A transition film layer and a method for manufacturing the same

Abstract

The application discloses a transition film layer and a preparation method thereof. The transition film layer is grown on a bottom layer film-coated substrate. The transition film layer is a transition layer of the bottom layer film-coated substrate and an upper layer target film layer. The transition film layer is an iron-based film. The application introduces an intermediate transition film layer between incompatible bottom layer film-coated substrates and upper layer target film layers. The transition film layer, the bottom layer film-coated substrate and the upper layer target film layer are all compatible. The transition film layer overcomes the problem that the upper layer target film layer grows poorly on the bottom layer film-coated substrates. The transition film layer solves the problem that a silicon film grows poorly when the silicon film is plated on high-aluminum, high-nickel and high-copper substrates in the prior art.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of material preparation, and particularly relates to a transitional film layer and a preparation method thereof. BACKGROUND

[0002] Chemical vapor deposition (CVD) is a common surface treatment method. This technology mainly uses one or more gas phase compounds or elements containing film elements to perform a chemical reaction on the surface of a substrate (substrate) to generate a thin film. Since the film layer changes the physical and chemical properties of the substrate surface, it can provide functions such as improving hardness, enhancing acid and alkali resistance, increasing chemical inertness, changing surface conductivity, changing surface color, etc., thereby expanding the original application range of the substrate. Among various chemical vapor deposition methods, the most basic one is thermal chemical vapor deposition, which uses heat to promote the pyrolysis or mutual reaction of raw gas and deposits on the surface of the substrate, and finally generates a thin film. In order to reduce the reaction temperature, auxiliary means such as plasma enhancement, radio frequency enhancement, ultraviolet enhancement, free radical enhancement, laser induction, etc. are usually used.

[0003] The film layer generated by chemical vapor deposition on the surface of a metal or ceramic substrate, mainly composed of silicon elements, with one or more of hydrogen, oxygen, carbon, nitrogen, phosphorus, fluorine, chlorine, etc. as the guest, has an amorphous or crystalline structure, and is one of the most commonly used functional films. Since this type of film is mainly composed of silicon elements, it can be referred to as a silicon film. Compared with the original substrate, the silicon film itself or after further modification, has the functions of chemical inertness, acid resistance, alkali resistance, wear resistance, and change of surface conductivity, and is widely used in analytical instruments, petrochemical industry, hydrogen energy, aerospace, semiconductors, biochemistry, medicine, etc. and is in great demand in some fields. For example, in the monitoring of volatile organic compounds (VOCs) in the atmospheric environment, during the sampling, storage, and analysis of gas samples, any metal surface that comes into contact with the gas sample needs to be passivated with a silicon film. This sampling equipment includes stainless steel sampling cans (sump cans), constant flow samplers, particulate filters, sampling pipelines, sampling valves, etc., as well as analytical and detection equipment such as pre-concentrators, chromatographs, and mass spectrometers. In the field of chromatographic analysis, the inner surface of a stainless steel gas or liquid chromatographic column is usually treated with a silicon film to reduce the adsorption of the target compounds being analyzed, thereby improving the peak shape and increasing the efficiency of chromatographic analysis. In the field of hydrogen energy and semiconductors, silicon films are often used on the inner surface of the delivery pipeline for ultra-pure substances to reduce the contamination of metal ions released from the pipeline and to reduce corrosion of the pipeline.

[0004] Silicon material films are generally prepared by thermal chemical deposition. For example, patent CN105112886B (a kind of inert surface treatment technology) discloses a method for depositing a silicon material film layer on a substrate. Patent CN103866262B (a method for preparing a silanized film on the surface of stainless steel) discloses a method for preparing a silanized film on the surface of stainless steel. Patent CN111220832A (a method for processing an overvoltage detection sensor and an overvoltage detection sensor) discloses a method for depositing a non-silicon material on the surface of a high-purity silicon wafer and modifying it into silicon dioxide. The basic principle of these patents is to use silicon-containing gases such as silane, disilane, alkylsilane, alkoxy silane, chlorosilane, etc. to perform thermal decomposition in a vacuum environment to obtain silicon or other doped elements (such as hydrogen, oxygen, carbon, etc.) on the substrate to form a silicon material film.

[0005] Since the film layer is grown on the surface of the substrate (or substrate), in order to generate a uniform and dense film layer, the surface of the substrate must be suitable for film growth (or compatible with the film). However, the inventors have found in practice that not all substrates are suitable for the growth of silicon material films. In general, the surfaces of metals such as iron, chromium, cobalt, manganese, and the surfaces of non-metals such as glass, ceramic, silicon wafer, carbon fiber are more suitable for the growth of silicon material films, and these substrates can be referred to as silicon material compatible substrates; while pure aluminum or aluminum alloy, pure nickel or high nickel-containing hastelloy (B series), pure copper or high copper alloy, pure silver or high silver alloy, etc. are not suitable for the growth of silicon material films, and these substrates can be referred to as silicon material incompatible substrates. When plating on incompatible substrates, problems such as uneven film layer, loose texture, poor wear resistance and easy peeling may occur, resulting in the generated film having no practical value. For example, the plating method disclosed in CN105112886B works well on stainless steel, low nickel-containing hastelloy (C and G series), glass, ceramic and other materials, but on high-content metal materials such as hastelloy B series alloy, the generated film layer is uneven in color, loose in texture and not wear-resistant. This undesirable phenomenon is likely due to the enrichment of aluminum, nickel, copper and silver, which causes the silicon material film layer to grow unevenly on the surface of the substrate, with a growth rate perpendicular to the surface of the substrate much faster than the horizontal growth rate. This incompatibility has been reported in some scientific literature, such as Bellangera P. et al. (2017) reported the abnormal growth of polycrystalline silicon film on aluminum substrate; Budini et al. (2012) reported that amorphous silicon hydrogen film on nickel substrate would locally crystallize, causing the film layer to be loose.

[0006] And as stainless steel, aluminum alloy, high nickel, copper alloy, silver alloy, etc. Silicon material film incompatible substrate is also a commonly used material in the manufacture of instruments and industrial equipment, and its surface often needs to be plated with a silicon material film. However, the existing technology cannot effectively solve the plating problem on these substrates. SUMMARY

[0007] The embodiment of the present application provides a transition film and a preparation method thereof, which can solve the problem of uneven growth of a silicon material film layer on the surface of a silicon material film incompatible substrate in the prior art.

[0008] To achieve the above object, the technical scheme adopted by the present application is as follows:

[0009] In one aspect of the present application, a transition film is provided, which is grown on a bottom layer plating substrate, and the transition film is a transition layer of the bottom layer plating substrate and an upper layer target film layer, and the transition film is an iron-based film.

[0010] The present application changes the surface properties of the original plating substrate by introducing a transition film, so that the subsequent target film layer can continue to deposit.

[0011] As a further scheme of the present application: the thickness of the iron-based film is nanoscale thickness.

[0012] In the present application, the transition layer iron-based film plays a role of connecting the past and the future, so the thickness of the iron-based film only needs to be a few to tens of nanometers, and increasing the thickness will not have a better effect on the subsequent silicon material film plating.

[0013] In another aspect of the present application, a preparation method of a transition film is also provided, which comprises the following steps:

[0014] An iron compound is vaporized to deposit iron on a bottom layer plating substrate to form an iron-based film, and the iron compound is one of anhydrous ferric chloride, pentacarbonyl iron, and ferrocene.

[0015] In the present application, before the silicon material film gas phase reaction, a gas phase metal compound is first introduced, heated to decompose, and a nanoscale iron-based transition layer is formed on the surface of the workpiece, changing the chemical properties of the substrate surface, so that the subsequent silicon material film gas phase reaction can proceed smoothly and uniformly. The gas phase metal compound refers to a metal compound that has a sufficient vapor pressure (>200 Pa) at room temperature or under heating (<300 DEG C) conditions, such as ferric chloride FeCl3, pentacarbonyl iron Fe(CO)5, and ferrocene. The high vapor pressure of these metal compounds allows them to be introduced into the reaction chamber in a gaseous state, and after decomposition, they become metal and deposit into a film.

[0016] As a further scheme of the present application: when the iron-containing compound is anhydrous ferric chloride, the method comprises the following steps:

[0017] S1, placing anhydrous ferric chloride in a sealed container and vacuumizing;

[0018] S2, heating the sealed container to sublimate the anhydrous ferric chloride and introducing H2 carrier gas to a pressure of 1-2 atm;

[0019] S3, introducing the ferric chloride vapor into a vacuum reaction furnace containing a bottom-layer coated substrate by the H2 carrier gas and reacting at 350-1000℃.

[0020] Optionally, the pressure of the sealed container after introducing the H2 carrier gas is independently selected from 1 atm, 1.2 atm, 1.4 atm, 1.6 atm, 1.8 atm, and 2 atm.

[0021] Optionally, the lower limit of the reaction temperature in the vacuum reaction furnace is independently selected from 350℃, 400℃, 450℃, 500℃, 550℃, 600℃, 650℃, and 700℃; and the upper limit of the reaction temperature in the vacuum reaction furnace is independently selected from 750℃, 800℃, 850℃, 900℃, 950℃, and 1000℃.

[0022] In the present application, the iron-based film is generated by thermal decomposition or mutual reaction of the iron-containing gaseous compound. Specifically, the elemental iron is generated by reduction of FeCl3 vapor in an H2 atmosphere containing NH3 and deposited on the surface of the workpiece. In addition, the sealed container in the present application can be a stainless steel sealed container.

[0023] As a further scheme of the present application: in step S2, the H2 carrier gas is high-purity H2 doped with 0.1-0.5% (v / v) NH3;

[0024] Preferably, the heating temperature is 200-250℃.

[0025] Optionally, the amount of NH3 doped in the H2 carrier gas is independently selected from 0.1%, 0.2%, 0.3%, 0.4%, and 0.5%.

[0026] Optionally, the lower limit of the heating temperature is independently selected from 200℃, 210℃, 220℃, and 230℃; and the upper limit of the heating temperature is independently selected from 235℃, 240℃, and 250℃.

[0027] In the embodiments of the present application, the high-purity H2 is H2 with a purity of ≥99.999%.

[0028] As a further scheme of the present application: in step S3, the reaction time is 2-90 min;

[0029] Preferably, the reaction time is 10-30 min.

[0030] Optionally, the lower limit of the reaction time is independently selected from 2 min, 5 min, 10 min, 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min; and the upper limit of the reaction time is independently selected from 50 min, 55 min, 60 min, 65 min, 70 min, 75 min, 80 min, 85 min, 90 min.

[0031] As a further scheme of the present application, before step S1, the method further comprises:

[0032] The bottom-layer plated substrate is pretreated, including degreasing, oil removal and oxide layer removal.

[0033] The bottom-layer plated substrate is placed into a vacuum reaction furnace, vacuumed, and preheated at a temperature of 280-380℃.

[0034] Preferably, the preheating temperature is 300-350℃.

[0035] Optionally, the preheating temperature is independently selected from 280℃, 300℃, 320℃, 340℃, 350℃, 360℃, 380℃.

[0036] As a further scheme of the present application, in step S1, the vacuuming specifically comprises: vacuuming to below 0.1 Pa to remove air in the sealed container, and replacing with high-purity nitrogen.

[0037] Preferably, the number of times of replacing with high-purity nitrogen is 2.

[0038] In the embodiments of the present application, the high-purity nitrogen is nitrogen with a purity of ≥99.999%.

[0039] As a further scheme of the present application, after step S3, the method further comprises:

[0040] Under the condition of maintaining the reaction temperature, the excess H2, NH4Cl generated by the reaction, and unreacted FeCl3 are removed.

[0041] As a further scheme of the present application, the method further comprises:

[0042] The upper-layer target film layer is deposited on the iron-based film.

[0043] The present application has the following beneficial effects:

[0044] 1. The present application introduces an intermediate transition film layer between the incompatible bottom layer plated film substrate and the upper layer target film layer, and uses the characteristics that the transition film layer is compatible with the bottom layer plated film substrate and the upper layer target film layer, to overcome the problem that the upper layer target film layer grows poorly on these bottom layer plated film substrates, and solve the problem of poor growth of silicon material film in the prior art when plating silicon material film on high aluminum, high nickel, high copper and other substrates.

[0045] 2. The deposition process of the iron-based transition film layer and the subsequent silicon material film plating process of the present application can be organically integrated in the plating process. Because both use thermal chemical vapor deposition method, the iron-based transition film layer and the target film layer can be completed in the same operation procedure. Therefore, the cost of implementing the iron-based transition film layer is limited.

[0046] 3. Like the target film layer-silicon material film, the present application uses the method of vapor deposition, has extremely high plating property, and can perform transition layer coating on complex-shaped substrates. The transition layer plating generated by the present application can completely cover all exposed surfaces of the workpiece, and can be applied to workpieces that cannot be performed by traditional spraying process. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 is the plating process flow chart of the existing silicon material film;

[0048] Figure 2 is the plating process flow chart of the silicon material film after the iron film layer pretreatment of the present application;

[0049] Figure 3 is the scanning electron microscope image of the silicon material film on the surface of the aluminum alloy workpiece in Example 1 of the present application;

[0050] Figure 4 is the scanning electron microscope image of the silicon material film on the surface of the aluminum alloy workpiece in Comparative Example 1 of the present application. DETAILED DESCRIPTION

[0051] The present application will be described in detail below with reference to the examples.

[0052] Unless otherwise specified, the raw materials in the examples are commercially purchased and directly used without treatment; the instruments and equipment used adopt the recommended use parameters of the manufacturers.

[0053] The plating process flow of the existing silicon material film is shown in Figure 1 The workpiece is first subjected to conventional surface pretreatment (degreasing, removing oil, removing oxide layer, etc.), and then is placed in a vacuum reaction furnace, sealed, vacuumed to remove air in the furnace, and then preheating is started. After reaching the pre-set reaction temperature (between 200-1200℃), the reaction gas is added for film forming reaction. After the film layer reaches the expected thickness, the heating / voltage is stopped, the workpiece is allowed to cool down, and the vacuum pump is started to discharge the reaction residual gas. After the temperature drops, the furnace is opened to take out the workpiece, and the finished product is obtained after quality inspection.

[0054] In order to coat the silicon film on the incompatible substrate, the application discloses a method, which inserts an iron film layer modification process on the basis of the existing silicon film coating process. After the workpiece is preheated, the surface of the silicon film incompatible substrate is modified by the iron film layer modification process before the silicon film coating gas phase reaction. After the iron film layer modification process is completed, the original route is continued to perform the silicon film coating gas phase reaction. The improved process flowchart after the application is shown in Figure 2 .

[0055] The application proposes that the iron-based transition film can be realized by thermal decomposition of the iron gas phase metal compound. The iron gas phase metal compound (under heating conditions) can be selected from anhydrous ferric chloride, pentahydroxy iron, ferrocene and the like. In the application, the first choice is anhydrous ferric chloride (FeCl3). FeCl3 is a black-brown solid powder at room temperature, but when heated to a temperature range of 150-250℃, the saturated gaseous vapor pressure of FeCl3 reaches the level of hundreds of pascals (hPa), and there is enough amount of FeCl3 sublimed into the gas phase, which can be used as the source of iron element for chemical vapor deposition. The anhydrous ferric chloride has low cost, is easy to gasify and has simple operation, and the reduced iron element transition layer has better compatibility than other metals.

[0056] The technical principle of the application is that the gaseous FeCl3 (or Fe2Cl6 gas polymerized from FeCl3) sublimed in a high-purity hydrogen (H2) atmosphere at about 200℃ is brought into a vacuum reaction furnace with a temperature of 200-600℃. At this temperature, the excess hydrogen gas reduces FeCl3 into iron element and deposits on the surface of the substrate to form a very thin iron-based film. The overall chemical reaction formula of the process is:

[0057] 2FeCl3 (gas) + 3H2 (gas, excess) 2Fe (solid, amorphous film layer) + 6HCl (gas)

[0058] The generated HCl gas and excess H2 are discharged by a vacuum pump. In order to promote the reaction, 0.1-0.5% (v / v) of ammonia gas (NH3) can be doped in the high-purity H2. Since the iron-based film in the application only needs to change the surface properties of the substrate, the thickness only needs to be several to several tens of nanometers. The process of depositing the iron-based film can be completed in several minutes to one hour.

[0059] Example 1

[0060] The experimental 7075 aluminum alloy workpiece has a size of 10cm×7cm×48cm. According to the method in the application, an iron-based film intermediate layer is added, and then silicon film coating is performed. The whole process includes the following steps in sequence:

[0061] (1) The aluminum alloy workpiece is degreased, ultrasonically cleaned, rinsed with pure water, and then dried at 110°C;

[0062] (2) The aluminum alloy workpiece is placed in a vacuum reaction furnace, and vacuum is applied until the pressure in the furnace is <0.01 Pa. Heating is started, and the temperature is set to 320°C. At the same time, high-purity nitrogen is used to replace the atmosphere twice, and then vacuum is applied until the pressure in the furnace is <0.01 Pa.

[0063] (3) After the temperature of the vacuum reaction furnace reaches the set value of 320°C, 20 minutes are waited to ensure that the temperature of the workpiece is uniform, and at the same time, the vacuum degree in the furnace is maintained at <0.01 Pa.

[0064] (4) The reaction gas for preparing the iron film layer is prepared: 2 g of FeCl3 powder is placed in a stainless steel sealed container (FeCl3 vapor generator) with a volume of about 1 L. The container is placed in the middle of a tubular heating furnace, and a gas inlet pipe and a gas outlet pipe are respectively installed on the two sides. The air in the container is removed by a vacuum system, and then replaced with nitrogen twice. After the stainless steel sealed container is heated to 200°C by a tubular furnace, high-purity H2 doped with 0.3% (v / v) NH3 is introduced into the container to about 1 atm.

[0065] (5) The high-purity H2 doped with 0.3% NH3 and passed through the FeCl3 sealed container in step (4) is introduced into the vacuum reaction furnace containing the aluminum alloy workpiece to be plated with a film. The flow rate is controlled at about 200 mL / min, and the equilibrium pressure in the vacuum reaction furnace is about 5 kPa to 20 kPa.

[0066] (6) After 15 minutes of heat preservation, the excess H2, NH3, and NH4Cl generated are removed by opening the vacuum system.

[0067] (7) The iron film layer is pretreated by replacing the atmosphere with high-purity nitrogen twice.

[0068] (8) The temperature of the vacuum reaction furnace is increased to the silicon film plating temperature, and the conventional silicon film plating is performed according to the steps in the prior art. Figure 2

[0069] After the entire process is completed, the 7075 aluminum alloy workpiece is uniformly plated with a layer of light-colored rainbow silicon film, and the scanning electron microscope image is shown in Figure 3 . The Auger electron spectroscopy test results show that the thickness of the uppermost silicon film is about 140 nm, the thickness of the intermediate iron film layer is about 26 nm, and the 7075 aluminum alloy base material is below.

[0070] Example 2

[0071] ​Monel 400 nickel-copper alloy workpiece, size 16 cm x 5 cm x 28 cm, according to the method in the application, an iron-based film interlayer is added, and then a silicon film is plated. The treatment process includes the following steps in sequence:

[0072] (1) ultrasonic cleaning of the nickel-copper alloy workpiece, pure water rinsing, and then drying at 110°C;

[0073] (2) the nickel-copper alloy workpiece is placed in a vacuum reaction furnace, vacuum is drawn to a pressure <0.01 Pa in the furnace, heating is started, and the temperature is set to 320°C. At the same time that heating starts, high-purity nitrogen is used to replace the atmosphere 2 times, and finally vacuum is drawn to a pressure <0.01 Pa in the furnace;

[0074] (3) after the temperature of the vacuum reaction furnace reaches the set value of 320°C, 20 minutes are waited to ensure that the temperature inside the workpiece is uniform, and at the same time the vacuum degree in the furnace is maintained <0.01 Pa.

[0075] (4) preparation of the iron film layer reaction gas: 3 g of FeCl3 powder is weighed and placed in a stainless steel sealed container with a volume of about 1 L. The container is placed in the middle of a tubular heating furnace, and gas inlet and outlet pipes are installed on both sides. The air in the container is removed using a vacuum system, and nitrogen is used to replace the atmosphere 2 times. After the stainless steel sealed container is heated to 200°C using a tubular furnace, high-purity H2 doped with 0.3% (v / v) NH3 is introduced at a flow rate of 200 mL / min to about 1 atm.

[0076] (5) high-purity H2 doped with 0.3% NH3 and passed through the FeCl3 sealed container is introduced into the reaction furnace. The flow rate is controlled at about 200 mL / min, and the equilibrium pressure in the vacuum reaction furnace is about 5 kPa to 20 kPa.

[0077] (6) after holding for 30 minutes, the vacuum system is turned on to remove excess H2, NH3, and NH4Cl generated.

[0078] (7) the iron film layer is pretreated by replacing the atmosphere with high-purity nitrogen 2 times.

[0079] (8) the temperature of the vacuum reaction furnace is increased to the silicon film plating temperature, and a silicon film is deposited by chemical decomposition of a silicon-containing gas according to the steps in the Figure 2 application.

[0080] After the entire process is completed, the nickel-copper alloy workpiece is uniformly plated with a layer of silvery white silicon film. Auger electron spectroscopy test results show that the thickness of the surface silicon film is about 220 nm, the thickness of the iron film layer below is about 43 nm, and the Monel 400 nickel-copper alloy base material is below that.

[0081] Comparative Example 1

[0082] The experimental 7075 aluminum alloy workpiece has a size of 10 cm x 7 cm x 48 cm, is directly coated according to the existing silicon film coating method, and attempts are made several times. The film layer is uneven or gray spots appear, as shown in the scanning electron microscope image. Figure 4

[0083] Comparative Example 2

[0084] The Monel 400 nickel-copper alloy workpiece has a size of 16 cm x 5 cm x 28 cm, is coated according to the existing silicon film method (chemical decomposition and deposition into a film using a silicon-containing gas, Chinese patent CN105112886B), and the effect is not ideal. The film layer is loose, uneven, and has color spots.

[0085] Comparative Example 3

[0086] The Monel 400 nickel-copper alloy workpiece has a size of 16 cm x 5 cm x 28 cm, is coated according to the existing silicon film method (chemical decomposition and deposition into a film using a silicon-containing gas, Chinese patent CN103866262B), and the effect is not ideal. The film layer is loose, uneven, and has color spots.

[0087] Comparative Example 4

[0088] The Monel 400 nickel-copper alloy workpiece has a size of 16 cm x 5 cm x 28 cm, is coated according to the existing silicon film method (chemical decomposition and deposition into a film using a silicon-containing gas, Chinese patent CN111220832A), and the effect is not ideal. The film layer is loose, uneven, and has color spots.

[0089] The above is only a few embodiments of the present application, and does not limit the present application in any form. Although the preferred embodiments are disclosed as above, they are not intended to limit the present application. Any skilled person in the art can make some changes or modifications to the above disclosed technical content without departing from the scope of the technical solution of the present application, which are equivalent to equivalent embodiments and belong to the scope of the technical solution.​

Claims

1. A method for producing a transition film layer, characterized by, The application relates to a method for preparing a transition film layer on a bottom-layer plated film substrate. The method comprises the following steps: S1, placing anhydrous ferric chloride in a sealed container and vacuumizing; S2, heating the sealed container to 200-250 DEG C to sublimate the anhydrous ferric chloride, and introducing H2 carrier gas to a pressure of 1-2 atm, wherein the H2 carrier gas is high-purity H2 doped with 0.1-0.5% NH3 by volume fraction; S3, introducing the ferric chloride vapor into a vacuum reaction furnace containing the bottom-layer plated film substrate to react at 350-1000 DEG C. The transition film layer is grown on the bottom-layer plated film substrate, and the transition film layer is a transition layer of the bottom-layer plated film substrate and an upper-layer target film layer, wherein the transition film layer is an iron-based film, the upper-layer target film layer is a silicon material film, the bottom-layer plated film substrate is a silicon material film incompatible substrate including aluminum or copper, and the silicon material film is a film layer mainly composed of silicon elements and containing one or more of hydrogen, oxygen, carbon, nitrogen, phosphorus, fluorine and chlorine elements as guests, and having an amorphous or crystalline structure, which is generated on the surface of a substrate by chemical vapor deposition. In step S3, the reaction time is 2-90 min.

2. The method for producing a transition film layer according to claim 1, wherein In step S3, the reaction time is 10-30 min.

3. The method of claim 2, wherein the transition film layer is formed by a process selected from the group consisting of sputtering, vacuum deposition, and ion plating. Before step S1, the method further comprises:

4. The method of claim 1, wherein the transition film layer is formed by a process selected from the group consisting of sputtering, vacuum deposition, and ion plating. Pretreating the bottom-layer plated film substrate, including degreasing, oil removal and oxide layer removal; Placing the bottom-layer plated film substrate into a vacuum reaction furnace, vacuumizing and preheating at a temperature of 280-380 DEG C. The preheating temperature is 300-350 DEG C.

5. The method of claim 4, wherein the transition film layer is formed by a process selected from the group consisting of sputtering, evaporation, and ion plating. In step S1, the vacuumizing specifically comprises: vacuumizing to 0.1 Pa or below to remove air in the sealed container, and replacing with high-purity nitrogen.

6. The method of claim 1, wherein the transition film layer is formed by a process selected from the group consisting of sputtering, evaporation, and ion plating. The replacing frequency of the high-purity nitrogen is 2 times.

7. The method of claim 6, wherein the transition film layer is formed by sputtering. After step S3, the method further comprises:

8. The method of claim 1, wherein the transition film layer is formed by a process selected from the group consisting of sputtering, evaporation, and ion plating. Under the condition of maintaining the reaction temperature, removing excess H2, NH4Cl generated by the reaction and unreacted FeCl3. ​

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