JP2017115215A - Organic EL display device manufacturing equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mask holding tool capable of corresponding to the model change of a display device while suppressing a film blur and a film irregularity.SOLUTION: A mask holding tool 108 comprises: a plurality of magnets 110 for fixing, on a filming region over a filmed face 116a of a substrate 116, a mask 118 having a plurality of corresponding openings; and a fixing member 114 for fixing and arranging the magnets 110. The mask holding tool 108 is so arranged that the magnets 110 establish a magnetic field of 50 to 500 G at the maximum may be formed on the film-deposition face 116a of a substrate 116. The magnets 110 are arranged at a spacing of 5 to 15 mm from the film-deposition face 116a of the substrate 116.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a mask holding fixture for fixing a mask to a substrate and a sputtering apparatus provided with the same.

  As a method for forming a thin film on a substrate, a method using a sputtering apparatus is known. A sputtering apparatus is an apparatus for forming a thin film on a substrate by using a so-called sputtering phenomenon by introducing a gas for discharge into a vacuum chamber and applying a voltage between electrodes to generate plasma discharge. The sputter phenomenon is a phenomenon in which target particles are ejected when positive ions in plasma collide with a target.

  In manufacturing a display device, when a thin film is deposited in a limited region, a method of forming a thin film through a mask having an opening in the deposition region has been developed (for example, Patent Document 1). In this method, a mask provided with an opening is brought into contact with the film formation surface of the substrate, and a thin film is formed and patterned through the opening.

  For example, in a manufacturing process of an organic electroluminescence (EL) display, a film-forming mask made of a metal is used for coating a light emitting layer that emits red (R), green (G), and blue (B) light. ing.

  Further, it is also used for forming a thin film used as a sealing film for preventing moisture absorption to a light emitting element of a flat panel display such as an organic EL display.

  Here, the surface opposite to the film formation surface of the substrate is brought into close contact with the fixed holding holder on which the magnet is arranged. As a result, the magnet disposed in the fixed holding holder attracts the mask by magnetic force through the substrate, so that the mask and the substrate are in close contact with each other, and the mask is fixed and held on the substrate.

  For example, in Patent Document 2, a plurality of slit-like through-holes parallel to each other are used as a pattern, and a pattern mask made of a ferromagnetic material for forming a constituent element corresponding to the pattern on the substrate, and the plane of the pattern mask A magnetic force attracting means including a single magnet that is magnetized in the vertical direction and has only a specific magnetic pole in the entire pattern formation region of the pattern mask, and the magnetic force attracting means is brought into contact with the pattern mask through the substrate A pattern mask fixing and holding method is disclosed in which the pattern mask is attracted by the magnetic force of the magnet and the pattern mask is held at a predetermined position on the substrate.

JP 2002-217518 A

  However, in the method of Patent Document 1, it is necessary to use a mask according to the model of the display device, and it is necessary to optimize the layout of the magnets arranged in the fixed holding holder for each model (or mask layout). Therefore, there is a problem of lacking mass productivity.

  In the method of Patent Document 1, for example, in the case of sputtering film formation, there is a concern that so-called film unevenness may occur due to a leakage magnetic field formed by a magnet near the film formation surface of the substrate.

  In order to reduce film unevenness, it is conceivable to reduce the leakage magnetic field. However, for example, in the case of so-called vertical in-line sputtering film formation in which the substrate is placed perpendicular to the horizontal plane, the attractive force between the magnet and the mask is weakened, and the mask in contact with the substrate is bent by its own weight. There is a case where If a gap is generated between the mask and the substrate due to this bending, there is a concern that the film-forming material may wrap around the mask shielding portion and so-called film blurring may occur.

  That is, it has been found that there is a trade-off relationship between the control of film unevenness and the control of film blur.

  In view of the above problems, an object of the present invention is to provide a mask holding device that can suppress film blur and film unevenness and can cope with a model change of a display device.

  One aspect of a mask holding device according to the present invention is a plurality of magnets for fixing a mask having a plurality of openings corresponding to film formation regions on a film formation surface of a substrate, and a plurality of magnets are fixedly arranged. And a plurality of magnets are arranged so as to form a magnetic field having a maximum value of 50 G or more and 500 G or less on the film formation surface of the substrate.

It is the perspective view and exploded perspective view explaining the structure of the sputtering device which concerns on one Embodiment of this invention. It is sectional drawing explaining the structure of the sputtering device which concerns on one Embodiment of this invention. It is a partially expanded sectional view explaining the structure of the sputtering device which concerns on one Embodiment of this invention. It is a top view explaining arrangement | positioning of the magnet which the mask holding fixture which concerns on one Embodiment of this invention has. It is a figure explaining the setting of magnetic field simulation. It is a figure explaining the setting of magnetic field simulation. It is a graph which shows the result of a magnetic field simulation.

  Embodiments of the present invention will be described below with reference to the drawings. However, the present invention can be implemented in many different modes and should not be construed as being limited to the description of the embodiments exemplified below. In addition, the drawings may be schematically represented with respect to the width, thickness, shape, and the like of each part in comparison with actual aspects for the sake of clarity of explanation, but are merely examples, and the interpretation of the present invention is not limited. It is not limited. In addition, in the present specification and each drawing, elements similar to those described above with reference to the previous drawings are denoted by the same reference numerals, and detailed description may be omitted as appropriate.

  In this specification, when a member or region is “on (or below)” another member or region, this is directly above (or directly below) the other member or region unless otherwise specified. ) As well as the case above (or below) other members or regions, i.e., another component is included above (or below) other members or regions. Including cases.

<First Embodiment>
[Constitution]
With reference to drawings, the structure of the sputtering apparatus 100 and the mask holding fixture 108 which concern on this embodiment is demonstrated. FIG. 1A is a perspective view illustrating the configuration of a sputtering apparatus 100 according to this embodiment. FIG. 1B is an exploded perspective view illustrating the configuration of the sputtering apparatus 100 according to this embodiment. FIG. 2 is a cross-sectional view illustrating the configuration of the sputtering apparatus 100 according to this embodiment. FIG. 3 is a partially enlarged cross-sectional view illustrating the configuration of the sputtering apparatus 100 according to the present embodiment.

  The sputtering apparatus 100 according to this embodiment includes a vacuum chamber 102, a substrate holding tool 104, a target holding tool 106, and a mask holding tool 108. The sputtering apparatus 100 according to this embodiment is a so-called vertical in-line type that performs film formation by placing a substrate 116 perpendicular to a horizontal plane. In the following description, the direction from the target holding device 106 toward the substrate holding device 104 is “down”, and the direction from the substrate holding device 104 toward the target holding device 106 is “up”.

  The vacuum chamber 102 partitions an external space and a processing space and has, for example, a box shape. The vacuum chamber 102 has a substrate carry-in port 102a, a substrate carry-out port 102b, a gas introduction port 102c, and an exhaust port 102d on its wall portion.

  The substrate carry-in port 102 a is provided on one side surface of the vacuum chamber 102 for carrying the substrate 116 before film formation into the vacuum chamber 102. The substrate carry-out port 102b is provided on the side surface of the vacuum chamber 102 opposite to the side surface where the substrate carry-in port 102a is provided in order to carry the substrate 116 after the film formation process out of the vacuum chamber 102. A substrate transfer means (not shown) is provided inside the vacuum chamber 102. The substrate transport unit has, for example, a carrier on which the substrate 116 is mounted, and is configured to sequentially transport the substrate 116 to a position facing a sputtering target 122 described later.

  The gas inlet 102c is connected to a gas supply system such as a gas supply source via a gas supply pipe (not shown). Thereby, a sputtering gas composed of an inert gas such as argon or a reactive gas used in reactive sputtering can be introduced into the vacuum chamber 102 at a constant flow rate. The exhaust port 102d is connected to a vacuum exhaust system such as a rotary pump or a turbo molecular pump via an exhaust pipe (not shown). Thus, by controlling the gas introduction amount and the exhaust amount, the inside of the vacuum chamber 102 can be maintained at a desired degree of vacuum by a desired gas.

  The substrate holding device 104 is provided in the lower part in the vacuum chamber 102. The substrate holding instrument 104 has a first surface 104a and a second surface 104b opposite to the first surface 104a. The substrate holding device 104 is a member that supports the substrate 116, and the substrate 116 is disposed on the first surface 104a. For example, an upper end portion and a lower end portion of the substrate 116 are fixed to the substrate holding instrument 104 by a substrate pressing member 120 provided in the vacuum chamber 102. The substrate holder 104 is made of a metal material and has conductivity. The substrate holding instrument 104 is connected to a power source 124.

  The target holding device 106 is provided in the upper part of the vacuum chamber 102 so as to face the substrate holding device 104. The target holding device 106 is also called a backing plate, and is a member that supports the sputtering target 122. The sputtering target 122 may be disposed on the first surface 106a side of the target holding device 106 by bonding with a bonding layer (not shown) such as In or In alloy. The target holding device 106 is connected to a power source 124.

  A space between the target holding device 106 and the substrate holding device 104 in the processing chamber inside the vacuum chamber 102 functions as a discharge space. The target holding device 106 is made of a metal material, and copper is used as the metal material, for example. Since the surface of the sputtering target 122 becomes hot during the sputtering film formation, a flow path may be provided in the target holding device 106, and the entire sputtering target 122 may be cooled by flowing a cooling liquid through the flow path during the sputtering film formation. . This can prevent the bonding layer from being dissolved and peeled off. The target holding device 106 is connected to a power source 124 and also functions as an electrode that applies a voltage to the sputtering target 122.

  In this embodiment, a negative voltage is applied to the sputtering target 122 side and a positive voltage is applied to the substrate 116 side to generate a discharge in the discharge space. By this discharge, the gas introduced into the discharge space is turned into plasma, and ions generated thereby are accelerated toward the sputtering target 122 and collide with the sputtering target 122. Thereby, particles constituting the sputtering target 122 are knocked out of the sputtering target 122 and deposited on the substrate 116 to form a thin film.

  The mask holding device 108 is provided below the substrate holding device 104 inside the vacuum chamber 102. The mask holding device 108 includes a plurality of magnets 110 and a fixing member 114.

  Here, on the first surface 104 a side of the substrate holding instrument 104, a mask 118 is disposed in contact with the substrate 116. The mask 118 in this embodiment has a plurality of openings 118a. The plurality of openings 118 a correspond to film formation regions on the film formation surface 116 a of the substrate 116. The mask 118 is made of a metal plate, and the metal material is preferably a metal material having a small linear thermal expansion coefficient. Examples of the metal material having a small linear thermal expansion coefficient include nickel, nickel alloy, iron, stainless steel, aluminum, aluminum alloy, and carbon.

  A thin film is formed and patterned on the substrate 116 through the plurality of openings 118a. An area other than the opening 118a of the mask 118 may be referred to as a shielding part 118b. On the film formation surface 116a of the substrate 116, a thin film is not deposited in a region in contact with the shielding portion 118b of the mask 118.

  The plurality of magnets 110 are provided to fix the mask 118 on the film formation surface 116 a of the substrate 116. The plurality of magnets 110 are disposed on the second surface 104 b side of the substrate holding instrument 104.

  The fixing member 114 fixes and arranges a plurality of magnets. In the present embodiment, the fixing member 114 is disposed such that the plurality of magnets 110 and the second surface 104b of the substrate holding instrument 104 face each other. The plurality of magnets 110 and the second surface 104b of the substrate holding device 104 may be disposed so as to contact each other, or may be disposed such that a gap is formed between them.

  A planar layout of the plurality of magnets 110 will be described. FIG. 4 is a plan view for explaining the arrangement of the magnets 110 included in the mask holding device 108 according to the present embodiment. The plurality of magnets 110 constitute a plurality of magnet groups 112. Each of the plurality of magnet groups 112 includes a plurality of magnets 110 each having an S pole and an N pole that are periodically and linearly connected. The directions of magnetic moments of the plurality of magnets 110 constituting each of the plurality of magnet groups 112 are all equal. Here, the magnetic moment means a magnetic dipole moment. Further, the length direction of each of the plurality of magnet groups 112 is parallel to the direction of the magnetic moment of each of the plurality of magnets 110.

  The plurality of magnet groups 112 are arranged in parallel to each other. In the present embodiment, the plurality of magnet groups 112 are arranged so as to intersect any side of the rectangular substrate 116, and are arranged so that the acute angle side of each side forms approximately 45 °. Yes. In other words, each of the plurality of magnets 110 is arranged so that the long side direction intersects any side of the rectangular substrate 116, and the acute angle side of each side is arranged at approximately 45 °. Has been.

  The magnetic moments of the plurality of magnet groups 112 may all be directed in the same direction (parallel), or may be in a reverse direction (antiparallel) in the adjacent magnet group 112.

  The plurality of magnets 110 form a magnetic field around them, but the magnetic field formed on the mask 118 side with respect to the first surface 104a of the substrate holding device 104 is referred to as a leakage magnetic field in this specification. In this specification, an absolute value of a component perpendicular to the thickness direction of the substrate 116 among magnetic fields formed on the deposition surface 116a of the substrate 116 is referred to as a vertical magnetic field.

  In the present embodiment, the plurality of magnets 110 are arranged on the film formation surface 116a of the substrate 116 so as to form a vertical magnetic field having a maximum value of 50G or more and 500G or less. More preferably, the plurality of magnets 110 are arranged on the film formation surface 116a of the substrate 116 so as to form a vertical magnetic field having a maximum value of 50G or more and 400G or less.

  By having such a configuration, it is possible to provide a mask holding device 108 that can suppress film blurring and film unevenness and can cope with a model change of the display device.

  If the maximum value of the vertical magnetic field formed on the film formation surface 116a of the substrate 116 by the plurality of magnets 110 is smaller than 50G, the attractive force between the substrate 116 and the mask 118 becomes insufficient, and the mask 118 is bent by its own weight. I'll be stuck. When a gap is generated between the mask 118 and the substrate 116 due to this bending, there is a concern that the film forming material may go around the shielding portion 118b of the mask 118 and so-called film blur may occur in the formed thin film. On the other hand, when the maximum value of the vertical magnetic field formed on the film formation surface 116a of the substrate 116 is larger than 500 G, plasma is generated by the leakage magnetic field formed by each of the plurality of magnet groups 112 superimposed during sputtering film formation. Since the density is disturbed, there is a concern that a so-called film unevenness corresponding to the pattern of the plurality of magnet groups 112 may occur in the formed thin film. Therefore, the maximum value of the vertical magnetic field should be designed to be 500 G or less, preferably the maximum value of the vertical magnetic field should be designed to be 400 G, more preferably 200 G or less.

  In the present embodiment, the plurality of magnet groups 112 have been described as being disposed so as to form approximately 45 ° with any side of the rectangular substrate 116, but the present invention is not limited to this. In the plurality of magnet groups 112, the perpendicular magnetic field on the film formation surface 116 a of the substrate 116 only needs to satisfy the above condition, and the angle formed with any side of the rectangular substrate 116 is arbitrary.

  In the present embodiment, a so-called vertical in-line sputtering apparatus that performs film formation by placing the substrate 116 perpendicular to the horizontal plane has been described as an example. However, the present invention is not limited to this. The present invention can also be applied to a sputtering apparatus in which a film is formed by setting the substrate 116 in parallel to a horizontal plane.

  In the present embodiment, each of the plurality of magnet groups 112 has been described with respect to a configuration in which the plurality of magnets 110 are connected in a line, but the present invention is not limited to this. In each of the plurality of magnet groups 112, the vertical magnetic field on the film formation surface 116a of the substrate 116 only needs to satisfy the above-described condition, and the plurality of magnets 110 may be arranged in a line at a constant interval. That is, the S poles of the first magnets constituting the magnet group 112 may be connected to the N poles of the second magnets adjacent to the first magnets, or may be arranged at a certain interval.

  Moreover, although the mask holding instrument 108 which concerns on this embodiment demonstrated the aspect applied to sputtering method as a film-forming method, it is not restricted to this. The mask holder 108 according to the present embodiment can be applied to, for example, a CVD method or a vapor deposition method as a film forming method.

[Film formation method]
Next, a method for forming a thin film using the sputtering apparatus 100 according to this embodiment will be described. First, a sputtering target 122 for forming a desired thin film is placed on the target holding device 106 in the vacuum chamber 102.

  Next, the substrate 116 is placed on the substrate holding device 104 in the external space, and the 118 mask is aligned and brought into contact with the substrate 116. Thereafter, the mask holding device 108 is installed on the second surface 104 b side of the substrate holding device 104, and the mask 118 is fixed to the substrate 116.

  Next, the mask holding device 108, the substrate holding device 104, the substrate 116, and the mask 118, which are integrally fixed, are carried into the vacuum chamber 102 through the substrate carry-in port 102a.

  Next, the inside of the vacuum chamber 102 of the sputtering apparatus 100 is exhausted by a vacuum exhaust system connected to the exhaust port 102d, and the inside of the vacuum chamber 102 is depressurized to a predetermined degree of vacuum.

  Next, an inert gas such as Ar gas is introduced into the vacuum chamber 102 through the gas inlet 102c, and the pressure is increased to a predetermined degree of vacuum.

  Next, a voltage is applied to the sputtering target 122 to generate glow discharge between the sputtering target 122 and the wall surface of the vacuum chamber 102, thereby generating plasma on the substrate 116 side of the sputtering target 122. Ar positively ionized by this plasma is attracted to the sputtering target 122. Then, Ar ions collide with the sputtering target 122, and the constituent particles of the sputtering target 122 are blown off and deposited on the substrate 116. In this way, a thin film is deposited on the surface of the substrate 116.

  At this time, the film thickness of the thin film is calculated according to the distance between the sputtering target 122 and the substrate 116, the power supply frequency applied to the sputtering target 122, the power, and the film formation time so as to have a predetermined film thickness.

  After a thin film having a predetermined thickness is deposited on the substrate 116, the substrate 116 is unloaded from the vacuum chamber 102 through the substrate unloading port 102b.

[Magnetic field simulation]
A layout to be taken by the plurality of magnets 110 and the plurality of magnet groups 112 in order to satisfy the above-described condition of the vertical magnetic field will be described with reference to the result of the magnetic field simulation. 5 and 6 are diagrams for explaining the setting of the magnetic field simulation. FIG. 5 is a diagram for explaining a layout on the plane of the plurality of magnets 110 used in the magnetic field simulation, and FIG. 6 is a diagram for explaining a cross section taken along the line AA ′ of FIG. As illustrated, the plurality of magnet groups 112 have a length direction in the y-axis direction and are arranged in parallel to each other. The short side length W of each of the plurality of magnets 110, the long side length L of each of the plurality of magnets 110, the distance D between two adjacent magnet groups 112, and the film formation of the magnet 110 and the substrate 116 The optimum condition was searched for by the magnetic field simulation for the distance MS to the surface 116a.

  FIG. 7 is a graph showing the results of magnetic field simulation. The horizontal axis is the x coordinate, and the x coordinate of the broken line in the graph corresponds to x0 shown in FIG. The vertical axis represents a vertical magnetic field formed by the plurality of magnet groups 112 on the film formation surface 116 a of the substrate 116. The definition of the vertical magnetic field in this specification is as described above.

  In the magnetic field simulation shown in the graph of FIG. 7, the short side length W of each of the plurality of magnets 110 is 2.5 mm, the long side length L of each of the plurality of magnets 110 is 10 mm, and two adjacent two The distance D between the magnet groups 112 is 15 mm. The graph of FIG. 7 shows the results of three conditions of 3.5 mm, 4.0 mm, and 5.0 mm with respect to the distance MS between the plurality of magnet groups 112 and the film formation surface 116 a of the substrate 116.

  As can be seen from FIG. 7, in particular, if the distance MS between the plurality of magnet groups 112 and the film formation surface 116a of the substrate 116 is 4 mm or more, the absolute value of the vertical magnetic field on the film formation surface 116a of the substrate 116 is 400G or less.

  That is, it is preferable that the plurality of magnets 110 be arranged with an interval of 5 mm or more and 15 mm or less from the film formation surface 116 a (or the mask 118) of the substrate 116.

  If the distance is less than 5 mm, the plasma density is disturbed by the leakage magnetic field formed by each of the stacked magnet groups 112 during sputtering film formation. There is a concern that so-called film unevenness corresponding to the pattern 112 occurs. If the distance is greater than 15 mm, the suction force between the substrate 116 and the mask 118 will be insufficient, and the mask 118 will be bent by its own weight. When a gap is generated between the mask 118 and the substrate 116 due to this bending, there is a concern that the film forming material may go around the shielding portion 118b of the mask 118 and so-called film blur may occur in the formed thin film.

  Each of the plurality of magnet groups 112 preferably has a distance D between 10 mm and 18 mm, and the optimum value is 15 mm.

  If the distance D between adjacent magnet groups 112 is less than 10 mm, the plasma density is disturbed by the leakage magnetic field formed by each of the plurality of magnet groups 112 superimposed during sputtering film formation. In addition, there is a concern that so-called film unevenness corresponding to the pattern of the plurality of magnet groups 112 may occur. If the distance D between adjacent magnet groups 112 is greater than 10 mm, the attractive force between the substrate 116 and the mask 118 will be insufficient, and the mask 118 will be bent by its own weight. When a gap is generated between the mask 118 and the substrate 116 due to this bending, there is a concern that the film forming material may go around the shielding portion 118b of the mask 118 and so-called film blur may occur in the formed thin film.

  Each of the plurality of magnets 110 preferably has a short side length W of 2 mm or more and 4 mm or less, and an optimum value is 2.5 mm.

  If the length W of each short side of the plurality of magnets 110 is smaller than 2 mm, the attractive force between the substrate 116 and the mask 118 will be insufficient, and the mask 118 will be bent by its own weight. When a gap is generated between the mask 118 and the substrate 116 due to this bending, there is a concern that the film forming material may go around the shielding portion 118b of the mask 118 and so-called film blur may occur in the formed thin film. On the other hand, if the length W of each short side of the plurality of magnets 110 is larger than 4 mm, the plasma density is disturbed by the leakage magnetic field formed by each of the plurality of magnet groups 112 superimposed during sputtering film formation. Therefore, there is a concern that so-called film unevenness corresponding to the pattern of the plurality of magnet groups 112 occurs in the formed thin film.

  Each of the plurality of magnets 110 has a long side length L that theoretically does not affect the magnetic field to be formed, and is not particularly defined, but is preferably 10 mm or more and 30 mm or less because it can be easily manufactured. The optimum value is 10 mm.

  The optimal layout of the plurality of magnet groups 112 has been described above with reference to the results of magnetic field simulation.

  An inert gas such as Ar is introduced into the vacuum chamber 102 and the inert gas is turned into plasma. When the ionized inert gas is accelerated toward the sputtering target 122 by the voltage applied between the substrate 116 and the sputtering target 122 and collides, the particles of the material of the sputtering target 122 are ejected, and the deposition surface of the substrate 116 is formed. A thin film is formed by depositing on 116a.

  The mask holding instrument 108 according to the present embodiment and the sputtering apparatus 100 using the same have been described above. According to the sputtering apparatus 100 using the mask holding instrument 108 according to the present embodiment, it is possible to provide a mask holding instrument 108 that can suppress film blurring and film unevenness and can cope with a model change of the display device.

  However, these are merely examples, and the technical scope of the present invention is not limited thereto. Indeed, various modifications will be apparent to those skilled in the art without departing from the spirit of the invention as claimed in the claims. Therefore, it should be understood that these changes also belong to the technical scope of the present invention.

  DESCRIPTION OF SYMBOLS 100: Sputtering apparatus 102: Vacuum chamber 102a: Substrate carrying-in port 102b: Substrate carrying-out port 102c: Gas introduction port 102d: Exhaust port 104: Substrate holding tool 104a: First surface 104b: Second surface 106: Target holding device 108: Mask Holding instrument 110: Magnet 112: Magnet group 114: Fixing member 116: Substrate 116a: Film formation surface 118: Mask 118a: Opening portion 118b: Shielding portion 120: Substrate pressing member 122: Sputtering target 124: Power supply

Claims (8)

A plurality of magnets for fixing a mask having a plurality of openings corresponding to the film formation region on the film formation surface of the substrate;
A fixing member for fixing and arranging the plurality of magnets;
The plurality of magnets are arranged so as to form a magnetic field having a maximum value of 50 G or more and 500 G or less on a film formation surface of the substrate.   2. The mask holding device according to claim 1, wherein the plurality of magnets are arranged so as to form a magnetic field having a maximum value of 50 G or more and 400 G or less on a film formation surface of the substrate.   2. The mask holding device according to claim 1, wherein the plurality of magnets are arranged with an interval of 5 mm or more and 15 mm or less from a film formation surface of the substrate. The plurality of magnets constitute a plurality of magnet groups arranged in parallel to each other,
2. The mask holding device according to claim 1, wherein each of the plurality of magnet groups has a distance from an adjacent magnet group of 10 mm or more and 18 mm or less.   2. The mask holding device according to claim 1, wherein each of the plurality of magnets has a short side length of not less than 2 mm and not more than 4 mm.   2. The mask holding device according to claim 1, wherein each of the plurality of magnets has a long side length of 10 mm or more and 30 mm or less.   The mask holding device according to any one of claims 1 to 6, wherein the plurality of magnets are arranged such that the long side direction intersects any side of the substrate. A vacuum chamber;
A mask holding device according to any one of claims 1 to 7, provided inside the vacuum chamber;
A sputtering apparatus comprising: a target holding instrument arranged to face the mask holding instrument.