacuate the chamber to 4.0 × 10⁻⁶. -3 Pa; then, a mixture of Ar and NF3 gas was introduced, with an Ar flow rate of 2500 sccm and an NF3 flow rate of 700 sccm, and the working pressure of the chamber was adjusted to 250 Pa; the remote plasma source was turned on, the radio frequency power was set to 4000 W, and no substrate bias was applied, and the DLC surface was fluorinated for 10 min to form a surface-infiltrated fluorinated layer with a thickness of 50 nm; after the treatment, the gas supply was stopped, the plasma source was turned off, and the chamber was evacuated to 4.0 × 10⁻⁶ Pa. -3 The pressure was maintained at 10 Pa for 10 minutes, then nitrogen gas was introduced to backfill to atmospheric pressure. The substrate was then removed to obtain a high-hardness hydrophobic modified DLC film.

[0034] Comparative Example 1 High sp3 content DLC films were prepared using the above method, but without subsequent NF3 active group treatment. This sample served as a benchmark for comparing the hydrophobic modification effect of this invention. The initial water contact angle of the sample in Comparative Example 1 was 72°, and its surface was in an initial wetted state.

[0035] Comparative Example 2 To compare the effects of different plasma treatment methods on the structure and properties of DLC films, conventional fluorine-containing plasma was used to treat DLC films with high sp3 content. In this treatment method, the plasma directly acts on the sample surface, and a certain proportion of ions and electrons are present in the system, usually accompanied by ion bombardment effect. Under these conditions, according to the plasma surface interaction mechanism, ion bombardment may cause rearrangement of the carbon structure on the surface of the DLC film, leading to the conversion of sp3 bonds to sp2 bonds, and may also produce surface etching, resulting in morphological changes and increased roughness. At the same time, the mechanical properties of the film (such as hardness) may be affected to some extent. In contrast, this invention uses active fluorine-containing groups generated by a remote plasma source for treatment. Under conditions of virtually no ion bombardment, surface modification is achieved through a diffusion mechanism, which is beneficial for maintaining the structural integrity of the DLC film while taking into account its mechanical properties and surface hydrophobicity.

[0036] The specific principle and process of remote plasma fluorination treatment are as follows: A remote plasma source generates plasma by ionizing process gas through discharge, and then transports the active groups in the plasma to the downstream processing chamber along the gas flow direction. During the transport of plasma from the generation region to the DLC film surface, electrons and ions rapidly decay due to their high recombination rate, while neutral active particles such as free radicals are retained and gradually become dominant. Therefore, the particles reaching the sample surface are mainly highly chemically active fluorine-containing neutral free radicals with extremely low kinetic energies, typically less than 5 eV, and possess almost no ion bombardment capability. These low-energy neutral fluorine-containing active groups act on the DLC surface through chemisorption and, with the help of the sp(s) in the DLC film... 2 The continuous distribution region of the carbon network preferentially diffuses into the interior of the surface layer, forming a penetrating fluorinated layer. Because no substrate bias voltage is applied during the process, and the plasma source is spatially separated from the substrate, the high-energy ion bombardment effect is significantly weakened, thus avoiding the sp-like effects commonly found in traditional direct plasma processing. 3 →sp 2 Structural transformation and surface etching damage.

[0037] Table 1 Comparison of Finished Product Performance Parameters

[0038] As shown in Table 1 above, Example 1 exhibits superior results in terms of water contact angle, surface energy, degree of fluorine-containing functional group introduction, nanohardness, elastic modulus, film-substrate bonding state, coefficient of friction, wear rate, and surface roughness. Example 1 achieves a water contact angle of 126° and a surface energy reduced to 18.6 mN·m. -1 This indicates that the NF3 active groups generated by the remote plasma can form an effective fluorinated structure on the surface of the DLC host layer, transforming the film surface from an initial wetted state to a stable hydrophobic state. Simultaneously, the nanohardness of Example 1 remains at 38 GPa, the elastic modulus is 460 Pa, and the film-substrate bonding level reaches HF1, demonstrating that after forming a 35 nm surface-penetrated fluorinated layer, the high sp[unclear] of the DLC host layer... 3 The structure showed no significant damage, and the film maintained high hardness and good adhesion. Compared to Comparative Example 2, Example 1 employed a remote plasma treatment method, avoiding surface structural damage caused by direct bombardment with conventional fluorine-containing plasma. Therefore, its hardness, elastic modulus, and surface roughness were all superior to Comparative Example 2. In terms of tribological performance, Example 1 had an average coefficient of friction of 0.060 and a wear rate of 1.1 × 10⁻⁶. -7 mm 3 ·N -1 ·m -1 This is significantly lower than the 0.105 and 3.9 × 10⁻⁶ values ​​in Comparative Example 1. -7 mm 3 ·N -1 ·m-1 The results indicate that NF3 active group treatment for an appropriate time can passivate the dangling bonds and active sites on the DLC surface, reduce adhesion in the early stages of friction, and improve wear resistance while maintaining the load-bearing skeleton of the DLC main layer.

[0039] Based on the above data, Example 1 achieves a good balance between hydrophobicity, mechanical properties, bonding properties, and tribological properties, making it the optimal embodiment of this application. Comparative Example 1, without NF3 active group treatment, did not form an effective fluorinated structure, had a water contact angle of only 72°, high surface energy, and the highest wear rate, indicating that simply using high sp3... 3 While DLC films possess the basic characteristics of hard films, it is difficult to simultaneously achieve high hydrophobicity and low abrasion performance.

[0040] Table 2 Comparison of Durability and Stability Performance

[0041] Table 2 shows that Example 1 maintained high hydrophobicity and mechanical stability after water immersion, friction cycling, salt spray treatment, and heat treatment. The water contact angle of Example 1 remained at 122° after 24 hours of water immersion and 119° after 100 friction cycles, indicating that the 35nm surface-penetrated fluorinated layer is not simply a surface adsorption layer, but rather forms a relatively stable fluorine-modified structure on the DLC surface, thus maintaining good hydrophobicity even in water environments and after mild friction. Regarding film bonding and damage resistance, Example 1 showed a film peeling area of ​​only 0.8% after 20 thermal cycles, and a scratch critical load of 22N, both superior to Examples 2, 3, and the two comparative examples. This result demonstrates that the 350nm Ti metal transition layer and the 650nm high-sp... 3 A relatively stable interfacial transition relationship was formed between the DLC substrate layers, enabling the film to maintain good film-substrate adhesion under thermal cycling and mechanical scratching conditions. Regarding wear and corrosion resistance, Example 1 showed a wear track width of 82 μm and a corrosion current density of 0.18 μA·cm² after 1000 m of friction under a 5 N load. -2 These are all superior results among their respective groups. This result indicates that Example 1 reduces surface energy through a moderately thick infiltrated fluorinated layer, combined with high sp... 3 The DLC substrate provides load-bearing support, enabling the film to exhibit more stable surface protection performance in both frictional contact and corrosive environments.

[0042] The results in Table 2 show that Example 1 not only exhibits the best performance in terms of initial hydrophobicity and mechanical properties, but also demonstrates superior performance retention after water immersion, friction cycling, salt spray, heat treatment, and thermal cycling. This indicates that the Ti metal transition layer thickness of 350 nm, the DLC main layer thickness of 650 nm, and the sp... 3 The 76% bond content and the 35nm surface-diffused fluorinated layer form a more reasonable structural match, giving the film hydrophobic durability, film stability, wear resistance and corrosion resistance.

[0043] This invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of this invention. To provide the public with a thorough understanding of this invention, specific details are described in detail in the following preferred embodiments; however, those skilled in the art will fully understand the invention even without these details. Furthermore, to avoid unnecessary misunderstanding of the essence of this invention, well-known methods, processes, procedures, components, and circuits are not described in detail.

[0044] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A high-hardness hydrophobic modified DLC film, characterized in that, Includes a substrate, a metal transition layer disposed on the surface of the substrate, and a high sp content disposed on the surface of the metal transition layer. 3 DLC main layer with high content and formed in high sp 3 The DLC substrate has an infiltrated fluorinated layer on its surface.

2. The high-hardness hydrophobic modified DLC film according to claim 1, characterized in that, The substrate is one of 316L stainless steel, cemented carbide, or monocrystalline silicon wafer.

3. The high-hardness hydrophobic modified DLC film according to claim 1, characterized in that, The metal transition layer is a Ti layer, a Cr layer, or a TiCr alloy layer, with a thickness of 300–400 nm.

4. A method for preparing a high-hardness hydrophobic modified DLC film, used to prepare the high-hardness hydrophobic modified DLC film according to any one of claims 1-3, characterized in that, Includes the following steps: S1: Perform surface pretreatment on the substrate to remove oxide layers, scratches, and contaminants, and then clean and dry it; S2: The pretreated substrate is placed in a vacuum chamber, argon gas is introduced, and the substrate surface is etched and activated by an ion beam to remove the residual oxide layer and increase surface activity. S3: A metal transition layer is deposited on the activated substrate surface using magnetron sputtering technology; S4: High sp2 deposits are made on the surface of the metal transition layer using filtered cathode vacuum arc technology. 3 DLC main layer; S5: The substrate with the deposited DLC main layer is placed in the remote plasma processing chamber, and a mixture of fluorine source gas and inert gas is introduced. Low-energy neutral fluorine-containing active groups are generated by the remote plasma source to fluorinate the DLC surface, forming a surface-penetrating fluorinated layer, and finally the high-hardness hydrophobic modified DLC film is obtained.

5. The method for preparing a high-hardness hydrophobic modified DLC film according to claim 4, characterized in that, S1 specifically includes: S11: Place the substrate in the cleaning agent aqueous solution and perform ultrasonic cleaning for 5-15 minutes; S12: Remove the substrate and rinse it with deionized water 1 to 3 times; S13: Place the rinsed substrate in anhydrous ethanol and ultrasonically clean for 5-15 minutes. S14: Remove the substrate and dry it at 60-80℃ for 10-30 minutes.

6. The method for preparing a high-hardness hydrophobic modified DLC film according to claim 4, characterized in that, S2 specifically includes: S21: Place the pretreated matrix in a vacuum chamber and evacuate the chamber to a pressure below 4 × 10⁻⁶. -3 Pa; S22: Introduce argon gas into the chamber, control the argon gas flow rate to 400-600 sccm, and adjust the chamber pressure to 0.3-0.8 Pa; S23: Set the substrate bias voltage to -400 to -600V, the duty cycle to 50% to 70%, turn on the ion source, and set the ion source current to 80 to 120A; S24: Perform ion beam etching on the substrate surface for 20–40 min.

7. The method for preparing a high-hardness hydrophobic modified DLC film according to claim 4, characterized in that, S3 specifically includes: S31: Place the ion-beam etched and activated substrate into the magnetron sputtering deposition chamber, and evacuate the chamber to a pressure below 5 × 10⁻⁶. -3 Pa; S32: Introduce argon gas into the chamber, control the argon gas flow rate to 100-300 sccm, and adjust the working pressure of the chamber to 0.2-0.8 Pa; S33: Turn on the power supply for the metal target, wherein the metal target is a Ti target, a Cr target, or a TiCr alloy target, with a purity of 99.99% or higher; S34: Set the substrate bias voltage to -50 to -150V and the duty cycle to 40% to 80%; S35: Employs a high-power pulsed magnetron sputtering mode, setting the peak power density of the target material to 500–1500 W / cm³. 2 The pulse frequency is 100–1000 Hz, and the pulse width is 50–200 μs; S36: Deposit a metal transition layer on the substrate surface for 5 to 20 minutes, and control the thickness of the metal transition layer to be 300 to 400 nm.

8. The method for preparing a high-hardness hydrophobic modified DLC film according to claim 4, characterized in that, S4 specifically includes: S41: Place the substrate with the deposited metal transition layer in the filter cathode vacuum arc deposition chamber, and evacuate the chamber to a pressure below 4 × 10⁻⁶. -3 Pa; S42: Set the magnetic field parameters of the filter bend and control the magnetic field current to 1-5A to guide the arc spot to operate stably and filter large particles. S43: Turn on the high-purity graphite target arc power supply and set the arc current to 60-80A; S44: Set the substrate bias voltage to -50 to -200V and the duty cycle to 50% to 80%; S45: Depositing high sp on the surface of the metal transition layer 3 The DLC substrate layer was deposited at a concentration of 10–30 min for a time of 500–800 nm. 3 The bond content is greater than 65%.

9. The method for preparing a high-hardness hydrophobic modified DLC film according to claim 4, characterized in that, S5 specifically includes: S51: Place the substrate with the deposited DLC host layer in the remote plasma processing chamber, and evacuate the chamber to a pressure below 5 × 10⁻⁶. -3 Pa; S52: Introduce a mixture of Ar and NF3 into the chamber, wherein the flow rate of Ar is 1500-2500 sccm and the flow rate of NF3 is 300-700 sccm, and adjust the working pressure of the chamber to 150-250 Pa. S53: Turn on the remote plasma source, set the radio frequency power to 2500-4000W, and do not apply the substrate bias voltage; S54: Low-energy neutral fluorine-containing active groups are generated by a remote plasma source to fluorinate the DLC surface. The treatment time is 1 to 10 minutes, forming a surface-penetrating fluorinated layer with a thickness of 20 to 50 nm. S55: After the process is complete, stop the gas supply, turn off the plasma source, and evacuate the chamber to a pressure below 5 × 10⁻⁶. - 3 After maintaining the pressure at 5-10 min, nitrogen gas is introduced to backfill to atmospheric pressure. The substrate is then removed to obtain the high-hardness hydrophobic modified DLC film.

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