Atomic layer deposition (ALD) type optical thin film coating apparatus

Abstract

The present invention relates to a thin film coating apparatus for coating, by an atomic layer deposition (ALD) method, an optical thin film on a plurality of substrates to be subjected to deposition. The optical thin film coating apparatus according to the present invention coats, by an atomic layer deposition (ALD) method, an optical thin film on a plurality of substrates to be subjected to deposition, and comprises: a cylindrical rotating body configured to support the substrates and to rotate around a central axis that is an axis horizontal to the ground surface; a process chamber which seals a space in which the rotating body and the substrates rotate, and provides thereinside a processing space in which a deposition gas is sprayed; a plurality of gas spray portions which are connected to the process chamber and are installed on sides thereof facing the substrates, and spray different gases to the processing space; and an exhaust unit which is connected to the process chamber and discharges the remaining gas from the processing space.

Description

Optical thin film coating device using atomic layer deposition (ALD) method

[0001] The present invention relates to a thin film coating device, and more particularly, to a thin film coating device that coats an optical thin film on a plurality of deposition target substrates using an atomic layer deposition (ALD) method.

[0002] Optical thin film coatings include anti-reflection coatings, optical filter coatings, color coatings, and protective coatings.

[0003] A typical anti-reflection coating is implemented with a multilayer structure of repeating thin films with high and low refractive indices, and it utilizes the destructive interference phenomenon between the reflected light reflected at the thin film interface and the transmitted light passing through the thin film thickness region. As the number of repetitions of the multilayer structure increases, the reflectance of the thin film shows a characteristic that it is lowered, and in order to minimize the reflectance, each thin film is formed with a different thickness. For example, in the case of camera lenses, a reflectance of 1.0% or less is usually required, and such anti-reflection coating is applied to both the front and back of the 5-6 lenses included in the smartphone camera system. In this case, the coating thin film is a combination of SiO2 (refractive index 1.46) and TiO2 (refractive index 2.40) to lower the reflectance in the visible light wavelength band.

[0004] PVD (Physical Vapor Deposition) devices are representative devices for performing these optical thin film coatings. Specifically, E-Beam PVD and Sputter PVD devices are widely used. Figure 1 (a) schematically illustrates an E-Beam PVD device, and Figure 1 (b) schematically illustrates a Sputter PVD device.

[0005] E-Beam PVD prepares a source (11) such as SiO2 or TiO2 in a solid state in the form of powder or granules, and generates vapor through strong electron beam heating. The generated vapor reaches the surface of the coating target and forms a film. Due to the nature of the E-Beam PVD method, the coating film is characterized by being soft, and to compensate for this, a device that implements a film with high hardness characteristics by irradiating the film formation process with an ion beam is being developed. The productivity of E-Beam PVD is determined by how many substrates can be processed in a single batch. Specifically, productivity is being improved by loading a large number of substrates onto a dome-shaped frame (12) located on the upper part of the device, but this has clear limitations depending on the structure of the substrate and the device.

[0006] Sputter PVD is a method in which a solid-state metal material such as Si, Al, Ti, Nb, and an insulator material such as SiO2 and Al2O3 is formed as a target (13), and the target is subjected to ions generated from plasma to collide with the target so that the generated target atoms are deposited on the surface of the coating object. Sputter PVD uses a method in which ions generated from plasma in front of the target physically collide to detach the target material and deposit it on the surface of the coating object. The sputter PVD method has the advantage of being able to obtain a film with higher hardness than the E-beam PVD method. Due to the characteristics of the device, the productivity of sputter PVD increases in proportion to the size of the target, but there is a clear limit to increasing the size of the target and device because the drum (14) has a rotating structure.

[0007] In addition, in the case of the PVD method of Fig. 1, which is mainly used for optical thin film coating, since the deposition is performed with strong straightness, a relatively uniform deposition can be formed on a flat substrate surface, but there is a disadvantage in that the deposition uniformity or conformality rapidly deteriorates on a curved substrate surface.

[0008] Recently, with the continuous improvement of smartphone camera lens systems, the curvature of microlenses has increased, leading to situations where conventional PVD deposition methods cannot meet the film quality standards. Furthermore, the optical coating industry encompasses a wide range of coatings for various products, including interior components like automotive dashboards and headlight lenses. Therefore, there is a pressing need for new optical deposition equipment capable of satisfying deposition uniformity and coverage even on non-standardized deposition targets.

[0009] The present invention proposes an ALD device capable of forming a micrometer-level deposition layer in a general-purpose coating field, including optical coating, rather than an atomic layer deposition (ALD) device that performs nanometer-level fine deposition on a standardized flat substrate used in the semiconductor or display fields.

[0010] The present invention proposes an optical thin film coating device capable of performing uniform deposition on a substrate having a three-dimensional or curved shape or a substrate having a high aspect ratio.

[0011] The present invention proposes an optical thin film coating device capable of increasing the productivity and yield of optical thin films by applying a structure that overcomes the limitation of low deposition speed of existing ALD devices.

[0012] In order to achieve the above object, the optical thin film coating device of the present invention is a thin film coating device for coating an optical thin film on a plurality of deposition target substrates by an atomic layer deposition (ALD) method, the thin film coating device comprising: a cylindrical rotating body configured to support the substrates and rotating about an axis horizontal to the ground as a central axis; a process chamber that seals a space in which the rotating body and the substrates rotate and provides a processing space in which a deposition gas is injected therein; a plurality of gas injection units connected to the process chamber and installed on a side facing the substrate, the gas injection units injecting different gases into the processing space; and an exhaust unit connected to the process chamber and exhausting residual gas from the processing space.

[0013] In addition, the optical thin film coating device of the present invention may further include a fixing part coupled to the rotating body and providing a surface on which the substrate is mounted.

[0014] In addition, the optical thin film coating device of the present invention may include a cylindrical rotating body having a radius R, and a process chamber having a first cylindrical chamber wall spaced apart from the rotating body in a direction opposite to the central axis at a predetermined distance and having a radius larger than the radius R, and a second cylindrical chamber wall spaced apart from the rotating body in a direction of the central axis at a predetermined distance and having a radius smaller than the radius R.

[0015] In addition, in the optical thin film coating device of the present invention, the gas injection unit is arranged on the side of the first chamber wall, and can inject gas into the processing space from the side of the first chamber wall.

[0016] In addition, in the optical thin film coating device of the present invention, the gas injection unit is arranged on the second chamber wall side, and can inject gas into the processing space from the second chamber wall side.

[0017] In addition, the optical thin film coating device of the present invention may include a precursor gas injection unit that injects a precursor gas into the processing space, a reaction gas injection unit that injects a reaction gas that reacts with the precursor gas, and an inert gas injection unit that injects an inert gas different from the precursor gas and the reaction gas.

[0018] In addition, in the optical thin film coating device of the present invention, the processing space is divided into a precursor section, which is a space where the precursor gas is sprayed, a reaction section, which is a space where the reaction gas is sprayed, and an inert section, which is a space where the inert gas is sprayed, by a partition wall protruding from the first chamber wall or the second chamber wall, and the protruding partition wall can provide a space where the rotating body and the substrate move through an open gap.

[0019] In addition, the optical thin film coating device of the present invention may be formed such that the first precursor section, the first inactive section, the first reaction section, and the second inactive section constitute one unit processing space, and the process chamber includes a plurality of unit processing spaces.

[0020] In addition, the optical thin film coating device of the present invention may include a plasma generating device in the reaction gas injection unit.

[0021] In addition, the optical thin film coating device of the present invention, the process chamber includes a third chamber wall connecting the first chamber wall and the second chamber wall at one side of the first chamber wall and the second chamber wall, and a fourth chamber wall connecting the first chamber wall and the second chamber wall at the other side of the first chamber wall and the second chamber wall, and the third chamber wall and the fourth chamber wall may be donut-shaped.

[0022] In addition, in the optical thin film coating device of the present invention, the exhaust section is arranged on the second chamber wall side, and can exhaust gas from the processing space toward the second chamber wall side.

[0023] In addition, in the optical thin film coating device of the present invention, the exhaust section is arranged on the side of the first chamber wall, and can exhaust gas from the processing space toward the side of the first chamber wall.

[0024] In addition, the optical thin film coating device of the present invention further includes a load lock chamber that accommodates the substrate and is connected to the process chamber; a valve that controls the opening and closing state of each chamber between the load lock chamber and the process chamber; and a transfer unit that transfers the substrate from the load lock chamber to the process chamber.

[0025] In addition, the optical thin film coating device of the present invention may further include a heater disposed on the first chamber wall or the second chamber wall to heat the processing space.

[0026] The optical thin film coating device of the present invention overcomes the limitation of low productivity of existing atomic layer deposition devices in the semiconductor industry in introducing atomic layer deposition technology to the optical thin film coating industry, and presents a device capable of performing deposition on a non-standard substrate having a three-dimensional or curved shape.

[0027] The optical thin film coating device of the present invention has a structure that combines a spatial type method capable of improving the deposition speed in an atomic layer deposition method and a batch type method capable of increasing the unit processing amount, thereby maximizing the production rate of thin film coating.

[0028] The optical thin film coating device of the present invention can improve the productivity of optical thin film coatings by shortening the cycle time of atomic layer deposition. This enables the formation of multilayer thin films with cumulative thicknesses ranging from several hundred nanometers to several micrometers in the optical coating field to achieve deposition rates that are feasible for mass production.

[0029] The optical thin film coating device of the present invention has a structure capable of minimizing the volume of a process chamber in which a vacuum is formed. This minimizes the gap between the process chambers housing the substrate, thereby significantly reducing the consumption of deposition gases required for the process and shortening the process time.

[0030] In addition, the optical thin film coating device of the present invention has the advantage of being able to minimize the space where incomplete reactions occur by reducing unnecessary vacuum areas inside the process chamber, and preventing the generation of particles and foreign substances due to incomplete reactions in advance.

[0031] The optical thin film coating device of the present invention is designed to rotate around an axis parallel to the ground as its central axis, so that when expansion of the device is required, the processing space can be expanded in the longitudinal direction of the central axis. This enables expansion of the thin film coating device of the present invention without being restricted by the fact that the space in which the device is installed generally has a vertical height limit.

[0032] The optical thin film coating device of the present invention can perform atomic layer deposition in a low-temperature process including a plasma unit, thereby performing deposition without causing deformation to a plastic substrate on which an optical thin film is formed.

[0033] Figure 1 schematically illustrates an E-Beam PVD device and a Sputter PVD device, which are devices for performing conventional optical thin film coating.

[0034] FIG. 2 is a perspective view schematically illustrating an optical thin film coating device using an atomic layer deposition method according to one embodiment of the present invention.

[0035] FIG. 3 is a side view schematically illustrating an optical thin film coating device according to one embodiment of the present invention.

[0036] Fig. 4 is a cross-sectional view taken along line AA in Fig. 2.

[0037] FIG. 5 is a partial perspective view illustrating a deposition target substrate mounted on an optical thin film coating device according to one embodiment of the present invention.

[0038] FIG. 6 is a cross-sectional view schematically illustrating an optical thin film coating device according to another embodiment of the present invention.

[0039] Figure 7 is a conceptual diagram illustrating the processing space of the optical thin film coating device of the present invention.

[0040] FIG. 8 is a side view illustrating an optical thin film coating device according to another embodiment of the present invention, to explain the expandability of the device of the present invention.

[0041] FIG. 9 is a partial perspective view illustrating a deposition target substrate mounted on an optical thin film coating device according to another embodiment of the present invention.

[0042] The advantages and features of the present invention, and the methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms. These embodiments are provided solely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined solely by the scope of the claims.

[0043] Although terms like "first" and "second" are used to describe various components, these components are not limited by these terms. These terms are used merely to distinguish one component from another. Therefore, it should be understood that a "first" component referred to below may also be a "second" component within the technical scope of the present invention.

[0044] In the examples below, terms such as “include” or “have” mean that a feature or component described in the specification is present, and do not preclude the possibility that one or more other features or components may be added.

[0045] For convenience of explanation, the sizes of components in the drawings may be exaggerated or reduced. For example, the sizes and shapes of each component shown in the drawings are arbitrarily shown for convenience of explanation, and thus the present invention is not necessarily limited to what is shown.

[0046] Identical reference numerals throughout the specification refer to identical components.

[0047] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening.

[0048] When an element or layer is referred to as being "on" or "on" another element or layer, this includes not only directly on the other element or layer, but also whether or not there are other intervening elements or layers. Conversely, when an element is referred to as being "directly on" or "directly on" the other element or layer, this means that there are no intervening elements or layers.

[0049] Spatially relative terms such as "below," "beneath," "lower," "above," and "upper" may be used to readily describe the relationship between one component or another as depicted in the drawings. Spatially relative terms should be understood to include different directions of use or operation of the element in addition to the directions depicted in the drawings.

[0050] The individual features of the various embodiments of the present invention can be partially or wholly combined or combined with each other, and as can be fully understood by those skilled in the art, various technical connections and operations are possible, and each embodiment can be implemented independently of each other or can be implemented together in a related relationship.

[0051] Hereinafter, with reference to the attached drawings, the optical thin film coating device (100) of the present invention using the atomic layer deposition (ALD) method will be described in detail.

[0052] First, in explaining the present invention, the optical thin film coating includes an anti-reflection coating, an optical filter coating, a color coating, a protective coating, etc. The objects (i.e., substrate (P)) to which the thin film coating is applied using the device of the present invention are wide-ranging, such as eyeglass lenses, smartphone camera lenses and accessories, display cover glasses, military infrared lens systems, automobile headlight lenses and reflectors, automobile dashboard covers, etc. It goes without saying that the optical thin film coating device of the present invention can be widely applied to objects on which a thin film is formed for efficient and selective transmission of light.

[0053] The optical thin film coating device (100) of the present invention introduces atomic layer deposition (ALD) technology to the optical thin film coating industry. The optical thin film coating device (100) of the present invention is a device that coats an optical thin film on a plurality of deposition target substrates (P) by the atomic layer deposition (ALD) method. The optical thin film coating device (100) of the present invention provides a device that can perform deposition on a non-standard substrate having a three-dimensional or curved shape. The optical thin film coating device (100) of the present invention has a structure that combines a spatial type method that can improve the deposition speed in the atomic layer deposition method and a batch type method that can increase the unit throughput, thereby maximizing the production rate of the thin film coating.

[0054] Hereinafter, an optical thin film coating device (100) according to one embodiment of the present invention will be described with reference to FIGS. 2 to 4.

[0055] FIG. 2 is a perspective view schematically illustrating an optical thin film coating device (100) according to one embodiment of the present invention, FIG. 3 is a side view schematically illustrating an optical thin film coating device (100) according to one embodiment of the present invention, and FIG. 4 is a cross-sectional view taken along line AA in FIG. 2.

[0056] Referring to FIGS. 2 to 4, the optical thin film coating device (100) of the present invention includes a rotating body (110), a fixed part (120), a process chamber (130), a gas injection part (140), an exhaust part (150), a load lock chamber (160), and a heater (170).

[0057] The optical thin film coating device (100) of the present invention performs deposition on the substrate (P) by rotating the substrate (P) about an axis horizontal to the ground as the central axis. The optical thin film coating device (100) of the present invention includes a cylindrical rotating body (110) that rotates about an axis horizontal to the ground as the central axis. The rotating body (110) is a cylindrical rotating body having a radius R and is configured to support a plurality of substrates (P).

[0058] In order to provide a surface on which a plurality of substrates (P) are mounted, the optical thin film coating device (100) of the present invention includes a fixing member (120) coupled to a rotating body (110). The fixing member (120) is coupled to the rotating body (110) and provides a surface on which a plurality of deposition target substrates (P) are mounted. The fixing member (120) serves as a basic unit on which a plurality of substrates are mounted. The fixing member (120) serves as a basic unit of transport that moves a plurality of substrates from a load lock chamber (120) described below. This fixing member (120) may be, for example, a jig plate.

[0059] The rotating body (110) may be a frame structure that forms a cylindrical frame and provides a position where the fixing member (120) is fixed. The fixing member (120) may be a plate that forms the cylindrical surface of the rotating body (110). The cross-section perpendicular to the central axis of the rotating body (110) and the fixing member (120) is most ideally circular, but may also be polygonal depending on the unit shape of the jig plate to be actually mounted. The fixing member (120) may vary depending on the shape of the substrate to be mounted, and of course, may be formed in various shapes and structures in order to optimize the process quality. In describing the optical thin film coating device (100) of the present invention, the fixing member (120) is exemplified as a jig plate, but the scope of the present invention is not limited thereto.

[0060] The optical thin film coating device (100) of the present invention includes a donut-shaped process chamber (130) surrounding a rotating body (110) and a fixed part (120).

[0061] The process chamber (130) seals the space in which the rotor (110) and the substrate (P) rotate, and provides a processing space (S) into which a deposition gas is sprayed. The process chamber (130) is an area where a vacuum is formed, and the optical thin film coating device (100) of the present invention can minimize the area where a vacuum is formed by forming the process chamber (130) in a donut shape.

[0062] Accordingly, by minimizing the gap of the process chamber (130) that accommodates the substrate (P), the consumption of deposition gas required for the process can be significantly reduced, and the process time can also be shortened. In addition, the optical thin film coating device (100) of the present invention has the advantage of being able to minimize the space where incomplete reactions occur by reducing unnecessary vacuum areas inside the process chamber (130), and preventing the generation of particles and foreign substances due to incomplete reactions in advance.

[0063] The process chamber (130) includes a cylindrical first chamber wall (131), a cylindrical second chamber wall (132), a donut-shaped third chamber wall (133), and a donut-shaped fourth chamber wall (134).

[0064] The first chamber wall (131) is arranged at a predetermined distance from the rotating body (110) in the opposite direction of the central axis and has a radius greater than the radius R. The second chamber wall (132) is arranged at a predetermined distance from the rotating body (110) in the direction of the central axis and has a radius smaller than the radius R. The third chamber wall (133) connects the first chamber wall (131) and the second chamber wall (132) at one side of the first chamber wall (131) and the second chamber wall (132). The fourth chamber wall (134) connects the first chamber wall (131) and the second chamber wall (132) at the other side of the first chamber wall (131) and the second chamber wall (132). The third chamber wall (133) and the fourth chamber wall (134) have a donut shape.

[0065] The first chamber wall (131), the second chamber wall (132), the third chamber wall (133), and the fourth chamber wall (134) seal the processing space, and a vacuum is formed in the space sealed by each chamber wall, and various gases for deposition can be sprayed.

[0066] An optical thin film coating device (100) according to one embodiment of the present invention is connected to a process chamber (130) and installed on a side facing a substrate (P), and includes a plurality of gas injection units (140) that inject different gases into a processing space.

[0067] An optical thin film coating device (100) according to one embodiment of the present invention is structured such that deposition is performed on a substrate (P) through a deposition gas injected from the first chamber wall (131) side. A fixing member (120) and a plurality of substrates (P) mounted thereon are arranged in a direction facing the first chamber wall (131). A plurality of gas injection members (140) are arranged on the first chamber wall (131) side to inject various gases into a processing space (S) in a direction following the arc of a rotating body (110) from the outside of the process chamber (130).

[0068] Referring to FIG. 4, the gas injection unit (140) includes a precursor gas injection unit (141) that injects a precursor gas, a reaction gas injection unit (142) that injects a reaction gas that reacts with the precursor gas, and an inert gas injection unit (143) that injects an inert gas. Depending on the arrangement of the gas injection unit (140), the processing space (S) within the process chamber (130) can be divided into a precursor section (S1), a reaction section (S2), and an inert section (S3). The precursor gas injection unit (141) forms the precursor section (S1), the reaction gas injection unit (142) forms the reaction section (S2), and the inert gas injection unit (143) forms the inert section (S3).

[0069] The precursor section (S1), the reaction section (S2), and the inert section (S3) can be separated by a partition wall (135) protruding from the first chamber wall (131) and / or the second chamber wall (132). At this time, the protruding partition wall (135) is not a partition wall that independently seals each processing space (S1, S2, S3), and the partition wall (135) provides a space through which the rotor (110) and the substrate (P) move through an open gap.

[0070] The precursor gas injection unit (141) injects precursor gas into the process chamber (130). Thin films used for optical coatings may include, for example, SiO2, Si3N4, TiO2, and Al2O3 in the visible light region. At this time, precursors supplying Si include BTBAS, 3DMAS, HMDSO, TSA, and DIPAS, precursors supplying Ti include TiCl4, and precursors supplying Al include, for example, TMA. In addition, as precursors for metal coatings other than optical coatings, halide, alkyl, and amine series Al, Ti, and Ag precursors may be exemplified. The precursor gas injected from the precursor gas injection unit (141) of the present invention may include the precursor gases supplying Si, Ti, and Al described above.

[0071] The reaction gas injection unit (142) injects reaction gas into the process chamber (130). At this time, the reaction gas injection unit (142) may include a plasma generation device (144).

[0072] The plasma generating device (144) may be placed on the outer surface of the process chamber (130) against the fixing member (120) and the substrate (P). The plasma generating device (144) may be placed, for example, on the first chamber wall (131) as illustrated. The plasma generating device (144) includes a space for accommodating a reaction gas therein, and may convert the reaction gas into plasma by applying energy that forms plasma to the space for accommodating the reaction gas.

[0073] The plasma generating device (144) is preferably a remote plasma type that forms plasma outside the process chamber (130) and injects the plasma into the inside of the process chamber (130). The substrate (P) to which the optical coating is applied is mostly manufactured using optical plastic (polymer). When targeting a plastic substrate, a low-temperature process of 100 degrees Celsius or less is often required. Since the types and processes of reactive gases that are activated in this low-temperature range are limited, it is preferable to generate and supply active species in a remote manner when supplying the reactive gas. However, the scope of the present invention is not limited thereto, and may of course include a direct plasma method in which the plasma and the substrate are in direct contact.

[0074] In addition, the method of generating plasma by the plasma generating device (144) includes CCP (Capacitively Coupled Plasma) Plasma, ICP (Inductively Coupled Plasma) Plasma, ECR (Electron Cyclotron Resonance) Plasma, Helicon Plasma, Hollow Cathode Plasma, etc., and can be included in the scope of the present invention if it is a form desirable for generating the desired active species.

[0075] The reaction gas that is converted into plasma from the reaction gas injection unit (142) and plasma generation device (144) contains O2.

[0076] Meanwhile, the optical thin film coating device (100) of the present invention includes an inert gas injection unit (143) between the precursor gas injection unit (141) and the reaction gas injection unit (142). The inert gas injection unit (143) injects an inert gas that is distinct from the precursor gas and the reaction gas. As the inert gas, for example, Ar gas or N2 gas can be used.

[0077] Meanwhile, the gas injection unit (140) may include a diffuser or shower head (145) configuration. The precursor gas injection unit (141), the reaction gas injection unit (142), and the inert gas injection unit (143) may include a diffuser or shower head (145) configuration in which a plurality of holes are arranged in a specific pattern.

[0078] In the case of the atomic layer deposition (ALD) method, the same precision as in the chemical vapor deposition (CVD) process utilizing a gas phase reaction is not required, but the larger the area of ​​the rotating body (110) and the substrate (P) to be deposited, the more important the uniformity in the axial direction becomes. Accordingly, the gas injection unit (140) can achieve such uniformity by including a configuration that promotes uniform gas injection, such as a shower head (145).

[0079] The optical thin film coating device (100) of the present invention can control the deposition rate of the thin film by controlling the amount of gas injected by the gas injection unit (140) and the rotational speed of the rotor (110). In addition, by controlling the type of process gas dispersed through the gas injection unit (140), layers of different components can be deposited in multiple stages. A method for performing a deposition process using the optical thin film coating device (100) of the present invention will be described later.

[0080] Referring to FIGS. 2 and 3, the optical thin film coating device (100) of the present invention includes an exhaust unit (150) connected to a process chamber (130) to exhaust residual gas. In the present embodiment, the exhaust unit (150) is disposed on the second chamber wall (132) side of the process chamber (130) and exhausts gas from the processing space (S) toward the second chamber wall (132).

[0081] The exhaust section (150) is formed by penetrating the second chamber wall (132) and includes an exhaust port (151) for exhausting gas from the processing space (S), an exhaust pipe (152) extending from the exhaust port (151) and moving the remaining gas to the exhaust pump (153), and a pump (153).

[0082] The optical thin film coating device (100) of the present invention further includes a load lock chamber (160) connected to a process chamber (130). A substrate to be loaded into the load lock chamber (160) and an unloaded substrate can be stored. The substrate can be stored in the load lock chamber (160) in a form secured to a fixing member (120) such as a jig plate. In addition, the optical thin film coating device (100) of the present invention may further include a valve (161) for controlling the opening and closing state of each chamber between the load lock chamber (160) and the process chamber (130), and a transfer unit (162) for transferring the substrate between the load lock chamber (160) and the process chamber (130).

[0083] For example, a method of loading and unloading the entire rotor (110) with the fixed part (120) and the substrate (P) already mounted along the arc of the rotor (110) requires a load lock with a very large volume. In addition, a transport device that takes into account the entire load of the rotor (110) is required. If a load lock with a large volume is required, a large valve is also required.

[0084] Accordingly, the optical thin film coating device (100) of the present invention is designed such that the central axis of the rotating body (110) is arranged horizontally to the ground, and the direction of input of the jig plate, which is the fixed part (120), is parallel to the central axis of the rotating body (110). Therefore, as illustrated in FIG. 3, the valve (161) for isolation between the load lock chamber (160) and the process chamber (130) can be reduced to the level of the cross-section of a unit jig plate. Minimizing the volume of the load lock chamber (160) means that the pumping and venting time within the load lock can be minimized, thereby shortening the input and discharge time of the tray. This is directly related to the improvement of the productivity of the vacuum-based optical thin film coating device (100).

[0085] In addition, the optical thin film coating device (100) of the present invention further includes a heater (170) connected to the process chamber (130) to heat the processing space (S).

[0086] The optical thin film coating device (100) of the present invention may include a heater (170) disposed on a first chamber wall (131) or a second chamber wall (132) to indirectly heat the fixing member (120) and the substrate (P). The heater (170) forms an appropriate temperature required for the deposition process. The heater (170) may be freely installed within a range where it does not interfere with the port line of the exhaust member (150) on the first chamber wall (131) or the second chamber wall (132) of the process chamber (130).

[0087] Meanwhile, FIG. 5 is a partial perspective view illustrating various shapes of a substrate (P) mounted on an optical thin film coating device (100) according to one embodiment of the present invention.

[0088] Figure 5 (a) illustrates a state in which substrates (P), which are smartphone camera injection lenses, are mounted on a fixed portion (120). Anti-reflection coating can be performed on the smartphone camera injection lens using an atomic layer deposition method.

[0089] Typically, micro lenses (lens area having a diameter of 5 mm or less) that constitute a smartphone lens system are manufactured by injection molding plastic (polymer) materials. These micro lenses are mounted in groups of 200 to 300 on a plastic lens coating jig (e.g., patent number: KR 10-1418411). The lens coating jig serves as a basic transport unit in a coating process line, much like a wafer in a semiconductor process. The lens coating jig, on which individual micro lenses are mounted, can be mounted and aligned on a jig plate (e.g., a flat aluminum material processed product), which is a fixing member (120). At this time, the jig plate, which is the concave member (120), can be processed to have a concave section with the same area as the lens coating jig into which the lens coating jig can be inserted.

[0090] Figure 5 (b) illustrates a state in which wafer-shaped substrates (P) having a diameter of several inches are mounted on a fixing member (120). Atomic layer deposition using the optical thin film coating device (100) of the present invention can be performed to form an oxide passivation layer on a micro LED or semiconductor laser (VCSEL) manufactured on the wafer surface. . It goes without saying that the optical thin film coating device (100) of the present invention can also be utilized to form a thin film such as Al2O3 in this process.

[0091] The microfabrication process for microLEDs and VCSELs is similar to semiconductor manufacturing, but GaAs substrates are primarily used instead of silicon. Due to the inherent difficulty of scaling up the substrate material, circular flat substrates measuring 4 inches (100 mm) or 5 inches (125 mm) in diameter are often used. One way to increase productivity while using small-diameter substrates is to process a large number of substrates at once.

[0092] In this case, the jig plate, which is the fixing member (120), may include a concave pocket into which the wafer can be inserted in the plane direction. The fixing member (120) may be applied without limitation as long as it has a configuration that allows each wafer to be fixed without being detached by centrifugal force during drum rotation.

[0093] Hereinafter, a process of coating an optical thin film on a substrate (P) using the above-described optical thin film coating device (100) using atomic layer deposition (ALD) will be described in detail.

[0094] First, the process chamber (130) where the process is performed is formed in a vacuum state. The process chamber (130) is maintained in a vacuum state, and the load lock chamber (160) isolated by the valve (161) is vented. The inside of the load lock chamber (160) may also be pumped to lower the pressure below that of the process chamber (130). The load lock chamber (160) and the process chamber (130) may be formed in a vacuum, and the valve (161) therebetween may be opened. On the other hand, a case where the load lock chamber (160) and the process chamber (130) are in an atmospheric pressure state is also included in the scope of the present invention.

[0095] At this time, the transport unit (162) inserts the fixing part (120) on which the substrate is mounted, such as a jig plate, into the process chamber (130). The number of jig plates inserted into the process chamber (130) from the load lock chamber (160) may be the same as the number of surface divisions of the rotating body (110). The fixing part (120) is clamped and fixed to the rotating body (110) of the process chamber (130). The rotating body (110) is rotated discontinuously by the number of divisions of the rotating body (110) and all of the fixing parts (120) are inserted and fixed. The valve (161) between the load lock chamber (160) and the process chamber (130) is closed.

[0096] After the jig plate, the fixing member (120), is loaded, the heater (170) is activated to begin preheating the substrate (P). Simultaneously with the start of preheating, the rotating body (110) is accelerated and rotated to the rotation speed required for the process. If the heater (170) for heating is not arranged in all sections along the arc of the process chamber (130), uneven preheating may occur if the rotating body (110) is heated while stationary, so it is preferable to preheat while rotating the rotating body (110).

[0097] After the rotor (110) reaches an appropriate rotation speed for preheating and processing, an inert gas is injected through the inert gas injection unit (143). When the flow of the inert gas becomes stable, the precursor gas and the reaction gas are supplied through the precursor gas injection unit (141) and the reaction gas injection unit (142), respectively. For example, when depositing a SiO2 layer on a substrate (P), the precursor gas may be 3DMAS, and the reaction gas may be an oxygen active species supplied through a remote plasma. At this time, the inert gas may be a general purge gas such as Ar. By maintaining this gas injection state for a certain period of time, a thin film with a desired thickness can be deposited. The deposition time may be determined according to the deposition rate verified through a sample test of the same thin film in advance.

[0098] When depositing a TiO2 layer on a SiO2 layer, i.e., performing multi-stage deposition, the flow of precursor gas and reaction gas is stopped and only the inert gas is maintained while waiting for a certain period of time. The waiting time refers to the time during which the remaining precursor gas can be sufficiently exhausted through the exhaust unit (150).

[0099] Next, in order to deposit TiO2, precursor gas and reaction gas are supplied through the precursor gas injection unit (141) and reaction gas injection unit (142), respectively. For example, TiCl4 can be injected as a precursor gas for depositing a TiO2 layer on a substrate (P), and oxygen active species supplied through remote plasma are supplied as a reaction gas.

[0100] By maintaining the above conditions for a certain period of time, SiO2 and TiO2 thin films of a desired thickness can be deposited. The above sequence can be repeated a desired number of times to perform coating until the target reflectivity characteristics are achieved. The rotation speed of the rotor (110) and the gas injection through the gas injection unit (140) can be controlled according to the target thickness of each layer and the number of repetitions.

[0101] After the multilayer thin film coating is completed, the fixing member (120) and the substrate (P) are discharged to the outside of the load lock chamber (160) in the reverse order of their introduction. If a low-temperature process is performed, the temperature of the jig plate can be sufficiently cooled to room temperature during the venting process. However, if a process of 100 degrees or higher is performed within the process chamber (130), a separate cooling means can be placed within the load lock chamber (160).

[0102] Hereinafter, an optical thin film coating device (100') according to another embodiment of the present invention will be described with reference to FIG. 6.

[0103] An optical thin film coating device (100') according to another embodiment is substantially the same as the optical thin film coating device (100) described with reference to FIGS. 2 to 5. The optical thin film coating device (100') performs deposition on a substrate (P) by rotating the substrate (P) about an axis parallel to the ground, like the optical thin film coating device (100). The optical thin film coating device (100') includes a cylindrical rotating body (110) that rotates about an axis parallel to the ground. In addition, the optical thin film coating device (100') of the present embodiment includes a fixing member (120) coupled to the rotating body (110) to provide a surface on which a plurality of substrates (P) are mounted. In addition, the optical thin film coating device (100') of the present embodiment includes a donut-shaped process chamber (130) that surrounds the rotating body (110) and the fixing member (120).

[0104] However, the difference between the optical thin film coating device (100) and the optical thin film coating device (100') is the arrangement direction of the gas injection unit (140) and the exhaust unit (150). The optical thin film coating device (100') according to the present embodiment has a direction in which the gas injected into the processing space (S) within the process chamber (130) is injected in contrast to the optical thin film coating device (100). The optical thin film coating device (100') according to the present embodiment is characterized in that the gas is injected and exhausted from the inside of the cylinder toward the outside.

[0105] The gas injection unit (140) of the optical thin film coating device (100') is arranged on the side of the second chamber wall (132) and injects gas from the side of the second chamber wall (132) to the processing space (S). In addition, the exhaust unit (150) of the optical thin film coating device (100') is arranged on the side of the first chamber wall (131) and exhausts gas from the processing space (S) to the side of the first chamber wall (131).

[0106] Except for the contrasting directions of gas injection and exhaust, each configuration and technical feature of the optical thin film coating device (100) described above are identical. Therefore, a duplicate description of the configuration of the above-described rotating body (110), fixed part (120), process chamber (130), gas injection part (140), exhaust part (150), load lock chamber (160), and heater (170) is omitted.

[0107] FIG. 7 is a conceptual diagram for further explanation of the processing space (S) of an optical thin film coating device (100, 100') according to various embodiments of the present invention.

[0108] Referring to FIG. 7, the processing space (S) within the process chamber (130) may be composed of a predetermined unit processing space including a precursor section (S1), a reaction section (S2), and an inert section (S3). Here, the unit processing space refers to a section in which deposition of one cycle time of atomic layer deposition is performed. Specifically, the unit processing space refers to a section sequentially including a first precursor section (S1), a first inert section (S3), a first reaction section (S2), and a second inert section (S3).

[0109] As illustrated in FIG. 7, the process chamber (130) may include multiple repetitions of such unit processing spaces. FIG. 7 illustrates a configuration in which the unit processing spaces are arranged in two repetitions. However, the scope of the present invention is not limited thereto, and may include a configuration in which the unit processing spaces within the process chamber (130) are repeated N times.

[0110] In addition, the cycle time for each rotation speed of the rotor (110) can be calculated in each case where the unit processing space of one cycle is repeated once, twice, three times, or four times. The more times the unit processing space of one cycle is repeated or the faster the rotation speed of the rotor (110), the higher the deposition rate per unit time tends to be.

[0111] At this time, although Fig. 7 illustrates that the precursor section (S1), the reaction section (S2), and the inert section (S3) each have the same length or ratio, this is exemplary and is not limited thereto. The ratio of each section of the precursor section (S1), the reaction section (S2), and the inert section (S3) may be changed in consideration of the reaction characteristics of the injected precursor gas and the reaction gas. In other words, the precursor section (S1), the reaction section (S2), and the inert section (S3) are not assumed to be equally divided.

[0112] The optical thin film coating device (100, 100') of the present invention can improve the productivity of optical thin film coating by shortening the cycle time of atomic layer deposition. This makes it possible to achieve a deposition rate that is mass-producible when forming multilayer thin films with a cumulative thickness ranging from several hundred nanometers to several micrometers in the optical coating field.

[0113] FIG. 8 is a side view illustrating an optical thin film coating device (100'') according to another embodiment of the present invention, and FIG. 9 is a partial perspective view illustrating a deposition target substrate mounted on an expanded optical thin film coating device (100'').

[0114] The optical thin film coating device (100) of the present invention is designed to have a structure that rotates around an axis horizontal to the ground as a central axis, so that the processing space can be expanded in the longitudinal direction of the central axis when expansion of the device is required. The optical thin film coating device (100'') according to another embodiment of the present invention shows a state in which the optical thin film coating device (100) described above is expanded by repeating it approximately twice. The optical thin film coating device of the present invention has an advantage in that the device can be expanded without being restricted by the fact that the space in which the device is installed (e.g., a rental coating factory, etc.) generally has a vertical height limit.

[0115] The extended optical thin film coating device (100'') is suitable for performing deposition on a long substrate. For example, as illustrated in FIG. 9, the extended optical thin film coating device (100'') is suitable for performing anti-reflection coating on a car dashboard cover as a target substrate.

[0116] Recent automobiles, with their increasing smart features, are often designed with integrated instrument panels and dashboards. To enhance aesthetic appeal, the dashboards tend to be curved within a range of 1 to 1.8 meters, corresponding to the width of the vehicle's interior. The entire surface of the integrated instrument panel and dashboard undergoes an anti-reflective coating process to enhance visibility. The expanded optical thin film coating device (100'') of the present invention can be suitably utilized in this process.

[0117] The dashboard cover substrate is approximately 1 to 1.8 meters long and 0.3 meters wide, with a very large aspect ratio, making deposition difficult using conventional thin film coating equipment. Considering the PVD device in Fig. 1 (b), expanding the device's size in the height direction for production could be considered, but this not only limits the space in which the device is located, but also entails numerous limitations, such as changes to the load lock chamber and tray transport device.

[0118] In contrast, since the optical thin film coating device (100'') of the present invention has a rotation axis of the rotating body (110) and the process chamber (130) that is horizontal to the ground, it is easy to expand the device while maintaining the same diameter by repeatedly combining unit process chambers (130) (for example, a unit process chamber having a cylindrical height of 0.5 meters) in a direction horizontal to the ground. In addition, as illustrated, only a change in the longitudinal direction of the load lock chamber (160) is required, so there is an advantage of high expandability.

[0119] When the device is expanded by repeatedly combining as illustrated in FIG. 8, an expanded version of the device can be designed simply by repeatedly connecting the same height of the rotating body (110) and the process chamber (130) and repeatedly arranging a plurality of gas injection units (140) per unit process chamber (130).

[0120] The gas injection unit (140) also has the advantage of being able to be arranged without expanding the connection between the auxiliary parts, as shown. In the case of conventional CVD or PVD processes, if the shower head or target is segmented, the deposition uniformity is likely to deteriorate between the gaps, but the atomic layer deposition (ALD) process does not show a noticeable deterioration in uniformity due to its fundamental characteristics. In addition, when using remote plasma, it has the advantage of being able to compensate for the deposition uniformity at the level of shape change of the shower head that passes the active species.

[0121] Although embodiments of the present invention have been described with reference to the attached drawings, those skilled in the art will appreciate that the present invention can be implemented in other specific forms without altering the technical spirit or essential characteristics of the present invention. Therefore, the embodiments described above should be understood to be illustrative in all respects and not restrictive.

Claims

1. In a thin film coating device that coats an optical thin film on a plurality of deposition target substrates by atomic layer deposition (ALD), A cylindrical rotating body configured to support the above substrate and rotate around an axis that is horizontal to the ground; A process chamber that seals the space in which the above-mentioned rotating body and substrate rotate and provides a processing space in which a deposition gas is sprayed inside; A plurality of gas injection units connected to the process chamber and installed on a side facing the substrate, and injecting different gases into the processing space; and A thin film coating device, comprising: an exhaust unit connected to the process chamber and exhausting residual gas from the processing space; 2. In paragraph 1, A thin film coating device further comprising a fixing member coupled to the rotating body and providing a surface on which the substrate is mounted.

3. In paragraph 1, The above rotating body is a cylindrical rotating body having a radius R, The above process chamber is, A cylindrical first chamber wall is arranged at a predetermined distance from the rotating body in the opposite direction of the central axis and has a radius greater than the radius R; and A thin film coating device comprising a cylindrical second chamber wall arranged at a predetermined interval in the direction of the central axis from the rotating body and having a radius smaller than the radius R.

4. In paragraph 3, The above gas injection unit, A thin film coating device, which is arranged on the side of the first chamber wall and injects gas into the processing space from the side of the first chamber wall.

5. In paragraph 3, The above gas injection unit, A thin film coating device disposed on the second chamber wall side and spraying gas into the processing space from the second chamber wall side.

6. In paragraph 4 or 5, A precursor gas injection unit that injects precursor gas into the above processing space, A reaction gas injection unit that injects a reaction gas that reacts with the above precursor gas, and A thin film coating device comprising an inert gas injection unit that injects an inert gas other than the precursor gas and the reaction gas.

7. In paragraph 6, The above processing space is, By a partition protruding from the first chamber wall or the second chamber wall, the space is divided into a precursor section where the precursor gas is injected, a reaction section where the reaction gas is injected, and an inert section where the inert gas is injected. A thin film coating device in which the above protruding bulkhead provides a space through which the rotor and substrate move through an open gap.

8. In paragraph 7, The first precursor section, the first inert section, the first reaction section and the second inert section are made into one unit processing space, A thin film coating device, wherein the above process chamber is formed to include a plurality of unit processing spaces.

9. In paragraph 6, The above reaction gas injection unit is a thin film coating device including a plasma generating device.

10. In paragraph 3, The above process chamber is, A third chamber wall connecting the first chamber wall and the second chamber wall at one side of the first chamber wall and the second chamber wall, and A fourth chamber wall is included connecting the first chamber wall and the second chamber wall on the other side of the first chamber wall and the second chamber wall, A thin film coating device, wherein the third chamber wall and the fourth chamber wall are donut-shaped.

11. In paragraph 4, The above exhaust part, A thin film coating device, disposed on the second chamber wall side, for exhausting gas from the processing space toward the second chamber wall side.

12. In paragraph 5, The above exhaust part, A thin film coating device, arranged on the side of the first chamber wall, for exhausting gas from the processing space toward the side of the first chamber wall.

13. In paragraph 1, A load lock chamber accommodating the substrate and connected to the process chamber; A valve controlling the opening / closing state of each chamber between the load lock chamber and the process chamber; and A thin film coating device further comprising a transfer unit for transferring the substrate from the load lock chamber to the process chamber.

14. In paragraph 3, A thin film coating device further comprising a heater disposed on the first chamber wall or the second chamber wall to heat the processing space.

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