Silver film growth method and optical film layer
By depositing the silver self-immersion layer and continuous silver film in the process cavity according to preset parameters, the problem of difficult control of the surface uniformity and roughness of the silver film in the prior art is solved, and silver film preparation with low thickness, small surface roughness and small grain size is achieved.
Patent Information
- Application Number
- CN202411977118.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2025-05-02
AI Technical Summary
In the prior art, when preparing metal silver films, it is difficult to control the evaporation rate and deposition rate, resulting in difficult control of the surface uniformity and roughness of the silver film.
A silver film growth method is employed, including heating the substrate in the degassing chamber to remove impurities, then cooling in the process chamber while standing, then depositing on the substrate to form a silver self-immersion layer at a preset deposition power and target base distance, and depositing on the side it is away from the substrate to form a continuous silver film.
Through this method, silver films with low thickness, small surface roughness and small surface grain size can be prepared, which improves the uniformity and quality of the silver film.
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Figure CN119913466A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of optoelectronic technology, and in particular to a silver film growth method and an optical film layer. Background Art
[0002] When light propagates on the surface of a metal, it can excite a special electromagnetic wave mode, namely surface plasma, which has a modulating effect on the light field. In applications that use metallic silver films and light to generate surface plasma, the thickness, roughness and grain size of the metallic silver film largely affect the distribution of the surface plasma. At present, the main technologies for preparing metallic silver films include thermal evaporation and magnetron sputtering. However, the evaporation rate of the thermal evaporation method is difficult to control, resulting in poor surface uniformity of the metallic silver film. The deposition rate of the magnetron sputtering method is too fast, resulting in difficulty in controlling the surface roughness of the metallic silver film. Summary of the invention
[0003] In order to overcome the technical problems mentioned in the above technical background, the present application embodiment provides a silver film growth method, the method comprising:
[0004] providing a substrate;
[0005] placing the substrate in a degassing chamber for heating treatment;
[0006] Transferring the heated substrate to a process chamber and allowing it to cool;
[0007] Depositing a silver self-wetting layer on the substrate in the process chamber according to a preset deposition power and target-substrate distance;
[0008] The substrate on which the silver self-wetting layer is deposited is left to stand still, and then a continuous silver film is deposited on a side of the silver self-wetting layer away from the substrate at a preset deposition power and target-substrate distance.
[0009] In a possible implementation, in the step of placing the substrate in a degassing chamber for heating, the method includes:
[0010] placing the substrate on a heated base in a degassing chamber;
[0011] The heating base is controlled to heat the substrate to remove impurities on the surface of the substrate, and the number of particles with a size exceeding 40 nm per unit area on the surface of the substrate does not exceed a preset number of particles.
[0012] In a possible implementation, in the step of placing the substrate in a process chamber for static cooling, the method includes:
[0013] Transferring the heated substrate to a deposition base in the process chamber and cooling it for a first standing time at room temperature, wherein the first standing time is 360s to 600s;
[0014] A first inert gas is introduced into the process chamber, wherein the flow rate of the first inert gas is 50 sccm to 100 sccm, and the time for introducing the first inert gas lasts for 5 s to 10 s, wherein the first inert gas includes argon.
[0015] In a possible implementation, in the step of depositing a silver self-wetting layer on the substrate according to a preset deposition power and target-substrate distance, the method includes:
[0016] The process chamber comprises a first side and a second side opposite to each other, and a second inert gas is continuously introduced into the first side and the second side respectively, the flow rate of the second inert gas is 20 sccm to 30 sccm, and the second inert gas comprises helium;
[0017] Setting the deposition power and target-substrate distance of the process chamber;
[0018] According to the set deposition power and the target-substrate distance and at room temperature, the silver particles are controlled to be deposited on the substrate to form a silver self-infiltration layer with a thickness of 2nm to 4nm, wherein the deposition power is 2000w to 3000w, the target-substrate distance is 4000steps to 5000steps, and the deposition time of the silver self-infiltration layer is 0.2s to 0.4s.
[0019] In a possible implementation, in the step of leaving the substrate on which the silver self-wetting layer is deposited to stand still and then depositing a continuous silver film on a side of the silver self-wetting layer away from the substrate at a preset deposition power and target-substrate distance, the method includes:
[0020] The substrate on which the silver self-wetting layer is deposited is placed in the process chamber for a second resting time, and a second inert gas is introduced into the process chamber during the second resting time, wherein the second resting time is 15s to 20s, the flow rate of the second inert gas is 20sccm to 30sccm, and the second inert gas includes helium;
[0021] After standing for the second standing time, silver particles are deposited on the side of the silver self-wetting layer away from the substrate at room temperature with the preset deposition power and the target-substrate distance to form a silver film with a thickness of 40nm to 50nm, wherein the deposition time of the silver film is 3.7s to 4s.
[0022] In a possible implementation, after the step of allowing the substrate on which the silver self-wetting layer is deposited to stand still and then depositing a continuous silver film on a side of the silver self-wetting layer away from the substrate at a preset deposition power and target-substrate distance, the method further includes:
[0023] transferring the substrate on which the silver self-wetting layer and the silver film are deposited into a cooling chamber;
[0024] Introducing a protective gas into the cooling chamber so that the pressure in the process chamber reaches 0.5 Torr to 1 Torr, and stopping the introduction of the protective gas after 15s to 20s, wherein the protective gas includes nitrogen;
[0025] The substrate on which the silver self-wetting layer and the silver film are deposited is cooled.
[0026] Another object of the present application is to provide an optical film layer, the optical film layer comprising:
[0027] substrate;
[0028] A silver self-wetting layer is disposed on the substrate;
[0029] The silver film is arranged on a side of the silver self-wetting layer away from the substrate.
[0030] In a possible implementation, in a direction perpendicular to the plane where the substrate is located, the silver self-wetting layer has a first thickness, the silver film has a second thickness, and the first thickness is less than the second thickness;
[0031] The first thickness is 2 nm to 4 nm, and the second thickness is 40 nm to 50 nm.
[0032] In a possible implementation manner, the roughness of the silver film on a side away from the substrate is 0.50 nm to 0.60 nm.
[0033] In a possible implementation, an average grain size of the silver film on a side away from the substrate is 20 nm to 21 nm.
[0034] Based on any one of the above aspects, the embodiments of the present application provide a silver film growth method and an optical film layer. Thus, through the above scheme, a silver film with low thickness, small surface roughness and small surface grain size can be prepared. BRIEF DESCRIPTION OF THE DRAWINGS
[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.
[0036] Figure 1 A flow chart of the steps of a silver film growth method provided in this embodiment;
[0037] Figure 2 A schematic diagram of the surface of the silver self-wetting layer under a scanning electron microscope provided in this embodiment;
[0038] Figure 3 A schematic diagram of the surface of a silver film under a scanning electron microscope provided in this embodiment;
[0039] Figure 4 A schematic diagram of the thickness of the silver film provided in this embodiment;
[0040] Figure 5 A schematic diagram of the surface of a silver film under an atomic force test provided in this embodiment;
[0041] Figure 6 This is a schematic diagram of an optical film layer provided in this embodiment.
[0042] Icon: 1-optical film layer, 10-substrate, 20-silver self-wetting layer, 30-silver film. DETAILED DESCRIPTION
[0043] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.
[0044] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.
[0045] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.
[0046] In the description of this application, it should be noted that the terms "upper", "lower", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the application is usually placed when in use, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.
[0047] It should be noted that, in the absence of conflict, different features in the embodiments of the present application may be combined with each other.
[0048] In order to solve the technical problems mentioned in the aforementioned background technology, the inventor innovatively designed the following technical solution, and the specific implementation solution of the present application will be described in detail below with reference to the accompanying drawings.
[0049] See also Figure 1 , Figure 1 A flow chart of the steps of a silver film growth method provided in this embodiment. The method comprises:
[0050] Step S110, providing a substrate;
[0051] In this step, the substrate is the basic material in semiconductor manufacturing and other thin film technology applications. The materials used to make the substrate include silicon, quartz, etc. The size of the substrate can be 8 inches. The specific material and size of the substrate are not specifically limited here and need to be selected according to actual conditions.
[0052] Step S120, placing the substrate in a degassing chamber for heating treatment;
[0053] In this step, the substrate is placed on a heated base in a degassing chamber (DEGAS chamber) and impurities on the surface of the substrate are removed by heating.
[0054] Step S130, transferring the heated substrate to a process chamber for cooling;
[0055] In this step, the substrate is transferred from the degassing chamber to the process chamber for the deposition process. First, the heated substrate is left to cool down to lower its temperature to room temperature, which is crucial to ensure the quality and uniformity of the deposition.
[0056] It is worth noting that, in this embodiment, when the deposition process is performed in the process chamber, it is necessary to ensure that the deposition base supporting the substrate in the process chamber is at room temperature, and the entire deposition process needs to be performed at room temperature.
[0057] Step S140, depositing a silver self-wetting layer on the substrate in the process chamber according to a preset deposition power and target-substrate distance;
[0058] In this embodiment, after the substrate is cooled to an appropriate temperature, a magnetron sputtering method is used to start the deposition process. First, a silver self-wetting layer is deposited on the substrate. During the deposition process, the deposition power and the target-substrate distance need to be controlled. The target-substrate distance is the distance between the sputtering target and the substrate to ensure that the uniformity and thickness of the silver self-wetting layer meet the design requirements. The formation of the silver self-wetting layer is to improve the adhesion and functionality of the subsequent silver film.
[0059] Step S150, after the substrate with the silver self-wetting layer deposited thereon is left to stand, a continuous silver film is then deposited on the side of the silver self-wetting layer away from the substrate at a preset deposition power and target-substrate distance.
[0060] In this embodiment, the substrate on which the silver self-wetting layer is deposited is subjected to a static treatment to ensure that the silver self-wetting layer and the silver film are more firmly bonded, and then the silver film is deposited at the same deposition power and target-substrate distance.
[0061] Furthermore, step S120 may be implemented in the following manner.
[0062] First, the substrate is placed on a heated base in a degassing chamber;
[0063] In this embodiment, the heating temperature of the heating base may be 200°C.
[0064] Next, the heating base is controlled to heat the substrate to remove impurities on the surface of the substrate, and the number of particles with a size exceeding 40 nm per unit area on the surface of the substrate does not exceed a preset number of particles.
[0065] In this embodiment, since impurities on the substrate surface, such as particles, greatly increase the roughness and grain size of the silver film, it is necessary to strictly control the number of particles on the substrate surface and avoid the appearance of large-sized particles before entering the process chamber. In this step, the substrate is pre-treated by heating the base to remove volatile impurities on the substrate surface, to ensure that the substrate surface is clean when entering the process chamber, and to avoid attachable particles from entering the process chamber. For example, when the size of the substrate is 8 inches, it should be ensured that the number of particles on the substrate surface exceeding 40nm does not exceed 100.
[0066] Further, step S130 may be implemented in the following manner.
[0067] First, the heated substrate is transferred to a deposition base in a process chamber and cooled at room temperature for a first standing time, wherein the first standing time is 360s to 600s.
[0068] In this embodiment, the heated substrate is transferred to a process chamber for cooling for a first standing time to reduce the temperature of the substrate so that the temperature of the substrate and the temperature of the deposition base are both at room temperature to ensure that the subsequent deposition process is carried out at room temperature. The first standing time is 360s to 600s. Exemplarily, the first standing time is 360s, 400s, 440s, 480s, 520s, 560s and 600s, etc.
[0069] In this embodiment, if the temperature of the deposition base is too high or the temperature of the deposition base continues to rise, performing the deposition process under such conditions may cause the surface roughness and grain size of the silver film deposited on the substrate to deteriorate, so it is necessary to ensure that the subsequent deposition process is carried out at room temperature.
[0070] Next, a first inert gas is introduced into the process chamber. The flow rate of the first inert gas is 50 sccm to 100 sccm. The time for introducing the first inert gas lasts for 5 s to 10 s. The first inert gas includes argon.
[0071] In this embodiment, in order to further purify the environment in the process chamber, a first inert gas is introduced into the process chamber. Due to its stable chemical properties, the first inert gas will not react with the substrate or other materials in the process chamber, thereby preventing unnecessary chemical reactions or impurity contamination during the deposition process. The flow rate of the first inert gas is 50 sccm to 100 sccm. Exemplarily, the flow rate of the first inert gas is 50 sccm, 60 sccm, 70 sccm, 80 sccm, 90 sccm and 100 sccm. The unit "sccm" represents standard cubic centimeters per minute. This flow range can ensure that the gas environment in the process chamber is fully purified while avoiding unnecessary costs or equipment burdens that may be caused by excessive flow rates.
[0072] In addition, the first inert gas is introduced for 5s to 10s. For example, the first inert gas is introduced for 5s, 6s, 7s, 8s, 9s, and 10s, so that the first inert gas can fully flow through the process chamber and effectively remove possible impurity particles or volatile substances, while also preventing unnecessary waste of resources due to excessive ventilation time. Specifically, the first inert gas includes argon, which has stable chemical properties, and the specific type of the first inert gas is not specifically limited herein.
[0073] Further, step S140 can be implemented in the following manner.
[0074] The process chamber comprises a first side and a second side opposite to each other. First, a second inert gas is continuously introduced into the first side and the second side. The flow rate of the second inert gas is 20 sccm to 30 sccm. The second inert gas comprises helium.
[0075] In this embodiment, the first side and the second side opposite to each other of the process chamber are the front and the back of the process chamber, and there are channels for introducing gas into the process chamber at the front and the back of the process chamber. The second inert gas is introduced into the first side and the second side of the process chamber to ensure uniform distribution of gas in the process chamber. The flow rate of the second inert gas is 20 sccm to 30 sccm. By way of example, the flow rate of the second inert gas is 20 sccm, 25 sccm, 30 sccm, etc.
[0076] It is worth noting that the second inert gas is introduced into the first side and the second side of the process chamber until the entire deposition process is completed (that is, before the deposited silver self-wetting layer and the silver film are transferred to the cooling chamber). The second inert gas can be helium. As an inert gas, helium will not react with the silver self-wetting layer, but can provide a stable atmosphere, which is conducive to the stability of the silver self-wetting layer. The specific type of the second inert gas is not specifically limited here.
[0077] Next, the deposition power and target-substrate distance of the process chamber are set;
[0078] Then, according to the set deposition power and target-substrate distance and at room temperature, the silver particles are controlled to deposit on the substrate to form a silver self-wetting layer with a thickness of 2nm to 4nm, wherein the deposition power is 2000w to 3000w, the target-substrate distance is 4000steps to 5000steps, and the deposition time of the silver self-wetting layer is 0.2s to 0.4s.
[0079] In this embodiment, the deposition power has a significant effect on the migration time of the sputtered silver particles on the substrate surface, which is directly related to key characteristics such as the number of nuclei, stress in the film, and surface roughness. The target-substrate distance affects the flight path and energy of the sputtered silver particles, and thus affects the crystallization and deposition rate of the silver film. In this step, after the first inert gas is introduced, the deposition power of 2000w / s to 3000w / s in the process chamber reaches a deposition power of 2000w to 3000w within 1s. Exemplarily, the deposition power is 2000w, 2200w, 2400w, 2600w, 2800w and 3000w, etc. The use of a larger deposition power speed is to be able to quickly start the sputtering process to ensure that the deposition power remains stable when entering the saturated sputtering rate.
[0080] At the same time, the target-substrate distance is set to 4000 steps to 5000 steps. For example, the target-substrate distance is 4000 steps, 4200 steps, 4400 steps, 4600 steps, 4800 steps and 5000 steps. By adjusting the target-substrate distance in this range, the silver film deposition with lower roughness and grain size can be achieved. According to the set deposition power and target-substrate distance, a silver self-wetting layer with a thickness of 2 nm to 4 nm is finally formed on the substrate. For example, the thickness of the silver self-wetting layer is 2 nm, 3 nm and 4 nm, etc., wherein the deposition time of the silver self-wetting layer is 0.2 s to 0.4 s. For example, the deposition time of the silver self-wetting layer is 0.2 s, 0.3 s and 0.4 s, etc.
[0081] In this embodiment, a silver self-wetting layer is first formed on the substrate. On the one hand, it provides a wetting effect for the subsequent deposition process and optimizes the distribution uniformity of silver particles; on the other hand, it can fully release the heat accumulation and stress effect in the early stage of deposition, thereby avoiding the increase of roughness and grain size due to local accumulation of silver particles.
[0082] It is worth noting that the formation of the silver self-wetting layer on the substrate is carried out at room temperature.
[0083] Further, step S150 can be implemented in the following manner.
[0084] First, the substrate deposited with the silver self-wetting layer is placed in a process chamber for a second standing time, and a second inert gas is introduced into the process chamber during the second standing time, wherein the second standing time is 15s to 20s, and the flow rate of the second inert gas is 20sccm to 30sccm.
[0085] In this embodiment, after the preparation of the silver self-wetting layer is completed, the substrate on which the silver self-wetting layer is deposited is allowed to stand for a second standing time, the second standing time being 15s to 20s, and illustratively, the second standing time is 15s, 16s, 17s, 18s, 19s, and 20s, etc. The substrate on which the silver self-wetting layer is deposited is allowed to stand for the second standing time to ensure that the silver self-wetting layer has enough time to undergo physical or chemical changes, and at the same time, the efficiency is not affected by an excessively long standing time.
[0086] At the same time, a second inert gas is introduced during the second static time, and the flow rate of the second inert gas is 20 sccm to 30 sccm. For example, the flow rate of the second inert gas is 20 sccm, 25 sccm, and 30 sccm. The flow rate of the second inert gas introduced in this step should be the same as the flow rate of the first inert gas introduced in step S130 to avoid degradation of deposition quality due to sudden changes in the deposition environment.
[0087] Next, after standing for a second standing time, silver particles are deposited on the side of the silver self-wetting layer away from the substrate at a preset deposition power and target-substrate distance at room temperature to form a silver film with a thickness of 40nm to 50nm, wherein the deposition time of the silver film is 3.7s to 4s.
[0088] In this embodiment, the deposition power and target-substrate distance set at this time are the same as the values of depositing the silver self-wetting layer. In this step, silver particles are deposited on the side of the silver self-wetting layer away from the substrate to form a silver film with a thickness of 40nm to 50nm. For example, the thickness of the silver film is 40nm, 45nm, and 50nm, etc., wherein the deposition time of the silver film is 3.7s to 4s, and for example, the deposition time of the silver film is 3.7s, 3.8s, 3.9s, and 4s, etc. The deposition time of the silver film ensures that the silver film can reach the required thickness while avoiding unevenness or excessive consumption of materials caused by excessive deposition.
[0089] It is worth noting that the formation of the silver film on the substrate on which the silver self-wetting layer is deposited is carried out at room temperature.
[0090] Furthermore, after step S150, the method further includes:
[0091] First, the substrate on which the silver self-wetting layer and the silver film are deposited is transferred into a cooling chamber;
[0092] Then, a third protective gas is introduced into the cooling chamber to make the gas pressure in the cooling chamber reach 0.5 Torr to 1 Torr. After 15s to 20s, the introduction of the protective gas is stopped, wherein the protective gas includes nitrogen.
[0093] Next, the substrate on which the silver self-wetting layer and the silver film are deposited is cooled.
[0094] In this embodiment, after the silver film deposition is completed, the substrate deposited with the silver self-wetting layer and the silver film is transferred to a cooling chamber for cooling, and a protective gas is introduced into the cooling chamber so that the air pressure in the process chamber is 0.5 Torr to 1 Torr. For example, the air pressure in the process chamber is 0.5 Torr, 0, 6 Torr, 0.7 Torr, 0.8 Torr, 0.9 Torr and 1 Torr, etc. The unit "Torr" represents Torr. The time for introducing the protective gas lasts for 15s-20s. For example, the time for introducing the protective gas lasts for 15s, 16s, 17s, 18s, 19s and 20s, etc. Then, the substrate deposited with the silver self-wetting layer and the silver film is cooled, and the cooling time can be 120s. This step can ensure the stable deposition of the silver film, and the internal heat energy can be fully released to form a highly uniform silver film.
[0095] In this embodiment, the above-mentioned silver film growth method is used to conduct an experiment. Specifically, a bare wafer substrate is provided. First, a silver self-wetting layer is deposited on the bare wafer substrate. Figure 2 , Figure 2 The surface morphology of the silver self-wetting layer under SEM (scanning electron microscope), and then the silver film is deposited on the substrate with the silver self-wetting layer, and finally the silver film formed on the bare wafer substrate is as follows Figure 3 As shown, Figure 3 The surface morphology of the silver film under SEM (scanning electron microscope) is shown in Figure 2. Figure 4 As shown, the thickness of the silver film is in the range of 40nm to 50nm. Figure 5 , Figure 5 The surface morphology of the silver film under atomic force testing is shown in Figure 1, with a surface roughness of 0.50nm to 0.60nm and an average surface grain size of 20.51nm. Therefore, in this embodiment, there is no need to introduce other film material preparation processes. The silver film is used as its own silver self-wetting layer to form a substrate with a silver film and a silver self-wetting layer deposited thereon. This not only has a low-thickness silver film, but also can reduce the surface roughness and grain size of the silver film. It also avoids the possibility of surface plasma concentration attenuation caused by the introduction of other film layers.
[0096] Based on the same inventive concept, see Figure 6 Another object of the present application is to provide an optical film layer 1, the optical film layer 1 comprising: a substrate 10, a silver self-wetting layer 20 and a silver film 30. The silver self-wetting layer 20 is disposed on the substrate 10, and the silver film 30 is disposed on a side of the silver self-wetting layer 20 away from the substrate 10.
[0097] In this embodiment, a silver film 30 is prepared on the substrate 10 to generate and transmit the surface plasma evanescent wave downward, thereby modulating the light field. It is worth noting that a silver self-wetting layer 20 is first deposited on the substrate 10. During the deposition process, it can provide a wetting effect for the subsequent deposition process and can fully release the heat accumulation and stress effect at the initial stage of deposition, thereby avoiding the phenomenon of increased roughness and increased grain size due to local accumulation of silver particles.
[0098] For further information, see Figure 6 In a direction perpendicular to the plane where the substrate 10 is located, the silver self-wetting layer 10 has a first thickness d1, and the silver film has a second thickness d2, and the first thickness d1 is less than the second thickness d2. The first thickness d1 is 2nm to 4nm, and the second thickness d2 is 40nm to 50nm.
[0099] In applications that utilize metal surfaces and light-generated plasma, it is usually necessary to prepare a low-thickness silver film 30, mainly to generate and transmit surface plasma evanescent waves downward. This evanescent wave will decay rapidly when propagating in the medium, so its propagation distance is limited, usually only on the order of the wavelength. In order to effectively utilize these evanescent waves in specific applications, the silver film 30 needs to be thin enough so that the evanescent wave can be generated and transmitted on the lower surface of the silver film. In this embodiment, the silver self-wetting layer 20 has a first thickness d1, and the first thickness d1 is 2nm to 4nm. For example, the first thickness d1 of the silver self-wetting layer 10 is 2nm, 3nm, and 4nm. The silver film 30 has a second thickness d2, and the second thickness d2 is 40nm to 50nm. For example, the second thickness d2 of the silver film 30 is 40nm, 45nm, and 50nm.
[0100] Furthermore, the roughness of the silver film 30 on the side away from the substrate 10 is 0.50 nm to 0.60 nm.
[0101] In applications using metal surfaces and light-generated plasma, it is necessary to prepare a silver film 30 with low roughness and low grain size, which is beneficial to improve the optical and mechanical properties of the optical film layer 1. In this embodiment, the roughness of the silver film 30 on the side away from the substrate 10 is 0.50nm to 0.60nm. For example, the roughness of the silver film 30 on the side away from the substrate 10 is 0.50nm, 0.51nm, 0.52nm, 0.54nm, 0.55nm, 0.56nm, 0.57nm, 0.58nm, 0.59nm and 0.60nm. The average grain size of the silver film 30 on the side away from the substrate 10 is 20nm to 21nm. For example, the average grain size of the silver film 30 on the side away from the substrate 10 is 20nm and 21nm.
[0102] In summary, the present application provides a silver film growth method and an optical film layer. In the silver film growth method, a substrate is first provided, and then the substrate is placed in a process chamber for cooling, and then a silver self-wetting layer is deposited on the substrate in the process chamber according to a preset deposition power and target-substrate distance. Finally, the substrate with the silver self-wetting layer deposited is left to stand, and then a silver film is deposited on the side of the silver self-wetting layer away from the substrate at a preset deposition power and target-substrate distance. In this way, through the above scheme, a silver film with low thickness, small surface roughness and small surface grain size can be prepared.
[0103] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. A method for growing a silver film, characterized in that: The method comprises: providing a substrate; placing the substrate in a degassing chamber for heating treatment; Transferring the heated substrate to a process chamber and allowing it to cool; Depositing a silver self-wetting layer on the substrate in the process chamber according to a preset deposition power and target-substrate distance; The substrate with the silver self-wetting layer deposited thereon is left to stand still, and then a continuous silver film is deposited on a side of the silver self-wetting layer away from the substrate at a preset deposition power and target-substrate distance.
2. The silver film growth method according to claim 1, characterized in that: In the step of placing the substrate in a degassing chamber for heat treatment, the method comprises: placing the substrate on a heated base in a degassing chamber; The heating base is controlled to heat the substrate to remove impurities on the surface of the substrate, and the number of particles with a size exceeding 40 nm per unit area on the surface of the substrate does not exceed a preset number of particles.
3. The silver film growth method according to claim 1, characterized in that: In the step of transferring the heated substrate to a process chamber for cooling, the method further comprises: Transferring the heated substrate to a deposition base in the process chamber and cooling it for a first standing time at room temperature, wherein the first standing time is 360s to 600s; A first inert gas is introduced into the process chamber, wherein the flow rate of the first inert gas is 50 sccm to 100 sccm, and the time for introducing the first inert gas lasts for 5 s to 10 s, wherein the first inert gas includes argon.
4. The silver film growth method according to claim 1, characterized in that: In the step of depositing a silver self-wetting layer on the substrate according to a preset deposition power and target-substrate distance, the method comprises: The process chamber comprises a first side and a second side opposite to each other, and a second inert gas is continuously introduced into the first side and the second side respectively, the flow rate of the second inert gas is 20 sccm to 30 sccm, and the second inert gas comprises helium; Setting the deposition power and target-substrate distance of the process chamber; According to the set deposition power and the target-substrate distance and at room temperature, the silver particles are controlled to be deposited on the substrate to form a silver self-infiltration layer with a thickness of 2nm to 4nm, wherein the deposition power is 2000w to 3000w, the target-substrate distance is 4000steps to 5000steps, and the deposition time of the silver self-infiltration layer is 0.2s to 0.4s.
5. The silver film growth method according to claim 1, characterized in that: In the step of leaving the substrate on which the silver self-wetting layer is deposited to stand still and then depositing a continuous silver film on a side of the silver self-wetting layer away from the substrate at a preset deposition power and target-substrate distance, the method comprises: Allowing the substrate on which the silver self-wetting layer is deposited to stand in the process chamber for a second standing time, wherein the second standing time is 15s to 20s; After standing for the second standing time, silver particles are deposited on the side of the silver self-wetting layer away from the substrate at room temperature with the preset deposition power and the target-substrate distance to form a silver film with a thickness of 40nm to 50nm, wherein the deposition time of the silver film is 3.7s to 4s.
6. The silver film growth method according to claim 1, characterized in that: After the step of leaving the substrate with the silver self-wetting layer deposited thereon to stand still and then depositing a continuous silver film on the side of the silver self-wetting layer away from the substrate at the preset deposition power and target-substrate distance, the method further comprises: transferring the substrate on which the silver self-wetting layer and the silver film are deposited into a cooling chamber; Introducing protective gas into the cooling chamber so that the pressure in the cooling chamber reaches 0.5 Torr to 1 Torr, and stopping the introduction of protective gas after 15s to 20s, wherein the protective gas includes nitrogen; The substrate on which the silver self-wetting layer and the silver film are deposited is cooled.
7. An optical film layer, characterized in that: The optical film layer comprises: substrate; A silver self-wetting layer is disposed on the substrate; The silver film is arranged on a side of the silver self-wetting layer away from the substrate.
8. The optical film layer according to claim 7, characterized in that: In a direction perpendicular to the plane where the substrate is located, the silver self-wetting layer has a first thickness, the silver film has a second thickness, and the first thickness is less than the second thickness; The first thickness is 2 nm to 4 nm, and the second thickness is 40 nm to 50 nm.
9. The optical film layer according to claim 7, characterized in that: The roughness of the silver film on a side away from the substrate is 0.50nm-0.60nm.
10. The optical film layer according to claim 7, characterized in that: The average grain size of the silver film on a side away from the substrate is 20 nm to 21 nm.