A crystalline Cu / amorphous MgCuY corrosion-resistant multilayer film and a preparation method thereof

Abstract

The present invention discloses a corrosion-resistant multi-layer film of crystalline Cu / amorphous MgCuY, its preparation method and application, which includes multiple layers of crystalline Cu layers and multiple layers of amorphous MgCuY layers; the multiple layers of crystalline Cu layers and the multiple layers of amorphous MgCuY layers are alternately stacked, and the atomic percentage contents of each element in the amorphous MgCuY layer are Mg: 80%-90%, Cu: 3%-8%, Y: 7%-12%; the single-layer thickness of the amorphous MgCuY layer is 4±0.5 nm, the single-layer thickness of the crystalline Cu layer is 40±2 nm, and the total thickness of the multi-layer film is 1.04±0.02 μm. A large number of interlayer interfaces can serve as a diffusion barrier for corrosive substances and corrosion cracks, effectively improving the corrosion resistance of the thin film.

Description

Technical Field

[0001] The present invention belongs to the field of material surface protection, and relates to a crystalline Cu / amorphous MgCuY corrosion-resistant multilayer film and a preparation method thereof. Background Art

[0002] Components that have been in service in harsh environments for a long time are prone to corrosion on the surface, resulting in huge economic losses and unpredictable safety hazards. For various metal components, people usually cover a protective layer on the surface to isolate it from the surrounding corrosive media in order to prevent or delay corrosion, which meets the industry's pursuit of production cost and efficiency. Pure copper thin films not only have good comprehensive physical properties such as thermal conductivity, electrical conductivity, bonding property, and processability, but also have low economic costs and are widely used in the fields of electronic appliances, transportation, electric power, instrumentation, and traditional machinery manufacturing. However, when copper thin films are exposed to oxygen-containing water, oxidizing acids, or some marine atmospheric environments containing chloride ions and high temperature and high salinity, their surfaces are prone to corrosion and the formation of verdigris, which will then lead to material failure.

[0003] Common anti-corrosion film layer technologies include organic coatings, inorganic coatings, electrochemical coatings, etc. However, as the service environment of parts becomes more severe and complex, under certain special conditions, these traditional single protective layers all have certain limitations, and there are problems such as limited protection effect, short service life, and environmental pollution. For example, since it is difficult for copper to form a stable and dense oxide, special passivators need to be used, and the heavy metal waste liquid generated after passivation will pollute the environment; therefore, there is an urgent need to develop a method that can effectively improve the corrosion resistance of pure copper thin films and is environmentally friendly. Summary of the Invention

[0004] The purpose of the present invention is to overcome the above-mentioned disadvantages of the prior art, and provide a crystalline Cu / amorphous MgCuY corrosion-resistant multilayer film, a preparation method thereof, and an application thereof, which effectively improve the corrosion resistance of the thin film.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions:

[0006] A crystalline Cu / amorphous MgCuY corrosion-resistant multilayer film includes multiple layers of crystalline Cu layers and multiple layers of MgCuY amorphous layers;

[0007] The multiple layers of crystalline Cu layers and multiple layers of MgCuY amorphous layers are alternately stacked, and the atomic percentage contents of each element in the MgCuY amorphous layer are Mg: 80%-90%, Cu: 3%-8%, Y: 7%-12%;

[0008] The single-layer thickness of the MgCuY amorphous layer is 4±0.5 nm, the single-layer thickness of the crystalline Cu layer is 40±2 nm, and the total thickness of the multilayer film is 1.04±0.02 μm.

[0009] A method for preparing the corrosion-resistant multi-layer film of crystalline Cu / amorphous MgCuY, comprising the following steps:

[0010] Step (1), placing the substrate into a sealed cavity;

[0011] Step (2), installing a metal Cu target on the A target holder as the A target, and installing an MgCuY alloy target on the B target holder as the B target;

[0012] Step (3), evacuating the sealed cavity to the required vacuum degree, then introducing an ionization gas, adjusting the working pressure, and then alternately sputtering with the A target and the B target to alternately deposit an amorphous MgCuY layer and a crystalline Cu layer on the substrate until the thickness reaches the requirement, thereby obtaining the corrosion-resistant multi-layer film of crystalline Cu / amorphous MgCuY.

[0013] Preferably, the substrate is a circular single-crystalline silicon wafer with one side polished, and the diameter is 50 mm.

[0014] Preferably, before the substrate is placed into the sealed cavity, it is ultrasonically cleaned with distilled water and alcohol for 10 - 15 minutes in sequence, and then dried.

[0015] Preferably, the cavity vacuum degree is 7.8×10 -4 -8.0×10 -4 Pa.

[0016] Preferably, the ionization gas is Ar gas, the gas flow rate is 20 ± 2 sccm, and the working pressure is 2.5 - 2.6 Pa.

[0017] Preferably, the A target uses a DC power supply, the power is 20 ± 1 W, and the deposition rate is 8 ± 0.6 nm / min.

[0018] Preferably, the B target uses an RF power supply, the power is 30 ± 1 W, and the deposition rate is 4 ± 0.4 nm / min.

[0019] Preferably, during sputtering, the substrate rotates at a constant speed of 3 revolutions per minute.

[0020] Preferably, after the deposition of the corrosion-resistant multi-layer film of crystalline Cu / amorphous MgCuY is completed, wait for the sealed cavity to cool for 60 - 90 min and then take it out from the sealed cavity.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The crystalline Cu / amorphous MgCuY multilayer film of the present invention is composed of alternating stacks of crystalline Cu layers and amorphous MgCuY layers. A large number of interlayer interfaces can serve as diffusion barriers for corrosive substances and corrosion cracks, effectively improving the corrosion resistance of the film. Electrochemical tests were carried out in a 3.5% (mass fraction) NaCl solution, and the results showed that its corrosion resistance was significantly better than that of pure Cu films and MgCuY films.

[0023] The multilayer film of the present invention is prepared by magnetron sputtering technology. This method is simple to operate, easy to control conditions, and has good repeatability. By adjusting parameters and deposition time, the film thickness can be precisely controlled, and then the required multilayer structure can be obtained, which is easy to promote. Brief Description of the Drawings

[0024] Figure 1 is a high-resolution transmission electron microscope cross-sectional photograph of the crystalline Cu / amorphous MgCuY multilayer film prepared in Example 1 of the present invention. The inset is the fast Fourier transform pattern of a local area within the layer.

[0025] Figure 2 is a representative potentiodynamic polarization curve of the Cu film prepared in the comparative example of the present invention and the crystalline Cu / amorphous MgCuY multilayer film prepared in Example 1 in a 3.5% (mass fraction) NaCl solution.

[0026] Figure 3 is the alternating current impedance spectrum of the Cu film prepared in the comparative example of the present invention and the crystalline Cu / amorphous MgCuY multilayer film prepared in Example 1 in a 3.5% (mass fraction) NaCl solution, including the Nyquist curve and the Bode plot. Detailed Description of the Invention

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0028] It should be noted that the terms "front", "rear", "left", "right", "upper" and "lower" used in the following description refer to the directions in the drawings, and the terms "inner" and "outer" respectively refer to the directions towards or away from the geometric center of a specific component.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this invention belongs. The terms used in the specification of this invention are for the purpose of describing specific embodiments only and are not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the related listed items.

[0030] The corrosion-resistant multilayer film of crystalline Cu / amorphous MgCuY described in the present invention is composed of alternating superposition of crystalline Cu layers and MgCuY amorphous layers, wherein the atomic percentage content of each element in the MgCuY amorphous layer is Mg: 80%-90%, Cu: 3%-8%, and Y: 7%-12%.

[0031] The multilayer film is prepared by alternately depositing a Cu target and a MgCuY target through magnetron sputtering technology. The single-layer thickness of the MgCuY amorphous layer is 4 ± 0.5 nm, the single-layer thickness of the crystalline Cu layer is 40 ± 2 nm, and the total thickness of the multilayer film is 1.04 ± 0.02 μm.

[0032] Its preparation method specifically includes the following steps:

[0033] (1) The single-sided polished circular optical monocrystalline silicon substrate is ultrasonically cleaned with distilled water and alcohol for 10-15 minutes in sequence to ensure cleanliness. After drying, it is placed on the substrate stage of the magnetron sputtering equipment for film coating. The diameter of the circular monocrystalline silicon substrate is 50 mm.

[0034] (2) The metal Cu target is installed on the A target holder as the A target, and the MgCuY alloy target is installed on the B target holder as the B target.

[0035] The A target uses a DC power supply with a power of 20 ± 1 W and a deposition rate of 8 ± 0.6 nm / min.

[0036] The B target uses an RF power supply with a power of 30 ± 1 W and a deposition rate of 4 ± 0.4 nm / min.

[0037] (3) When preparing the multilayer film, the magnetron sputtering equipment is evacuated, and the vacuum degree is 7.8×10 -4 -8.0×10 -4After reaching the required vacuum degree, introduce the ionization gas, and adjust the working pressure. The ionization gas is Ar gas, the gas flow rate is 20±2 sccm, and the working pressure is 2.5 - 2.6 Pa. Alternately sputter with a DC target and an RF target, and control the working time of the two targets to achieve the required single-layer thickness. When preparing the multi-layer film, first sputter-deposit a MgCuY amorphous layer on the silicon substrate with the B RF target for 1 - 1.1 min, and then sputter-deposit a crystalline Cu layer on this MgCuY amorphous layer with the A DC target for 5 - 5.1 min. Alternately deposit in this way to form a crystalline Cu / amorphous MgCuY multi-layer film, and finally reach the total thickness of the multi-layer film. The single-layer thickness of the MgCuY amorphous layer in the multi-layer film is 4±0.5 nm, the atomic percentage content of each element in the MgCuY layer is Mg: 80% - 90%, Cu: 3% - 8%, Y: 7% - 12%, the single-layer thickness of the crystalline Cu layer is 40±2 nm, and the total thickness of the multi-layer film is 1.04±0.02 μm.

[0038] In the present invention, the deposition rate of the target material needs to be accurately obtained before film coating, and sputtering is carried out at room temperature. During the process of sputtering and depositing the thin film, the substrate table rotates at a constant speed of 3 r / min to ensure the uniformity of the thin film. After the multi-layer film deposition is completed, it is furnace-cooled for 60 - 90 min and then taken out from the sputtering chamber.

[0039] Example 1, Preparation of crystalline Cu / amorphous MgCuY multi-layer film:

[0040] Step (1): Ultrasonically clean a circular single-side polished single-crystalline silicon substrate with a diameter of 50 mm with distilled water and alcohol for 15 minutes respectively. After drying, place it on the substrate table of the magnetron sputtering equipment to prepare for film coating;

[0041] Step (2): Install Cu on the A DC target as the A target, and install the MgCuY alloy on the B RF target as the B target.

[0042] Step (3): During operation, first close the sputtering chamber door, turn on the chiller, and pre-pump the vacuum with a mechanical pump. When the vacuum degree is lower than 10 Pa, turn on the molecular pump to continue pumping the vacuum. When the air pressure in the vacuum chamber is pumped to 7.8×10 -4Pa, open the Ar gas valve, adjust the Ar gas flow rate to 20 sccm, the working pressure to 2.5 Pa, and set the rotation speed of the substrate tray to 3 r / min. Then set the power of the power supply. The set power of DC target A is 20 W, and the deposition rate is 8 nm / min; the set power of RF target B is 30 W, and the deposition rate is 4 nm / min. When preparing the multilayer film, first sputter-deposit a MgCuY amorphous layer on the silicon substrate using RF target B for 1 min, and then sputter-deposit a crystalline Cu layer on this MgCuY amorphous layer using DC target A for 5 min. Alternately deposit the crystalline Cu layer and the MgCuY amorphous layer in this way to form a crystalline Cu / amorphous MgCuY multilayer film. After completion, take it out of the sputtering chamber after furnace cooling for 60 min. The total thickness of the final multilayer film is 1.04 μm, where the single-layer thickness of the MgCuY amorphous layer is 4 nm, and the composition of the MgCuY layer is Mg 85 Cu5Y 10 (atomic percentage), and the single-layer thickness of the crystalline Cu layer is 40 nm.

[0043] Example 2

[0044] The raw materials and methods used in this example are the same as those in Example 1, except that:

[0045] In step (1), ultrasonic cleaning is performed for 13 minutes.

[0046] In step (2), the power of target A is 19 W, and the deposition rate is 8.6 nm / min. The power of target B is 29 W, and the deposition rate is 4.4 nm / min.

[0047] In step (3), the molecular pump evacuates to 8.0×10 -4 Pa, the Ar gas flow rate is 22 sccm, the working pressure is 2.6 Pa, the deposition time of the MgCuY amorphous layer is 1.1 min, and the deposition time of the crystalline Cu layer is 5.1 min. After completion, take it out of the sputtering chamber after furnace cooling for 80 min. The single-layer thickness of the MgCuY amorphous layer is 4.5 nm, the composition of the MgCuY layer is Mg 90 Cu3Y7 (atomic percentage), the single-layer thickness of the crystalline Cu layer is 42 nm, and the total thickness of the multilayer film is 1.06 μm.

[0048] Example 3

[0049] The raw materials and methods used in this example are the same as those in Example 1, except that:

[0050] In step (2), the power of target A is 21 W, and the deposition rate is 7.4 nm / min. The power of target B is 31 W, and the deposition rate is 3.6 nm / min.

[0051] In step (3), the molecular pump evacuates to 7.9×10 -4Pa, the Ar gas flow rate is 18 sccm, the working pressure is 2.55 Pa, the deposition time of the MgCuY amorphous layer is 1.1 min, the deposition time of the crystalline Cu layer is 5.1 min, and after completion, it is taken out from the sputtering chamber after furnace cooling for 80 min. The thickness of the single MgCuY amorphous layer is 3.5 nm, and the composition of the MgCuY layer is Mg 80 Cu8Y 12 (atomic percentage), the thickness of the single crystalline Cu layer is 38 nm, and the total thickness of the multilayer film is 1.02 μm.

[0052] Example 4

[0053] The raw materials and methods used in this example are the same as those in Example 1, except that:

[0054] In step (1), ultrasonic cleaning is performed for 10 minutes.

[0055] In step (3), the composition of the MgCuY layer is Mg87Cu4Y9, and after the film coating is completed, it is taken out from the sputtering chamber after furnace cooling for 90 min.

[0056] Comparative example, preparation of a metal Cu film:

[0057] The raw materials and methods used in this comparative example are the same as those in Example 1, except that:

[0058] In step (3), the molecular pump evacuates to 8.0×10 -4 Pa, the working pressure is 2.6 Pa, only target A is used for sputtering deposition of metal Cu, the total thickness of the thin film is 1.0 - 1.08 μm, and it is taken out from the sputtering chamber after furnace cooling for 90 min.

[0059] The following describes the structure of the crystalline Cu / amorphous MgCuY multilayer film and its significantly improved corrosion resistance in conjunction with the accompanying drawings:

[0060] Figure 1 This is a high-resolution transmission electron microscope cross-sectional photograph of the crystalline Cu / amorphous MgCuY multilayer film prepared in Example 1 of the present invention. The inset is the fast Fourier transform pattern of a local area within the layer. As shown in the figure, the crystalline Cu / amorphous MgCuY multilayer film has a continuous and clear layered structure, where the thicknesses of the crystalline Cu layer and the MgCuY amorphous layer are approximately 40 nm and approximately 4 nm, respectively. The corresponding fast Fourier transform patterns indicate that they are the crystalline Cu layer and the amorphous MgCuY amorphous layer, respectively.

[0061] Figure 2Representative potentiodynamic polarization curves obtained by electrochemical testing of the Cu film prepared in the comparative example of the present invention and the crystalline Cu / amorphous MgCuY multilayer film of Example 1 in a 3.5% (mass fraction) NaCl solution. As shown in the figure, the corrosion potential (-0.23 V) of the crystalline Cu / amorphous MgCuY multilayer film is more positive than that of the Cu film (-0.24 V). At the same time, the corrosion current density of the crystalline Cu / amorphous MgCuY multilayer film (3.0×10 -6 A·cm -2 ) is lower than that of the Cu film (3.7×10 -6 A·cm -2 ), indicating that the crystalline Cu / amorphous MgCuY multilayer film has better corrosion resistance.

[0062] Figure 3 The electrochemical impedance spectroscopy of the Cu film prepared in the comparative example of the present invention and the crystalline Cu / amorphous MgCuY multilayer film of Example 1 in a 3.5% (mass fraction) NaCl solution. Among them, the radius of the capacitive reactance arc of the crystalline Cu / amorphous MgCuY multilayer film in the Nyquist curve is significantly larger than that of the pure Cu film, and the |Z| of the crystalline Cu / amorphous MgCuY multilayer film in the Bode diagram 0.01Hz and the phase angle in the intermediate frequency range (100 - 1000 Hz) are larger, indicating that the corrosion resistance is significantly better than that of the pure Cu film.

[0063] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device.

[0064] It should be understood that the above description is for illustrative purposes and not for limitation. By reading the above description, many embodiments and many applications other than the provided examples will be obvious to those skilled in the art. Therefore, the scope of this teaching should not be determined by reference to the above description, but should be determined by reference to the full scope of the foregoing claims and the equivalents of these claims. For the sake of completeness, all articles and references, including patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the foregoing claims is not intended to abandon such subject matter, nor should it be considered that the applicant has not considered such subject matter as part of the disclosed inventive subject matter.

Claims

1. A crystalline Cu / amorphous MgCuY corrosion-resistant multi-layer film, characterized in that, It includes multiple layers of crystalline Cu layers and multiple layers of MgCuY amorphous layers; The multiple layers of crystalline Cu layers and multiple layers of MgCuY amorphous layers are alternately stacked. The atomic percentage content of each element in the MgCuY amorphous layer is Mg: 80%-90%, Cu: 3%-8%, and Y: 7%-12%; The single-layer thickness of the MgCuY amorphous layer is 4±0.5 nm, the single-layer thickness of the crystalline Cu layer is 40±2 nm, and the total thickness of the multi-layer film is 1.04±0.02 μm.

2. A preparation method of the crystalline Cu / amorphous MgCuY corrosion-resistant multilayer film according to claim 1, characterized in that, It includes the following steps: Step (1), putting the substrate into a sealed cavity; Step (2), installing the metal Cu target on the A target seat as target A, and installing the MgCuY alloy target on the B target seat as target B; Step (3), evacuating the sealed cavity. After reaching the required vacuum degree, introducing an ionization gas, adjusting the working pressure, and then alternately sputtering with target A and target B to alternately deposit the MgCuY amorphous layer and the crystalline Cu layer on the substrate until the thickness reaches the requirement, obtaining the corrosion-resistant multi-layer film of crystalline Cu / amorphous MgCuY.

3. The preparation method of the crystalline Cu / amorphous MgCuY corrosion-resistant multilayer film according to claim 2, wherein, The substrate is a circular single-crystalline silicon wafer with one side polished, and the diameter is 50 mm.

4. The preparation method of the crystalline Cu / amorphous MgCuY corrosion-resistant multilayer film according to claim 2, characterized in that, Before the substrate is put into the sealed cavity, it is ultrasonically cleaned with distilled water and alcohol for 10-15 minutes in sequence, and then dried.

5. The preparation method of the crystalline Cu / amorphous MgCuY corrosion-resistant multi-layer film according to claim 2, characterized in that, The cavity vacuum degree is 7.8×10 -4 -8.0×10 -4 Pa.

6. The preparation method of the crystalline Cu / amorphous MgCuY corrosion-resistant multi-layer film according to claim 2, characterized in that, The ionization gas is Ar gas, the gas flow rate is 20±2 sccm, and the working pressure is 2.5-2.6 Pa.

7. The preparation method of the crystalline Cu / amorphous MgCuY corrosion-resistant multilayer film according to claim 2, characterized in that, Target A uses a DC power supply, the power is 20±1 W, and the deposition rate is 8±0.6 nm / min.

8. The preparation method of the crystalline Cu / amorphous MgCuY corrosion-resistant multilayer film according to claim 2, characterized in that, Target B uses an RF power supply, the power is 30±1 W, and the deposition rate is 4±0.4 nm / min.

9. The preparation method of the crystalline Cu / amorphous MgCuY corrosion-resistant multilayer film according to claim 2, characterized in that, During sputtering, the substrate rotates at a constant speed of 3 revolutions per minute.

10. The preparation method of the crystalline Cu / amorphous MgCuY corrosion-resistant multi-layer film according to claim 2, characterized in that, After the deposition of the corrosion-resistant multi-layer film of crystalline Cu / amorphous MgCuY is completed, wait for the sealed cavity to cool for 60-90 min and then take it out from the sealed cavity.

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