Ag-mo / ag film with high ductility and fatigue resistance and preparation method thereof

Abstract

The application discloses an Ag-Mo / Ag film with high ductility and fatigue resistance and a preparation method, and belongs to the field of material surface modification. The Ag-Mo / Ag film comprises an elemental Ag layer and a micro-alloyed Ag-Mo layer, and the micro-alloyed Ag-Mo layer is attached to the surface of the elemental Ag layer. The thickness ratio of the micro-alloyed Ag-Mo layer to the elemental Ag layer is (1:9)-(1:1). The grain morphology of the elemental Ag layer and the micro-alloyed Ag-Mo layer is columnar crystal. The Ag-Mo / Ag film is prepared by introducing a micro-alloyed Ag-Mo layer with high-density nanotwins on the surface of the elemental Ag through co-sputtering. The Ag-Mo / Ag film has high ductility and fatigue resistance, is uniform and dense, and has high film-substrate adhesion. The application of the film is expected to significantly improve the performance and reliability of flexible electronic devices, and opens up new possibilities for the development of flexible electronic technology.

Description

TECHNICAL FIELD

[0001] The application relates to the field of material surface modification, and in particular to an Ag-Mo / Ag film with high ductility and fatigue resistance and a preparation method. BACKGROUND

[0002] With the progress of material science and advanced manufacturing technology, flexible electronic technology has been widely applied in the fields of wearable devices, consumer electronics, human-computer interaction, energy, etc. Due to high electrical conductivity and good mechanical flexibility, face-centered cubic (FCC) structure metal films such as gold, copper and silver are often used as flexible conductors or electrode materials. Micro-nano scale metal films often have a nano-crystalline polycrystalline structure. During the use of electronic devices, the metal film conductor will be subjected to cyclic loads such as stretching and bending, and the metal film is prone to abnormal grain growth, causing surface extrusion or fatigue cracks and other damages, which leads to a decrease in the electrical conductivity of the metal film and affects the functionality of the device. Therefore, it is crucial to develop metal film conductors with excellent fatigue resistance for the development and application of flexible electronic technology.

[0003] Studies have shown that the introduction of high-density oriented nanotwins through micro-alloying can significantly improve the fatigue resistance of FCC metals. However, the introduction of alloying elements and high-density nanotwins often leads to a significant decrease in the ductility of the metal film. How to design the microstructure / structure of the metal film while achieving high ductility and high fatigue resistance is still a difficult problem restricting the development of metal film conductors. SUMMARY

[0004] In view of the problems in the prior art, the application provides an Ag-Mo / Ag film with high ductility and fatigue resistance and a preparation method. A micro-alloyed Ag-Mo layer with high-density nanotwins is introduced on the surface of elemental Ag through co-sputtering. The film avoids the adverse effects of the introduction of alloying elements on the ductility and fully utilizes the fatigue resistance advantages of nanotwins.

[0005] The application is achieved by the following technical solutions:

[0006] An Ag-Mo / Ag film with high ductility and fatigue resistance comprises an elemental Ag layer and a micro-alloyed Ag-Mo layer, and the micro-alloyed Ag-Mo layer is attached to the surface of the elemental Ag layer. The thickness ratio of the micro-alloyed Ag-Mo layer to the elemental Ag layer is (1:9)-(1:1).

[0007] The grain morphology of the elemental Ag layer and the micro-alloyed Ag-Mo layer is columnar crystal. The proportion of twinned grains in the columnar crystal of the elemental Ag layer is 30-40%, and the proportion of twinned grains in the columnar crystal of the Ag-Mo layer is 100%.

[0008] Preferably, the micro-alloyed Ag-Mo layer has Ag of 97-99% and Mo of 1-3% in terms of atomic content percentage.

[0009] Preferably, the twin lamella spacing of the elemental Ag layer is about 35 nm, and the twin lamella spacing of the Ag-Mo layer is about 3 nm.

[0010] Preferably, the conductivity of the Ag-Mo / Ag film is up to 3.0*10 7 S m −1 .

[0011] A preparation method of an Ag-Mo / Ag film with high ductility and fatigue resistance, comprising the following processes:

[0012] An elemental Ag layer and a micro-alloyed Ag-Mo layer are sequentially deposited on a substrate by a direct current magnetron sputtering process in a vacuum environment, and the Ag-Mo / Ag film is obtained after cooling to room temperature.

[0013] The elemental Ag layer is deposited by using an Ag target, and the alloyed Ag-Mo layer is deposited by co-sputtering of an Ag target and a Mo target.

[0014] Preferably, the Ag target sputtering power is 120 W when sputtering the elemental Ag layer, and the Ag target sputtering power is 150 W and the Mo target sputtering power is 20 W when sputtering the micro-alloyed Ag-Mo layer.

[0015] Preferably, the argon gas pressure is 0.5 Pa and the substrate rotation speed is fixed at 10 r / min in the direct current magnetron sputtering process.

[0016] Preferably, the deposition rate is 0.36 nm / s when sputtering the elemental Ag layer, and the deposition rate is 0.45 nm / s when sputtering the micro-alloyed Ag-Mo layer.

[0017] Preferably, the deposition time of the elemental Ag layer is 1390-2500 s.

[0018] Preferably, the deposition time of the alloyed Ag-Mo layer is 223-1112 s.

[0019] Compared with the prior art, the present application has the following beneficial technical effects:

[0020] The application provides an Ag-Mo / Ag film with high ductility and fatigue resistance, which is a double-layer structure metal film of elemental Ag and micro-alloyed Ag-Mo. High-density aligned nanotwins are introduced into the surface Ag film by Mo micro-alloying, and high ductility and fatigue resistance are achieved. Due to the low content of micro-alloying elements, the low electron scattering effect of twin boundaries, and the unique double-layer structure design, the film has the same conductivity and ductility as the Ag film. In addition, due to the introduction of high-density nanotwins and the compatible plastic deformation capacity between micro-alloyed Ag-Mo and elemental Ag, the film surface fatigue extrusion is effectively inhibited, the fatigue crack initiation is delayed, and the crack propagation is hindered, greatly improving the fatigue life. The film not only avoids the adverse effects of introducing alloy elements on ductility, but also fully utilizes the fatigue resistance of nanotwins.

[0021] The application provides a preparation method of the Ag-Mo / Ag film with high ductility and fatigue resistance. The method introduces high-density nanotwins into the film by Mo micro-alloying of elemental Ag through co-sputtering, and reduces the adverse effects of nanotwin introduction on the ductility of the film through the double-layer structure design of elemental Ag and micro-alloyed Ag-Mo. The Ag-Mo / Ag film with high ductility and fatigue resistance is successfully prepared by a direct current magnetron sputtering deposition process. Due to the introduction of high-density nanotwins and the unique double-layer structure design, the Ag-Mo / Ag film not only maintains high conductivity and ductility, but also has significantly improved fatigue resistance due to the intrinsic high fatigue resistance of nanotwins and the compatible plastic deformation capacity between the micro-alloyed Ag-Mo layer and the elemental Ag layer. The film fatigue damage formation and expansion are effectively inhibited. The preparation method of the Ag-Mo / Ag film is simple and cost-effective, and is suitable for large-scale production. The application of the film is expected to significantly improve the performance and reliability of flexible electronic devices, and opens up new possibilities for the development of flexible electronic technology. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed in the embodiments. It should be understood that the following drawings only show some embodiments of the application, and therefore should not be considered as limiting the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0023] Figure 1 The X-ray diffraction pattern of the metal film of the application.

[0024] Figure 2 The planar transmission electron microscope (TEM) photo and the corresponding selected area electron diffraction pattern (SADP) of the Ag-Mo single-layer film of the comparative example of the application.

[0025] Figure 3 Transmission electron microscope (TEM) cross-section images of the thin films of the embodiments and comparative examples of the present application.

[0026] Figure 4 Statistical diagram of cracking strain of the Ag-Mo / Ag thin film of the present application.

[0027] Figure 5 Fatigue life curve of the Ag-Mo / Ag thin film of the present application. DETAILED DESCRIPTION

[0028] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0029] Therefore, the detailed description of the embodiments of the present application provided below in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without making creative efforts are within the scope of protection of the present application.

[0030] An Ag-Mo / Ag thin film with high ductility and fatigue resistance, comprising a single-element Ag layer and a micro-alloyed Ag-Mo layer attached to the surface of the single-element Ag layer; the thickness ratio of the micro-alloyed Ag-Mo layer to the single-element Ag layer is (1:9)-(1:1). The micro-alloyed Ag-Mo layer contains 97-99% of Ag and 1-3% of Mo in terms of atomic content percentage.

[0031] The single-element Ag layer has a columnar crystal grain morphology, and the proportion of twinned crystal grains in the columnar crystal is 30-40%, and the twinned crystal lamella spacing is about 35 nm.

[0032] The micro-alloyed Ag-Mo layer of the Ag-Mo / Ag thin film also has a columnar crystal grain morphology, and the proportion of twinned crystal grains in the columnar crystal is 100%, and the twinned crystal lamella spacing is about 3 nm.

[0033] The total thickness of the Ag-Mo / Ag film with high ductility and fatigue resistance is 1000 nm, which is composed of an elemental Ag layer and a micro-alloyed Ag-Mo layer, wherein the micro-alloyed Ag-Mo layer is a surface layer deposited on the surface of the elemental Ag layer. Under tensile conditions, the film cracking strain is increased by 2-6 times compared with the single-layer Ag-Mo film; by reasonably optimizing the thickness ratio of the micro-alloyed Ag-Mo layer, the fatigue life of the film can be increased by more than 4 times compared with the elemental Ag film under a fatigue strain amplitude of 1%.

[0034] The high-density nanotwin in the micro-alloyed Ag-Mo layer of the Ag-Mo / Ag film of the present application can adapt to ductility deformation by activating cross-twin dislocations under cyclic loading, effectively inhibiting stress concentration and delaying the initiation of fatigue cracks, so that the surface micro-alloyed Ag-Mo layer exhibits high inherent fatigue resistance. In addition, the elemental Ag layer and the micro-alloyed Ag-Mo layer have similar lattice constants and elastic moduli, so that the Ag / Ag-Mo interface exhibits excellent deformation compatibility under cyclic loading, and dislocations easily coordinate the deformation on both sides through the interface, thereby inhibiting the formation of interface damage. In addition, the presence of the surface micro-alloyed Ag-Mo layer effectively inhibits the fatigue extrusion of the lower elemental Ag layer and delays the initiation of fatigue cracks. At the same time, the fatigue damage on the surface is distributed in a network, indicating that the propagation of fatigue damage in the plane is hindered, which helps to consume plastic deformation energy and avoid damage to the conductive path of the film, thereby ensuring that the change of the film resistance is maintained at a relatively low level. The Ag-Mo / Ag film has ultra-high conductivity and excellent fatigue resistance, and the conductivity of the film is as high as 3.0×10 7 S m −1 The unique double-layer structure design gives the film excellent fatigue resistance.

[0035] The present application also provides a preparation method of the above-mentioned Ag-Mo / Ag film with high ductility and fatigue resistance, comprising the following processes:

[0036] In a vacuum environment, an elemental Ag layer and a micro-alloyed Ag-Mo layer are sequentially deposited on a substrate by using a direct current magnetron sputtering process, and the Ag-Mo / Ag film is obtained after cooling to room temperature.

[0037] The elemental Ag layer is deposited by using an Ag single target, and the alloyed Ag-Mo layer is deposited by co-sputtering of an Ag target and a Mo target.

[0038] When sputtering the elemental Ag layer, the Ag target sputtering power is 120 W; when sputtering the micro-alloyed Ag-Mo layer, the Ag target sputtering power is 150 W, the Mo target sputtering power is 20 W, the argon gas pressure during deposition is 0.5 Pa, and the substrate rotation speed is fixed at 10 r / min.

[0039] In the preparation process, the substrate is first cleaned and dried, then the substrate is vacuum etched, then the etched substrate is pre-sputtered for a certain time, and finally the formal direct current magnetron sputtering is carried out.

[0040] In some embodiments, the substrate is ultrasonically cleaned with anhydrous ethanol for 15 min, and after cleaning, the substrate is dried using an electric hair dryer to remove dust and oil stains on the surface of the substrate.

[0041] In some embodiments, the substrate is etched in a vacuum coating chamber, Ar + Ion etching further removes impurities on the substrate, Ar + The etching power is 200 W, the etching pressure is 0.5 Pa, and the etching time is 5 min.

[0042] In some embodiments, 30 s of pre-sputtering is performed before formal sputtering deposition, and the argon gas is ventilated for 30 s before pre-sputtering, and the gas flow is 40 sccm to remove adsorbed substances on the surface of the target material.

[0043] The Ag-Mo / Ag film provided in the application combines magnetron sputtering single target sputtering and double target co-sputtering deposition technology, and by accurately setting the sputtering parameters, the uniformity and density of the film are ensured. Before formal deposition, the surface of the substrate is strictly cleaned and pretreated to ensure good bonding between the film and the substrate. During the deposition process, the substrate rotates at a constant speed of 10 r / min to ensure uniform deposition of the film. Finally, the film is naturally cooled to room temperature in a high vacuum environment to ensure uniformity of the film organization and minimization of defects.

[0044] Embodiment 1

[0045] A method for preparing an Ag-Mo / Ag film with high ductility and fatigue resistance, comprising the following processes:

[0046] Step 1, ultrasonically clean the polyimide substrate in anhydrous ethanol for 15 min, and then quickly dry it to make the surface of the polyimide substrate clean and neat.

[0047] Step 2, fix the cleaned polyimide substrate on the base plate and send it into the coating chamber, then vacuum the background to below 4x10 -4 Pa to start etching to further clean the polyimide substrate, the etching power is 200 W, the etching pressure is 0.5 Pa, and the time is 5 min.

[0048] Step 3, pre-sputter the Ag target and Mo target of the magnetron sputtering, introduce 30 s of argon gas to reach and stabilize the working pressure, and pre-sputter the target material for 30 s.

[0049] Step 4, Ag-Mo / Ag thin film was prepared on the substrate by direct current magnetron sputtering process.

[0050] Firstly, high purity Ag target (purity of 99.995 wt.%) was used for direct current magnetron sputtering, the sputtering power was 120 W, the substrate rotation speed was 10 r / min, the deposition pressure was set to 0.5 Pa, the argon flow rate was 40 sccm, and the deposition rate was 0.36 nm / s at room temperature for 1390 s to obtain a thickness of 500 nm of elemental Ag layer.

[0051] Then, Ag target (purity of 99.995 wt.%) and Mo target (purity of 99.95 wt.%) were used for direct current co-sputtering to deposit a micro-alloyed Ag-Mo thin film on the elemental Ag layer, the target sputtering power was 150 W and 20 W respectively, the substrate rotation speed was 10 r / min, the deposition pressure was set to 0.5 Pa, the argon flow rate was 40 sccm, and the deposition rate was 0.45 nm / s at room temperature for 1112 s to obtain a thickness of 500 nm of micro-alloyed Ag-Mo layer.

[0052] Step 4, after the sample was naturally cooled to room temperature in the vacuum coating chamber for 1 hour, the Ag-Mo / Ag thin film with a thickness of about 1000 nm was obtained.

[0053] The thickness of the elemental Ag layer and the micro-alloyed Ag-Mo layer in the Ag-Mo / Ag thin film was 500 nm, and the sample was named Ag-Mo500 / Ag500. Microstructure characterization of the prepared Ag-Mo / Ag thin film showed that the grain of the elemental Ag layer presented columnar crystal structure, and the proportion of twinned grain was relatively small. The grain of the micro-alloyed Ag-Mo layer also presented columnar crystal structure, and the proportion of twinned grain was 100%, and the interlamellar spacing of the twinned grain was very small, about 3 nm. The thin film presented obvious double-layer structure characteristics in the thickness direction.

[0054] Example 2

[0055] A method for preparing Ag-Mo / Ag thin film with high ductility and fatigue resistance, comprising the following processes:

[0056] Step 1, the polyimide substrate was cleaned in anhydrous ethanol for 15 min and then quickly dried to make the surface of the polyimide substrate clean and tidy.

[0057] Step 2, the cleaned polyimide substrate was fixed on the substrate and sent into the coating chamber, and then the background vacuum degree was pumped to 4×10 -4 Pa or below to start etching to further clean the polyimide substrate, the etching power was 200 W, the etching pressure was 0.5 Pa, and the time was 5 min.

[0058] Step 3, the magnetron sputtering Ag target and Mo target were pre-sputtered, and 30 s of argon was introduced to reach and stabilize the working pressure, and the target material was pre-sputtered for 30 s.

[0059] Step 4, Ag-Mo / Ag thin film was prepared on the substrate by direct current magnetron sputtering process.

[0060] First, high-purity Ag target (purity 99.995 wt.%) was used for direct current magnetron sputtering, sputtering power was 120 W, substrate rotation speed was 10 r / min, deposition pressure was set to 0.5 Pa, argon flow rate was 40 sccm, and 2223 s was deposited at room temperature with a deposition rate of 0.36 nm / s to obtain a thickness of 800 nm of elemental Ag layer.

[0061] Then, Ag target (purity 99.995 wt.%) and Mo target (purity 99.95 wt.%) were used for direct current co-sputtering to deposit micro-alloyed Ag-Mo film on the elemental Ag layer, the sputtering power of the target material was 150 W and 20 W respectively, the substrate rotation speed was 10 r / min, the deposition pressure was set to 0.5 Pa, the argon flow rate was 40 sccm, and 445 s was deposited at room temperature with a deposition rate of 0.45 nm / s to obtain a thickness of 200 nm of micro-alloyed Ag-Mo layer.

[0062] Step 4, after the sample was naturally cooled to room temperature in the vacuum coating chamber for 1 hour, an Ag-Mo / Ag thin film with a thickness of about 1000 nm was obtained. The thickness of the elemental Ag layer and the micro-alloyed Ag-Mo layer was 800 nm and 200 nm respectively, and the sample was named Ag-Mo200 / Ag800.

[0063] The microstructure of the prepared Ag-Mo / Ag thin film was characterized, and the results showed that the grain of the elemental Ag layer presented columnar crystal structure, and the proportion of twinned grain was relatively small. The grain of the micro-alloyed Ag-Mo layer also presented columnar crystal structure, and the proportion of twinned grain was 100%, and the interlamellar spacing of the twinned grain was very small, about 3 nm. The thin film showed obvious double-layer structure characteristics in the thickness direction.

[0064] Example 3

[0065] A method for preparing Ag-Mo / Ag thin film with high ductility and fatigue resistance, comprising the following processes:

[0066] Step 1, the polyimide substrate was ultrasonically cleaned in anhydrous ethanol for 15 min and then quickly dried to make the surface of the polyimide substrate clean and tidy.

[0067] Step 2, the cleaned polyimide substrate is fixed on the base plate and sent into the coating chamber, then the background vacuum degree is pumped to 4x10 -4 Step 4, the Ag-Mo / Ag film is prepared on the substrate by direct current magnetron sputtering process.

[0068] Step 3, the Ag target and Mo target of magnetron sputtering are pre-sputtered, 30 s of argon is introduced to reach and stabilize the working pressure, and the target material is pre-sputtered for 30 s.

[0069] Step 4, the Ag-Mo / Ag film is prepared on the substrate by direct current magnetron sputtering process.

[0070] First, high-purity Ag target (purity 99.995 wt.%) is used for direct current magnetron sputtering, sputtering power is 120 W, base plate rotation speed is 10 r / min, deposition pressure is set to 0.5 Pa, argon flow rate is 40 sccm, deposition rate is 0.36 nm / s at room temperature, and 2500 s is deposited to obtain a thickness ~ 900 nm of elemental Ag layer.

[0071] Then, Ag target (purity 99.995 wt.%) and Mo target (purity 99.95 wt.%) are used for direct current co-sputtering to deposit micro-alloyed Ag-Mo film on the elemental Ag layer, the sputtering power of the target material is 150 W and 20 W respectively, the base plate rotation speed is 10 r / min, the deposition pressure is set to 0.5 Pa, the argon flow rate is 40 sccm, the deposition rate is 0.45 nm / s at room temperature, and 223 s is deposited to obtain a thickness of 100 nm of micro-alloyed Ag-Mo layer.

[0072] Step 4, the sample is taken out after natural cooling in the vacuum coating chamber for 1 hour to room temperature, and an Ag-Mo / Ag film with a thickness of about 1000 nm is obtained. The thickness of the elemental Ag layer and the micro-alloyed Ag-Mo layer is 900 nm and 100 nm respectively, and the sample is named Ag-Mo100 / Ag900.

[0073] The microstructure of the prepared Ag-Mo / Ag film is characterized, the results show that the grain of the elemental Ag layer presents columnar crystal structure, the proportion of twin grain is relatively small, the grain of the micro-alloyed Ag-Mo layer also presents columnar crystal structure, the proportion of twin grain is 100%, and the twin lamella spacing is very small, about 3 nm. The film presents obvious double-layer structure characteristics in the thickness direction.

[0074] It should be noted that the total thickness of the Ag-Mo / Ag thin film prepared in the above embodiments 1-3 is 1000 nm, which is only exemplary. As long as the thickness ratio of the micro-alloyed Ag-Mo layer and the elemental Ag layer is controlled, Ag-Mo / Ag thin films with different thicknesses can be prepared by adjusting the deposition time.

[0075] Comparative Example 1

[0076] The difference between the present comparative example and the embodiments 1-3 is that there is no addition of elemental Ag layer, which is a single-layer micro-alloyed Ag-Mo thin film, wherein the thickness of the Ag-Mo layer is 1000 nm, and the thin film is named as Ag-Mo. The rest of the methods are the same as the embodiments 1-3.

[0077] Comparative Example 2

[0078] The difference between the present comparative example and the embodiments 1-3 is that there is no addition of surface micro-alloyed Ag-Mo thin film, which is a single-layer elemental Ag thin film, wherein the thickness of the elemental Ag layer is 1000 nm, and the thin film is named as Ag. The rest of the methods are the same as the embodiments 1-3.

[0079] Figure 1 The XRD experimental results of the metal thin films prepared in the embodiments 1-3 and the comparative examples 1-2 are shown, and the significant (111) out-of-plane preferred orientation of the thin films is explained. Figure 2 The planar TEM photos and the corresponding SADP of the micro-alloyed Ag-Mo thin film prepared by direct current magnetron dual-target co-sputtering are shown, which reveals the microstructure characteristics of the nanocrystals in the micro-alloyed Ag-Mo thin film. Figure 3 The cross-sectional TEM experimental results of the metal thin films prepared in the embodiments 1-2 and the comparative example 1 are shown, which reveals the double-layer structure characteristics of the elemental Ag layer and the micro-alloyed Ag-Mo layer in the thickness direction and the high-density nanotwin characteristics existing in the micro-alloyed Ag-Mo layer. Figure 4 The high cracking strain of the Ag-Mo / Ag thin film is shown, and under the condition of uniaxial tension, the cracking strain of the thin film is increased by 2-6 times compared with the single-layer Ag-Mo thin film. Figure 5 The curve of the fatigue life of the Ag-Mo / Ag thin film with the thickness of the micro-alloyed Ag-Mo layer is shown, and the fatigue loading strain amplitude is 1%, and the loading mode is tension-tension fatigue. The test results show that the fatigue life of the thin film prepared by the present application increases first and then decreases with the increase of the thickness of the surface micro-alloyed Ag-Mo layer. When the thickness of the surface micro-alloyed Ag-Mo layer is 200 nm, the fatigue life of the thin film reaches the best, and the fatigue life of the thin film is increased by more than 4 times compared with the elemental Ag thin film.

[0080] The above merely illustrates the technical idea of the present application, and cannot limit the protection scope of the present application. Any modification made according to the technical idea of the present application on the basis of the technical scheme falls within the protection scope of the present application.

Claims

1. An Ag-Mo / Ag thin film having high ductility and fatigue resistance, characterized by, The Ag-Mo / Ag thin film comprises a single-element Ag layer and a micro-alloyed Ag-Mo layer, the micro-alloyed Ag-Mo layer is attached to the surface of the single-element Ag layer, the thickness ratio of the micro-alloyed Ag-Mo layer to the single-element Ag layer is (1:9)-(1:1), and the thickness of the micro-alloyed Ag-Mo layer is 100 nm or 200 nm. The grain morphology of the single-element Ag layer and the micro-alloyed Ag-Mo layer is columnar crystal, the proportion of twinned grain in the columnar crystal of the single-element Ag layer is 30-40%, and the proportion of twinned grain in the columnar crystal of the Ag-Mo layer is 100%.

2. The Ag-Mo / Ag film having high ductility and fatigue resistance according to claim 1, wherein The micro-alloyed Ag-Mo layer contains 97-99% of Ag and 1-3% of Mo in terms of atomic content percentage.

3. The Ag-Mo / Ag thin film with high ductility and fatigue resistance according to claim 1, characterized in that, The interlamellar spacing of the twinned grain in the single-element Ag layer is 35 nm, and the interlamellar spacing of the twinned grain in the Ag-Mo layer is 3 nm.

4. The Ag-Mo / Ag film according to claim 1, wherein the Ag-Mo / Ag film has a high ductility and fatigue resistance, and is characterized in that, The conductivity of the Ag-Mo / Ag thin film is up to 3.0 x 10 7 S·m 1 .

5. A method for preparing the Ag-Mo / Ag film having high ductility and fatigue resistance according to any one of claims 1 to 4, characterized by, The method comprises the following processes: The single-element Ag layer and the micro-alloyed Ag-Mo layer are sequentially deposited on a substrate by a direct current magnetron sputtering process in a vacuum environment, and the Ag-Mo / Ag thin film is obtained after cooling to room temperature. The single-element Ag layer is deposited by using an Ag target, and the alloyed Ag-Mo layer is deposited by co-sputtering of an Ag target and a Mo target.

6. The method of claim 5, wherein the Ag-Mo / Ag film has high ductility and fatigue resistance. When the single-element Ag layer is sputtered, the sputtering power of the Ag target is 120 W; when the micro-alloyed Ag-Mo layer is sputtered, the sputtering power of the Ag target is 150 W, and the sputtering power of the Mo target is 20 W.

7. The method of claim 5, wherein the Ag-Mo / Ag film has high ductility and fatigue resistance. In the direct current magnetron sputtering process, the argon gas pressure is 0.5 Pa, and the substrate rotation speed is fixed at 10 r / min.

8. The method of claim 5, wherein the Ag-Mo / Ag film has high ductility and fatigue resistance. When the single-element Ag layer is sputtered, the deposition rate is 0.36 nm / s; when the micro-alloyed Ag-Mo layer is sputtered, the deposition rate is 0.45 nm / s.

9. The method of claim 5, wherein the Ag-Mo / Ag film has high ductility and fatigue resistance. The deposition time of the single-element Ag layer is 1390-2500 s.

10. The method of claim 5, wherein the Ag-Mo / Ag film has high ductility and fatigue resistance. The deposition time of the alloyed Ag-Mo layer is 223-1112 s.

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