Apparatus for preventing chamber window contamination in pulsed laser deposition.

Abstract

One embodiment of the present invention relates to an apparatus for preventing chamber window contamination in pulsed laser deposition (PLD), which involves irradiating a thin film with a pulsed laser and depositing the resulting plume onto a substrate. This apparatus improves upon the conventional technique in which deposition material is deposited on a chamber window, requiring the process to be stopped and maintenance work performed. This apparatus enables the PLD process to be performed for a long period of time without replacing the chamber window.

Description

[Technical Field]

[0001] The following embodiment relates to an apparatus for preventing chamber window contamination in pulsed laser deposition (PLD), which involves irradiating a thin film with a pulsed laser and depositing the resulting plume onto a substrate. This improves on the conventional technique in which deposition material is also deposited on the chamber window, requiring the process to be interrupted and maintenance work performed. This allows the PLD process to be performed for a long period of time without replacing the chamber window. [Background technology]

[0002] Recently, with the miniaturization and high integration of electronic and electrical devices, the elements used in each device are also becoming smaller and more highly integrated. Oxide thin film elements such as superconductors and semiconductors are widely used to achieve the miniaturization and high integration of the elements, and it is most important that such thin films are formed thinly, widely, and uniformly.

[0003] Sputtering deposition or pulsed laser deposition is widely used to form such superconductor, semiconductor or oxide thin films, and devices are completed by depositing a superconducting thin film on a substrate, or depositing an electrode on a substrate, depositing a dielectric thin film on the electrode, and then depositing an electrode on the electrode.

[0004] Generally, a pulsed laser deposition device is a device that places a target (thin film) opposite a substrate in a vacuum chamber, and then focuses and irradiates a pulsed laser beam, the focal length and angle of which are adjusted using lenses and mirrors outside the chamber, onto the target to deposit a thin film on the substrate.

[0005] Here, the high temperature target on which the pulsed laser beam is focused generates atomic gas, which reaches the substrate in the form of a plume, and deposition occurs due to a chemical reaction on the surface of the substrate.

[0006] However, in conventional pulsed laser deposition devices, the deposition material evaporates and scatters during long-term processing, and is deposited on the transparent chamber window, which is located where the laser enters the vacuum chamber, reducing the energy of the pulsed laser beam. This results in a decrease in the amount of deposition and poor uniformity of the thin film.

[0007] According to conventional techniques, after a certain amount of processing has been performed, maintenance work is performed by wiping the chamber window with an abrasive or replacing the chamber window itself before performing another deposition process. This results in a significant time loss in the entire process, and also results in a significant economic loss due to the cost of replacing the chamber window.

[0008] Patent Document 1 discloses a configuration in which a laser window is protected based on a screen. However, since the number of screens is limited due to the structure, while this is suitable for experimental applications, it has a limit in that the chamber window protection efficiency is lower than conventional methods for production applications. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] KR 10-0745610B [Patent Document 2] KR 10-2275410B Summary of the Invention [Problem to be solved by the invention]

[0010] An object of one embodiment of the present invention is to overcome the limitations of the conventional pulsed laser deposition apparatus described above by providing an apparatus for preventing contamination of a chamber window in pulsed laser deposition, which can perform a deposition process for a long time by protecting the chamber window using a predetermined film and preventing deposition material from being deposited on the chamber window. [Means for solving the problem]

[0011] According to one embodiment, there is provided an apparatus for preventing contamination of a chamber window during pulsed laser deposition that is provided in a pulsed laser deposition apparatus, the apparatus including: a film portion disposed within a predetermined distance from a chamber window of the vacuum chamber; and a film transport device that transports the film portion, wherein contamination of the chamber window is prevented based on the film portion, and the film portion is transported based on the film transport device so that the pulsed laser is controlled to transmit a non-contaminated portion of the film portion.

[0012] The film transport device may also include: a cover portion attached to the inside of the vacuum chamber and arranged to cover the chamber window; an opening provided on one side of the cover portion and arranged behind the chamber window based on the incident direction of the pulsed laser; an unwinding roller arranged on one side inside the cover portion and from which the film portion is unwound; a take-up roller arranged on the other side inside the cover portion and from which the film portion unwound from the unwinding roller and passed through the opening is taken up; and a first motor that rotates the unwinding roller and the take-up roller.

[0013] The film portion is formed into a predetermined rectangle, and the film transport device includes: a cover portion attached to the inside of the vacuum chamber and arranged to cover the chamber window, an opening provided at the center of the cover portion and arranged behind the chamber window based on the incident direction of the pulsed laser, a fixing jig for fixing the film portion, a first actuator for moving the fixing jig vertically, and a second actuator for moving the fixing jig horizontally, and can be configured to alternately perform a first transport step in which the film portion is moved a first length in the horizontal direction and a second transport step in which the film portion is moved a second length in the vertical direction.

[0014] In addition, the opening includes: a brush positioned a predetermined length away from the vacuum chamber and attached to one side facing the chamber window, and the unwinding roller includes: a first roller installed inside the vacuum chamber with the film portion wound up a predetermined length, a second roller positioned a first length away from the first roller in a first direction, and a third roller positioned a second length away from the second roller in a "second direction having a predetermined acute angle with respect to the first direction," and the third roller can be positioned so that an imaginary plane connecting the central axis of the third roller and the central axis of the winding roller is parallel to the chamber window.

[0015] and a lower end bar extending between the left end of the upper bar and the right end of the film portion is fixed to the lower end of the film portion. The lower end bar is a lower end bar extending from the right end of the upper bar and the right end of the film portion is fixed to the upper end of the film portion. The lower end bar is a lower end bar extending between the left end of the upper bar and the right end of the film portion is fixed to the lower ... lower end of the lower end bar and the The second actuator may include a first support base disposed on the other side of the interior of the cover, and a first-second guide connected to the first support base. The second actuator may include: a third motor fixed to one side of the first-first guide or the first-second guide, a second threaded shaft which is a rotation shaft of the third motor, a second bearing fixed to the first-second guide or one side of the first-first guide, a second-first guide connected to the second threaded shaft, a second support base fixed between the first-first guide and the first-second guide, and a second-second guide connected to the second support base. One side of the upper bar, an upper end of the left bar, or an upper end of the right bar may be fixed to the second-first guide, and one side of the lower bar, a lower end of the left bar, or a lower end of the right bar may be fixed to the second-second guide.

[0016] The film contamination detection device further includes a light emitting unit that irradiates light onto the chamber window from outside the chamber window at a predetermined angle, a light receiving unit that corresponds to the angle of incidence of the illumination from the light emitting unit and is disposed at a point where reflected light is received, and a detection control unit that is connected to the light emitting unit and the light receiving unit and determines whether the film is contaminated, and the detection control unit is configured to: start visible light photography with the light receiving unit, wait for a first period, irradiate visible light of a first color with the light emitting unit for a second period, and detect contamination with the second color with the light emitting unit. a step of irradiating visible light of two hues during a third period, a step of irradiating visible light of a third hue during a fourth period by the light emitting unit, a step of starting infrared photography by the light receiving unit, a step of waiting during the fifth period, a step of irradiating infrared light by the light emitting unit during a sixth period, a step of starting ultraviolet photography by the light receiving unit, a step of waiting during the seventh period, a step of irradiating ultraviolet light by the light emitting unit during an eighth period, a step of ending photography by the light receiving unit, and a step of recording an image of the film unit based on the images photographed by the light receiving unit during the first to eighth periods. and a step of determining whether the film part is contaminated, wherein the step of determining whether the film part is contaminated comprises the steps of: extracting, from a first frame included in a first period of the video, hue codes corresponding to each pixel constituting the first frame, and calculating a first matrix; extracting, from a second frame included in a second period of the video, hue codes corresponding to each pixel constituting the second frame, and calculating a second matrix; extracting, from a third frame included in a third period of the video, hue codes corresponding to each pixel constituting the third frame, and calculating a third matrix; extracting, from a fourth frame included in a fourth period of the video, hue codes corresponding to each pixel constituting the fourth frame, and calculating a fourth matrix; extracting, from a fifth frame included in a fifth period of the video, hue codes corresponding to each pixel constituting the fifth frame, and calculating a fifth matrix; and extracting, from a sixth frame included in a sixth period of the video, hue codes corresponding to each pixel constituting the sixth frame, and calculating a sixth matrix.The method may include the steps of: calculating a seventh matrix by extracting a color code corresponding to each pixel constituting a seventh frame from a seventh frame included in a seventh period of the image; calculating an eighth matrix by extracting a color code corresponding to each pixel constituting the eighth frame from an eighth frame included in an eighth period of the image; calculating "1st matrix - 2nd matrix = 9-1th matrix," "1st matrix - 3rd matrix = 9-2th matrix," "1st matrix - 4th matrix = 9-3th matrix," "5th matrix - 6th matrix = 9-4th matrix," and "7th matrix - 8th matrix = 9-5th matrix," calculating determinants for each of the 9-1st matrix to 9-5th matrix; and determining that the film unit is contaminated if at least one of the determinants is equal to or greater than a critical value. [Effects of the Invention]

[0017] According to an embodiment, in a pulsed laser deposition process, a chamber window provided in a vacuum chamber is prevented from being contaminated by a deposition device, so that the deposition process can be performed continuously for a long period of time.

[0018] In addition, by transporting the anti-reflective coated film inside the vacuum chamber, different portions of the film can be positioned to block the chamber window at different times, thereby maximizing the film replacement cycle.

[0019] By placing a predetermined brush around the periphery of the opening where the film is exposed, contamination of the film that has not yet been exposed to the opening can be prevented.

[0020] In addition, the device can be constructed based on a rollable film or a predetermined rectangular film, and the contamination prevention device can be designed according to the film material and other process environments.

[0021] Furthermore, by arranging the unwinding rollers in a zigzag (Z-shape), contamination of the film wound around the unwinding rollers can be prevented.

[0022] The rectangular film can be transported in two axial directions based on two actuators. In addition, contamination of the film can be sensed and the film transport cycle can be adjusted appropriately. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a flowchart showing a deposition process of a pulsed laser deposition apparatus. [Figure 2] FIG. 1 is a diagram showing a pulsed laser deposition apparatus. [Figure 3] 1 illustrates an apparatus for preventing chamber window contamination in pulsed laser deposition according to one embodiment of the present invention. [Figure 4] FIG. 10 illustrates an apparatus for preventing contamination of a chamber window in pulsed laser deposition according to another embodiment of the present invention. [Figure 5] 1 is a diagram showing the structure of a take-up roller of an apparatus for preventing contamination of a chamber window in pulsed laser deposition according to an embodiment of the present invention; [Figure 6] 1 is a diagram showing the structure of an actuator of an apparatus for preventing contamination of a chamber window in pulsed laser deposition according to an embodiment of the present invention. [Figure 7] 1 is a diagram illustrating a film portion transfer method of an apparatus for preventing contamination of a chamber window in pulsed laser deposition according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. However, since various modifications can be made to the embodiments, the scope of the patent application is not limited to these embodiments. It should be understood that all modifications, equivalents, and alternatives to the embodiments are included in the scope of the patent.

[0025] Specific structural or functional descriptions of the embodiments are disclosed for illustrative purposes only and may be modified and implemented in various forms. Therefore, the embodiments are not limited to the specific disclosed forms, and the scope of this specification includes modifications, equivalents, or alternatives within the technical spirit.

[0026] Although terms such as "first" or "second" are used to describe various components, such terms should be interpreted only to distinguish one component from another. For example, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component.

[0027] When a component is referred to as being "coupled" to another component, it may be directly coupled or connected to the other component, but it should be understood that there may be other components in between.

[0028] The terms used in the examples are merely for the purpose of explanation and should not be construed as limiting. The singular expressions include the plural expressions unless the context clearly dictates otherwise. In this specification, the terms "comprise" or "have" and the like specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described above in the specification, and should be understood not to preclude the presence or additional possibility of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0029] Unless otherwise defined, all terms, including technical or scientific terms, used herein have the same meaning as commonly understood by a person of ordinary skill in the art to which the embodiments pertain. Terms defined in commonly used dictionaries should be interpreted to have a meaning consistent with the meaning they have in the context of the relevant art, and should not be interpreted in an idealized or overly formal sense unless expressly defined in this application.

[0030] Furthermore, with reference to the accompanying drawings, the same components are given the same reference numerals regardless of the reference numerals, and redundant descriptions thereof will be omitted. In describing the embodiments, if it is determined that a detailed description of related publicly known technology may obscure the gist of the embodiments, the detailed description thereof will be omitted.

[0031] The advantages and features of the present invention, as well as methods for achieving them, will become apparent from the following detailed description of the embodiments in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and may be embodied in various different forms. However, the present embodiments are provided so that the disclosure of the present invention will be complete and will fully convey the scope of the invention to those skilled in the art. The present invention is defined only by the claims.

[0032] In the embodiments of the present invention, unless otherwise defined, all terms, including technical or scientific terms, used herein have the same meaning as commonly understood by a person of ordinary skill in the art to which the present invention belongs. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning they have in the context of the relevant art, and should not be interpreted in an idealized or overly formal sense unless explicitly defined in the embodiments of the present invention.

[0033] The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for illustrating the embodiments of the present invention are illustrative only, and the present invention is not limited to the illustrated matters. Furthermore, when describing the present invention, if it is determined that a detailed description of related prior art may unnecessarily obscure the gist of the present invention, such a detailed description will be omitted. When terms such as "comprise," "have," and "consist" are used in this specification, other parts may be added unless "only" is used. When a component is expressed in the singular, it also includes the plural unless otherwise explicitly stated.

[0034] When interpreting elements, they are interpreted as including a margin of error even if there is no explicit statement otherwise.

[0035] In the case of a description of a positional relationship, for example, when the positional relationship of two parts is described using terms such as "above," "on top of," "below," or "next to," one or more other parts may be located between the two parts, as long as "immediately" or "directly" is not used.

[0036] The positions and thicknesses of the components shown in the drawings are shown for convenience of explanation, and the present invention is not necessarily limited to the sizes and thicknesses of the components shown in the drawings.

[0037] The features of the various embodiments of the present invention may be partially or wholly combined or combined with each other, and various technical interlocking and driving mechanisms are possible, as will be readily understood by those skilled in the art, and each embodiment may be implemented independently of the others or may be implemented together in a linked relationship.

[0038] A superconductor is a material whose electrical resistance becomes zero at temperatures below its critical temperature (Tc) and exhibits perfect diamagnetism known as the Meissner effect. First-generation superconductivity was first discovered in 1911 when the electrical resistance of mercury became zero at a temperature of 4.2 K in liquid helium, while second-generation superconductivity was discovered in 1986 as a copper oxide superconductor.

[0039] Oxide superconductors (REBCO: RE is one or more rare earth elements (Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu)) contain rare earth oxides, such as (YBa2Cu3O 7-x ), (GdBa2Cu3O 7-x ), or RE, Ba, and Cu are individual oxide particle materials, or two or more of these elements are complex oxide particles.

[0040] The most important requirement for using second-generation high-temperature superconductor (HTS) wire in superconducting devices is a high critical current (IC) value under a high magnetic field. In particular, the critical current density (JC) should be as large as possible even under a large magnetic field applied in any direction. The limit of the critical current density is determined by the action of artificial pins (flux pinning centers) that prevent magnetic flux lines from moving against the Lorentz force when they enter from the outside and are distributed within the superconductor. Many researchers and inventors have developed methods to increase the magnitude of the critical current under a magnetic field by doping the superconducting layer with nano-sized non-superconducting particles.

[0041] Generally, the material constituting the artificial pin may include at least one of BaHfO3, SrHfO3, CaHfO3, BaZrO3, BaSnO3, etc., a solid solution thereof, or a mixture of two or more thereof.

[0042] The superconducting layer of REBCO-based high-temperature superconducting wire can be produced by a variety of methods, including pulsed laser deposition (PLD), metal-organic chemical vapor deposition (MOCVD), metal-organic deposition (MOD), and reactive co-evaporation (RCE).

[0043] Among these, the PLD method is particularly effective in obtaining biaxially oriented thin films. The PLD method, one of the methods for depositing superconductors, is known as the most convenient and effective technology for manufacturing high-temperature superconductors (HTS). By depositing oxide superconducting layers using the PLD method, it is possible to form oxide superconducting layers with good film quality, resulting in high superconducting properties.

[0044] The PLD method uses a laser focused from a lens to strike a solid REBCO target, extracting the target material from its surface to form a plume-like plasma, which is then crystallized on the surface of a wire heated to a high temperature. The advantages of PLD are that it forms a thin film with a chemical composition close to that of the target material, has low contamination, and has a high deposition rate. However, it has the disadvantage of lower productivity compared to other manufacturing methods.

[0045] In order to increase productivity with the PLD method, a method has been used in which multiple lasers are irradiated onto the target to increase the deposition amount.

[0046] The pulsed laser deposition process can be carried out according to the flow chart shown in FIG.

[0047] The pulsed laser deposition apparatus is equipped with a supply reel and a take-up reel as a means for transporting the substrate (wire). These reels can be configured as separate chambers outside the chamber, and the wire is supplied by operating the reels with a drive unit. To transport a long wire, the speeds of the supply reel and the take-up reel should be synchronized with each other.

[0048] The vacuum chamber C is connected to a vacuum pump V, which evacuates the vacuum chamber C until the pressure therein is reduced to a pressure that meets the process conditions.

[0049] The substrate heating means heats the rear surface of the wire material on which deposition is being performed (electric heater) so that the deposition material is deposited properly during deposition.

[0050] The cylindrical target (made of the same material as the superconducting layer) rotates around the center of the cylinder, and when the rotation is complete, it moves horizontally to the left (right) and then rotates again, allowing the target material to be deposited evenly on the outside of the cylinder, greatly improving the productivity and uniformity / quality of the wire.

[0051] The pulse laser preferably has a high energy density and an excellent output so as to obtain a sufficient deposition amount on the target.

[0052] Applicable types of lasers include Ar-F (193 nm), Kr-F (248 nm), Xe-Cl (308 nm), excimer laser, YAG laser, CO2 laser, etc.

[0053] A laser beam emitted from the outside is introduced into the vacuum chamber C through a chamber window O provided on one side of the vacuum chamber C. The entrance O is treated with an anti-reflection coating to prevent the laser beam L from being reflected.

[0054] After reducing the pressure (vacuum) inside the vacuum chamber C using the vacuum pump V, ionized gas from the oxygen ionizer is injected into the vacuum chamber C. The internal pressure of the vacuum chamber C is maintained constant by adjusting the flow control valve, and an oxygen atmosphere is formed.

[0055] The tilt angle and length of the artificial pins can be varied by adjusting the atmospheric pressure during PLD deposition, and can also be adjusted by the pulse laser frequency of the PLD system and the atmospheric pressure inside the chamber.

[0056] After the deposition is completed, the nitrogen gas valve introduces nitrogen gas (dry air) into the chamber and adjusts it to the same pressure as the standby pressure, then opens the vacuum chamber C and finally removes the wire W.

[0057] According to one embodiment, there is provided an apparatus for preventing contamination of a chamber window O during pulsed laser L deposition, which is provided in a pulsed laser L deposition apparatus, and which includes a film portion 1 disposed within a predetermined distance from the chamber window O of the vacuum chamber C, and a film transport device for transporting the film portion 1, and which prevents contamination of the chamber window O based on the film portion 1 and transports the film portion 1 based on the film transport device, and is controlled so that the pulsed laser L passes through a non-contaminated portion of the film portion 1.

[0058] The configuration of a typical pulsed laser L deposition device used to manufacture superconducting wires is shown in Figure 2. When a pulsed laser L is irradiated onto a target T (thin film) through a chamber window O, the target T diffuses into a plume P and is deposited onto a substrate W (evaporation target) placed above.

[0059] At this time, the material diffused in the form of plume P does not only diffuse upward but also radially, so it is deposited on the chamber window O and the inner surface of the vacuum chamber, etc. As a result, the material deposited on the chamber window O may reduce the transmittance of the pulsed laser L or cause some reflection / refraction.

[0060] Such contamination of the chamber window O causes the thin film to be formed unevenly during the deposition process, resulting in defects. To prevent this, in conventional techniques, maintenance work such as wiping the chamber window O or replacing the chamber window O is performed after a certain amount of work or time.

[0061] On the other hand, the technology described in Patent Document 1 is provided with a pair of screens that block the chamber window O, and the two screens cross to protect the chamber window O, so that the deposition operation can be extended until the two screens become contaminated.

[0062] However, since the system is not equipped with only two screens, but can be equipped with at most four screens structurally, there is a limit in that the continuous time of the process cannot be dramatically increased.

[0063] In one embodiment of the present invention, the film portion 1 is unwound or moved up and down and left and right to expose only a portion of the film portion 1, and based on this, contamination of the chamber window O can be prevented for a long period of time.

[0064] For example, in one embodiment using a "rectangular" film portion 1 (Figure 4) described below, if the area of ​​the opening 20 is 1 and the area of ​​the film portion 1 is 30, the process can be carried out continuously for 30 times the conventional process time.

[0065] The film part 1 and the chamber window O are subjected to an anti-reflection coating treatment, so that the pulse laser L and the like are not reflected and most of the components are transmitted to be irradiated onto the target T.

[0066] In the above description, "the pulsed laser L is controlled to pass through the non-contaminated portion of the film portion 1" means that a portion of the area of ​​the film portion 1 that has not yet been exposed to the opening 20 is exposed to the opening 20, and the pulsed laser L is controlled to pass through the portion that has not been contaminated by the deposition material.

[0067] For example, in the case of a "rectangular" film portion 1, region A is positioned at the opening 20 and the deposition process is carried out for time B. If it is determined that region A is contaminated to a level above the standard value, the film portion 1 is moved left and right or up and down, and then the deposition process is carried out for a further time D on region C.

[0068] The film transport device may also include: a cover part 2 attached to the inside of the vacuum chamber C and arranged to cover the chamber window O; an opening 20 provided on one side of the cover part 2 and arranged behind the chamber window O based on the incident direction of the pulsed laser L; an unwinding roller 31 arranged on one side inside the cover part 2 and from which the film part 1 is unwound; a winding roller 32 arranged on the other side inside the cover part 2 and from which the film part 1 unwound from the unwinding roller 31 and passed through the opening 20 is wound; and a first motor that rotates the unwinding roller 31 and the winding roller 32.

[0069] In the above embodiment, a film portion 1 having a predetermined length is placed inside the vacuum chamber C while being wound around the unwinding roller 31, and while the process is being carried out, the winding roller 32 and / or the unwinding roller 31 are rotated continuously or intermittently to expose an uncontaminated portion of the film portion 1 to the opening 20.

[0070] The cover part 2 is fixed inside the vacuum chamber C so as to cover the chamber window O to prevent the deposition material from coming into contact with the film part 1.

[0071] The opening 20 may be formed by drilling a circular hole on one side of the cover 2, as shown in FIG. 3 or FIG.

[0072] 3(a) is a view of the cover part 2 as viewed from inside the vacuum chamber C, and FIG. 3(b) is a view of the cover part 2 as viewed from above the vacuum chamber C.

[0073] For ease of explanation, Figure 3(a) shows the take-up roller 32, unwinding roller 31, and film part 1 arranged inside the cover part 2 so that they can be seen, but in reality, the relevant parts are blocked by the cover part 2, and only a part of the film part 1 is exposed and visible inside the opening 20.

[0074] The film portion 1, which has been exposed to the deposition material through the opening 20 for a certain period of time and is partially contaminated, is wound onto the winding roller 32.

[0075] The film portion 1 is formed into a predetermined rectangular shape, and the film transport device includes: a cover portion 2 attached to the inside of the vacuum chamber C and arranged to cover the chamber window O, an opening 20 provided at the center of the cover portion and arranged behind the chamber window O based on the incident direction of the pulsed laser L, a fixing jig 41 for fixing the film portion 1, a first actuator for moving the fixing jig 41 vertically, and a second actuator for moving the fixing jig 41 horizontally, and can be configured to alternately perform a first transport step in which the film portion 1 is moved by a first length in the horizontal direction and a second transport step in which the film portion 1 is moved by a second length in the vertical direction.

[0076] In the above embodiment, a rectangular film portion 1 is placed inside a vacuum chamber C, and while the process is being carried out, the film portion 1 is continuously or intermittently moved up and down or left and right, exposing an uncontaminated portion of the film portion 1 to the opening 20.

[0077] The fixing jig 41 fixes the film part 1 and maintains a predetermined tension on the film part 1. As a result, the opening 20 is exposed with the film part 1 stretched out taut, and the pulsed laser L is transmitted without being refracted / reflected and irradiated onto the target T.

[0078] First, the process may start with one side corner of the film unit 1 exposed to the opening 20, and then, if it is determined that the exposed portion is contaminated, the film unit 1 is moved to the left or right (first moving step) to expose the uncontaminated portion of the film unit 1, and the contaminated portion of the film unit 1 is hidden so that it is accommodated inside the cover unit 2. This process is repeated until the first row of the film unit 1 is contaminated, and then the second moving step is performed to move the film unit 1 upward or downward.

[0079] Next, after the second row of film portion 1 has been contaminated, the process can be carried out while the film portion 1 is further transported to the right or left (the opposite direction to the previous transport direction).

[0080] According to the above process, the film part 1 is transported along the trajectory shown in FIG. 4(c).

[0081] FIG. 4(a) shows the position of the film part 1 before the process starts and the position of the film part 1' after the process is completed.

[0082] Additionally, the opening 20 may include a brush that is disposed at a predetermined distance from the vacuum chamber C and attached to one side facing the chamber window O.

[0083] The brush can be applied to both the rolled film portion 1 and the rectangular film portion 1 embodiments.

[0084] The unwinding roller 31 includes: a first roller 311 that is installed inside the vacuum chamber C with the film portion 1 wound up to a predetermined length; a second roller 312 that is arranged at a first length distance from the first roller 311 in a first direction; and a third roller 313 that is arranged at a second length distance from the second roller 312 in a "second direction having a predetermined acute angle with respect to the first direction," and the third roller 313 can be arranged so that an imaginary plane connecting the central axis of the third roller 313 and the central axis of the winding roller 32 is parallel to the chamber window O.

[0085] The unwinding roller 31 and the take-up roller 32 may be arranged in a predetermined "Z" shape as shown in FIG. 5 (so that the line connecting the rotation axes of the first roller 311-second roller 312-third roller 313-take-up roller 32 forms a "Z"), thereby preventing the deposition material from passing through the brush or, in embodiments without a brush, preventing the film portion 1 not exposed to the opening 20 from being contaminated by the deposition material.

[0086] A cover part 2' can be protruded between the film parts 1 arranged in the "Z" shape to block the plume that flows into the inside of the cover part 2 from coming close to the first roller 311 or the second roller 312.

[0087] The fixing jig 41 includes: an upper end bar to which the upper end of the film portion 1 is fixed; a left end bar extending downward from the left end of the upper end bar and to which the left end of the film portion 1 is fixed; a right end bar extending downward from the right end of the upper end bar and to which the right end of the film portion 1 is fixed; and a lower end bar extending between the left end bar and the right end bar and to which the lower end of the film portion 1 is fixed. The first actuator includes: a second motor 421 disposed on one side inside the cover portion 2; a first screw shaft 422 which is a rotation shaft of the second motor 421; a first bearing 423 which supports an end of the first screw shaft 422; a first-first guide 424 connected to the first screw shaft 422; a first support stand 425 disposed on the other side inside the cover portion 2; and a first-second guide 424 connected to the first support stand 425. the second actuator includes a third motor 431 fixed to one side of the first-first guide 424 or the first-second guide 426, a second threaded shaft 432 as a rotation shaft of the third motor 431, a second bearing 433 fixed to one side of the first-second guide 426 or the first-first guide 424, a second-first guide 434 connected to the second threaded shaft 432, a second support 435 fixed between the first-first guide 424 and the first-second guide 426, and a second-second guide 436 connected to the second support 435, and one side of the upper bar, the upper end of the left bar, or the upper end of the right bar may be fixed to the second-first guide 434, and one side of the lower bar, the lower end of the left bar, or the lower end of the right bar may be fixed to the second-second guide 436.

[0088] The fixing jig 41 fixes the four corners of the film part 1 to maintain a predetermined tension on the film part 1, and is connected to the first actuator and the second actuator to change the point exposed to the opening 20.

[0089] The first actuator can move the second actuator up and down (vertically) based on a ball screw structure.

[0090] The second motor 421 is installed inside the vacuum chamber C and rotates when supplied with current, thereby rotating the first screw shaft 422 .

[0091] When the first screw shaft 422 rotates, the 1-1 guide 424 connected to the first screw shaft 422 is moved up and down along the threads, and the 1-2 guide 426 fixed / connected to the 1-1 guide 424 by the fixing jig 41 is moved up and down along the first support base 425.

[0092] The second actuator can transfer the fixing jig 41 / film unit 1 in the left-right direction (horizontal direction) based on a ball screw structure.

[0093] The second actuator, whose vertical position is determined by the first actuator, adjusts the horizontal position of the 2-1 guide 434 based on the third motor 431, thereby adjusting the point at which the film portion 1 is exposed to the opening 20.

[0094] Meanwhile, the film transport device can be controlled to transport the film portion 1 continuously at a predetermined constant speed or to transport the film portion at regular time intervals.

[0095] Figure 7 shows a diagram illustrating the transport speed of the film portion 1. Figure 7(a) shows an embodiment in which the film portion 1 is continuously transported at a uniform speed during the process, and Figure 7(b) shows an embodiment in which the film portion 1 is transported at a uniform speed at regular time intervals or when contamination of the film portion 1 is detected / determined.

[0096] When the film part 1 is transferred as shown in FIG. 7(a), there is almost no decrease in thin film uniformity due to contaminated film part 1, so the quality of the product can be maintained at a very high level. When the film part 1 is transferred as shown in FIG. 7(b), wear on the film part 1 can be minimized, so the cost of replacing the film part 1 and maintenance time can be reduced.

[0097] The film contamination detection device further includes a film contamination detection device, which includes: a light emitting unit that irradiates light onto the chamber window O from outside the chamber window O at a predetermined angle; a light receiving unit that is disposed at a point where reflected light is received, corresponding to the illumination incident angle of the light emitting unit; and a detection control unit that is connected to the light emitting unit and the light receiving unit and determines whether the film part 1 is contaminated, and the detection control unit includes: a step of starting visible light photography with the light receiving unit; a step of waiting during a first period; a step of irradiating visible light of a first color with the light emitting unit during a second period; a step of irradiating visible light of a second color by the light emitting unit for a third period, a step of irradiating visible light of a third color by the light emitting unit for a fourth period, a step of starting infrared photography by the light receiving unit, a step of waiting for the fifth period, a step of irradiating infrared light by the light emitting unit for a sixth period, a step of starting ultraviolet photography by the light receiving unit, a step of waiting for the seventh period, a step of irradiating ultraviolet light by the light emitting unit for an eighth period, a step of ending photography by the light receiving unit, and and a step of determining whether film unit 1 is contaminated, wherein the step of determining whether film unit 1 is contaminated comprises the steps of: extracting, from a first frame included in a first period of the video, hue codes corresponding to each pixel constituting the first frame, to calculate a first matrix; extracting, from a second frame included in a second period of the video, hue codes corresponding to each pixel constituting the second frame, to calculate a second matrix; extracting, from a third frame included in a third period of the video, hue codes corresponding to each pixel constituting the third frame, to calculate a third matrix; extracting, from a fourth frame included in a fourth period of the video, hue codes corresponding to each pixel constituting the fourth frame, to calculate a fourth matrix; extracting, from a fifth frame included in a fifth period of the video, hue codes corresponding to each pixel constituting the fifth frame, to calculate a fifth matrix; and extracting, from a sixth frame included in a sixth period of the video, hue codes corresponding to each pixel constituting the sixth frame, to calculate a sixth matrix.The method may include the steps of: calculating a seventh matrix by extracting a color code corresponding to each pixel constituting a seventh frame from a seventh frame included in a seventh period of the image; calculating an eighth matrix by extracting a color code corresponding to each pixel constituting the eighth frame from an eighth frame included in an eighth period of the image; calculating "1st matrix - 2nd matrix = 9-1th matrix," "1st matrix - 3rd matrix = 9-2th matrix," "1st matrix - 4th matrix = 9-3rd matrix," "5th matrix - 6th matrix = 9-4th matrix," and "7th matrix - 8th matrix = 9-5th matrix," calculating determinants for each of the 9-1st matrix to 9-5th matrix; and determining that the film unit 1 is contaminated if at least one of the determinants is equal to or greater than a critical value.

[0098] The light emitting unit may be configured in the form of a module / system capable of emitting visible light, infrared light, and ultraviolet light of a number of different colors.

[0099] The light receiving unit is a predetermined camera module / system, and can capture and detect visible light, infrared light, and ultraviolet light emitted from the light emitting unit.

[0100] In the step of starting visible light photography in the light receiving unit, the operation of the pulsed laser L is temporarily stopped, and it is sensed (photographed) whether the illumination irradiated from the light receiving unit is refracted / reflected by the chamber window O and the film unit 1 and enters the light receiving unit (photographed continuously during the first to fourth periods).

[0101] In the step of waiting during the first period, visible light photography is continued so as to ensure a sufficient number of frames of images while the light emitting unit is not in operation.

[0102] In the step of irradiating visible light of a first color from the light emitting unit for a second period, the step of irradiating visible light of a second color from the light emitting unit for a third period, and the step of irradiating visible light of a third color from the light emitting unit for a fourth period, the visible light of three different colors is refracted / reflected by the chamber window O / film unit 1 and captured as an image.

[0103] Next, in the steps described below, the contamination of the film portion 1 is sensed / determined by comparing the image frames in the first period in which the light emitting portion is not activated with the image frames in the second to fourth periods.

[0104] In the step of starting infrared photography with the light receiving unit, the emission of visible light from the light emitting unit is stopped, and photography is started with the infrared camera.

[0105] In the step of waiting during the fifth period, an image is captured in a state where infrared rays are not irradiated from the light emitting unit.

[0106] In the step of irradiating infrared rays from the light-emitting unit for a sixth period, an image is captured by an infrared camera of the light-receiving unit during the sixth period in which the infrared rays are irradiated from the light-emitting unit.

[0107] In the step of starting ultraviolet photography with the light receiving unit, the infrared radiation from the light emitting unit is stopped and photography is started with the ultraviolet camera.

[0108] In the step of waiting during the seventh period, an image is captured in a state where ultraviolet light is not irradiated from the light emitting unit.

[0109] In the step of irradiating infrared light from the light-emitting unit for an eighth period, an image is captured by an ultraviolet camera of the light-receiving unit during the eighth period in which ultraviolet light is irradiated from the light-emitting unit.

[0110] In the step of ending the photographing of the light receiving unit, photographing from all the cameras of the light receiving unit is stopped after the first to eighth periods.

[0111] In the step of determining whether the film part 1 is contaminated based on the images captured by the light receiving part during the first to eighth periods, the visible light image, infrared image, and ultraviolet image captured when no visible light, infrared light, or ultraviolet light is irradiated are compared with the visible light image, infrared image, and ultraviolet image captured when visible light, infrared light, or ultraviolet light is irradiated, to determine whether the film part 1 is contaminated.

[0112] In the step of calculating a first matrix by extracting hue codes corresponding to each pixel constituting the first frame from a first frame included in a first period of the image, a first frame, which is one of the frames of the image corresponding to the first period, is extracted, and a hue code (#000000 to #FFFFFF) for each pixel is extracted from the first frame, and a first matrix having each hue code for each pixel as a component is calculated.

[0113] Here, the image may be composed of a predetermined square image (having the same number of horizontal / vertical pixels), and the generated first matrix is ​​a square matrix.

[0114] The steps of calculating the second matrix to the eighth matrix are performed / processed in the same manner as described above.

[0115] In the step of calculating "1st matrix - 2nd matrix = 9-1st matrix," "1st matrix - 3rd matrix = 9-2nd matrix," "1st matrix - 4th matrix = 9-3rd matrix," "5th matrix - 6th matrix = 9-4th matrix," and "7th matrix - 8th matrix = 9-5th matrix," subtraction is performed based on the calculated eight matrices, thereby calculating matrices 9-1 through 9-5.

[0116] The matrix calculated by subtraction in this way is data indicating the difference before and after the operation of the light emitting unit.

[0117] In the step of calculating the determinant for each of the 9-1 matrix to the 9-5 matrix, the determinant for each of the 9-1 matrix to the 9-5 matrix, which are square matrices, is calculated, and based on the calculated determinant, it can be determined how much of visible light, infrared light, and ultraviolet light of three different hues is reflected and received by the light receiving unit.

[0118] In the step of determining that the film portion 1 is contaminated if at least one of the determinants is equal to or greater than a critical value, the film portion 1 can be determined to be contaminated if the calculated determinant is equal to or greater than a predetermined critical value.

[0119] In this case, the critical values ​​may be set differently for the determinants of the 9-1st to 9-5th matrices.

[0120] For example, if the critical value for the determinant of the 9-1st matrix is ​​35, then the critical value for the determinant of the 9-5th matrix may be designated as 24.

[0121] Although the present invention has been described in detail above with reference to the accompanying drawings, the present invention is not necessarily limited to such examples and may be variously modified within the scope of the technical concept of the present invention. Therefore, the disclosed embodiments of the present invention are intended to illustrate, rather than limit, the technical concept of the present invention, and the scope of the technical concept of the present invention is not limited by such embodiments. Therefore, the above-described embodiments should be understood to be illustrative in all respects and not restrictive. The scope of protection of the present invention should be interpreted in accordance with the following claims, and all technical concepts within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

[0122] Accordingly, other implementations, other embodiments, and equivalents of the claims are within the scope of the following claims. [Explanation of symbols]

[0123] L: Pulse laser C: Vacuum chamber O: Chamber window P: Plume T: Target W: Substrate V: Vacuum pump A: Device to prevent contamination of chamber window 1: Film section 2: Cover part 20: Opening 31: Unwinding roller 311: First Roller 312: Second Roller 313: Third Roller 32: Winding roller 41: Fixture 421: Second motor 422: First screw shaft 423: First bearing 424: Guide 1-1 425:1st support stand 426: Guide 1-2 431: Third motor 423: Second screw shaft 433: Second bearing 434: Guide 2-1 435:Second support stand 436: 2nd-2nd Guide

Claims

1. 1. A device for preventing contamination of a chamber window in pulsed laser deposition, the device being provided in a pulsed laser deposition device, comprising: a film portion disposed within a predetermined distance from a chamber window of the vacuum chamber; a film transport device that transports the film portion, The film portion is used as a base to prevent contamination of the chamber window, The film portion is transported based on the film transport device, and the pulsed laser is controlled to transmit a non-contaminated portion of the film portion. This is a device to prevent contamination of chamber windows in pulsed laser deposition.

2. The film transport device is a cover attached to the inside of the vacuum chamber and arranged to cover the chamber window; an opening provided on one side of the cover and disposed behind a chamber window based on an incident direction of the pulsed laser; a winding roller disposed on one side of the cover and winding the film portion; a take-up roller disposed on the other side of the interior of the cover portion, for taking up the film portion unwound from the unwinding roller and passing through the opening; a first motor that rotates the unwinding roller and the winding roller; 10. An apparatus for preventing chamber window contamination in pulsed laser deposition according to claim 1.

3. The film portion is formed into a predetermined rectangular shape, The film transport device is a cover attached to the inside of the vacuum chamber and arranged to cover the chamber window; an opening provided at the center of the cover and positioned behind a chamber window with respect to the incident direction of the pulsed laser; a fixing jig for fixing the film portion; a first actuator that moves the fixture in a vertical direction; a second actuator that moves the fixing jig in a horizontal direction, a first transport step in which the film portion is transported by a first length in the horizontal direction; a second transport step in which the film portion is transported a second length in the vertical direction; 10. An apparatus for preventing chamber window contamination in pulsed laser deposition according to claim 1.

4. The film transport device is The film portion is continuously transported at a predetermined constant speed, or The film portion is controlled to be transported at regular time intervals.

10. An apparatus for preventing chamber window contamination in pulsed laser deposition according to claim 1.

5. further comprising a film contamination detection device; The film contamination detection device includes: a light emitting unit that irradiates the chamber window with light at a predetermined angle from outside the chamber window; a light receiving unit disposed at a point where the reflected light is received, corresponding to an illumination incident angle of the illumination unit; a detection control unit connected to the light emitting unit and the light receiving unit, for determining whether the film unit is contaminated; 10. An apparatus for preventing chamber window contamination in pulsed laser deposition according to claim 1.

Images