Coating equipment and coating method

Abstract

The invention provides coating equipment and a coating method, and the coating method comprises the following steps: placing a substrate in a vacuum environment, and introducing at least one reaction source and a first oxygen source into the vacuum environment; the reaction source is heated through the hot wire to generate active groups, the active groups are deposited on the surface of the substrate to form a metal film layer, and meanwhile the first oxygen source catalyzes the active groups and the residual reactants. The coating equipment comprises a hot filament CVD device and an RPD device, wherein the hot filament CVD device is provided with a hot filament process cavity; the RPD device is provided with an RPD process cavity, the hot filament CVD device and the RPD device are sequentially arranged along the conveying direction of the substrate, and the hot filament process cavity is communicated with the RPD process cavity. According to the coating equipment and the coating method, the damage to the substrate during coating can be effectively reduced, so that the photoelectric conversion efficiency of the solar cell is improved.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to a coating device and a coating method. Background Art

[0002] In the field of solar cell technology, a metal oxide conductive film needs to be deposited on a substrate as a front electrode. The front electrode has both light-transmitting and conductive functions, and is primarily used to collect photogenerated carriers, provide a conductive path, and optimize optical performance to improve the cell's photoelectric conversion efficiency. Currently, magnetron sputtering is commonly used to deposit metal oxide films. Magnetron sputtering uses high-energy ions to bombard a target material to achieve material sputtering and film formation on the substrate. However, the high-energy ions are accelerated by an electric field to bombard the substrate surface, which can easily cause the substrate atoms to shift, forming structural defects such as vacancies and interstitial atoms, resulting in low photoelectric conversion efficiency for solar cells. Summary of the Invention

[0003] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a coating method that can effectively reduce damage to the substrate during coating, thereby improving the photoelectric conversion efficiency of solar cells.

[0004] The present application also proposes a coating device for implementing the above coating method.

[0005] The coating method according to an embodiment of the present application includes the following steps: placing the substrate in a vacuum environment, and introducing at least one reaction source and a first oxygen source into the vacuum environment; The reaction source is heated by a hot wire to generate active radicals, and the active radicals are deposited on the surface of the substrate to form a metal film layer, while the first oxygen source catalyzes the active radicals and residual reactants.

[0006] According to the coating method of the embodiment of the present application, there are at least the following beneficial effects: the reaction source is used to provide raw materials for the deposition and formation of the metal film layer, and the generation of active groups by heating and decomposing the reaction source by a hot wire depends on a chemical reaction. Compared with the coating method of magnetron sputtering physical bombardment, the physical bombardment of the substrate by high-energy ions is avoided. The process of depositing the metal film layer in the present application is more gentle and can effectively reduce damage to the substrate. In addition, the first oxygen source is used to oxidize the residual reaction source element or metastable intermediate product, which is beneficial to ensure the purity of the metal film layer and make the chemical uniformity of the metal film layer better. Therefore, the coating method of the present application can effectively reduce the damage to the substrate during coating, thereby improving the photoelectric conversion efficiency of the solar cell.

[0007] According to some embodiments of the present application, after a metal film layer is deposited on a substrate, the substrate is transferred to an oxidation transition chamber, and an oxidizing and reducing gas is introduced into the oxidation transition chamber and decomposed to further oxidize the metal film layer.

[0008] According to some embodiments of the present application, after the metal film layer is oxidized, the substrate is transferred to a vacuum growth chamber having a second oxygen source, a first gas source, and a second gas source. In the vacuum growth chamber, the first gas source is ionized to form a high-energy plasma that bombards the metal target to sputter out metal atoms, and the second oxygen source oxidizes the metal atoms to form a metal oxide. The metal oxide is deposited on the metal film layer to form an epitaxial growth layer, and at the same time, the second gas source inhibits the oxidation of the epitaxial growth layer.

[0009] According to some embodiments of the present application, the flow rate of the first gas source is 50 sccm to 300 sccm, the flow rate of the second gas source is 0 to 30 sccm, and the flow rate of the second oxygen source is 5 sccm to 50 sccm.

[0010] According to some embodiments of the present application, the thickness of the epitaxial growth layer is 100 nm to 500 nm.

[0011] According to some embodiments of the present application, the vacuum degree in the vacuum growth chamber is 0.2 Pa to 1 Pa.

[0012] According to some embodiments of the present application, at least one reaction source includes a first reaction source and a second reaction source, and the first reaction source, the second reaction source and the first oxygen source are all in a gaseous state and introduced into a vacuum environment. The introduction amount of the first reaction source is 200 sccm to 600 sccm, the introduction amount of the second reaction source is 20 sccm to 70 sccm, and the introduction amount of the first oxygen source is 50 sccm to 500 sccm.

[0013] According to some embodiments of the present application, the vacuum degree of the vacuum environment is 0.3Pa to 0.7Pa.

[0014] The coating device according to an embodiment of the present application is used for coating a film on a substrate, and the coating device includes a hot wire CVD device and an RPD device; The hot wire CVD device is equipped with a hot wire process chamber; The RPD device is equipped with an RPD process chamber; Among them, along the conveying direction of the substrate, the hot wire CVD device and the RPD device are arranged in sequence, and the hot wire process chamber is connected to the RPD process chamber.

[0015] The coating equipment according to the embodiment of the present application has at least the following beneficial effects: a hot wire CVD device and an RPD device are used to coat the substrate in sequence, which can take into account the high efficiency of hot wire CVD coating and the high quality of RPD coating, and reduce damage to the substrate, which is beneficial to improving the coating efficiency while ensuring the coating quality.

[0016] According to some embodiments of the present application, the coating equipment also includes an oxidation device, which is provided with an oxidation transition chamber. Along the conveying direction of the substrate, the oxidation device is located between the hot wire CVD device and the RPD device. The oxidation transition chamber is connected to the hot wire process chamber, and the oxidation transition chamber is connected to the RPD process chamber.

[0017] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present application is further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is a schematic structural diagram of the coating equipment according to an embodiment of the present application; Figure 2 This is a flow chart of the coating method according to an embodiment of the present application.

[0019] Reference numerals: feed chamber 101 , hot wire process chamber 102 , oxidation transition chamber 103 , RPD process chamber 104 , discharge chamber 105 ; Guide rail 201 , hot wire coating structure 202 , target material 203 , plasma generator 204 . DETAILED DESCRIPTION

[0020] The following describes in detail embodiments of the present application. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application.

[0021] In the description of this application, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on this application.

[0022] In the description of this application, "several" means more than one, "plurality" means two or more, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The terms "first" and "second" are used solely to distinguish technical features and are not to be construed as indicating or implying relative importance, or as implicitly specifying the number or order of the technical features indicated.

[0023] In the description of this application, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in this application based on the specific content of the technical solution.

[0024] In the description of this application, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of this application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples.

[0025] The following describes the embodiments of the present application in conjunction with the accompanying drawings: refer to Figure 1 and Figure 2 According to the coating method of the embodiment of the present application, a film is coated on a substrate, and the coating method includes the following steps: placing the substrate in a vacuum environment, and introducing at least one reaction source and a first oxygen source into the vacuum environment, heating the reaction source by a hot wire to generate active groups, and causing the active groups to be deposited on the surface of the substrate to form a metal film layer, while the first oxygen source catalyzes the active groups and residual reactants. Among them, at least one reaction source is used to provide raw materials for the deposition and formation of the metal film layer, and the first oxygen source is used to oxidize the residual reaction source element or metastable intermediate product, which is beneficial to ensure the purity of the metal film layer and make the chemical uniformity of the metal film layer better. Therefore, compared with the coating method of magnetron sputtering physical bombardment, the present application relies on chemical reactions to generate active groups by heating and decomposing the reaction source by hot wire, avoiding the physical bombardment of the substrate by high-energy ions, and the process of depositing the metal film layer is more gentle, which can effectively reduce the damage to the substrate, and the formed metal film layer has higher purity, which is beneficial to improving the photoelectric conversion efficiency of solar cells.

[0026] Specifically, the substrate can be a perovskite single-junction substrate, which is placed on a carrier, which transports the substrate along the guide rail 201. The vacuum chamber can form a vacuum environment, and the hot wire can be a tungsten wire. To accommodate large-area coating, multiple hot wires can form a hot wire matrix. When the reaction source is a single source, it can be an organic silicon source, for example, hexamethyldisiloxane, which is pyrolyzed by the hot wire using CVD to remove the methyl group, and the Si-O skeleton is reorganized to form SiO or SiO2 (different products are formed by controlling the amount of the first oxygen source). Alternatively, it can be an organic titanium source, for example, tetraisopropyl titanate, which is pyrolyzed by the hot wire to remove the isopropoxy group, and oxidized to form TiO2 (a small amount of the first oxygen source is required to assist). When two reaction sources are used, they can be an indium source and a tin source. For example, the indium source can be trimethylindium or indium chloride, and the tin source can be tin tetrachloride or an organotin compound. The coating process based on these two sources is an ITO (Indium Tin Oxide) molding process. The first oxygen source can be gaseous water, which can decompose at high temperatures to produce oxygen.

[0027] When there are three reaction sources, they can be indium source, gallium source and zinc source, or lanthanum source, strontium source and manganese source, or copper source, indium source and sulfur source, or barium source, strontium source and titanium source. Taking indium source, gallium source and zinc source as an example, the coating based on indium source, gallium source and zinc source is IGZO (Indium Gallium Zinc Oxide) forming process.

[0028] In addition, based on the coating direction of this application, by replacing different reaction source combinations, metal oxide conductive materials with good conductivity and high transmittance such as IWO (Indium Tungsten Oxide), IZO (Indium Zinc Oxide), AZO (Aluminum-doped Zinc Oxide), and GZO (Gallium-doped Zinc Oxide) can be deposited on the substrate to prepare perovskite solar cells with coatings of different materials.

[0029] Taking the reaction sources including indium source and tin source as an example, the coating process is as follows: the hot wire generates heat, the indium source and tin source decompose to produce indium atoms, tin atoms or free radicals, and the oxygen molecules can be activated at high temperature to form oxygen atoms or oxygen free radicals. The decomposed or activated indium atoms, tin atoms, free radicals, oxygen atoms and oxygen free radicals reach the surface of the substrate through diffusion movement. On the surface of the substrate, the indium atoms, tin atoms and oxygen atoms react chemically to form indium oxide and tin oxide, that is, the first oxygen source has the role of participating in the growth of the metal film layer and performing residual reaction. Indium oxide and tin oxide are deposited on the surface of the substrate to form a metal film layer. The formation of the metal film layer in the coating method of the present application relies on chemical vapor deposition, which effectively reduces the damage to the substrate. The deposition rate, the composition ratio of the metal film layer and the structure of the metal film layer crystal can also be regulated by adjusting the ratio of the indium source, the tin source and the first oxygen source to improve the photoelectric conversion efficiency of the solar cell.

[0030] refer to Figure 1 and Figure 2In some embodiments, after a metal film layer is deposited on a substrate, the substrate is transferred to an oxidation transition chamber 103, and an oxidizing-reducing gas is introduced into the oxidation transition chamber 103 and decomposed. The oxidizing-reducing gas may be ozone, oxygen, nitrogen dioxide, nitrous oxide, hydrogen peroxide vapor, or the like, to further oxidize the metal film layer. Taking ozone as an example, ozone can decompose to form oxygen atoms and oxygen molecules, which are used to further oxidize the growth of the metal film layer to improve the structural stability and electrical conductivity of the metal film layer, thereby further improving the photoelectric conversion efficiency of the solar cell.

[0031] Specifically, the active groups generated by the decomposition of the indium source and the tin source are deposited on the substrate, and the metal film layer formed is a seed layer precursor. The thickness of the seed layer precursor can be 5nm to 15nm. For example, the thickness of the seed layer precursor can be 5nm, 7nm, 10nm, 12nm or 15nm. The seed layer precursor contains amorphous or microcrystalline indium tin oxide. Ozone decomposition produces oxygen atoms and oxygen molecules, which can further oxidize the amorphous or microcrystalline indium tin oxide to promote the grain growth of the indium tin oxide metal film layer. The seed layer formed after growth is more compact and has better structural stability, and is beneficial to improving the transmittance of the metal film layer, so as to optimize the light-transmitting and conductive properties of the metal film layer, thereby further improving the photoelectric conversion efficiency of the solar cell.

[0032] refer to Figure 1 and Figure 2 In some embodiments, after the metal film layer is oxidized, the substrate is transferred to a vacuum growth chamber having a second oxygen source, a first gas source, and a second gas source. In the vacuum growth chamber, the first gas source is ionized to form a high-energy plasma that bombards the metal target 203 to sputter out metal atoms, and the second oxygen source oxidizes the metal atoms to form a metal oxide. The metal oxide is deposited on the metal film layer to form an epitaxial growth layer. At the same time, the second gas source inhibits the oxidation of the epitaxial growth layer. Specifically, the first gas source can be argon, and the second gas source can be hydrogen. There is a high-voltage electric field in the vacuum growth chamber. Under the action of the high-voltage electric field, the argon is ionized to form a high-energy plasma. Plasma, the vacuum chamber also has a metal target 203, the metal target 203 can be an indium tin target 203, high-energy argon ions bombard the metal target 203 to sputter out indium tin metal atoms, the sputtered metal atoms combine with the second oxygen source to form metal oxide, the metal oxide is deposited on the metal film layer to form an epitaxial growth layer, hydrogen ionization can form hydrogen atoms, the hydrogen atoms react with the active oxygen in the vacuum growth chamber to consume the active oxygen, reduce excessive oxygen over-oxidation of the epitaxial growth layer, and retain oxygen vacancies, which is beneficial to increase the conductivity of the epitaxial growth layer, thereby improving the photoelectric conversion efficiency of the solar cell.

[0033] It should be noted that the present application sequentially adopts hot-wire CVD (Catalytic Chemical Vapor Deposition or Hot-Wire CVD), oxidation and RPD (Reactive Plasma Deposition) for coating. The hot-wire CVD process has a fast deposition rate and is suitable for the rapid nucleation of the seed layer, which facilitates the rapid coverage of the substrate by the seed layer. At this time, there is no need to consider the molding quality. On the one hand, the seed layer can block the surface of the substrate to prevent the surface of the substrate from being contaminated, bombarded and subjected to unnecessary chemical reactions. On the other hand, it can also provide nucleation sites for the formation of the epitaxial growth layer, thereby facilitating the uniform growth of the epitaxial growth layer to obtain a higher quality epitaxial growth layer. RPD can achieve the growth of thin films with high crystalline quality at low temperatures. In summary, the coating method of the present application can take into account both coating efficiency and coating quality, which is beneficial to obtaining a higher quality coating in a shorter time.

[0034] In addition, in the present application, a step of oxidizing the metal film layer is provided between the hot wire CVD and RPD processes. On the one hand, the crystallization quality of the metal film layer can be improved, so that the metal film layer has better structural stability, which is convenient for the subsequent deposition and formation of the epitaxial growth layer. On the other hand, the oxidation transition chamber 103 can also block the cross-gas interference between the hot wire process chamber 102 and the RPD process chamber 104, ensuring that the hot wire CVD coating and the RPD coating can be carried out relatively independently to avoid cross-contamination of the two processes, so that the coating operation can be carried out continuously, that is, when the previous substrate is placed in the RPD process chamber 104 to deposit the epitaxial growth layer in a preset order, the next substrate can be placed in the hot wire process chamber 102 to deposit the metal film layer, which is beneficial to improving the coating efficiency.

[0035] refer to Figure 1 and Figure 2 In other embodiments, a vacuum region may be provided between the hot wire process chamber 102 and the RPD process chamber 104 for isolation, and the length of the vacuum region may be adjusted according to the isolation effect. Alternatively, an isolation chamber may be additionally provided between the hot wire process chamber 102 and the RPD process chamber 104. A valve may be provided at the connection between the isolation chamber and the hot wire process chamber 102, and a valve may also be provided at the connection between the isolation chamber and the RPD process chamber 104. When a metal film layer is deposited on the substrate, the valves at the isolation chamber and the RPD process chamber 104 are closed. After the deposition of the metal film layer is completed, the substrate is transferred to the RPD process chamber 104 to deposit an epitaxial growth layer. At this time, the valve at the connection between the isolation chamber and the hot wire process chamber 102 is closed.

[0036]

[0037] The above table is for the case of metal film layer and epitaxial growth layer thickness of 130 nm plated film, the independent variable is the substrate temperature and the plating time, and different substrate temperatures and plating times correspond to different plating effects.

[0038] The transmittance of 400-1200 nm wavelength band is higher, the light is easier to transmit, and it is more conducive to the photoelectric conversion of the solar cell. The sheet resistance (i.e., the square resistance, unit: Ω / sq, which represents ohms per square) represents the resistance value of the edge-to-edge of the square thin film conductive material with a unit of 1, and the lower the sheet resistance, the higher the photoelectric conversion efficiency of the solar cell.

[0039] Magnetron sputtering is a kind of PVD (Physical Vapor Deposition, physical vapor deposition). Referring to the above table, the present application is based on the combination of hot wire CVD and RPD plating method, compared with the use of RPD, PVD and hot wire CVD alone, it has obvious plating advantages.

[0040] For example, referring to Figure 1 and Figure 2 In the present application, the hot wire CVD and RPD combined plating method is adopted, the hot wire matrix composed of tungsten wires is arranged in the hot wire process chamber 102, the temperature of the hot wire matrix is set to 2000℃, the substrate (wafer) is carried by the carrier plate, and the substrate can be placed on the temperature-controllable carrier plate equipped with a water-cooled circulation system to control the substrate temperature by adjusting the cooling liquid flow rate inside the carrier plate and the moving speed of the carrier plate along the guide rail. The substrate temperature is stably maintained at 300℃ during the hot wire CVD process and the RPD process. The oxidation transition chamber 103 is filled with oxidation-reduction gas, the RPD process chamber has an indium-tin target material, and is provided with a plasma generator 204 and a connected gas inlet pipeline.

[0041] In the coating process, the substrate is placed on the carrier plate and sent into the hot wire process chamber 102, which is a vacuum chamber, and the hot wire process chamber 102 is connected to a reaction source, such as an indium source and a tin source, and simultaneously connected to gaseous water as a first oxygen source. The heating is turned on to maintain the hot wire matrix at about 2000°C, and the substrate temperature is stabilized at 300°C. A about 10nm thick indium tin oxide seed layer precursor is deposited on the surface of the substrate. Then the carrier plate transfers the substrate to the oxidation transition chamber 103 along the guide rail 201, and the oxidation transition chamber 103 is connected to an oxidation-reduction gas, so that the seed layer precursor is oxidized and crystallized to form a more stable seed layer. When the thickness of the seed layer reaches the preset value, the substrate is transferred to the RPD process chamber 104, which is connected to argon, hydrogen and oxygen and maintained in a vacuum. In the case where the substrate temperature is maintained at 300°C, the argon is ionized by the plasma generator 204 to generate high-energy plasma to bombard the indium tin target, and the sputtered indium tin metal atoms react with oxygen to form indium tin oxide, depositing a about 120nm thick epitaxial growth layer on the seed layer. The coating is completed, and the transmittance of the coated substrate is 91% and the sheet resistance is 6Ω / sq. The transmittance and sheet resistance are better than those of the substrate coated by RPD or hot wire CVD alone at 300°C, and the time is shorter. That is, the coating method in the present application improves the coating efficiency while improving the coating quality.

[0042] It should be noted that in the above coating process, the total coating time is 4min, and the coating time of each process can be adjusted as needed.

[0043] In addition, as can be seen from the graph, compared with the single PVD coating method, under the condition of 200°C, the transmittance of the combined coating method of hot wire CVD and RPD is higher, and the sheet resistance is lower, improving the coating quality.

[0044] Alternatively, compared with the single hot wire CVD coating method, the coating time of the combined coating method of hot wire CVD and RPD is significantly shorter, and the transmittance after coating is higher and the sheet resistance is lower, balancing the coating efficiency and coating quality.

[0045] In other embodiments, the specific coating process can refer to the steps of a substrate temperature of 300°C and a coating time of 4min, and only the temperature and coating time of the substrate need to be adjusted. Here, it is not necessary to repeat.

[0046] It should be noted that current magnetron sputtering coating processes typically require ultra-high temperature processes (i.e., substrate temperatures exceeding 300°C to ensure ordered crystal growth, reduce resistance, and improve crystallinity) and plasma pretreatment (to clean the substrate surface). Ultra-high temperature treatment is costly and can easily cause deformation of the substrate carrier. Therefore, the coating method in this application limits the substrate temperature to below 300°C while ensuring the transmittance and square resistance of the coating, which helps reduce costs and alleviate carrier deformation.

[0047] refer to Figure 1 and Figure 2 In some embodiments, the flow rate of the first gas source is 50 sccm (standard cubic centimeters per minute) to 300 sccm, the flow rate of the second gas source is 0 to 30 sccm, and the flow rate of the second oxygen source is 5 sccm to 50 sccm. Specifically, the first gas source is argon, and the flow rate of argon can be 160 sccm. The second gas source can be hydrogen, and the flow rate of hydrogen can be 12 sccm. The second oxygen source is oxygen, and the flow rate of oxygen can be 20 sccm. Argon is primarily used as a sputtering gas, and controlling its flow rate can adjust the sputtering rate and film density. Hydrogen may be used for reduction reactions or affect the chemical composition of the film. Controlling its flow rate can adjust the reduction degree and chemical properties of the film. Oxygen is used for oxidation reactions. Controlling its flow rate can adjust the oxidation state and chemical composition of the film. Limiting the ratio of each component is beneficial for optimizing the coating method and improving the coating quality.

[0048] refer to Figure 1 and Figure 2 In some embodiments, the thickness of the epitaxial growth layer is 100 nm to 500 nm. For example, the thickness of the epitaxial growth layer can be 100 nm, 120 nm, 140 nm, 160 nm, 180 nm, 200 nm, 220 nm, 240 nm, 280 nm, 300 nm, 320 nm, 340 nm, 360 nm, 380 nm, 400 nm, 420 nm, 440 nm, 460 nm, 480 nm or 500 nm. Limiting the thickness of the epitaxial growth layer can ensure the crystallization quality of the epitaxial growth layer and provide the required optoelectronic properties.

[0049] refer to Figure 1 and Figure 2 In some embodiments, the vacuum degree in the vacuum growth chamber is 0.2 Pa to 1 Pa to avoid degradation of the coating quality and effectively avoid additional increase in square resistance.

[0050] refer to Figure 1 and Figure 2In some embodiments, at least one reaction source includes a first reaction source and a second reaction source. The first reaction source, the second reaction source, and the first oxygen source are all in a gaseous state and introduced into the vacuum environment. The introduction amount of the first reaction source is 200 sccm to 600 sccm, the introduction amount of the second reaction source is 20 sccm to 70 sccm, and the introduction amount of the first oxygen source is 50 sccm to 500 sccm. Specifically, the first reaction source is an indium source, and the introduction amount of the indium source can be 400 sccm. The second reaction source is a tin source, and the introduction amount of the tin source can be 50 sccm. The first oxygen source can be water vapor, and the introduction amount of water vapor can be 100 sccm. Among them, controlling the introduction amount of the indium source can adjust the indium content in the film, affecting the electrical properties (such as carrier concentration and mobility) and optical properties (such as transmittance) of the film. The introduction amount of the tin source determines the doping concentration of tin in the film, thereby regulating the conductivity and stability of the film. Precise control of tin content can avoid performance degradation caused by over-doping. Water vapor is used as an oxidant, and its introduction amount directly affects the oxidation degree of the film and the progress of the residual reaction, which is beneficial to further optimize the composition and structure of the coating and improve the coating quality.

[0051] refer to Figure 1 and Figure 2 In some embodiments, the vacuum degree of the vacuum environment is 0.3 PPa to 0.7 Pa, which is beneficial to further optimize the transport and reaction kinetics of reactants, reduce impurities and contamination, and thus improve the coating quality.

[0052] refer to Figure 1 The coating apparatus according to an embodiment of the present application is used to coat a film on a substrate. The coating apparatus includes a hot-wire CVD device and an RPD device. The hot-wire CVD device is provided with a hot-wire process chamber 102, and the RPD device is provided with an RPD process chamber 104. The hot-wire CVD device and the RPD device are arranged sequentially along the conveying direction of the substrate, and the hot-wire process chamber 102 is connected to the RPD process chamber 104. The hot-wire process chamber 102 is used to introduce a first reaction source, a second reaction source, and a first oxygen source. The hot-wire CVD chamber has a hot-wire coating structure 202 to provide the necessary heat for coating the substrate. The temperature of the substrate in the hot-wire CVD chamber can be adjusted by changing the conveying speed, etc. The RPD process chamber 104 is used to introduce a first gas source, a second gas source, and a second oxygen source to further deposit an epitaxial growth layer. Through the cooperation of the two coating devices, it is possible to better balance the coating quality and coating efficiency.

[0053] Specifically, the RPD process chamber 104 contains a target 203 and a plasma generator 204 . The plasma generator 204 is capable of generating and maintaining a stable, highly active plasma region, which is used to ionize a working gas (such as argon, oxygen, nitrogen, etc.) to form a high-energy plasma.

[0054] refer to Figure 1 In some embodiments, the coating apparatus further includes an oxidation device, which includes an oxidation transition chamber 103. The oxidation device is located between the hot-filament CVD device and the RPD device along the substrate conveyance direction. The oxidation transition chamber 103 communicates with the hot-filament process chamber 102, and the oxidation transition chamber 103 communicates with the RPD process chamber 104. Specifically, the oxidation transition chamber 103 is used to introduce ozone to further oxidize the metal film layer deposited during the hot-filament CVD coating step, thereby improving the coating quality. Furthermore, the oxidation transition chamber 103 isolates the hot-filament process chamber 102 from the RPD process chamber 104, ensuring that the coatings in each process are isolated from each other, preventing interference contamination, facilitating the continuous coating operation, and improving coating efficiency.

[0055] In addition, along the conveying direction, a feed chamber 101 can be provided at the front end of the hot wire process chamber 102, and a discharge chamber 105 can be provided at the end of the RPD process chamber 104. The feed chamber 101 and the discharge chamber 105 can isolate the coating chamber from the external environment, preventing external dust, impurities, etc. from contaminating the high vacuum environment inside the coating chamber, thereby ensuring the coating quality. At the same time, it can also prevent the waste gas, waste materials, etc. generated during the coating process from polluting the external environment. At the same time, the feed chamber 101 is also used to continuously feed the substrates to be coated into the coating chamber, while the discharge chamber 105 is used to continuously output the substrates that have been coated. This design allows the coating process to be carried out continuously without frequent shutdowns, thereby significantly improving production efficiency.

[0056] The embodiments of the present application have been described in detail above with reference to the accompanying drawings. However, the present application is not limited to the above embodiments. Various modifications can be made within the scope of knowledge possessed by ordinary technicians in the relevant technical field without departing from the purpose of the present application. In addition, the embodiments of the present application and the features of the embodiments can be combined with each other unless there is a conflict.

Claims

1. A film coating method, characterized in that: The steps include: placing the substrate in a vacuum environment, and introducing at least one reaction source and a first oxygen source into the vacuum environment; The reaction source is heated by a hot wire to generate active radicals, and the active radicals are deposited on the surface of the substrate to form a metal film layer, while the first oxygen source catalyzes the active radicals and residual reactants.

2. The coating method according to claim 1, wherein: After the metal film layer is deposited on the substrate, the substrate is transferred to an oxidation transition chamber, and an oxidizing and reducing gas is introduced into the oxidation transition chamber and decomposed to further oxidize the metal film layer.

3. The coating method according to claim 2, wherein: After oxidizing the metal film layer, the substrate is transferred to a vacuum growth chamber having a second oxygen source, a first gas source, and a second gas source. In the vacuum growth chamber, the first gas source is ionized to form a high-energy plasma that bombards a metal target to sputter out metal atoms, and the second oxygen source oxidizes the metal atoms to form a metal oxide. The metal oxide is deposited on the metal film layer to form an epitaxial growth layer, and the second gas source suppresses the oxidation of the epitaxial growth layer.

4. The coating method according to claim 3, wherein: The flow rate of the first gas source is 50 sccm to 300 sccm, the flow rate of the second gas source is 0 to 30 sccm, and the flow rate of the second oxygen source is 5 sccm to 50 sccm.

5. The coating method according to claim 3, wherein: The thickness of the epitaxial growth layer is 100 nm to 500 nm.

6. The coating method according to claim 3, wherein: The vacuum degree in the vacuum growth chamber is 0.2 Pa to 1 Pa.

7. The coating method according to claim 1, wherein: The at least one reaction source includes a first reaction source and a second reaction source. The first reaction source, the second reaction source and the first oxygen source are all in gaseous form and introduced into the vacuum environment. The introduction amount of the first reaction source is 200 sccm to 600 sccm, the introduction amount of the second reaction source is 20 sccm to 70 sccm, and the introduction amount of the first oxygen source is 50 sccm to 500 sccm.

8. The coating method according to claim 1, wherein: The vacuum degree of the vacuum environment is 0.3Pa to 0.7Pa.

9. A film coating device for coating a film on a substrate, characterized in that: include: Hot wire CVD device, equipped with a hot wire process chamber; RPD device, equipped with RPD process chamber; Wherein, along the conveying direction of the substrate, the hot wire CVD device and the RPD device are arranged in sequence, and the hot wire process chamber is connected to the RPD process chamber.

10. The coating equipment according to claim 9, characterized in that: The coating equipment also includes an oxidation device, which is provided with an oxidation transition chamber. Along the conveying direction of the substrate, the oxidation device is located between the hot wire CVD device and the RPD device. The oxidation transition chamber is connected to the hot wire process chamber, and the oxidation transition chamber is connected to the RPD process chamber.

Images