Evaporation and magnetic control mixed coating method and equipment

Abstract

The invention relates to the technical field of semiconductor optical coating, in particular to an evaporation and magnetic control mixed coating method and equipment. Plating a first base coat on the substrate by adopting a reactive magnetron sputtering mode, and plating a second base coat on the first base coat by adopting an electron beam evaporation mode; plating a functional layer on the second base layer by adopting an electron beam evaporation mode; and plating a first protective layer on the functional layer by adopting an electron beam evaporation mode, and plating a second protective layer on the first protective layer by adopting a reaction magnetron sputtering mode. According to the invention, two coating modes of electron beam evaporation coating and reaction magnetron sputtering coating are combined, the first base coat on the end face of the substrate and the second protective layer on the outermost layer are formed by adopting the reaction magnetron sputtering coating mode, the reaction magnetron sputtering coating is compact in film formation and can be used as the waterproof layer on the outermost layer, the particle energy is relatively high during film formation, and the film formation efficiency is high. The substrate is firmly combined and is not easy to fall off; and the functional layer is coated by adopting an electron beam evaporation mode, so that the coating efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor optical coating technology, and in particular to a method and apparatus for hybrid evaporation and magnetron coating. Background Technology

[0002] With advancements in optical coating technology, the requirements for optical coating on chips are becoming increasingly stringent, resulting in a wide variety of film types and thicknesses. In the production process, to improve efficiency, electron beam evaporation is commonly used for chip end-face coating due to its high coating rate and shorter cycle time. However, this high rate can lead to film quality deviations, easily forming columnar voids, which in turn makes the optical film susceptible to moisture absorption, affecting its optical properties. Besides electron beam evaporation, reactive magnetron sputtering produces films with good uniformity, dense formation, and strong adhesion to the substrate. However, reactive magnetron sputtering has higher equipment and maintenance costs, and its coating speed is slower than electron beam evaporation, making it unsuitable for cost control if used exclusively. Generally, chip end-face coating employs a single method: electron beam evaporation, with its high speed, is suitable for mass production; reactive magnetron sputtering, while slower, produces denser films with lower stress, making it suitable for high-precision chip end-face coating with stringent film quality requirements.

[0003] Therefore, overcoming the shortcomings of the existing technology is an urgent problem to be solved in this technical field. Summary of the Invention

[0004] The technical problem to be solved by this invention is that neither electron beam evaporation coating nor reactive magnetron sputtering coating can simultaneously meet the requirements of good film quality and low cost.

[0005] The present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides a method for hybrid evaporation and magnetron coating, comprising:

[0007] A first underlayer 20 is deposited on the substrate 11 by reactive magnetron sputtering, and a second underlayer 21 is deposited on the first underlayer 20 by electron beam evaporation.

[0008] A functional layer 3 is deposited on the second substrate 21 by electron beam evaporation.

[0009] A first protective layer 40 is deposited on the functional layer 3 by electron beam evaporation, and a second protective layer 41 is deposited on the first protective layer 40 by reactive magnetron sputtering.

[0010] Preferably, when the optical film formed on the substrate 11 is a high-reflection optical film, the first substrate 20 and the second substrate 21 are silicon oxide films; the functional layer 3 is a film layer composed of alternating layers of titanium oxide film and silicon oxide film, wherein the last film of the functional layer 3 is a titanium oxide film; the first protective layer 40 and the second protective layer 41 are silicon oxide films.

[0011] Preferably, the total thickness of the first substrate 20 and the second substrate 21 is 212nm ± 1nm, wherein the thickness of the first substrate 20 is 30nm-50nm and the thickness of the second substrate 21 is 162nm-182nm.

[0012] Preferably, when coating the first substrate 20, the process parameters corresponding to reactive magnetron sputtering are: ion source power of 400W±10W, ion source argon flow rate of 20Sccm±2Sccm, silicon target power of 800W±10W, silicon target argon flow rate of 60Sccm±2Sccm, and silicon target oxygen flow rate of 10Sccm±2Sccm.

[0013] Preferably, in the process of cyclically depositing titanium dioxide and silicon dioxide using electron beam evaporation to form functional layer 3, the process parameters corresponding to electron beam evaporation during titanium dioxide deposition are as follows: ion source power of 400W±10W, ion source argon flow rate of 30Sccm±2Sccm, ion source oxygen flow rate of 10Sccm±2Sccm, and electron gun beam current of 350mA±2mA.

[0014] Preferably, in the process of cyclically depositing titanium dioxide and silicon dioxide using electron beam evaporation to form functional layer 3, the process parameters corresponding to electron beam evaporation during silicon dioxide deposition are as follows: ion source power of 300W±10W, ion source argon flow rate of 20Sccm±2Sccm, ion source oxygen flow rate of 10Sccm±2Sccm, and electron gun beam current of 80mA±2mA.

[0015] Preferably, the total thickness of the first protective layer 40 and the second protective layer 41 is 509.05nm ± 1nm, wherein the thickness of the first protective layer 40 is 409.5nm-439.05nm and the thickness of the second protective layer 41 is 70nm-100nm.

[0016] In a second aspect, the present invention provides an apparatus for hybrid evaporation and magnetron sputtering, applicable to the method of hybrid evaporation and magnetron sputtering described in the first aspect, comprising: an electron beam evaporation assembly 5, a reactive magnetron sputtering assembly 6, an ion source 7, and a heater 8; wherein the ion source 7 is used to provide high-energy plasma clusters and a stable discharge environment to the electron beam evaporation assembly 5 and the reactive magnetron sputtering assembly 6, and the heater 8 is used to heat the apparatus cavity;

[0017] The electron beam evaporation assembly 5 is provided with at least two crucibles 50, and the at least two crucibles 50 are respectively filled with the raw materials required for coating;

[0018] The reactive magnetron sputtering assembly 6 is provided with a target 60.

[0019] Preferably, the electron beam evaporation assembly 5 is provided with a first crystal control probe 51, a first correction plate 52, and a first coating baffle 53 from top to bottom; the first crystal control probe 51 is used to monitor the thickness of the second substrate 21, the functional layer 3, and the first protective layer 40; the first correction plate 52 is used to ensure the uniformity of the film thickness of the second substrate 21, the functional layer 3, and the first protective layer 40; and the first coating baffle 53 is used to prevent the film material from moving onto the substrate 11 during pre-melting.

[0020] The reactive magnetron sputtering assembly 6 includes, from top to bottom, a second crystal control probe 61, a second correction plate 62, and a second coating baffle 63; the second crystal control probe 61 is used to monitor the thickness of the first underlayer 20 and the second protective layer 41, the second correction plate 62 is used to ensure the uniformity of the film thickness of the first underlayer 20 and the second protective layer 41, and the second coating baffle 63 is used to prevent the film material from moving onto the substrate 11 during pre-melting.

[0021] Preferably, a first electromagnetic shield 54 is provided on the outside of the electron beam evaporation assembly 5, and the height of the first electromagnetic shield 54 is higher than the height of the film material; a second electromagnetic shield 64 is provided on the outside of the reactive magnetron sputtering assembly 6, and the height of the second electromagnetic shield 64 is higher than the height of the target material 60.

[0022] The beneficial effects of this invention are as follows: This invention combines electron beam evaporation coating and reactive magnetron sputtering coating. Reactive magnetron sputtering coating is used to form the first underlayer 20 and the outermost second protective layer 41 on the end face of the substrate 11. Reactive magnetron sputtering coating results in a dense film, which can be used as the outermost waterproof layer to reduce moisture absorption. The particles have high energy during film formation, which ensures a strong bond with the substrate 11 and prevents them from falling off. Electron beam evaporation is used to coat the functional layer 3, which improves the coating efficiency. Combining the two coating methods can obtain a better optical film while ensuring efficiency, greatly improving the yield of finished products. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments of the present invention will be briefly described below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0024] Figure 1 This is a schematic diagram of the overall process of a hybrid evaporation and magnetron coating method provided in an embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the structure of an optical film produced by a hybrid evaporation and magnetron coating method provided in an embodiment of the present invention;

[0026] Figure 3 This is a schematic diagram of the design theory curve of a high-reflectivity optical film according to an embodiment of the present invention, which uses a hybrid evaporation and magnetron coating method.

[0027] Figure 4 This is a schematic diagram of the design of a high-reflectivity optical film system according to an embodiment of the present invention, which uses a hybrid evaporation and magnetron coating method.

[0028] Figure 5a This is a schematic diagram of the target current curves corresponding to different oxygen flow rates in a method for hybrid evaporation and magnetron coating provided in an embodiment of the present invention.

[0029] Figure 5b This is a schematic diagram of the target voltage curves corresponding to different oxygen flow rates in a hybrid evaporation and magnetron coating method provided in an embodiment of the present invention.

[0030] Figure 6 This is a schematic diagram of the oxide deposition rate under different oxygen flow rates in a hybrid evaporation and magnetron coating method provided in an embodiment of the present invention;

[0031] Figure 7 This is an SPM image of an oxide deposited after introducing different oxygen flow rates, provided in an embodiment of the present invention, using a hybrid evaporation and magnetron coating method.

[0032] Figure 8 This is a schematic diagram of a 3M adhesive film stretching experiment of a hybrid evaporation and magnetron coating method provided in an embodiment of the present invention;

[0033] Figure 9 This is a schematic diagram illustrating the completion of a coating process using a hybrid evaporation and magnetron coating method provided in an embodiment of the present invention.

[0034] Figure 10This is a schematic diagram of the water vapor transmission detection curve of a high-reflectivity optical film provided by an embodiment of the present invention, which utilizes a hybrid evaporation and magnetron coating method.

[0035] Figure 11 This is a schematic diagram of thin film stress testing for a hybrid evaporation and magnetron coating method provided in an embodiment of the present invention;

[0036] Figure 12 This is a schematic diagram of the thin film warpage test of a hybrid evaporation and magnetron coating method provided in an embodiment of the present invention;

[0037] Figure 13a This is a schematic diagram of the overall structure of an evaporation and magnetron hybrid coating device provided in an embodiment of the present invention;

[0038] Figure 13b This is a detailed structural schematic diagram of an evaporation and magnetron hybrid coating device provided in an embodiment of the present invention;

[0039] Figure 14 This is a schematic diagram of a substrate frame for an evaporation and magnetron hybrid coating apparatus provided in an embodiment of the present invention;

[0040] Figure 15 This is a side view of the electron beam evaporation assembly and the reactive magnetron sputtering assembly of an evaporation and magnetron hybrid coating apparatus provided in an embodiment of the present invention;

[0041] Figure 16a This is a top view of the electromagnetic shielding cover of an evaporation and magnetron hybrid coating device provided in an embodiment of the present invention;

[0042] Figure 16b This is a side view of the electromagnetic shielding cover of an evaporation and magnetron hybrid coating device provided in an embodiment of the present invention. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0044] In the description of this invention, the terms "inner", "outer", "longitudinal", "lateral", "upper", "lower", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and do not require that this invention must be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0045] In this invention, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0046] In this invention, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a direct connection or an indirect connection through an intermediate medium.

[0047] Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0048] Example 1:

[0049] Embodiment 1 of the present invention provides a method for hybrid evaporation and magnetron coating, such as... Figure 1 and Figure 2 As shown, it includes:

[0050] In step 1, a first underlayer 20 is deposited on the substrate 11 by reactive magnetron sputtering, and a second underlayer 21 is deposited on the first underlayer 20 by electron beam evaporation.

[0051] In step 2, a functional layer 3 is deposited on the second substrate 21 by electron beam evaporation.

[0052] In step 3, a first protective layer 40 is deposited on the functional layer 3 by electron beam evaporation, and a second protective layer 41 is deposited on the first protective layer 40 by reactive magnetron sputtering.

[0053] This invention combines electron beam evaporation coating and reactive magnetron sputtering coating. Reactive magnetron sputtering coating is used to form the first underlayer 20 and the outermost second protective layer 41 on the end face of the substrate 11. The reactive magnetron sputtering coating forms a dense film, which can be used as the outermost waterproof layer to reduce moisture absorption. The particles have high energy during film formation, which ensures a strong bond with the substrate 11 and prevents them from falling off. Electron beam evaporation is used to coat the functional layer 3, which improves the coating efficiency. Combining the two coating methods can obtain a better optical film while ensuring efficiency, greatly improving the yield of finished products.

[0054] The coating method proposed in the embodiments of the present invention will be described in detail below with the example of a high-reflection optical film formed on the substrate 11. However, it is worth noting that for other types of optical films, the coating process, film material and equipment parameters are basically the same. The main difference is the number of coating layers and the thickness. For different optical films, the optimal solution needs to be calculated through experiments such as specific simulation software.

[0055] Continue reading Figure 2 When the optical film formed on the substrate 11 is a high-reflection optical film, the first substrate 20 and the second substrate 21 are silicon oxide films; the functional layer 3 is a film layer composed of alternating layers of titanium oxide film and silicon oxide film, wherein the last layer of the functional layer 3 is a titanium oxide film; the first protective layer 40 and the second protective layer 41 are silicon oxide films.

[0056] Before coagulation, the equipment cavity is cleaned and filled with the necessary coating material. The sputtering target is cleaned, and the substrate 11 is installed. After these operations, the equipment cavity is evacuated before coating, and the substrate 11 is heated. The heating temperature is 140℃-160℃, and the vacuum pressure is determined by the molecular collision probability, the mean free path of molecules, and the distance between the evaporation source and the surface of the substrate 11. After repeated experiments, the preferred solution is a heating temperature of 150℃, with the cavity vacuum reduced to 5*10... -6 The coating quality is optimal when the temperature is at the 150°C setting. 150°C effectively removes trace amounts of moisture from the cavity and increases the surface energy of the substrate 11, allowing the film to adhere better to the substrate 11.

[0057] Specifically, during electron beam evaporation coating, particles evaporated from the film material move in a straight line at a certain speed in space until they collide with other particles. Within a vacuum chamber, when the particle concentration and residual gas pressure are sufficiently low, these particles can maintain straight-line flight. Therefore, increasing the mean free path of the residual gas to reduce the probability of collisions with evaporated particles and evaporating the chamber to a high vacuum is necessary. Determining the internal pressure of the chamber is a crucial issue in the specific experimental research, and the specific research process is described below.

[0058] According to the molecular mean free path formula Where n is the number of molecules per unit volume, and σ is the molecular diameter, according to the theory of gas kinetics, the relationship between the mean free path λ of the molecules and the gas pressure p in the above equation can be denoted as: Assuming the mean free path λ of the molecules, i.e., the distance between the evaporation source and the substrate 11, is 100 cm, according to the formula, the required vacuum level is approximately 7 * 10⁻⁶. -3Pa. Since it is impossible for every molecule of the evaporated film to reach the surface of the substrate 11 without collision, it is also necessary to study the collision probability of molecules under the required vacuum conditions. According to the research conclusions of vacuum engineering, the molecular collision probability W is related to the molecular mean free path λ and the distance d between the evaporation source and the surface of the substrate 11 as follows: Let p = 7 * 10 -3 Substituting Pa into the above formula, we get W = 63%. If we take W = 10% and d = 50cm, we get p ≈ 1.4 * 10 -3 For the experimental setup in this embodiment, the distance between the evaporation source and the substrate 11 being coated is 50 cm, so p < 1.3 * 10⁻⁶. -3 Pa≈1*10 -5 Torr, after repeated experimental verification, in the optimal solution, when p = 5 * 10 -6 The coating quality is optimal when the coating is at its highest level (Tor).

[0059] A first underlayer 20 is formed by reactive magnetron sputtering, followed by a second underlayer 21 formed by electron beam evaporation. Specifically, since the particle energy of reactive magnetron sputtering is much higher than that of electron beam evaporation, the high-energy plasma clusters generated by the ion source and the sputtered high-energy particles bombard the substrate 11, effectively cleaning its surface and removing contaminants and oxide layers. This also alters the surface's chemical and physical properties, resulting in a higher-quality thin film. The film deposited by reactive magnetron sputtering exhibits better adhesion and higher uniformity to the substrate 11, ensuring a firm bond and preventing easy detachment.

[0060] Compared to reactive magnetron sputtering, electron beam evaporation has a deposition rate five times higher or more. The film in functional layer 3, relative to the first substrate 20 closest to the substrate 11 and the exposed second protective layer 41, does not require extremely high film density. Therefore, considering production efficiency and ensuring the reliability of the optical film, electron beam evaporation can be used for deposition, shortening the deposition time. Cyclic titanium dioxide and silicon dioxide deposition involves stacking one layer of titanium dioxide film followed by one layer of silicon dioxide film. In this embodiment, the outermost second protective layer 41 of the substrate 11 is set as a silicon dioxide film. Silicon dioxide films typically possess good optical properties, mechanical properties, and thermal stability. In contrast, the optical properties of titanium dioxide films are less ideal than those of silicon dioxide films in certain wavelength ranges, potentially affecting the transmission efficiency and performance of the optical chip. Furthermore, while titanium dioxide films also possess a certain mechanical strength, they are less stable than silicon dioxide films under certain extreme conditions. Regarding thermal stability, titanium dioxide films may have relatively poor thermal stability and may experience performance degradation at high temperatures.

[0061] After determining the coating sequence and method, before performing the coating operation, simulation software is used to design the required high-reflectivity optical film system, such as... Figure 3 As shown, this is the theoretical design curve for a high-reflectivity optical film. Figure 4 The figure shows the design system of a high-reflectivity optical film.

[0062] For reactive magnetron sputtering coating, the process gas flow rate is a crucial parameter, especially the flow rate of the reacting gases. Excessive flow rate can lead to target poisoning, while insufficient flow rate results in incomplete reaction and significant material absorption. Therefore, finding a suitable reactive gas flow rate is essential. The following section compares parameters under different gas flow rates to determine the optimal flow rate for reactive magnetron sputtering coating with strong ionization capabilities, thereby obtaining reactive gas flow rate parameters for a denser film structure.

[0063] In reactive magnetron sputtering, the discharge characteristics, coating rate, and surface roughness after film formation are all related to the oxygen flow rate in the equipment cavity. Therefore, the oxygen flow rate parameter of the equipment needs to simultaneously meet the requirements of having good discharge characteristics, good coating rate, and good surface roughness after oxygen is introduced.

[0064] The discharge characteristics of reactive magnetron sputtering mainly refer to the characteristics of the discharge process when the supplied reactive gas reacts with the sputtered particles during sputtering. This involves the movement of electrons under the influence of electric and magnetic fields, as well as the collisions of these electrons with gas molecules (such as argon), thereby generating plasma and initiating the sputtering process. In reactive magnetron sputtering, the discharge process is achieved by applying a voltage between the cathode target and the anode. Electrons fly towards the substrate 11 under the influence of the electric field, colliding with argon atoms along the way, ionizing them to produce Ar positive ions and new electrons. These new electrons continue to fly towards the substrate 11, while the Ar ions are accelerated towards the cathode target under the influence of the electric field, bombarding the target surface with high energy, causing the target material to sputter. The sputtered target atoms or molecules are deposited on the substrate 11 to form a thin film.

[0065] like Figure 5a The curves shown represent the target current curves corresponding to different oxygen flow rates. As the oxygen flow rate increases, the maximum current of the target material decreases from 220A to 120A, and then tends towards saturation. The discharge characteristics of the gas can be judged by the magnitude of the peak current; a higher peak current indicates a more intense gas discharge. Intense discharge processes generate a large number of secondary electrons, greatly increasing the collisions between secondary electrons and sputtered particles, thus enhancing the ionization ability of the target atoms. Under constant pressure, as the oxygen flow rate increases, the peak current of the target material gradually weakens, indicating that the ionization ability of the target atoms is decreasing. Figure 5bThe target voltage curves corresponding to different oxygen flow rates show that the peak voltage of the target increases from 560V to 590V with increasing oxygen flow rate and then tends to saturate. This is because during sputtering, the addition of oxygen forms an oxide layer on the target surface. As the oxygen flow rate increases, the reaction on the target surface becomes more and more intense, and the target voltage drops sharply after reaching the peak voltage.

[0066] Based on the above experiments, in the preferred scheme, the gas glow discharge is most intense, the atomic ionization rate is highest, the plasma resistance is lowest, and the target voltage is lowest when the oxygen flow rate is 10 Sccm. Therefore, in terms of discharge characteristics, an oxygen flow rate of 10 Sccm is the most suitable.

[0067] Regarding the coating rate, such as Figure 6 The figure shows the oxide deposition rate under different oxygen flow rates. As the oxygen flow rate increases, the deposition rate gradually decreases from 13.56 nm / min to 7.86 nm / min and tends to saturate. With the increase of oxygen flow rate, the target peak current gradually decreases, and the ion concentration also weakens accordingly.

[0068] The formula provided below is for calculating the volume fraction of oxygen in a mixture of oxygen and argon during sputtering: Where F(O2) is the volumetric flow rate of oxygen and F(Ar) is the volumetric flow rate of argon, both in Sccm. From the above formula, it can be seen that under a constant working pressure (i.e., a constant total value of F(O2) + F(Ar), as F(O2) increases, the volume fraction of oxygen continuously increases, and the partial pressure of oxygen gradually rises. This means that the value of F(Ar) decreases, and the partial pressure of Ar decreases. Since Ar has a stronger sputtering ability than oxygen, the reduction in Ar leads to a weakening of sputtering ability, resulting in a decrease in the film deposition rate. We can also see from the figure that as the oxygen flow rate increases, the target voltage gradually increases, and a slight "target poisoning" phenomenon occurs, causing a decrease in the deposition rate. Based on the above experimental results, in the preferred scheme, an oxygen flow rate of 10 Sccm is the most suitable for the deposition rate.

[0069] Regarding the surface roughness of the film, such as Figure 7 The image shown is an SPM image after oxide deposition with different oxygen flow rates, corresponding to scanning probe microscopy (SPM) images with an oxygen flow rate of 5 Sccm. Figure 7 (a) SPM images of oxygen flow rate at 10 Sccm (i.e.) Figure 7 (b) and oxygen flow rate of 15 Sccm (i.e. Figure 7(c) As shown in the figure, under these three flow rates, the film surface is uniform and dense, without island growth. The film surface is most dense when the oxygen flow rate is 10 Sccm. This is because when the oxygen flow rate is low, the ion concentration on the target surface is high, resulting in a stronger bombardment of the substrate 11 surface under the negative bias voltage, leading to higher surface roughness. As the oxygen flow rate increases, the ion density decreases, reducing the bombardment of the substrate 11 surface and lowering the surface roughness. However, with a continuous increase in flow rate, on the one hand, the bombardment of the substrate 11 surface weakens; on the other hand, due to the weakening of atomic and ionic capabilities, the mobility and diffusion migration ability of adsorbed atoms on the substrate 11 surface weakens, reducing the filling effect on defects such as pores, thus increasing the surface roughness of the film. In summary, through experimental comparison, in terms of the preferred scheme, an oxygen flow rate of 10 Sccm is the most suitable for film surface roughness.

[0070] After obtaining the oxygen flow rate most suitable for reactive magnetron sputtering coating according to the above research, the substrate 11 is coated. In this embodiment, the high-reflectivity optical film requires 7 layers.

[0071] In one embodiment, such as Figure 2 As shown, when the substrate 11 is coated with a high-reflectivity optical film, the total thickness of the first substrate 20 and the second substrate 21 is 212nm ± 1nm, wherein the thickness of the first substrate 20 is 30nm-50nm, and the thickness of the second substrate 21 is 162nm-182nm. Specifically, the total thickness of the first substrate 20 and the second substrate 21 is the optimal solution obtained through simulation software, and its value cannot be changed.

[0072] For the first substrate 20 coated using reactive magnetron sputtering, strict requirements are placed on various parameters of the ion source and the target process parameters during the coating process. Excessive power will result in significant surface roughness defects on the substrate 11, leading to poor film adhesion and easy film detachment. Conversely, insufficient power will result in unsatisfactory cleaning, poor film deposition quality, and also easy film detachment. Therefore, the process parameters for reactive magnetron sputtering on the first substrate 20 are as follows: ion source power 400W±10W, argon flow rate 20Sccm±2Sccm, silicon target power 800W±10W, argon flow rate 60Sccm±2Sccm, and oxygen flow rate 10Sccm±2Sccm. After repeated experiments and verifications, the optimal coating parameters for the first layer (20 layers) in the preferred scheme are: ion source power of 400W, argon flow rate of 20 Sccm, silicon target power of 800W, argon flow rate of 60 Sccm, and oxygen flow rate of 10 Sccm. After the first layer (20 layers) coating is completed, repeated film stretching tests were performed using 3M adhesive. Figure 8 As shown, the left side shows the first layer 20 made with the preferred process parameters, and no film peeling occurs during the 3M adhesive peeling test; the right side shows the first layer 20 made with higher or lower power, and film peeling occurs during the 3M adhesive peeling test.

[0073] In electron beam evaporation deposition, spatter is one of the most serious phenomena affecting film quality, and this phenomenon should be mitigated as much as possible before deposition. During electron beam evaporation deposition, spatter causes film spots, called "pits," to appear on the film. These spots are formed when large film particles are deposited onto the surface of the substrate 11 along with the film vapor molecules, creating dot-like protrusions on the substrate 11 surface. Sometimes these are isolated spots, but in severe cases, they can form patches of fine spots. Large particles can even damage the surface of the substrate 11. The evaporation characteristics of various film materials are different, especially the significant difference between their melting point and evaporation temperature. Materials with a melting point higher than their evaporation temperature undergo direct vaporization from solid to gas, making them sublimation materials. Materials with a melting point lower than their evaporation temperature first transform from solid to liquid and then into gas to evaporate, making them non-sublimation materials. Materials with a melting point and evaporation temperature close to their evaporation temperature undergo simultaneous melting and evaporation from solid to gas, making them semi-sublimation materials. The second layer, titanium dioxide, is a non-sublimable material, making it most prone to splashing. This is because the liquid film will boil upon further heating, causing bubbles in the boiling film to escape and increasing the likelihood of splashing. Sometimes, significant splashing can occur even during pre-melting. Moisture in the film, or moisture escaping during pre-melting or vapor deposition, can also cause splashing.

[0074] Therefore, when selecting the titanium dioxide film material, it is advisable to choose a film material with fewer impurities and a suitable particle size. Before vapor deposition, the film material should be carefully pre-melted, and the titanium dioxide must be completely melted. In the coating equipment, when coating several materials with the same electron gun, in order to prevent the film material from being mixed with the film material during crucible rotation and the film material residue falling from the baffle from causing contamination, if contamination is found in the crucible film material, it should be replaced immediately. The crucible should be kept as clean as possible, and the film material should be dehumidified and placed in a vacuum chamber to dry.

[0075] After the above preparations, in one embodiment, during the process of forming functional layer 3 by cyclically depositing titanium dioxide and silicon dioxide using electron beam evaporation, the process parameters for electron beam evaporation during titanium dioxide deposition are as follows: ion source power 400W ± 10W, argon flow rate 30 Sccm ± 2 Sccm, oxygen flow rate 10 Sccm ± 2 Sccm, and electron gun beam current 350mA ± 2mA. Through repeated experimental verification, the optimal process parameters for electron beam evaporation deposition of titanium dioxide in the preferred embodiment are: ion source power 400W, argon flow rate 30 Sccm, oxygen flow rate 10 Sccm, and electron gun beam current 350mA.

[0076] As mentioned above, compared to reactive magnetron sputtering, electron beam evaporation has a faster deposition rate. The intermediate layer (specifically including the second underlayer 21, functional layer 3, and first protective layer 40) does not require extremely high film density compared to the first and last layers closest to the substrate 11. Therefore, electron beam evaporation is still used for the intermediate silicon oxide film. In one embodiment, during the cyclic deposition of titanium dioxide and silicon oxide to form the functional layer 3 using electron beam evaporation, the process parameters for electron beam evaporation during silicon oxide deposition are: ion source power of 300W ± 10W, ion source argon flow rate of 20 Sccm ± 2 Sccm, ion source oxygen flow rate of 10 Sccm ± 2 Sccm, and electron gun beam current of 80 mA ± 2 mA. After repeated experiments and verifications, the optimal process parameters for electron beam evaporation coating of titanium dioxide in the preferred scheme are: ion source power of 300W, ion source argon flow rate of 20Sccm, ion source oxygen flow rate of 10Sccm, and electron gun beam current of 80mA.

[0077] Here, we will use functional layer 3, which includes 5 layers, as an example for explanation. Following the process parameters for titanium dioxide and silicon dioxide deposition using the electron beam evaporation cycle described above, the substrate 11 undergoes the second to sixth layer depositions. Here, the second to sixth layers refer to the first underlayer 20 and the second underlayer 21 as a single layer; the second layer deposition essentially refers to the first layer of functional layer 3. Specifically, as... Figure 9As shown, the thickness of the second titanium oxide film 30 is 142.56 nm, the thickness of the third silicon oxide film 31 is 222.66 nm, the thickness of the fourth titanium oxide film 32 is 142.6 nm, the thickness of the fifth silicon oxide film 33 is 219.58 nm, and the thickness of the sixth titanium oxide film 34 is 134.77 nm. The superposition of the film thicknesses of the second to sixth layers is an optimal solution for achieving a specific high reflectivity, determined through experimental verification. In actual processing, systematic errors in the equipment during the coating process are allowed to cause the thickness of each film layer to fluctuate by 1 nm.

[0078] After completing the second to sixth layers of coating, a protective layer is applied. The protective layer is coated using electron beam evaporation and reactive magnetron sputtering, respectively. For details, please refer to [link to relevant documentation]. Figure 9 As shown, the total thickness of the first protective layer 40 and the second protective layer 41 is 509.05 nm ± 1 nm, wherein the thickness of the first protective layer 40 is 409.5 nm - 439.05 nm, and the thickness of the second protective layer 41 is 70 nm - 100 nm. The parameters used in the deposition process of the second protective layer 41 are the same as the optimal deposition parameters for the first underlayer 20: ion source power of 400 W, argon gas flow rate of 20 Sccm, silicon target power of 800 W, argon gas flow rate of 60 Sccm, and oxygen flow rate of 10 Sccm. After repeated experimental verification, the optimal thickness of the first protective layer 40 is 409.5 nm, and the optimal thickness of the second protective layer 41 is 100 nm, which meets the optical and stress requirements of the substrate 11. Since the first protective layer 40 is relatively thick, it is necessary to take advantage of the fast electron beam evaporation rate. The second protective layer 41 is coated with reactive magnetron coating, which forms a film with high density, effectively improving the moisture absorption phenomenon. The film stress is low, belonging to compressive stress, which greatly improves the adhesion of the overall film and makes it less prone to cracking during subsequent annealing processes.

[0079] like Figure 10 As shown, this is the water vapor transmission detection curve of the high-reflectivity optical film after coating in this embodiment. The coated film is placed in a water vapor transmission device for testing. As time goes on, the water vapor transmission rate approaches zero, indicating that the film has a good waterproof effect.

[0080] like Figure 11 As shown, this is a stress test of the deposited thin film in this embodiment. The entire thin film exhibits compressive stress (the stress is negative), indicating a tighter film-layer bond, which can effectively improve the problem of film cracking after annealing.

[0081] like Figure 12 As shown, the warpage test of the deposited film in this embodiment can be seen more intuitively. The film shows an inward concavity and uniform warpage.

[0082] Example 2:

[0083] This embodiment is a method for evaporation and magnetron hybrid coating provided in Embodiment 1, and provides an apparatus for implementing the evaporation and magnetron hybrid coating method described in Embodiment 1.

[0084] This embodiment provides an apparatus for hybrid evaporation and magnetron coating, such as... Figure 13a and Figure 13b As shown, the system includes: an electron beam evaporation assembly 5, a reactive magnetron sputtering assembly 6, an ion source 7, and a heater 8; the ion source 7 provides high-energy plasma clusters and a stable discharge environment to the electron beam evaporation assembly 5 and the reactive magnetron sputtering assembly 6, and the heater 8 heats the equipment cavity; the electron beam evaporation assembly 5 is provided with at least two crucibles 50, each containing raw materials required for coating; the reactive magnetron sputtering assembly 6 is provided with a target material 60. Figure 13a and Figure 13b It can be observed that two reactive magnetron sputtering components 6 are provided. In the embodiment of the present invention, only one reactive magnetron sputtering component 6 is used. Therefore, the other component with the same structure shown in the figure will not be described in detail.

[0085] In equipment that combines evaporation and magnetron sputtering for coating, such as Figure 14 As shown, a substrate frame 9 is provided above the equipment, and a substrate 11 is disposed on the substrate frame 9. The substrate 11 is located directly above the coating center of the electron beam evaporation assembly 5 and the reactive magnetron sputtering assembly 6.

[0086] Specifically, such as Figure 13b and Figure 15 As shown, the electron beam evaporation assembly 5 includes an electron gun emitting assembly 55, a crucible support plate 56, and a crucible base 57. The crucible support plate 56 is disposed on the crucible base 57, and at least two crucibles 50 are disposed on the crucible support plate 56. The electron gun emitting assembly 55 is disposed on the side of the crucible base 57. The main function of the electron gun emitting assembly 55 is to generate, focus, and accelerate thermionic electrons, providing the necessary energy and conditions for the subsequent evaporation process. In the electron gun emitting assembly 55, the accelerating electrode in the electron gun applies an electric field to the electron beam, enabling the electrons to obtain higher energy and speed. When the electron beam enters the crucible 50, its kinetic energy can be more effectively converted into thermal energy, instantly heating the material to be evaporated to an extremely high temperature.

[0087] Continue reading Figure 13b and Figure 15As shown, the reactive magnetron sputtering assembly 6 includes a magnetron sputtering target gun column 65 and an anode cover 66. The magnetron sputtering target gun column 65 is disposed below the anode cover 66, and the target material 60 is placed inside the anode cover 66, which is grounded. The magnetron sputtering target gun column 65 serves as a support structure for the target material 60, ensuring that the target material 60 maintains a stable position and state during sputtering. Furthermore, the magnetron sputtering target gun column 65 has a built-in magnetic field, which controls the particle movement of the metal target material. The magnetic field causes the metal atoms on the surface of the target material 60 to form a particle stream, i.e., a sputtering beam, and focuses and accelerates these sputtered particles, thereby improving sputtering efficiency.

[0088] In this embodiment of the invention, continuing the example from Embodiment 1, the optical film formed on the substrate 11 is described as a high-reflectivity optical film. The electron beam evaporation assembly 5 is provided with at least two crucibles 50, each containing silicon oxide and titanium oxide respectively. Specifically, in practical applications, the electron beam evaporation assembly 5 can have five crucibles 50. Taking this embodiment as an example, two crucibles 50 are used to hold silicon oxide and titanium oxide respectively, with the remaining three crucibles 50 serving as spares. The target material 60 is a silicon target.

[0089] In addition to the above structures, such as Figure 15 As shown, the electron beam evaporation assembly 5 is provided with a first crystal control probe 51, a first correction plate 52 and a first coating baffle 53 from top to bottom. The reactive magnetron sputtering assembly 6 includes a second crystal control probe 61, a second correction plate 62 and a second coating baffle 63 from top to bottom.

[0090] The first crystal control probe 51 is used to monitor the thickness of the second substrate 21, the functional layer 3, and the first protective layer 40. The first correction plate 52 is used to ensure the uniformity of the film thickness of the second substrate 21, the functional layer 3, and the first protective layer 40. Specifically, in the electron beam evaporation coating process, the main function of the first correction plate 52 is to adjust the spatial distribution of the material generated by electron beam evaporation. The first correction plate 52 reduces the thickness of the substrate glass film layer in that area by blocking and dispersing the evaporated material emitted by the evaporation source, mainly blocking the evaporated material directly above the evaporation source, so that the evaporated material can form a more uniform distribution when it reaches the substrate. In this way, the optical film on the substrate can obtain a more uniform thickness. The design of the correction plate usually requires precise calculation and optimization based on the characteristics of the evaporation source, the size and shape of the substrate, and the required film thickness distribution.

[0091] The first coating baffle 53 is used to prevent the film material from moving onto the substrate 11 during the pre-melting process. Specifically, before the formal coating, the electron beam evaporation assembly will pre-melt the film material. During the pre-melting process, the film material may sputter. Therefore, before the electron beam evaporation assembly 5 coats the film, the first coating baffle 53 blocks the substrate 11 to prevent the film material from sputtering onto the substrate 11 during the pre-melting process.

[0092] The second crystal control probe 61 is used to monitor the thickness of the first substrate 20 and the second protective layer 41, and the second correction plate 62 is used to ensure the uniformity of the film thickness of the first substrate 20 and the second protective layer 41. Specifically, in reactive magnetron sputtering, the sputtered material particles are deflected under the action of a magnetic field. The second correction plate 62 can further adjust the deposition position of these particles on the substrate to achieve a more uniform distribution. The design of the correction plate needs to take into account factors such as magnetic field distribution, size and shape of sputtering source and substrate characteristics. By adjusting the shape, size and position of the correction plate, effective control of sputtered material distribution can be achieved, thereby improving the uniformity of optical film.

[0093] The second coating baffle 63 is used to prevent the film material from moving onto the substrate 11 during pre-melting. Pre-sputtering is an important step in the reactive magnetron sputtering process. After the working gas is filled into the vacuum chamber of the equipment, the ion source 7 is ignited by applying voltage. Instead of directly sputtering onto the substrate 11, the second coating baffle 63 blocks the substrate 11 for pre-sputtering. Its main purpose is to fully remove oxides and other impurities from the target surface to ensure the purity of the target material during sputtering, thereby improving the quality of the film.

[0094] The biggest problem in the coating process of mixed reactive magnetron sputtering and electron beam evaporation coating is the electromagnetic interference between the two systems. This interference mainly occurs during the intervals between the alternating coating processes of the two systems. This interference can cause the ion source 7 to stop midway through ignition, disrupting the balance of the coating system. To solve this problem, an electromagnetic shielding system is introduced for the equipment. Figure 15 , Figure 16a and Figure 16bAs shown, a first electromagnetic shielding cover 54 is provided on the outside of the electron beam evaporation assembly 5, and the height of the first electromagnetic shielding cover 54 is higher than the height of the film material; a second electromagnetic shielding cover 64 is provided on the outside of the reactive magnetron sputtering assembly 6, and the height of the second electromagnetic shielding cover 64 is higher than the height of the target material 60. Without the first electromagnetic shielding cover 54 and the second electromagnetic shielding cover 64, electron conduction is slower, which will affect the normal ignition of the ion source 7. The so-called ignition of the ion source 7 refers to the process in which, during the operation of the ion source 7, after ions bombard the surface of the substrate 11, the ions release electrons to the surface of the substrate 11, forming an electron cloud. Subsequently, the electron cloud forms plasma under the action of an external electric field, thereby completing the gas discharge process. When the coating begins, the first electromagnetic shielding cover 54 and the second electromagnetic shielding cover 64 are placed on the outside of the coating system. The shielding covers absorb excess electrons and conduct them to the ground, maintaining the normal operation of the coating process. Figure 16a and Figure 16b The first electromagnetic shield 54 and the second electromagnetic shield 64 shown have the same structure and shape. The difference is that their dimensions differ due to the different dimensions of the electron beam evaporation assembly 5 and the reactive magnetron sputtering assembly 6, which will not be elaborated here.

[0095] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for hybrid evaporation and magnetron deposition, characterized in that, include: A first underlayer (20) is deposited on a substrate (11) by reactive magnetron sputtering, and a second underlayer (21) is deposited on the first underlayer (20) by electron beam evaporation. A functional layer (3) is deposited on the second substrate (21) by electron beam evaporation; A first protective layer (40) is deposited on the functional layer (3) by electron beam evaporation, and a second protective layer (41) is deposited on the first protective layer (40) by reactive magnetron sputtering.

2. The method for hybrid evaporation and magnetron coating according to claim 1, characterized in that, When the optical film formed on the substrate (11) is a high-reflection optical film, the first substrate layer (20) and the second substrate layer (21) are silicon oxide films; the functional layer (3) is a film layer composed of alternating layers of titanium oxide film and silicon oxide film, wherein the last layer of the functional layer (3) is a titanium oxide film; the first protective layer (40) and the second protective layer (41) are silicon oxide films.

3. The method for hybrid evaporation and magnetron coating according to claim 2, characterized in that, The total thickness of the first substrate (20) and the second substrate (21) is 212nm ± 1nm, wherein the thickness of the first substrate (20) is 30nm-50nm and the thickness of the second substrate (21) is 162nm-182nm.

4. The method for hybrid evaporation and magnetron coating according to claim 3, characterized in that, When coating the first substrate (20), the process parameters corresponding to reactive magnetron sputtering are: ion source power of 400W±10W, ion source argon flow rate of 20Sccm±2Sccm, silicon target power of 800W±10W, silicon target argon flow rate of 60Sccm±2Sccm, and silicon target oxygen flow rate of 10Sccm±2Sccm.

5. The method for hybrid evaporation and magnetron coating according to claim 3, characterized in that, In the process of forming a functional layer (3) by cyclically performing titanium dioxide and silicon dioxide coatings using electron beam evaporation, the process parameters corresponding to electron beam evaporation during titanium dioxide coating are as follows: ion source power is 400W±10W, ion source argon flow rate is 30Sccm±2Sccm, ion source oxygen flow rate is 10Sccm±2Sccm, and electron gun beam current is 350mA±2mA.

6. The method for hybrid evaporation and magnetron coating according to claim 5, characterized in that, In the process of forming a functional layer (3) by cyclically performing titanium dioxide and silicon dioxide coatings using electron beam evaporation, the process parameters corresponding to electron beam evaporation during silicon dioxide coating are as follows: ion source power is 300W±10W, ion source argon flow rate is 20Sccm±2Sccm, ion source oxygen flow rate is 10Sccm±2Sccm, and electron gun beam current is 80mA±2mA.

7. The method for hybrid evaporation and magnetron coating according to claim 1, characterized in that, The total thickness of the first protective layer (40) and the second protective layer (41) is 509.05nm ± 1nm, wherein the thickness of the first protective layer (40) is 409.5nm-439.05nm and the thickness of the second protective layer (41) is 70nm-100nm.

8. An apparatus for hybrid evaporation and magnetron sputtering coating, applicable to the hybrid evaporation and magnetron sputtering coating method according to any one of claims 1-7, characterized in that, include: Electron beam evaporation assembly (5), reactive magnetron sputtering assembly (6), ion source (7), and heater (8); the ion source (7) is used to provide high-energy plasma clusters and a stable discharge environment to the electron beam evaporation assembly (5) and the reactive magnetron sputtering assembly (6), and the heater (8) is used to heat the equipment cavity; The electron beam evaporation assembly (5) is provided with at least two crucibles (50), and the at least two crucibles (50) are respectively filled with the raw materials required for coating; The reactive magnetron sputtering assembly (6) is provided with a target (60).

9. The apparatus for hybrid evaporation and magnetron coating according to claim 8, characterized in that, The electron beam evaporation assembly (5) is provided with a first crystal control probe (51), a first correction plate (52), and a first coating baffle (53) from top to bottom. The first crystal control probe (51) is used to monitor the thickness of the second substrate (21), the functional layer (3), and the first protective layer (40). The first correction plate (52) is used to ensure the uniformity of the film thickness of the second substrate (21), the functional layer (3), and the first protective layer (40). The first coating baffle (53) is used to prevent the film material from moving onto the substrate (11) during the pre-melting process. The reactive magnetron sputtering assembly (6) includes, from top to bottom, a second crystal control probe (61), a second correction plate (62), and a second coating baffle (63); the second crystal control probe (61) is used to monitor the thickness of the first underlayer (20) and the second protective layer (41); the second correction plate (62) is used to ensure the uniformity of the film thickness of the first underlayer (20) and the second protective layer (41); and the second coating baffle (63) is used to prevent the film material from moving onto the substrate (11) during pre-melting.

10. The apparatus for hybrid evaporation and magnetron coating according to claim 8, characterized in that, The electron beam evaporation assembly (5) is provided with a first electromagnetic shield (54) on its outer side, and the height of the first electromagnetic shield (54) is higher than the height of the film material; the reactive magnetron sputtering assembly (6) is provided with a second electromagnetic shield (64) on its outer side, and the height of the second electromagnetic shield (64) is higher than the height of the target material (60).

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