A multi-principal element alloy thin film and a method of manufacturing the same

Abstract

The application provides a multi-main-component alloy thin film and a preparation method thereof. The multi-main-component alloy thin film is composed of atoms or non-equal atoms of Ta, Hf and W, and a chemical formula of the multi-main-component alloy thin film is Ta a Hf b W c ; wherein a is 30% to 50%, b is 15% to 35%, c is 30% to 45%, and a+b+c=1. The multi-main-component alloy thin film can be obtained by a multi-target direct-current magnetron sputtering thin film deposition method, the Ta-Hf-W multi-main-component alloy thin film is controllable and uniform, has good compactness, small surface roughness, high hardness and high elastic modulus.

Description

Technical Field

[0001] This invention belongs to the field of alloy materials, specifically relating to a multi-principal element alloy thin film and its preparation method. Background Technology

[0002] As materials research deepens, researchers have discovered that increasing the entropy value of an alloy can yield new alloy systems and improve the overall performance of the alloy material. Multi-principal element alloys (MPAs) can significantly increase the entropy value of an alloy system, resulting in many unique physical and chemical properties. MPAs are composed of five or more elements with equal or near-equal atomic ratios. The atomic ratio of each element is between 5% and 35%, and the atoms randomly occupy positions in the crystal lattice. Therefore, MPAs exhibit four unique effects: a high-entropy effect in thermodynamics, a slow diffusion effect in kinetics, a distortion effect in crystal structure, and a "cocktail" effect in performance. Further research has revealed that there is currently no strict definition for MPAs. Researchers also consider ternary or quaternary alloys to be MPAs. Under the synergistic effect of multiple mechanisms, MPAs are more likely to form simple body-centered cubic (BCC), face-centered cubic (FCC), or hexagonal close-packed (HCP) solid solution structures. Therefore, multi-principal element alloys possess many excellent properties, such as high strength and hardness, excellent oxidation resistance, friction and wear resistance, high fatigue resistance, high fracture toughness, and good corrosion resistance, making them promising functional and structural materials in fields such as national defense, chemical industry, and aerospace.

[0003] Multi-principal element alloy thin films are alloy thin films with multiple principal elements and high mixing entropy. Multi-principal element alloy thin films possess characteristics similar to bulk multi-principal element alloys, and even surpass them in some properties, such as higher hardness and elastic modulus, and lower surface roughness. High-hardness films can be used as wear-resistant coatings. However, the widely studied NbMoTaW has a hardness of only 16.0 GPa (Feng XB, et al. International Journal of Plasticity, 2017, 95: 264-277), therefore, multi-principal element alloy thin films with even higher hardness require further development.

[0004] Magnetron sputtering, with its high deposition rate, good film quality, controllable performance, strong adhesion to the substrate, and low impurity content, has become one of the most common methods for thin film preparation. Magnetron sputtering deposition most commonly employs single-target sputtering, where the sputtering target is a single alloy material. This technique allows for precise control of the stoichiometry of the film composition; however, its disadvantages include the complexity and high cost of alloy target preparation. With continuous advancements in preparation technology, multi-target magnetron sputtering is increasingly being applied to the preparation of multi-principal element thin films. Multi-target magnetron sputtering uses multiple pure metal targets or binary alloy targets, effectively avoiding the complex preparation process of a single alloy target. Furthermore, by changing the sputtering power, sputtering time, and the angle of the target perpendicular to the sample stage centerline, films with diverse compositions can be prepared, making film preparation more flexible and facilitating high-throughput screening of film composition and properties. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a multi-principal alloy thin film and its preparation method. The multi-principal alloy thin film is prepared using multi-target DC magnetron sputtering technology. The alloy thin film has ternary components, a single-phase body-centered cubic crystal structure, low surface roughness, and high hardness and elastic modulus properties.

[0006] In a first aspect, the present invention provides a multi-principal alloy thin film, wherein the multi-principal alloy thin film is composed of Ta, Hf, W, and other elements in equal or non-equal atomic ratios, and the chemical formula of the multi-principal alloy thin film is Ta. a Hf b W c Where a is 30%~50%, b is 15%~35%, c is 30%~45%, and a+b+c=1. In this invention, the multi-principal element alloy film is composed only of the main components Ta, Hf, and W in equiatomic or non-equiatomic ratios, and a very small amount of unavoidable impurities. When the composition of the multi-principal element alloy film is in a non-equiatomic ratio, the chemical formula Ta... a Hf b W c In the formula, a, b, and c all represent atomic ratios, and a + b + c = 1; the values ​​of a, b, and c range from 30% to 50%, 15% to 35%, and 30% to 45%, respectively. When the composition of the multi-principal alloy thin film is composed of equal atomic ratios, the chemical formula is denoted as TaHfW. The multi-principal alloy thin film provided by this invention is obtained by multi-target DC magnetron sputtering thin film deposition. The composition of this Ta-Hf-W multi-principal alloy thin film is controllable and uniform, with good density, low surface roughness, and high hardness and elastic modulus.

[0007] Preferably, the multi-principal-element alloy thin film has a single-phase body-centered cubic crystal structure, a surface roughness of 5.40~8.34 nm, a film hardness of 16.6~19.4 GPa, and an elastic modulus of 278.1~328.5 GPa.

[0008] Secondly, the method for preparing the multi-principal alloy thin film provided by the present invention includes magnetron sputtering deposition of Ta target, Hf target and W target at a set sputtering power to obtain multi-principal alloy thin film.

[0009] Preferably, the method for preparing the multi-principal element alloy thin film includes:

[0010] Substrate preparation: The substrate was ultrasonically cleaned in anhydrous ethanol, then washed with water and dried, and placed on the sample stage.

[0011] Target setup: Place the Ta, Hf, and W targets on the three DC sputtering target positions in the deposition chamber, and adjust the angle of the target perpendicular to the center line of the sample stage and the vertical distance between the target and the substrate.

[0012] Coating process: The vacuum level in the deposition chamber is evacuated to the set conditions, then high-purity argon gas is introduced, the gas flow rate is set, the working gas pressure in the deposition chamber is adjusted, the substrate is shielded with a baffle, and the target is pre-sputtered; then the rotation speed of the substrate is set and the baffle is opened for sputtering deposition, and a multi-principal element alloy thin film is obtained according to the set process parameters. In this invention, Ta, Hf, and W targets are used to prepare Ta thin film by magnetron sputtering deposition at a set sputtering power. a Hf b W c The multi-principal alloy thin film, Ta-Hf-W, was prepared by multi-target DC magnetron sputtering technology. The alloy thin film has ternary components, a single-phase body-centered cubic crystal structure, low surface roughness, and high hardness and elastic modulus.

[0013] Preferably, in the substrate processing step, the substrate is a monocrystalline silicon wafer; more preferably, the substrate is P-type monocrystalline silicon, having... <100> Crystal orientation structure.

[0014] Preferably, in the target material setting step, the Ta target, Hf target, and W target are all high-purity metal blocks with a purity ≥99.95%, a diameter of 60±10 mm, and a thickness of 3~5 mm.

[0015] Further preferably, in the substrate treatment step, the ultrasonic frequency is 60~80 Hz and the ultrasonic time is 10±5 min; and / or, the smooth surface of the substrate is polished with damping cloth before ultrasonic cleaning.

[0016] Further preferably, in the target setting step, the angle between the target and the center line of the sample stage is 20-40°; the vertical distance between the pure metal bulk target (Ta, Hf, W) and the substrate is 5-15 cm. Under the same preparation parameters, the angle affects the deposition rate of the thin film; too small or too large an angle will affect the thickness of the thin film. When the angle is 20-40°, the projected area of ​​the target relative to the substrate is relatively large, resulting in a faster deposition rate and higher efficiency.

[0017] Preferably, in the coating process, the vacuum degree of the deposition chamber is 6 × 10⁻⁶. -4 ~8×10 -4 Pa; the working gas pressure is 0.7~0.9 Pa; the inert gas is high-purity argon, the gas flow rate is 30~50 sccm, and the purity is ≥99.999%.

[0018] Further preferably, in the coating process, the sputtering power of the Ta target is 100-150 W, the sputtering power of the Hf target is 50-100 W, and the sputtering power of the W target is 100-150 W. The pre-sputtering time is 10-15 min, and the sputtering time is 1 ± 0.2 h. In this invention, for the sputtering power, if it is lower than the required sputtering power, the target is unlikely to glow easily, while if it is higher than the required sputtering power, it is easy to cause the equipment to overheat and affect the sputtering effect.

[0019] Preferably, the method for preparing the multi-principal element alloy thin film includes the following steps.

[0020] 1) Place the substrate in anhydrous ethanol for ultrasonic cleaning to remove contaminants adhering to the substrate surface, and then rinse the substrate with deionized water.

[0021] 2) Dry the cleaned substrate with compressed nitrogen to ensure a clean surface and prevent water stains from remaining.

[0022] 3) Fix the substrate with the smooth side down on the furnace tray, fix the furnace tray on the sample stage of the magnetron sputtering thin film deposition equipment, and rotate the sample stage baffle to adjust it to the position to cover the substrate.

[0023] 4) Place the Ta, Hf and W metal bulk targets on three different DC target positions in the deposition chamber, and adjust the angle of each target perpendicular to the center line of the sample stage and the vertical distance between each target and the sample stage.

[0024] 5) Adjust the vacuum level in the deposition chamber.

[0025] 6) Introduce argon gas into the deposition chamber, adjust the working gas pressure, set the sputtering power of the target material, and pre-sputter the target material.

[0026] 7) Set the rotation speed of the sample stage, open the substrate baffle, and perform sputter deposition on the smooth surface of the substrate to obtain a thin film.

[0027] 8) Cool the film to room temperature under vacuum.

[0028] Further preferably, the preparation method of the multi-principal element alloy thin film includes the following steps.

[0029] 1) Place the substrate in anhydrous ethanol for ultrasonic cleaning to remove contaminants adhering to the substrate surface, and then rinse the substrate with deionized water.

[0030] 2) Dry the cleaned substrate with compressed nitrogen to ensure a clean surface and prevent water stains from remaining.

[0031] 3) Fix the substrate with the smooth side down on the furnace tray, fix the furnace tray on the sample stage of the magnetron sputtering thin film deposition equipment, and rotate the sample stage baffle to adjust it to the position to cover the substrate.

[0032] 4) Place the Ta, Hf and W metal bulk targets on three different DC target positions in the deposition chamber, and adjust the angle of each target perpendicular to the center line of the sample stage and the vertical distance between each target and the sample stage.

[0033] 5) Use a mechanical pump to evacuate the deposition chamber to less than 8.0 Pa, and then use a molecular pump to evacuate the deposition chamber to less than 6.0 × 10⁻⁶ Pa. -4 ~8×10 -4 Pa.

[0034] 6) Introduce argon gas into the deposition chamber, adjust the working pressure to 0.7~0.9 Pa, turn on the DC power supply of the corresponding target material, set the sputtering power of the target material respectively, and pre-sputter the target material for 10~15 min; remove oxides and other impurities formed on the surface of the target material through pre-sputtering.

[0035] 7) Set the rotation speed of the sample stage to 15~30 r / min, open the substrate baffle, and perform sputtering deposition on the smooth surface of the substrate for 1±0.2h to obtain a thin film.

[0036] 8) After sputtering deposition is complete, turn off the DC power supply and argon gas, stop the sample stage rotation, and cool the film to room temperature under vacuum. Then remove it to reduce oxidation contamination. Finally, the Ta film is obtained on the substrate. a Hf b W c Multi-principal-element alloy thin films.

[0037] Thirdly, the present invention provides applications of the multi-principal alloy thin film or the multi-principal alloy thin film obtained by the preparation method, including applications in the surface modification of structural materials in the aerospace, defense, and chemical fields under extreme service conditions.

[0038] The beneficial effects of this invention are at least as follows:

[0039] 1. The Ta provided by this invention a Hf b W c The multi-principal element alloy thin film is prepared using multi-target DC magnetron sputtering, which employs co-sputtering with multiple targets made of pure metal bulk material. This method avoids complex target preparation processes. By changing the sputtering power or sputtering time of the targets, multi-principal element alloy thin films with various chemical compositions can be prepared. This method features high deposition rate, wide material applicability, and good repeatability. The pure metal targets used in this invention are simple and readily available, making it suitable for large-scale industrial production.

[0040] 2. The Ta prepared by this invention a Hf b W c The multi-principal element alloy thin film exhibits a uniform distribution of constituent elements and a single-phase body-centered cubic crystal structure. a Hf b W c Multi-principal element alloy films not only have high hardness and elastic modulus, but also low surface roughness.

[0041] 3. The elements in this invention are Ta, Hf and W, which can form high-hardness multi-principal element alloy thin films with a wide range of compositions.

[0042] 4. The Ta provided by this invention a Hf b W c Multi-principal element alloy thin films, prepared using multi-target DC magnetron sputtering technology, exhibit a surface roughness of 5.40–8.34 nm, a hardness of 16.6–19.4 GPa, and an elastic modulus of 278.1–328.5 GPa. Furthermore, the use of fewer metallic elements allows for broader applications, particularly in the surface modification of structural materials used in extreme service conditions such as aerospace, defense, and chemical industries, thereby improving the surface strength, hardness, and wear resistance of the materials. Attached Figure Description

[0043] 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 some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0044] Figure 1 Ta in Embodiment 1 of the present invention 0.43 Hf 0.14 W 0.43 SEM images of the surface and cross-sectional morphology of multi-principal element alloy thin films.

[0045] Figure 2 Ta in Embodiment 1 of the present invention 0.43 Hf 0.14 W 0.43 Surface scan EDS images of elements in multi-principal alloy thin films.

[0046] Figure 3 Ta in Embodiment 1 of the present invention 0.43 Hf 0.14 W 0.43 AFM image of the surface morphology of a multi-principal element alloy thin film.

[0047] Figure 4 Ta in Embodiment 1 of the present invention 0.43 Hf 0.14 W 0.43 XRD pattern of multi-principal element alloy thin film.

[0048] Figure 5 Ta in Embodiment 2 of the present invention 0.50 Hf 0.17 W 0.33 SEM images of the surface and cross-sectional morphology of multi-principal element alloy thin films.

[0049] Figure 6 Ta in Embodiment 2 of the present invention 0.50 Hf 0.17 W 0.33 Surface scan EDS images of elements in multi-principal alloy thin films.

[0050] Figure 7 Ta in Embodiment 2 of the present invention 0.50 Hf 0.17 W 0.33 AFM image of the surface morphology of a multi-principal element alloy thin film.

[0051] Figure 8 Ta in Embodiment 2 of the present invention 0.50 Hf 0.17 W 0.33XRD pattern of multi-principal element alloy thin film.

[0052] Figure 9 The images show the surface and cross-sectional morphology of the TaHfW multi-principal-element alloy thin film in Embodiment 3 of the present invention, as shown in the SEM images.

[0053] Figure 10 This is an elemental EDS image of the TaHfW multi-principal alloy thin film in Embodiment 3 of the present invention.

[0054] Figure 11 The image shows the surface morphology AFM image of the TaHfW multi-principal element alloy thin film in Example 3 of this invention.

[0055] Figure 12 The image shows the XRD pattern of the TaHfW multi-principal-element alloy thin film in Example 3 of this invention.

[0056] Figure 13 Ta in Comparative Example 1 of the present invention 0.64 Hf 0.12 W 0.24 SEM images of the surface and cross-sectional morphology of multi-principal element alloy thin films.

[0057] Figure 14 Ta in Comparative Example 1 of the present invention 0.64 Hf 0.12 W 0.24 Surface scan EDS images of elements in multi-principal alloy thin films.

[0058] Figure 15 Ta in Comparative Example 1 of the present invention 0.64 Hf 0.12 W 0.24 AFM image of the surface morphology of a multi-principal element alloy thin film.

[0059] Figure 16 Ta in Comparative Example 1 of the present invention 0.64 Hf 0.12 W 0.24 XRD pattern of multi-principal element alloy thin film. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0061] All raw materials used in the following embodiments are commercially available: the high-purity Ar gas used in this invention was purchased from Beijing Millennium Jingcheng Gas Co., Ltd., with a purity greater than or equal to 99.999%. The Ta, Hf, and W targets used in the thin films prepared by this invention are all commercially available products with a purity greater than or equal to 99.95%, and the silicon wafers are commercially available products. The high-vacuum magnetron sputtering coating equipment used in the thin films prepared by this invention is a magnetron sputtering coating equipment manufactured by Shenyang Scientific Instruments Co., Ltd., Chinese Academy of Sciences; the mechanical pump and molecular pump are supporting equipment of the high-vacuum magnetron sputtering coating equipment manufactured by the same company.

[0062] Example 1 Ta 0.43 Hf 0.14 W 0.43 Preparation of multi-principal element alloy thin films

[0063] Commercial P-type, crystal orientation <100> The single-crystal silicon wafer was treated with damped polishing, then ultrasonically cleaned in anhydrous ethanol at a frequency of 60-80 Hz for 10 min to remove impurities and contaminants adhering to the substrate surface. Next, the substrate was rinsed with deionized water and dried with compressed nitrogen to prevent surface water residue. The substrate was fixed face down on the furnace tray, which was then fixed to the sample stage of the magnetron sputtering thin film deposition system. The sample stage baffle was rotated to completely cover the substrate. Metal targets Ta, Hf, and W were placed sequentially on three different DC target positions in the deposition chamber. The angle of each metal target perpendicular to the center line of the sample stage was adjusted to 30°, and the vertical distance between the metal targets and the sample stage was adjusted to 10 cm. The deposition chamber was first evacuated to less than 8.0 Pa using a mechanical pump, and then the vacuum level was reduced to less than 6.0 × 10⁻⁶ Pa using a molecular pump. -4 High-purity argon gas with a purity greater than or equal to 99.999% was introduced into the deposition chamber at a flow rate of 40 sccm. The working pressure was set to 0.7 Pa. The sputtering power of the Ta target was set to 150 W, the Hf target to 60 W, and the W target to 150 W. The targets were pre-sputtered for 10 min to remove oxides and other impurities adhering to the target surface. After pre-sputtering, the sample stage rotation speed was set to 15 r / min, the sample stage baffle was opened, and formal sputtering began for 1 h. After sputtering, the DC constant current power supply and the argon gas switch were turned off, and the sample stage rotation was stopped. The film was allowed to cool to room temperature under vacuum before being removed to reduce oxidation contamination. Finally, the Ta film was obtained on the silicon wafer. 0.43 Hf 0.14 W 0.43 Multi-principal-element alloy thin films.

[0064] Chemical composition analysis of the multi-principal element alloy thin film was performed using an Oxford X-act energy dispersive spectroscopy (EDS, mounted on a scanning electron microscope). The surface and cross-sectional morphology SEM images and elemental surface scanning EDS spectra of the multi-principal element alloy thin film are shown below. Figure 1 and Figure 2 As shown: According to the quantitative calculation results of the software, the composition of this multi-principal element alloy film is Ta. 0.43 Hf 0.14 W 0.43 .

[0065] Ta was imaged using a Dimension ICON atomic force microscope (AFM) from Bruker GmbH, Germany. 0.43 Hf 0.14 W 0.43 The surface morphology of the multi-principal element alloy thin film was analyzed using tapping mode, with a scanning area of ​​10 μm × 10 μm. The surface roughness (Ra) of the film was analyzed using NanoScope Analysis software. The results are as follows: Figure 3 Shown:Ta 0.43 Hf 0.14 W 0.43 The surface AFM morphology of the multi-principal element alloy thin film is needle-like, and the surface roughness is 5.40 nm.

[0066] The surface roughness of a thin film affects its wear resistance. The coefficient of friction and wear rate of a thin film generally increase with increasing surface roughness. This is because a rough surface has a smaller contact area and higher contact pressure, which leads to a higher coefficient of friction and wear loss. Therefore, a smaller surface roughness is beneficial to improving the wear resistance of the thin film.

[0067] Ta was analyzed using a D8 Advance X-ray diffractometer (XRD) from BRUKER AXS GmbH, Germany. 0.43 Hf 0.14 W 0.43 XRD phase analysis was performed on multi-principal element alloy thin films. The operating voltage was 40 kV, the operating current was 40 mA, the X-ray source was Cu-Ka (λ = 0.15418 nm) rays, the grazing incidence angle was 1°, the scanning speed was 4° / min, the scanning step size was 0.02° / step, and the scanning range was 10°–90°. The results are as follows: Figure 4 As shown. Based on the extinction rules of lattice diffraction, the three diffraction peaks marked with black rhombuses in the spectrum can be determined to correspond to the (110), (200), and (211) crystal planes of the BCC structure phase, indicating that Ta 0.43 Hf 0.14 W 0.43 The crystal structure of the multi-principal element alloy thin film is a single-phase body-centered cubic (BCC) structure.

[0068] Because thin films are micro- and nano-scale materials, their hardness can only be measured using a nanoindenter. Vickers hardness and Rockwell hardness, which are typically used to measure the hardness of bulk alloys, cannot be used to measure the hardness of thin films. Therefore, an Agilent Technologies Nano Indenter G200 nanoindenter was used in continuous stiffness mode to measure the hardness of Ta... 0.43 Hf 0.14 W 0.43 The hardness of the multi-principal element alloy thin film was tested, and the results showed that Ta 0.43 Hf 0.14 W 0.43 The nanoindentation hardness of the multi-principal element alloy film is 19.4 GPa, and the elastic modulus is 328.5 GPa, which can be used in high-hardness and wear-resistant fields.

[0069] Example 2 Ta 0.50 Hf 0.17 W 0.33 Preparation of multi-principal element alloy thin films

[0070] Commercial P-type, crystal orientation <100> The single-crystal silicon wafer was treated with damped polishing, then ultrasonically cleaned in anhydrous ethanol at a frequency of 60-80 Hz for 10 min to remove impurities and contaminants adhering to the substrate surface. Next, the substrate was rinsed with deionized water and dried with compressed nitrogen to prevent surface water residue. The substrate was fixed face down on the furnace tray, which was then fixed to the sample stage of the magnetron sputtering thin film deposition system. The sample stage baffle was rotated to completely cover the substrate. Metal targets Ta, Hf, and W were placed sequentially on three different DC target positions in the deposition chamber. The angle of each metal target perpendicular to the center line of the sample stage was adjusted to 30°, and the vertical distance between the metal targets and the sample stage was adjusted to 10 cm. The deposition chamber was first evacuated to less than 8.0 Pa using a mechanical pump, and then the vacuum level was reduced to less than 6.0 × 10⁻⁶ Pa using a molecular pump. -4 High-purity argon gas with a purity greater than or equal to 99.999% was introduced into the deposition chamber at a flow rate of 40 sccm. The working pressure was set to 0.7 Pa. The sputtering power of the Ta target was set to 150 W, the Hf target to 50 W, and the W target to 110 W. The targets were pre-sputtered for 10 min to remove oxides and other impurities adhering to the target surface. After pre-sputtering, the sample stage rotation speed was set to 15 r / min, the sample stage baffle was opened, and formal sputtering began for 1 h. After sputtering, the DC constant current power supply and the argon gas switch were turned off, and the sample stage rotation was stopped. The film was allowed to cool to room temperature under vacuum before being removed to reduce oxidation contamination. Finally, the Ta film was obtained on the silicon wafer. 0.50 Hf 0.17 W 0.33Multi-principal-element alloy thin films.

[0071] Chemical composition analysis of the multi-principal element alloy thin film was performed using an Oxford X-act energy dispersive spectroscopy (EDS, mounted on a scanning electron microscope). The surface and cross-sectional morphology SEM images and elemental surface scanning EDS spectra of the multi-principal element alloy thin film are shown below. Figure 5 and Figure 6 As shown: According to the quantitative calculation results of the software, the composition of this alloy film is Ta. 0.50 Hf 0.17 W 0.33 .

[0072] Ta was imaged using a Dimension ICON atomic force microscope (AFM) from Bruker GmbH, Germany. 0.50 Hf 0.17 W 0.33 The surface morphology of the multi-principal element alloy thin film was analyzed using tapping mode, with a scanning area of ​​10 μm × 10 μm. The surface roughness (Ra) of the film was analyzed using NanoScope Analysis software. The results are as follows: Figure 7 Shown: Ta 0.50 Hf 0.17 W 0.33 The surface AFM morphology of the multi-principal element alloy thin film is needle-like, and the surface roughness is 6.52 nm.

[0073] Ta was analyzed using a D8 Advance X-ray diffractometer (XRD) from BRUKER AXS GmbH, Germany. 0.50 Hf 0.17 W 0.33 XRD phase analysis was performed on multi-principal element alloy thin films. The operating voltage was 40 kV, the operating current was 40 mA, the X-ray source was Cu-Ka (λ = 0.15418 nm) rays, the grazing incidence angle was 1°, the scanning speed was 4° / min, the scanning step size was 0.02° / step, and the scanning range was 10°–90°. The results are as follows: Figure 8 As shown. Based on the extinction rules of lattice diffraction, the three diffraction peaks marked with black rhombuses in the spectrum can be determined to correspond to the (110), (200), and (211) crystal planes of the BCC structure phase, indicating that Ta 0.50 Hf 0.17 W 0.33 The crystal structure of the multi-principal element alloy thin film is a single-phase body-centered cubic (BCC) structure.

[0074] Because thin films are micro- and nano-scale materials, their hardness can only be measured using a nanoindenter. Vickers hardness and Rockwell hardness, which are typically used to measure the hardness of bulk alloys, cannot be used to measure the hardness of thin films. Therefore, an Agilent Technologies Nano Indenter G200 nanoindenter was used in continuous stiffness mode to measure the hardness of Ta... 0.50 Hf 0.17 W 0.33 The hardness of the multi-principal element alloy thin film was tested, and the results showed that Ta 0.50 Hf 0.17 W 0.33 The nanoindentation hardness of the multi-principal element alloy film is 18.6 GPa, and the elastic modulus is 308.3 GPa.

[0075] Example 3: Preparation of TaHfW multi-principal element alloy thin films

[0076] Commercial P-type, crystal orientation <100> The single-crystal silicon wafer was treated with damped polishing, then ultrasonically cleaned in anhydrous ethanol at a frequency of 60-80 Hz for 10 min to remove impurities and contaminants adhering to the substrate surface. Next, the substrate was rinsed with deionized water and dried with compressed nitrogen to prevent surface water residue. The substrate was fixed face down on the furnace tray, which was then fixed to the sample stage of the magnetron sputtering thin film deposition system. The sample stage baffle was rotated to completely cover the substrate. Metal targets Ta, Hf, and W were placed sequentially on three different DC target positions in the deposition chamber. The angle of each metal target perpendicular to the center line of the sample stage was adjusted to 30°, and the vertical distance between the metal targets and the sample stage was adjusted to 10 cm. The deposition chamber was first evacuated to less than 8.0 Pa using a mechanical pump, and then the vacuum level was reduced to less than 6.0 × 10⁻⁶ Pa using a molecular pump. -4 Pa; High-purity argon gas with a purity greater than or equal to 99.999% was introduced into the deposition chamber at a flow rate of 40 sccm. The working pressure was set to 0.7 Pa. The sputtering power of the Ta target was set to 100 W, the sputtering power of the Hf target was set to 100 W, and the sputtering power of the W target was set to 100 W. The targets were pre-sputtered for 10 min to remove oxides and other impurities attached to the target surface. After the pre-sputtering was completed, the sample stage rotation speed was set to 15 r / min, the sample stage baffle was opened, and the formal sputtering was started for 1 h. After the sputtering was completed, the DC constant current power supply was turned off, the argon gas switch was turned off, the sample stage rotation was stopped, and the film was cooled to room temperature under vacuum before being taken out to reduce oxidation contamination. Finally, the TaHfW multi-principal alloy film was obtained on the silicon wafer.

[0077] Chemical composition analysis of the multi-principal element alloy thin film was performed using an Oxford X-act energy dispersive spectroscopy (EDS, mounted on a scanning electron microscope). The surface and cross-sectional morphology SEM images and elemental surface scanning EDS spectra of the multi-principal element alloy thin film are shown below. Figure 9 and Figure 10 As shown: According to the quantitative calculation results of the software, the composition of this multi-principal element alloy film is TaHfW multi-principal element alloy film.

[0078] Ta was imaged using a Dimension ICON atomic force microscope (AFM) from Bruker GmbH, Germany. 0.43 Hf 0.14 W 0.43 The surface morphology of the multi-principal element alloy thin film was analyzed using tapping mode, with a scanning area of ​​10 μm × 10 μm. The surface roughness (Ra) of the film was analyzed using NanoScope Analysis software. The results are as follows: Figure 11 As shown, the surface AFM morphology of the TaHfW multi-principal element alloy thin film is needle-like, and the surface roughness is 8.34 nm.

[0079] XRD phase analysis of TaHfW multi-principal element alloy thin films was performed using a D8 Advance X-ray diffractometer (XRD) from BRUKER AXS GmbH, Germany. The operating voltage was 40 kV, the operating current was 40 mA, the X-ray source was Cu-Ka (λ = 0.15418 nm), the grazing incidence angle was 1°, the scanning speed was 4° / min, the scanning step size was 0.02° / step, and the scanning range was 10°–90°. The results are as follows: Figure 12 As shown. Based on the extinction rules of lattice diffraction, it can be determined that the three diffraction peaks marked with black rhombuses in the spectrum correspond to the (110), (200) and (211) crystal planes of the BCC structure phase, respectively, indicating that the crystal structure of the TaHfW multi-principal alloy thin film is a single-phase body-centered cubic (BCC) structure.

[0080] Since thin films are micro- and nano-scale materials, their hardness can only be measured using a nanoindenter. Vickers hardness and Rockwell hardness, which are typically used to measure the hardness of bulk alloys, cannot be used to measure the hardness of thin films. Therefore, an Agilent Technologies Nano Indenter G200 nanoindenter was used in continuous stiffness mode to test the hardness of the TaHfW multi-principal element alloy thin film. The results showed that the nanoindentation hardness of the TaHfW multi-principal element alloy thin film was 16.6 GPa, and the elastic modulus was 278.1 GPa, making it suitable for applications in high-hardness and wear-resistant fields.

[0081] Comparative Example 1 Ta 0.64 Hf 0.12 W 0.24 Preparation of multi-principal element alloy thin films

[0082] Commercial P-type, crystal orientation <100> The single-crystal silicon wafer was treated with damped polishing, then ultrasonically cleaned in anhydrous ethanol at a frequency of 60-80 Hz for 10 min to remove impurities and contaminants adhering to the substrate surface. Next, the substrate was rinsed with deionized water and dried with compressed nitrogen to prevent surface water residue. The substrate was fixed face down on the furnace tray, which was then fixed to the sample stage of the magnetron sputtering thin film deposition system. The sample stage baffle was rotated to completely cover the substrate. Metal targets Ta, Hf, and W were placed sequentially on three different DC target positions in the deposition chamber. The angle of each metal target perpendicular to the center line of the sample stage was adjusted to 30°, and the vertical distance between the metal targets and the sample stage was adjusted to 10 cm. The deposition chamber was first evacuated to less than 8.0 Pa using a mechanical pump, and then the vacuum level was reduced to less than 6.0 × 10⁻⁶ Pa using a molecular pump. -4 High-purity argon gas with a purity greater than or equal to 99.999% was introduced into the deposition chamber at a flow rate of 40 sccm. The working pressure was set to 0.7 Pa. The sputtering power of the Ta target was set to 180 W, the Hf target to 40 W, and the W target to 80 W. The targets were pre-sputtered for 10 min to remove oxides and other impurities adhering to the target surface. After pre-sputtering, the sample stage rotation speed was set to 15 r / min, the sample stage baffle was opened, and formal sputtering began for 1 h. After sputtering, the DC constant current power supply and the argon gas switch were turned off, and the sample stage rotation was stopped. The film was allowed to cool to room temperature under vacuum before being removed to reduce oxidation contamination. Finally, the Ta film was obtained on the silicon wafer. 0.64 Hf 0.12 W 0.24 Multi-principal-element alloy thin films.

[0083] Chemical composition analysis of the multi-principal element alloy thin film was performed using an Oxford X-act energy dispersive spectroscopy (EDS, mounted on a scanning electron microscope). The surface and cross-sectional morphology SEM images and elemental surface scanning EDS spectra of the multi-principal element alloy thin film are shown below. Figure 13 and Figure 14 As shown: According to the quantitative calculation results of the software, the composition of this multi-principal element alloy film is Ta. 0.64 Hf 0.12 W 0.24 Multi-principal-element alloy thin films.

[0084] Ta was imaged using a Dimension ICON atomic force microscope (AFM) from Bruker GmbH, Germany. 0.64 Hf 0.12 W 0.24The surface morphology of the multi-principal element alloy thin film was analyzed using tapping mode, with a scanning area of ​​10 μm × 10 μm. The surface roughness (Ra) of the film was analyzed using NanoScope Analysis software. The results are as follows: Figure 15 Shown:Ta 0.64 Hf 0.12 W 0.24 The surface AFM morphology of the multi-principal element alloy thin film is columnar, and the surface roughness is 11.81 nm.

[0085] Ta was analyzed using a D8 Advance X-ray diffractometer (XRD) from BRUKER AXS GmbH, Germany. 0.64 Hf 0.12 W 0.24 XRD phase analysis was performed on multi-principal element alloy thin films. The operating voltage was 40 kV, the operating current was 40 mA, the X-ray source was Cu-Ka (λ = 0.15418 nm) rays, the grazing incidence angle was 1°, the scanning speed was 4° / min, the scanning step size was 0.02° / step, and the scanning range was 10°–90°. The results are as follows: Figure 16 As shown. This indicates that Ta 0.64 Hf 0.12 W 0.24 The crystal structure of the multi-principal element alloy thin film is amorphous.

[0086] Because thin films are micro- and nano-scale materials, their hardness can only be measured using a nanoindenter. Vickers hardness and Rockwell hardness, which are typically used to measure the hardness of bulk alloys, cannot be used to measure the hardness of thin films. Therefore, an Agilent Technologies Nano Indenter G200 nanoindenter was used in continuous stiffness mode to measure the hardness of Ta... 0.64 Hf 0.12 W 0.24 The hardness of the multi-principal element alloy thin film was tested, and the results showed that Ta 0.64 Hf 0.12 W 0.24 The nanoindentation hardness of the multi-principal alloy film is 12.3 GPa, and the elastic modulus is 242.6 GPa.

[0087] The properties of the multi-principal element alloy thin film materials obtained in the above embodiments and comparative examples are shown in Table 1.

[0088]

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-principal element alloy thin film, characterized in that, The multi-principal alloy thin film is composed of Ta, Hf, W in equal or non-equal atomic ratios, and the chemical formula of the multi-principal alloy thin film is Ta. a Hf b W c Wherein, a is 30%~50%, b is 15%~35%, c is 30%~45%, and a+b+c=1. The multi-principal alloy thin film has a single-phase body-centered cubic crystal structure, a surface roughness of 5.40~8.34 nm, a film hardness of 16.6~19.4 GPa, and an elastic modulus of 278.1~328.5 GPa. The multi-principal alloy thin film is prepared by the following method, including magnetron sputtering deposition of Ta, Hf, and W targets at a set sputtering power to obtain the multi-principal alloy thin film. The sputtering power of the Ta target is 100~150 W, the sputtering power of the Hf target is 50~100 W, and the sputtering power of the W target is 100~150 W.

2. The method for preparing a multi-principal element alloy thin film according to claim 1, characterized in that, The method for preparing the multi-principal element alloy thin film includes: Substrate preparation: The substrate was ultrasonically cleaned in anhydrous ethanol, then washed with water and dried, and placed on the sample stage; Target setup: Place the Ta, Hf, and W targets on the three DC sputtering target positions in the deposition chamber, and adjust the angle of the target perpendicular to the center line of the sample stage and the vertical distance between the target and the substrate. Coating process: The vacuum level of the deposition chamber is evacuated to the set condition, then high-purity argon gas is introduced, the gas flow rate is set, the working gas pressure of the deposition chamber is adjusted, the substrate is covered with a baffle and the target is pre-sputtered; then the rotation speed of the substrate is set and the baffle is opened for sputtering coating, and a multi-principal element alloy thin film is obtained according to the set process parameters.

3. The method for preparing multi-principal element alloy thin films according to claim 2, characterized in that, In the substrate processing step, the substrate is a monocrystalline silicon wafer.

4. The method for preparing multi-principal element alloy thin films according to claim 3, characterized in that, The substrate is P-type single-crystal silicon, having <100> Crystal orientation structure; and / or, in the target material setting step, the Ta target, Hf target, and W target are all high-purity metal blocks with a purity ≥99.95%, a diameter of 60±10 mm, and a thickness of 3~5 mm.

5. The method for preparing a multi-principal element alloy thin film according to claim 4, characterized in that, In the substrate treatment step, the ultrasonic frequency is 60~80 Hz and the ultrasonic time is 10±5 min; and / or, the smooth surface of the substrate is polished with damping cloth before ultrasonic cleaning.

6. The method for preparing a multi-principal element alloy thin film according to any one of claims 2-5, characterized in that, In the target setting step, the angle between the target and the center line of the sample stage is 20~40°; the vertical distance between the pure metal block target of Ta, Hf, W and the substrate is 5~15 cm.

7. The method for preparing a multi-principal element alloy thin film according to any one of claims 2-5, characterized in that, In the coating process, the vacuum level of the deposition chamber is 6 × 10⁻⁶. -4 ~8×10 -4 Pa; the working gas pressure is 0.7~0.9 Pa; the gas flow rate is 30~50 sccm, and the purity is ≥99.999%.

8. The method for preparing a multi-principal element alloy thin film according to claim 7, characterized in that, The pre-sputtering time is 10-15 min, and the sputtering time is 1 ± 0.2 h.

9. The method for preparing a multi-principal element alloy thin film according to any one of claims 2-5, characterized in that, Includes the following steps: 1) Place the substrate in anhydrous ethanol for ultrasonic cleaning to remove contaminants adhering to the substrate surface, and then rinse the substrate with deionized water. 2) Dry the cleaned substrate with compressed nitrogen to ensure a clean surface and prevent water stains from remaining. 3) Fix the substrate with the smooth side down on the furnace tray, fix the furnace tray on the sample stage of the magnetron sputtering thin film deposition equipment, and rotate the sample stage baffle to adjust it to the position to cover the substrate; 4) Place the Ta, Hf and W metal bulk targets on three different DC target positions in the deposition chamber, and adjust the angle of each target perpendicular to the center line of the sample stage and the vertical distance between each target and the sample stage. 5) Adjust the vacuum level in the deposition chamber; 6) Introduce argon gas into the deposition chamber, adjust the working gas pressure, set the sputtering power of the target material, and pre-sputter the target material; 7) Set the rotation speed of the sample stage, open the substrate baffle, and perform sputter deposition on the smooth surface of the substrate to obtain a thin film; 8) Cool the film to room temperature under vacuum.

10. The application of the multi-principal element alloy thin film according to claim 1 or the multi-principal element alloy thin film obtained by the preparation method according to any one of claims 2-9, characterized in that, This includes applications in the surface modification of structural materials in the aerospace, defense, and chemical industries under extreme service conditions.

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