Patent Publication Number: US-2017362698-A1

Title: Vapor deposition mask, vapor deposition device, method for manufacturing vapor deposition mask, and vapor deposition method

Description:
TECHNICAL FIELD 
     The present invention relates to a vapor deposition mask, a vapor deposition device, a method of producing the vapor deposition mask, and a vapor deposition method. 
     BACKGROUND ART 
     Recent years have witnessed practical use of a flat-panel display in various products and fields. This has led to a demand for a flat-panel display that is larger in size, achieves higher image quality, and consumes less power. 
     Under such circumstances, great attention has been drawn to an EL display device that (i) includes an EL element which uses electroluminescence (hereinafter abbreviated to “EL”) of an organic or inorganic material and that (ii) is an all-solid-state flat-panel display which is excellent in, for example, low-voltage driving, high-speed response, and light-emitting characteristics. 
     In order to achieve a full-color display, an EL display device includes a luminescent layer which outputs light of a desired color in correspondence with a plurality of sub-pixels constituting a pixel. 
     A luminescent layer is formed as a vapor deposition film on a film formation target substrate. Specifically, in a vapor deposition process, a fine metal mask (FMM) having highly-accurate apertures is used as a vapor deposition mask, and differing vapor deposition particles are vapor-deposited to each area of the film formation target substrate. 
       FIG. 16  is a cross-sectional view, of a film formation target substrate  530  and a vapor deposition mask  510 , illustrating a common conventional vapor deposition method of forming a luminescent layer. 
     According to such a conventional vapor deposition method, vapor deposition particles ejected from a vapor deposition source  520  are vapor-deposited on the film formation target substrate  530  via apertures  512  of the vapor deposition mask  510  while the film formation target substrate  530  and the vapor deposition mask  510  are brought into close contact with each other (see  FIG. 16 ). A vapor deposition film, as a luminescent layer  511  which emits a corresponding color of light, is therefore formed in each of a red sub-pixel area R, a green sub-pixel area G, and a blue sub-pixel area B in correspondence with positions of the respective apertures  512 . 
       FIG. 17  is a cross-sectional view, of the film formation target substrate  530  and the vapor deposition mask  510 , illustrating a problem of the vapor deposition method of forming a luminescent layer. Note that dotted arrows illustrated in  FIG. 17  indicate a path of vapor deposition particles. 
     In a case where a vapor deposition is made while the film formation target substrate  530  and the vapor deposition mask  510  are away from each other (see  FIG. 17 ), a vapor deposition pattern loses its accuracy. This consequently causes a reduction in display quality of an EL display device. 
     Specifically, vapor deposition particles which passed through an aperture  512  and then reached a surface of the vapor deposition mask  510  at an angle smaller than a given angle protrude to an outside of a green sub-pixel area G on which the vapor deposition particles are intended to be vapor-deposited. This causes a luminescent layer to be formed at a position displaced from an intended position of a film formation pattern, and consequently causes a so-called blur in a formed film. 
     Furthermore, a part of the vapor deposition particles which has protruded to the outside of the green sub-pixel area G reaches a red sub-pixel area R adjacent to the green sub-pixel area G. This causes a luminescent layer  511  that emits green light to be formed in the red sub-pixel area R, and consequently causes color mixture in the red sub-pixel area R. 
     Moreover, the vapor deposition particles will not reach a part of the green sub-pixel area G, and therefore no luminescent layer  511  is formed in that part of the green sub-pixel area G. This causes an amount of light emitted by the green sub-pixel area G to be uneven. 
     Note that, in order to prevent an amount of light emitted by a sub-pixel from becoming uneven, rotational film formation can be employed. According to the rotational film formation, a vapor deposition is made while the film formation target substrate  530  and the vapor deposition mask  510  are being rotated about a rotation axis in a direction perpendicular to their respective surfaces. However, in a case where a vapor deposition is made while the film formation target substrate  530  and the vapor deposition mask  510  as illustrated in FIG.  17  are rotated by 180°, vapor deposition particles go beyond the green sub-pixel area G, on which the vapor deposition particles are intended to be vapor-deposited, and reach the blue sub-pixel area B. This causes color mixture in the blue sub-pixel area B. 
     As has been discussed, according to the conventional vapor deposition method, the film formation target substrate  530  and the vapor deposition mask  510  are away from each other while a vapor deposition is made. This causes a vapor deposition pattern to lose its accuracy. Consequently, display quality of the EL display device is reduced in a case where a luminescent layer of an EL display device is formed by using the conventional vapor deposition method. 
     In order to address the above problem, there has been known a technique of making a vapor deposition while a film formation target substrate and a vapor deposition mask are in close contact with each other by magnetic force. According to the above method, (i) a magnetic mask is employed, and (ii) a magnet is provided on a side opposite to a side, of the film formation target substrate, on which the vapor deposition mask is provided. 
     With the above conventional technique, however, the magnetic force does not sufficiently act on the vapor deposition mask. This makes it difficult to cause the film formation target substrate and the vapor deposition mask to be in complete contact with each other. Furthermore, due to factors such as (i) an increase in bending of the vapor deposition mask resulting from an increase in size of the vapor deposition mask and (ii) mixing of a foreign matter in between the film formation target substrate and the vapor deposition mask, it is difficult for the film formation target substrate and the vapor deposition mask to be in complete contact with each other by magnetic force. 
     CITATION LIST 
     Patent Literature 
     [Patent Literature 1] 
     Japanese Patent Application Publication Tokukai No. 2012-89837 (Publication date: May 10, 2012) 
     SUMMARY OF INVENTION 
     Technical Problem 
     Patent Literature 1 discloses a glass-substrate-holding means which holds a glass substrate while a film such as a reflection layer is being formed on the glass substrate. The glass-substrate-holding means disclosed in Patent Literature 1 can hold the glass substrate because it has an attracting section which attracts and holds the glass substrate by van der Waals force. 
     In a case where a vapor deposition mask to which the technique disclosed in Patent Literature 1 is applied so that the vapor deposition mask includes the glass-substrate-holding means having the attracting section is employed when a vapor deposition film is to be formed on a film formation target substrate, a vapor deposition can be made while the film formation target substrate is being attracted to the vapor deposition mask. 
     However, the attracting section of the glass-substrate-holding means disclosed in Patent Literature 1 makes contact merely with a circumferential part of the glass substrate. Therefore, in a case where a vapor deposition is made by using the vapor deposition mask, to which the technique disclosed in Patent Literature 1 is applied so that the vapor deposition mask includes the glass-substrate-holding means having the attracting section, the film formation target substrate and the vapor deposition mask are away from each other at a center part of the vapor deposition mask. This causes a reduction in accuracy of a vapor deposition pattern. 
     The present invention has been attained in view of the above problem, and an objective of the present invention is to provide (i) a vapor deposition mask which can make closer contact with a film formation target substrate so as to achieve an improvement in accuracy of a vapor deposition pattern, (ii) a vapor deposition device, (iii) a method of producing the vapor deposition mask, and (iv) a vapor deposition method. 
     Solution to Problem 
     In order to attain the above objective, a vapor deposition mask in accordance with an aspect of the present invention is a vapor deposition mask having a plurality of apertures used to form a vapor deposition material on a film formation target substrate, the vapor deposition mask including: a fine-irregularities structure, provided on a contact surface of the vapor deposition mask, which is configured to attract, by van der Waals force, the film formation target substrate so as to surround the plurality of the apertures, the contact surface making contact with the film formation target substrate. 
     In order to attain the above objective, a vapor deposition device in accordance with an aspect of the present invention includes: the above vapor deposition mask; and a vapor deposition source configured to deposit the vapor deposition material on the film formation target substrate via the plurality of apertures of the vapor deposition mask. 
     In order to attain the above objective, a method of producing a vapor deposition mask in accordance with an aspect of the present invention is a method of producing a vapor deposition mask, the vapor deposition mask having a plurality of apertures used to form a vapor deposition material on a film formation target substrate, the vapor deposition mask including: a fine-irregularities structure, provided on a contact surface of the vapor deposition mask, which is configured to attract, by van der Waals force, the film formation target substrate so as to surround the plurality of the apertures, the contact surface making contact with the film formation target substrate, the method including the steps of: (a) forming the plurality of apertures in the vapor deposition mask; and (b) forming the fine-irregularities structure on the contact surface. 
     In order to attain the above objective, a vapor deposition method in accordance with an aspect of the present invention is a vapor deposition method of forming a film, having a given pattern, on a film formation target substrate, the method including the steps of: bringing the film formation target substrate into contact with the above vapor deposition mask so as to attract the film formation target substrate to the vapor deposition mask; and depositing the vapor deposition material on the film formation target substrate via the plurality of apertures of the vapor deposition mask. 
     Advantageous Effects of Invention 
     An aspect of the present invention makes it possible to provide a vapor deposition mask which can make closer contact with a film formation target substrate so as to achieve an improvement in accuracy of a vapor deposition pattern. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       (a) of  FIG. 1  is a lateral view illustrating a vapor deposition mask in accordance with Embodiment 1 of the present invention. (b) of  FIG. 1  is a plan view illustrating the vapor deposition mask in accordance with Embodiment 1 of the present invention. 
       (a) of  FIG. 2  is a cross-sectional view illustrating a configuration of the vapor deposition device in accordance with Embodiment 1 of the present invention. (b) of  FIG. 2  is a perspective view illustrating a configuration of a main part of the vapor deposition device in accordance with Embodiment 1 of the present invention. 
         FIG. 3  is a cross-sectional view, of a film formation target substrate and a vapor deposition mask, illustrating a vapor deposition method using the vapor deposition device in accordance with Embodiment 1 of the present invention. 
       (a) of  FIG. 4  is a cross-sectional view, of a film formation target substrate and a vapor deposition mask, illustrating a vapor deposition method using a conventional vapor deposition device. (b) of  FIG. 4  is a cross-sectional view, of a film formation target substrate and a vapor deposition mask, illustrating the vapor deposition method using the vapor deposition device in accordance with Embodiment 1 of the present invention. 
       (a) of  FIG. 5  is a cross-sectional view, of a film formation target substrate and a vapor deposition mask, illustrating a state where an edge part of the vapor deposition mask is in close contact with the film formation target substrate. (b) of  FIG. 5  is a cross-sectional view, of the film formation target substrate and the vapor deposition mask, illustrating a state where the vicinity of the edge part of the vapor deposition mask is in close contact with the film formation target substrate. (c) of  FIG. 5  is a cross-sectional view, of the film formation target substrate and the vapor deposition mask, illustrating a state where the entire vapor deposition mask is in close contact with the film formation target substrate. 
       (a) through (c) of  FIG. 6  are cross-sectional views illustrating how the vapor deposition mask in accordance with Embodiment 1 of the present invention is sequentially produced. 
         FIG. 7  is a lateral view illustrating another example of the vapor deposition device in accordance with Embodiment 1 of the present invention. 
         FIG. 8  is a lateral view illustrating further another example of the vapor deposition device in accordance with Embodiment 1 of the present invention. 
         FIG. 9  is a plan view illustrating a vapor deposition mask and a film formation target substrate in accordance with Embodiment 2 of the present invention in a state where the vapor deposition mask is caused to face the film formation target substrate. 
       (a) of  FIG. 10  is a plan view illustrating a vapor deposition mask and a film formation target substrate in accordance with Embodiment 3 of the present invention in a state where the vapor deposition mask is caused to face the film formation target substrate. (b) of  FIG. 10  is a cross-sectional view taken along a line A-A of (a) of  FIG. 10 . 
         FIG. 11  is a perspective view illustrating a configuration of a main part of a vapor deposition device in accordance with Embodiment 4 of the present invention. 
         FIG. 12  is a lateral view illustrating the vapor deposition mask in accordance with Embodiment 4 of the present invention. 
         FIG. 13  is a plan view illustrating another example of the vapor deposition mask in accordance with Embodiment 4 of the present invention. (b) of  FIG. 13  is a cross-sectional view taken along a line B-B of (a) of  FIG. 13 . 
         FIG. 14  is a perspective view illustrating a configuration of a main part of a vapor deposition device in accordance with Embodiment 5 of the present invention. 
         FIG. 15  is a lateral view illustrating a configuration of a main part of the vapor deposition device in accordance with Embodiment 5 of the present invention. 
         FIG. 16  is a cross-sectional view, of a film formation target substrate and a vapor deposition mask, illustrating a conventionally-common vapor deposition method of forming a luminescent layer. 
         FIG. 17  is a cross-sectional view, of a film formation target substrate and a vapor deposition mask, illustrating a problem of a conventional vapor deposition method of forming a luminescent layer. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Embodiment 1 
     The following description will discuss Embodiment 1 of the present invention with reference to (a) and (b) of  FIG. 1  through  FIG. 8 . 
     Configuration of Vapor Deposition Device  1   
     (a) of  FIG. 2  is a cross-sectional view illustrating a configuration of a vapor deposition device  1  in accordance with Embodiment 1. (b) of  FIG. 2  is a perspective view illustrating a configuration of a main part of the vapor deposition device  1  in accordance with Embodiment 1. 
     The vapor deposition device  1  is a device for forming a vapor deposition film, made of a vapor deposition material  22 , on a film formation area  31  (substrate film formation area) of a film formation target substrate  30 . Note that Embodiment 1 will discuss an example case where the vapor deposition film is formed as a luminescent layer  32  of an EL display device. 
     The vapor deposition device  1  includes a film formation chamber  2 , a vapor deposition mask  10 , a vapor deposition source  20 , a mask frame  15 , a mask holder  41  (vapor deposition mask holding member), a rotation mechanism  45 , a deposition preventing plate (not illustrated), a shutter (not illustrated), and the like. 
     The film formation chamber  2  houses therein the vapor deposition mask  10 , the vapor deposition source  20 , the mask frame  15 , the mask holder  41 , a rotation shaft  46  of the rotation mechanism  45 , the deposition preventing plate, the shutter, and the like. The film formation chamber  2  includes a vacuum pump (not illustrated) which carries out an evacuation of the film formation chamber  2  via an exhaust port (not illustrated) provided in the film formation chamber  2 , so as to be kept in a vacuum during vapor deposition. 
     The vapor deposition source  20  is provided, on a side opposite to a side where the film formation target substrate  30  is provided, so as to face the vapor deposition mask  10 . The vapor deposition source  20  can be, for example, a container which houses therein the vapor deposition material  22 . Note that the vapor deposition source  20  can alternatively be a container which directly houses therein the vapor deposition material  22  or can alternatively be configured to have a pipe of load lock system so that the vapor deposition material  22  is externally supplied. 
     The vapor deposition source  20  has, on its upper surface (i.e., on its surface which faces the vapor deposition mask  10 ), an ejection hole  21  via which the vapor deposition material  22  is ejected as vapor deposition particles. 
     The vapor deposition source  20  generates gaseous vapor deposition particles by heating the vapor deposition material  22  so that the vapor deposition material  22  is (i) evaporated (in a case where the vapor deposition material  22  is a liquid material) or (ii) sublimated (in a case where the vapor deposition material  22  is a solid material). The vapor deposition source  20  ejects, as gaseous vapor deposition particles, the vapor deposition material  22  thus subjected to gasification toward the vapor deposition mask  10  via the ejection hole  21 . 
     Note that each of (a) and (b) of  FIG. 2  illustrates a single vapor deposition source  20 . Embodiment 1 is, however, not limited as such. Alternatively, the vapor deposition device  1  in accordance with Embodiment 1 can include two or more vapor deposition sources  20 . 
     In a case where, for example, a luminescent layer which includes a host material and a dopant material is to be formed as a vapor deposition film, the vapor deposition device  1  can include (i) a first vapor deposition source for vapor-depositing the host material and (ii) a second vapor deposition source for vapor-depositing the dopant material. In a case where a luminescent layer, which includes a host material, a dopant material, and an assist material, is to be formed as a vapor deposition film, the vapor deposition device  1  can include (i) a first vapor deposition source for vapor-depositing the host material, (ii) a second vapor deposition source for vapor-depositing the dopant material, and (iii) a third vapor deposition source for vapor-depositing the assist material. 
     (a) and (b) of  FIG. 2  each illustrate an example case where a cylindrical vapor deposition source  20  having a single ejection hole  21  is provided. A shape of the vapor deposition source  20  and the number of ejection holes  21  are, however, not particularly limited. The vapor deposition source  20  can alternatively have, for example, a rectangular shape. A single vapor deposition source  20  needs to have at least one ejection hole  21 , and can therefore have a plurality of ejection holes  21 . In a case where the vapor deposition source  20  has a plurality of ejection holes  21 , the plurality of ejection holes  21  can be arranged, at equal intervals, in a one-dimensional manner (i.e., in a linear manner) or in a two-dimensional manner (i.e., in a planar (tiled) manner). 
     The mask frame  15 , configured to support the vapor deposition mask  10 , is provided at the back of the vapor deposition mask  10  (see (a) of  FIG. 2 ). 
     The mask frame  15 , whose center part is open, has a frame shape, and is configured to support the vapor deposition mask  10  at its edge part (at its circumferential part). 
     The mask frame  15  is fixed to the vapor deposition mask  10 , while sufficiently laying across the vapor deposition mask  10  in a tensioned state, so that the vapor deposition mask  10  does not bend. Specifically, the mask frame  15  is fixed to the vapor deposition mask  10 , for example, (i) by welding, with the use of laser, a circumferential part of the vapor deposition mask  10  to the mask frame  15  or (ii) by gluing the circumferential part of the vapor deposition mask  10  to the mask frame  15 . Note, however, that the mask frame  15  is not necessarily provided. Alternatively, the vapor deposition mask  10  can be directly mounted to the mask holder  41 . 
     The mask holder  41  includes a mask trestle  42  to which the vapor deposition mask  10  and the film formation target substrate  30  are mounted while they are being kept in close contact with each other. 
     There are provided, down below the mask trestle  42 , a deposition preventing plate (not illustrated), a shutter (not illustrated), and the like which are configured to prevent, from adhesion of an unnecessary vapor deposition material  22 , the vapor deposition mask  10 , the film formation area  31  of the film formation target substrate  30 , the rotation mechanism  40  provided in the film formation chamber  2 , and the like. 
     The rotation mechanism  45  includes (i) the rotation shaft  46 , (ii) a rotation driving section (not illustrated) such as a motor which rotates the rotation shaft  46 , and (iii) a rotation drive control section (not illustrated) configured to control an operation of the rotation driving section (see (a) of  FIG. 2 ). 
     The rotation shaft  46  is coupled to the mask holder  41 . The rotation drive control section controls the rotation driving section, such as a motor, to rotate the rotation shaft  46  as indicated by an arrow in (a) and (b) of  FIG. 2 . The rotation drive control section thus controls the mask holder  41  to rotate. The vapor deposition mask  10  and the film formation target substrate  30 , each of which is held by the mask holder  41 , rotate in response to the rotation of the mask holder  41 . 
     An effect of shadows caused by the vapor deposition mask  10  can be reduced, by thus rotating the vapor deposition mask  10  and the film formation target substrate  30  with use of the rotation mechanism  45  as discussed above. This makes it possible to evenly form a film, made of the vapor deposition material, on the film formation area  31  of the film formation target substrate  30 . 
     Embodiment 1 illustrates an example case where (i) the vapor deposition device  1  is a rotational vapor deposition device and (ii) the vapor deposition device  1  includes the rotation mechanism  45  so as not to be affected by the shadows. The vapor deposition device  1  does, however, not necessarily include the rotation mechanism  45 , provided that the shadows are negligible. 
     Embodiment 1 illustrates an example case where (i) the mask holder  41  includes the mask trestle  42  and (ii) the vapor deposition mask  10  and the film formation target substrate  30  are mounted to the mask trestle  42 . Embodiment 1 is, however, not limited as such. Alternatively, Embodiment 1 can be configured so that (i) a substrate holding member, such as an electrostatic chuck, can be employed as the mask holder  41 , (ii) the film formation target substrate  30  is held by the electrostatic chuck, and (iii) the film formation target substrate  30  and the vapor deposition mask  10  are brought into close contact with each other by a lifting mechanism (not illustrated) on which the vapor deposition mask  10  is placed. It is possible to restrain bending of the film formation target substrate  30 , by holding the film formation target substrate  30  with the use of the electrostatic chuck. 
     Vapor Deposition Mask  10   
     (a) of  FIG. 1  is a lateral view illustrating the vapor deposition mask  10  in accordance with Embodiment 1 of the present invention. (b) of  FIG. 1  is a plan view illustrating the vapor deposition mask  10  in accordance with Embodiment 1 of the present invention. 
     The vapor deposition mask  10  is prepared for forming, on the film formation target substrate  30 , a vapor deposition film made of the vapor deposition material  22 . 
     The vapor deposition mask  10  has a plurality of mask aperture areas  11 , which face respective film formation areas  31  of the film formation target substrate  30  when the vapor deposition mask  10  is placed to face the film formation target substrate  30  (see (b) of  FIG. 1 ). Each of the plurality of mask aperture areas  11  has a plurality of through-holes, serving as respective apertures  12 , which are arranged in a matrix manner so that vapor deposition particles (vapor deposition material  22 ) pass therethrough during vapor deposition. 
     Examples of the vapor deposition mask  10  can include a resin mask, a metal mask, and a mask having a structure in which a resin layer (e.g., resin mask) and a metal layer (e.g., metal mask) are laminated. 
     Examples of a metal employed as a material of which the vapor deposition mask  10  is made include magnetic metals such as iron, nickel, invar (alloy of iron and nickel), and stainless steel SUS430. Out of such magnetic metals, invar, which is an alloy of iron and nickel, can be suitably employed because it is hard to deform due to heat. 
     Note, however, that the metal is not limited to magnetic metal particles, and a non-magnetic metal can be alternatively employed as the metal. 
     Examples of a resin used as a material of which the vapor deposition mask  10  is made include polyimide, polyethylene, polyethylene naphthalate, polyethylene terephthalate, and epoxy resin. Those resins can be employed alone or in combination. 
     It is possible to form, by use of laser processing or the like, the apertures  12  with high accuracy, by employing the resins alone or in combination as a material of which the vapor deposition mask  10  is made. This allows an improvement in accuracy of positioning of the respective apertures  12  in a mask body  16 , and consequently allows an improvement in accuracy of a pattern of a vapor deposition film. 
     According to the example illustrated in (b) of  FIG. 2 , (i) the film formation target substrate  30  has four film formation areas  31  each having a slot shape and (ii) the vapor deposition mask  10  has four mask aperture areas  11  in conformity with the four film formation areas  31 . The film formation areas  31  and the mask aperture areas  11  are each not particularly limited in shape and number as above. For example, (i) the film formation areas  31  can each have a slit shape and/or (ii) the film formation target substrate  30  can have six film formation areas  31  in conformity with corresponding ones of the mask aperture areas  11  illustrated in (b) of  FIG. 1 . 
     The vapor deposition mask  10  includes the mask body  16  having a plate shape (see (a) and (b) of  FIG. 1 ). A fine-irregularities structure  14 , which attracts, by van der Waals force, the film formation target substrate  30 , is provided on a surface of the mask body  16 , which surface faces the film formation target substrate  30  (i.e., a contact surface which makes contact with the film formation target substrate  30 ), so as to surround each of the apertures  12  of the mask body  16 . 
     The fine-irregularities structure  14  is provided on at least a part of a contact area in which, out of all surfaces of the vapor deposition mask  10 , the contact surface makes contact with the film formation target substrate  30 . 
     According to Embodiment 1, the fine-irregularities structure  14  is provided across the contact area in which, out of all surfaces of the vapor deposition mask  10 , the contact surface makes contact with the film formation target substrate  30 . In other words, the fine-irregularities structure  14  is provided on an entire area (shaded part illustrated in (b) of  FIG. 1 ), other than the apertures  12 , of a front surface of the vapor deposition mask  10 . 
     The fine-irregularities structure  14  is composed of a plurality of long and thin structural elements  13  each protruding from the front surface of the mask body  16 . 
     The plurality of structural elements  13 , which constitute the fine-irregularities structure  14 , are each made of (i) a material which is identical to that of the mask body  16  or (ii) a material which is obtained by, for example, corroding the front surface of the mask body  16  so that the front surface is denatured (e.g., oxidized). The plurality of structural elements  13  and the mask body  16  are formed monolithically. 
     The plurality of structural elements  13  are formed so that, for example, (i) each of the plurality of structural elements  13  has a length (height measuring from the front surface of the mask body  16 ) of several micrometers and a diameter of several hundreds of nanometers and (ii) the plurality of structural elements  13  are provided on the front surface of the mask body  16  so as to have a density of 10 10  structural elements/cm 2 . 
     The plurality of structural elements  13  are therefore flexible and has a structure which can attract, by van der Waals force, the film formation target substrate  30  when they are brought into contact with the film formation target substrate  30 . 
     Structure of Fine-Irregularities Structure  14   
     The following description will discuss a preferable structure of the fine-irregularities structure  14  which causes intermolecular force, which is required to bring the vapor deposition mask  10  and the film formation target substrate  30  into close contact with each other, to act on a contact surface between the vapor deposition mask  10  and the film formation target substrate  30 . 
     In a case where the vapor deposition mask  10  is to be brought into close contact with the film formation target substrate  30  in a state where the film formation target substrate  30  is provided on a downside of the vapor deposition mask  10  in a vertical direction, a downward force acting, in the vertical direction, on the contact surface between the vapor deposition mask  10  and the film formation target substrate  30  is expressed by 0.0098×X(N), i.e., approximately (1/102)×X(N), where (i) X(gram) indicates a mass of the film formation target substrate  30  and (ii) 1 gf (1 gram-force)=0.0098N. 
     A condition to be satisfied by the vapor deposition mask  10  being in close contact with the film formation target substrate  30  is expressed by the following inequality (1): 
         F&gt; (1/102)× X    (1)
 
     where F(N) indicates an attraction force of the entire plurality of structural elements  13  provided on the vapor deposition mask  10  (i.e., intermolecular force acting on the film formation target substrate  30  and the vapor deposition mask  10 ). 
     Note that in a case where the vapor deposition mask  10  is to be brought into close contact with the film formation target substrate  30  in a state where the film formation target substrate  30  is provided on an upper side of the vapor deposition mask  10  in the vertical direction, a mass of the vapor deposition mask  10  is indicated by X(gram) in the above inequality (1). 
     By satisfying the above inequality (1), the intermolecular force acting on the film formation target substrate  30  and the vapor deposition mask  10  becomes sufficient. 
     Note, however, that, in a case where an excessive intermolecular force acts on the film formation target substrate  30  and the vapor deposition mask  10 , it becomes difficult, after the vapor deposition film is formed, to peel off the vapor deposition mask  10  from the film formation target substrate  30 . The vapor deposition mask  10  can be damaged in a case where such an excessive force acts on the vapor deposition mask  10  when the vapor deposition mask  10  is peeled off from the film formation target substrate  30 . 
     Note that, in a case where a vapor deposition mask  10  is made of an invar alloy, an NI alloy, or the like, its tensile strength is approximately 400 N/mm 2 , and in a case where a vapor deposition mask  10  is made of polyimide or the like, its tensile strength is approximately 50 N/mm 2 . 
     In view of the fact, it is preferable that the intermolecular force, acting on the film formation target substrate  30  and the vapor deposition mask  10 , is smaller than the tensile strength of the vapor deposition mask  10 . This allows the vapor deposition mask  10  to be easily peeled off from the film formation target substrate  30 , without damaging the vapor deposition mask  10 . 
     That is, a condition, under which the vapor deposition mask  10  is peeled off from the film formation target substrate  30  without damaging the vapor deposition mask  10 , is expressed by the following inequality (2): 
         F&lt;Y×S    (2)
 
     where Y indicates the tensile strength of the vapor deposition mask  10  and S indicates an area in which the plurality of structural elements  13  make contact with the film formation target substrate  30 . By satisfying the inequality ( 2 ), it is possible to easily peel off the vapor deposition mask  10  from the film formation target substrate  30 , while preventing the vapor deposition mask  10  from being damaged due to stress caused by a mechanical action (lifting-up and lifting-down) which occurs when the vapor deposition mask  10  is to be peeled off from the film formation target substrate  30 . 
     The intermolecular force F is expressed by the following expression (3): 
         F=F   0   ×S    (3)
 
     where F 0  indicates the intermolecular force acting on the plurality of structural elements  13  per unit surface area and S indicates an area in which the plurality of structural elements  13 , which cause the intermolecular force, make contact with the film formation target substrate  30 . 
     A range of the intermolecular force F 0  acting on the plurality of structural elements  13  per unit surface area and a range of the area S, in which the plurality of structural elements  13 , which causes the intermolecular force, make contact with the film formation target substrate  30 , are therefore expressed by the following inequality (4): 
       (1/102)× X&lt;F   0   ×S&lt;Y×S    (4)
 
     By determining (i) the intermolecular force F 0  acting on the plurality of structural elements  13  per unit surface area and (ii) the area S in which the plurality of structural elements  13  make contact with the film formation target substrate  30  so that the above (i) and (ii) satisfy the above inequality (4), it is possible that (a) the vapor deposition mask  10  and the film formation target substrate  30  are securely in close contact with each other and (b) the vapor deposition mask  10  is peeled off from the film formation target substrate  30  without damaging the vapor deposition mask  10 . 
     The area S, in which the plurality of structural elements  13  make contact with the film formation target substrate  30 , can alternatively be determined, based on the above inequality (4) based on the mass X of the film formation target substrate  30 , the tensile strength Y of the vapor deposition mask  10 , and the intermolecular force F 0  acting on the plurality of structural elements  13  per unit surface area. 
     Intermolecular Force Caused by Fine-Irregularities Structure  14   
     The following description will discuss a case where the vapor deposition mask  10  and the film formation target substrate  30  are to be brought into contact with each other in a state where the film formation target substrate  30  is provided on the underside of the vapor deposition mask  10  in the vertical direction. 
     The film formation target substrate  30  has a mass of approximately 15,212 grams in a case where a substrate having, for example, a density of 2.5 g/cm 3  and a G10 size (305 cm×285 cm×0.07 cm) is employed as the film formation target substrate  30 . It follows that the downward force acting, in the vertical direction, on a contact area between the vapor deposition mask  10  and the film formation target substrate  30  is approximately 149 (N). As such, in order for the film formation target substrate  30  and the vapor deposition mask  10  to be in close contact with each other, it is necessary to form the fine-irregularities structure  14  so that the intermolecular force, acting on the film formation target substrate  30  and the vapor deposition mask  10 , exceeds 149 (N). 
     In a case of employing, for example, a film formation target substrate  30  having a density of 2.5 g/cm 3  and a size of 32 cm×40 cm×0.07 cm, the film formation target substrate  30  has a mass of 224 grams. In such a case, the downward force, acting on the contact area between the vapor deposition mask  10  and the film formation target substrate  30 , in the vertical direction is approximately 2.2 (N). In a state where the vapor deposition mask  10  and the film formation target substrate  30  are in contact with each other and in a case where (i) the intermolecular force, per unit surface area of the plurality of structural elements  13 , which acts on the contact surface between the vapor deposition mask  10  and the film formation target substrate  30 , in the vertical direction is 8.3 N/cm 2  and (ii) the intermolecular force, per unit surface area of the plurality of structural elements  13 , which acts on the contact surface between the vapor deposition mask  10  and the film formation target substrate  30 , in a parallel direction is 2.3 N/cm 2 , it is possible to realize a stress sufficient for the vapor deposition mask  10  and the film formation target substrate  30  to be in close contact with each other, provided that the fine-irregularities structure  14  is formed in at least 1 cm 2  in total on the vapor deposition mask  10 . 
     The following description will discuss a case where the vapor deposition mask  10  and the film formation target substrate  30  are to be brought into contact with each other in a state where the film formation target substrate  30  is provided on the underside of the vapor deposition mask  10  in the vertical direction. 
     The vapor deposition mask  10  has a mass of 0.04×Z (gram), in a case where an invar alloy, employed as the vapor deposition mask  10 , (i) has a density of approximately 8 g/cm 3 , (ii) has a contact area in which, out of all surfaces of the vapor deposition mask  10 , the contact surface makes contact with the film formation target substrate is Z cm 2  and (iii) has a thickness of 50 μm. Accordingly, the downward force acting on the contact area between the vapor deposition mask  10  and the film formation target substrate  30  is expressed by 4×Z×10 −4 (N). 
     The intermolecular force acting on the contact surface between the vapor deposition mask  10  and the film formation target substrate  30  is 8.3×Z(N) in a case where the intermolecular force, acting on the plurality of structural elements  13 , is 8.3 N/cm 2  per unit surface area in a state where the vapor deposition mask  10  and the film formation target substrate  30  are in close contact with each other. 
     That is, the intermolecular force (8.3×Z(N)) acting on the contact surface between the vapor deposition mask  10  and the film formation target substrate  30  is four or more orders of magnitude greater than that of the downward force (4×Z×10 −4 (N)) acting on the contact area between the vapor deposition mask  10  and the film formation target substrate  30  in the vertical direction. 
     Note that the intermolecular force F 0, , acting on the plurality of structural elements  13  per unit surface area, falls within a range from approximately 0.1 N/mm 2  to 20 N/mm 2 , though it varies depending on a material, a length, and a diameter of each of the plurality of structural elements  13 . 
     Length of Structural Element  13   
     In order to reduce vapor deposition shadows so that the accuracy of a vapor deposition pattern is improved, it is preferable that the vapor deposition mask  10  is thin. In order to cause the vapor deposition mask  10  to be thin in thickness, it is preferable that a structural element  13  is short. 
     However, if (i) a foreign matter of greater than a structural element  13  is mixed in between the vapor deposition mask  10  and the film formation target substrate  30  or (ii) the vapor deposition mask  10  has a bending of greater than a structural element  13 , then the structural element  13  does not come into contact with the film formation target substrate  30 . This causes the vapor deposition mask  10  to be away from the film formation target substrate  30 . 
     A length of the structural element  13  is therefore preferably determined in accordance with (i) the bending of the vapor deposition mask  10  due to its own weight and (ii) a size of a foreign matter which happens to be mixed in between the vapor deposition mask  10  and the film formation target substrate  30 . 
     The vapor deposition mask  10  normally has a bending of approximately 100 μm. The foreign matter, which happens to be mixed in between the vapor deposition mask  10  and the film formation target substrate  30 , normally has a size of several micrometers in a normal direction of the film formation target substrate  30 . 
     As such, the structural element  13  preferably has a length falling within a range from, for example, several micrometers to 100 micrometers. 
     In order to further reduce the thickness of the vapor deposition mask  10 , it is more preferable that the vapor deposition mask  10  and the film formation target substrate  30  are brought into close contact with each other in a state where the structural element  13  has a length falling within a range from several hundreds of nanometers to 50 micrometers so that a foreign matter on the order of several micrometers is removed and the bending of the vapor deposition mask  10  is reduced as much as possible. 
     Thickness of Structural Element  13   
     In a case where (i) a structural element  13  has a small diameter and (ii) a foreign matter is mixed in between the vapor deposition mask  10  and the film formation target substrate  30 , the structural element  13 , which has come into contact with the foreign matter, easily deforms. This makes it possible for an intermolecular distance to be kept close between (i) a molecule constituting a structural element  13  which has not come into contact with the foreign matter and (ii) a molecule constituting the film formation target substrate  30 . This ultimately allows an improvement in degree of adhesion of the vapor deposition mask  10  to the film formation target substrate  30 . As such, the structural element  13  preferably has a small diameter. 
     Specifically, the structural element  13  preferably has a diameter of not greater than several micrometers, more preferably has a diameter of not greater than several hundreds of nanometers, and still more preferably has a diameter of not greater than several tens of nanometers. 
     Note, however, that it is not easy to form, on the mask body  16 , a structural element  13  having a diameter of not greater than several tens of nanometers. Even though such a structural element  13 , having a diameter of not greater than several tens of nanometers, can be successfully formed, it is likely that the structural element  13  is insufficient in strength. This being the case, the structural element  13  preferably has a diameter falling within a range from 50 nm to 500 nm. 
     Density of Structural Elements  13   
     The plurality of structural elements  13  are provided on a surface of the mask body  16  which surface faces the film formation target substrate  30 , so as to have a density that is determined in accordance with necessary intermolecular force. More specifically, such a density is determined in accordance with a mass of one of the vapor deposition mask  10  or the film formation target substrate  30 , which one is provided, in the vapor deposition step, on the underside of the other in the vertical direction. The following description will discuss a case where a vapor deposition is made in a state where the film formation target substrate  30  is provided on the underside of the vapor deposition mask  10  in the vertical direction. 
     The following description will discuss a case where a G10 substrate having, for example, a size of 305 cm×285 cm×0.07 cm is employed as the film formation target substrate  30 . 
     In a case where the G10 substrate has a density of 2.5 g/cm 3 , the G10 substrate has a mass of 305×285×0.07×2.5≈15 kg. It follows that the downward force of approximately 150 N acts on the contact surface between the vapor deposition mask  10  and the film formation target substrate  30 . 
     In a case where the apertures  12  occupy a space of ½ of the surface of the mask body  16  which surface faces the film formation target substrate  30 , an area in which the plurality of structural elements  13  are provided is 305×285÷2≈44,000 cm 2 . 
     Therefore, in order for the vapor deposition mask  10  and the film formation target substrate  30  to be in close contact with each other, it is necessary that the intermolecular force of not lower than 150 N acts on the plurality of structural elements  13  provided in an area of 44,000 cm 2 . That is, it is necessary that the intermolecular force of 150 N/44000 cm 2 ≈0.003 N/cm 2  acts on the plurality of structural elements  13  per unit surface area. 
     Note that the intermolecular force caused by a single structural element  13  is 10 μN. It follows that the plurality of structural elements  13  are preferably provided so as to have a density of not lower than 0.003 N/cm 2 ÷10 μN/structural element=340 structural elements/cm 2 . 
     Note, however, that (i) even in a case where a theoretically sufficient intermolecular force can act on the plurality of structural elements  13  and (ii) in a case where the plurality of structural elements  13  are provided so as to have an extremely low density, an area of a part becomes small in which an intermolecular distance between (a) a molecule constituting a structural element  13  and (b) a molecule constituting the film formation target substrate  30  comes close to several Angstroms (Å). This makes it impossible (i) to fill a gap between the foreign matter and the vapor deposition mask  10  and (ii) for the vapor deposition mask  10  and the film formation target substrate  30  to be in close contact with each other so that the plurality of structural elements  13  wrap (cover a surface of) the foreign matter. 
     This consequently causes no effective intermolecular force to act, around the foreign matter, on the vapor deposition mask  10  and the film formation target substrate  30 , and ultimately causes the vapor deposition mask  10  and the film formation target substrate  30  to be prevented from being in close contact with each other. 
     In view of the fact, the density at which the plurality of structural elements  13  are provided is preferably set in accordance with the diameter of the plurality of structural elements  13 . In a case where a preferable range of the diameter of the plurality of structural elements  13  is, for example, from several tens of nanometers to several hundreds of nanometers, the plurality of structural elements  13  preferably occupy a space of (10×10 −7 ) 2  cm 2 /structural element to (100×10 −7 ) 2  cm 2 /structural element when viewed from above. That is, the plurality of structural elements  13  are preferably provided so as to have a density which falls within a range from 10 10  structural elements/cm 2  to 10 12  structural elements/cm 2 . 
     Vapor Deposition Method 
     According to a vapor deposition method using the vapor deposition device  1 , the film formation target substrate  30  is first brought into contact with the vapor deposition mask  10  so that the film formation target substrate  30  is attracted to the vapor deposition mask  10  (film formation target substrate attracting step). While the vapor deposition mask  10  and the film formation target substrate  30  are in close contact with each other, the vapor deposition material  22  is deposited on the film formation target substrate  30  via the apertures  12  of the vapor deposition mask  10  (vapor deposition material depositing step). 
     This makes it possible to form a vapor deposition film, having a given pattern, on the film formation area  31  of the film formation target substrate  30 . 
     The vapor deposition method in accordance with Embodiment 1 can be employed as a method of producing an EL display device, such as an organic EL display device or an inorganic EL display device which includes a luminescent layer, in a case where, for example, the luminescent layer  32  is to be formed as a vapor deposition film on a vapor deposition surface of the film formation target substrate  30 . 
     The vapor deposition device  1  in accordance with Embodiment 1 can be also employed as a device for producing an EL display device, such as an organic EL display device or an inorganic EL display device, which includes a luminescent layer  32 . 
     Close Contact Between Vapor Deposition Mask  10  and Film Formation Target Substrate  30   
       FIG. 3  is a cross-sectional view, of the film formation target substrate  30  and the vapor deposition mask  10 , illustrating the vapor deposition method using the vapor deposition device  1  in accordance with Embodiment 1. 
     As has been discussed, the mask body  16  has, on its surface, the fine-irregularities structure  14  constituted by the plurality of structural elements  13  (see (a) of  FIG. 1  and  FIG. 3 ). With the configuration, the vapor deposition mask  10  attracts the film formation target substrate  30  because of intermolecular force (van der Waals force). 
     The film formation target substrate  30  has, on its surface, (i) irregularities which its base substrate inherently has and/or (ii) irregularities caused by, for example, wirings, electrodes, and driving elements provided on the film formation target substrate  30 . 
     It follows that the vapor deposition mask  10  will not attract the film formation target substrate  30  in a case where (i) the mask body  16  does not have thereon the fine-irregularities structure  14  and (ii) the film formation target substrate  30  and the vapor deposition mask  10  are merely brought into contact with each other. Consequently, it is not possible to bring the film formation target substrate  30  and the vapor deposition mask  10  into close contact with each other. 
     According to Embodiment 1, however, as has been discussed, since the fine-irregularities structure  14  is provided on the contact surface, of the vapor deposition mask  10 , which makes contact with the film formation target substrate  30 , i.e., the contact surface, of the mask body  16 , which makes contact with the film formation target substrate  30 , the van der Waals force acts to allow the vapor deposition mask  10  to attract the film formation target substrate  30  so as to come into close contact with the film formation target substrate  30 . 
     As has been discussed, the structural element  13  has a diameter, for example, on the order of a micron or less and preferably on the order of a submicron or less. The structural element  13  is therefore flexible and deformable. The structural element  13  constituting the fine-irregularities structure  14  thus has (i) a diameter smaller than the irregularities on the surface of the film formation target substrate  30  and (ii) flexibility. As such, the structural element  13  gets in between irregularities on the surface of the film formation target substrate  30  when the film formation target substrate  30  and the vapor deposition mask  10  are brought into contact with each other. This causes a significant increase in area of the part in which the intermolecular distance between (a) the molecule constituting the structural element  13  and (b) the molecule constituting the film formation target substrate  30  comes close to several Angstroms (A). This causes van der Waals force to act on the film formation target substrate  30  and the vapor deposition mask  10 , and consequently causes the film formation target substrate  30  and the vapor deposition mask  10  to be brought into close contact with each other. 
     Since the fine-irregularities structure  14  are provided so as to surround the plurality of the apertures  12 , it is possible for the vapor deposition mask  10  and the film formation target substrate  30  to securely be in close contact with each other, particularly around the apertures  12 . 
     This makes it possible to form a vapor deposition film (luminescent layer  32 ) on the film formation target substrate  30  in a state where the vapor deposition mask  10  and the film formation target substrate  30  are in close contact with each other so that the vapor deposition mask  10  is prevented from being raised around the apertures  12 . This consequently allows an improvement in accuracy of the vapor deposition pattern. 
     The fine-irregularities structure  14  is preferably formed across the contact area in which the vapor deposition mask  10  makes contact with the film formation target substrate  30 . This allows the vapor deposition mask  10  and the film formation target substrate  30  to be in close contact with each other across the contact area, by van der Waals force. It is therefore possible that the vapor deposition mask  10  and the film formation target substrate  30  are sufficiently in close contact with each other across the contact area. 
     In a case where, for example, the vapor deposition device  1  is employed to form, as a vapor deposition film, a luminescent layer  32  of an EL display device, it is possible to prevent vapor deposition particles, which are to be formed in an intended sub-pixel area, from reaching an unintended sub-pixel area. This makes it possible to prevent a deterioration in display quality due to a blur of a formed film, color mixture, and uneven luminescence in a single pixel which are caused by a reduction in accuracy of the vapor deposition pattern. 
     (a) of  FIG. 4  is a cross-sectional view, of a film formation target substrate  530  and a vapor deposition mask  510 , illustrating a vapor deposition method using a conventional vapor deposition device. (b) of  FIG. 4  is a cross-sectional view, of the film formation target substrate  30  and the vapor deposition mask  10 , illustrating the vapor deposition method using the vapor deposition device  1  in accordance with Embodiment 1. 
     According to the conventional vapor deposition method, (i) the vapor deposition mask  510  made of a magnetic substance is employed and (ii) a magnet  590  is provided on a side opposite to a side, of the film formation target substrate  530 , on which the vapor deposition mask  510  is provided. A vapor deposition is made in a state where the generated magnetic force keeps attracting the vapor deposition mask  510  toward the film formation target substrate  530 . 
     In the above method, however, the magnetic force does not sufficiently act on the vapor deposition mask  510  and therefore the vapor deposition mask  510  bends due to its own weight. This causes the vapor deposition mask  510  and the film formation target substrate  530  to be away from each other particularly in a center part of the vapor deposition mask  510 . 
     Furthermore, in a case where a foreign matter is mixed in between the film formation target substrate  530  and the vapor deposition mask  510 , the film formation target substrate  530  and the vapor deposition mask  510  are away from each other in a part where the foreign matter is mixed. Moreover, since the vapor deposition mask  510  is highly rigid, the film formation target substrate  530  and the vapor deposition mask  510  are away from each other not only in the part where the foreign matter is mixed but also across a contact surface where the vapor deposition mask  510  makes contact with the film formation target substrate  530 . 
     This causes a reduction in accuracy in a case where a vapor deposition pattern is formed by the conventional vapor deposition method. 
     In contrast, according to the vapor deposition mask  10  in accordance with Embodiment 1, the fine-irregularities structure  14  is formed on a surface, of the vapor deposition mask  10 , which faces the film formation target substrate  30 . This causes a significant increase in area of a part in which the intermolecular distance between (i) the molecule constituting the structural element  13  and (ii) the molecule constituting the film formation target substrate  30  comes close to several Angstroms (Å). 
     This causes intermolecular force to be sufficiently act on the vapor deposition mask  10  and the film formation target substrate  30 , and consequently allows the vapor deposition mask  10  and the film formation target substrate  30  to be in close contact with each other. 
     Even in a case where a foreign matter mixed in between the vapor deposition mask  10  and the film formation target substrate  30 , a structural element  13  which is in contact with the foreign matter deforms so that a intermolecular distance is kept small between (i) a molecule constituting a structural element  13  which does not come into contact with the foreign matter and (ii) the molecule constituting the film formation target substrate  30 . Furthermore, since the plurality of structural elements  13  deform along a surface of the foreign matter, it is possible to fill a gap between the foreign matter and the vapor deposition mask  10 . 
     As has been discussed above, even in a case where a foreign matter is mixed in between the vapor deposition mask  10  and the film formation target substrate  30 , intermolecular force sufficiently acts on the vapor deposition mask  10  and the film formation target substrate  30 . It is therefore possible to keep the vapor deposition mask  10  and the film formation target substrate  30  in close contact with each other. 
     This makes it possible to improve accuracy of the vapor deposition pattern. 
     The following description will discuss how the vapor deposition mask  10  and the film formation target substrate  30  are brought into close contact with each other. 
     (a) of  FIG. 5  is a cross-sectional view, of the film formation target substrate  30  and the vapor deposition mask  10 , illustrating a state where an edge part of the vapor deposition mask  10  is in close contact with the film formation target substrate  30 . (b) of  FIG. 5  is a cross-sectional view, of the film formation target substrate  30  and the vapor deposition mask  10 , illustrating a state where a vicinity of the edge part of the vapor deposition mask  10  is in close contact with the film formation target substrate  30 . (c) of  FIG. 5  is a cross-sectional view, of the film formation target substrate  30  and the vapor deposition mask  10 , illustrating a state where the entire vapor deposition mask  10  is in close contact with the film formation target substrate  30 . 
     Bending of a conventional large vapor deposition mask increases from its edge part toward its center part due to its own weight. This causes inadequate contact between the vapor deposition mask and a film formation target substrate. 
     In contrast, according to the vapor deposition mask  10  in accordance with Embodiment 1, the fine-irregularities structure  14  is provided across the contact area in which the contact surface makes contact with the film formation target substrate  30 . This makes it possible to cause the entire vapor deposition mask  10  to be in close contact with the film formation target substrate  30 . The following description will more specifically discuss how the vapor deposition mask  10  and the film formation target substrate  30  are brought into close contact with each other. 
     In the step of causing the film formation target substrate  30  to attract the vapor deposition mask  10  (film formation target substrate attracting step), the vapor deposition mask  10  whose edge part is supported by the mask frame  15  is approached to the film formation target substrate  30  (see (a) of  FIG. 5 ). 
     In so doing, since the vapor deposition mask  10  bends due to its own weight, a fine-irregularities structure  14 , provided in a center part of the vapor deposition mask  10 , does not come into contact with the film formation target substrate  30 . However, since the vapor deposition mask  10  is supported by the mask frame  15 , the bending of the vapor deposition mask  10  is small in its edge part. This causes the fine-irregularities structure  14 , provided around the edge part of the vapor deposition mask  10 , to come into contact with the film formation target substrate  30 . The intermolecular force, caused by the fine-irregularities structure  14 , causes the edge part of the vapor deposition mask  10  to come into close contact with the film formation target substrate  30 . 
     Since the edge part of the vapor deposition mask  10  has come into close contact with the film formation target substrate  30 , a part of the vapor deposition mask  10 , which part is closer to the center part than to the edge part, is then attracted toward the film formation target substrate  30 , and comes into close contact with the film formation target substrate  30  by the intermolecular force of the fine-irregularities structure  14  (see (b) of  FIG. 5 ). A part of the vapor deposition mask  10  which part has come into close contact with the film formation target substrate  30  causes the other part of the vapor deposition mask  10  to come close to a distance where the intermolecular force occurs between the vapor deposition mask  10  and the film formation target substrate  30 . This causes the vapor deposition mask  10  to come into close contact with the film formation target substrate  30  successively from the edge part to the center part. 
     The vapor deposition mask  10  is therefore brought into close contact with the film formation target substrate  30  so as to follow a surface shape of the film formation target substrate  30 . 
     Consequently, the vapor deposition mask  10  comes into close contact with the film formation target substrate  30  across a surface of the vapor deposition mask  10  which surface faces the film formation target substrate  30  (see (c) of  FIG. 5 ). 
     Note that the intermolecular force, acting on the vapor deposition mask  10  and the film formation target substrate  30 , has an anisotropy. For example, in a state where the vapor deposition mask  10  and the film formation target substrate  30  are in close contact with each other, (i) the intermolecular force which acts in a direction perpendicular to the contact surface between the vapor deposition mask  10  and the film formation target substrate  30  is 8.3 N/cm 2  per unit surface area and (ii) the intermolecular force which acts in a direction parallel to the contact surface between the vapor deposition mask  10  and the film formation target substrate  30  is 2.3 N/cm 2  per unit surface area. 
     In a case where the vapor deposition mask  10  is to be peeled off from the film formation target substrate  30  after a vapor deposition film is formed on the film formation target substrate  30 , it is possible for the vapor deposition mask  10  to be away from the film formation target substrate  30 , by applying force in a direction, for example, at an angle of 30° with the contact surface. 
     Method of Producing Vapor Deposition Mask  10   
     The following description will discuss a method of producing the vapor deposition mask  10  in accordance with Embodiment 1. 
     Each of (a) through (c) of  FIG. 6  is a cross-sectional view illustrating how the vapor deposition mask  10  in accordance with Embodiment 1 is sequentially produced. 
     The following description will discuss the method of producing the vapor deposition mask  10  in which method a casting mold  60  (stamp) whose one side has a plurality of protrusions  61  is employed to form a fine-irregularities structure  14  on a metal plate  50  (see (a) of  FIG. 6 ). 
     The metal plate  50 , in which a plurality of apertures  12  have already been formed, is first caused to face the casting mold  60  whose plurality of protrusions  61  are impregnated with a liquid which can corrode or dissolve a metal (see (a) of  FIG. 6 ). 
     Subsequently, the plurality of protrusions  61  of the casting mold  60  are pressed against a surface of the metal plate  50  (see (b) of  FIG. 6 ). 
     This causes parts of the surface of the metal plate  50 , which parts are in contact with the plurality of protrusions  61 , to be corroded or dissolved. Consequently, t the plurality of protrusions  61  of the casting mold  60  are transferred to the surface of the metal plate  50  (see (c) of  FIG. 6 ). This allows production of a vapor deposition mask  10  which has, on its surface, the fine-irregularities structure  14  constituted by a plurality of structural elements  13 . 
     Examples of the liquid, which can corrode or dissolve metal, include acidic liquids, such as dilute hydrochloric acid and dilute sulfuric acid. 
     The casting mold  60  is made of a material which (i) is resistant to an acidic liquid and (ii) can be impregnated with such an acidic liquid. Examples of such a material include a crosslinkable resin and a crosslinkable rubber, and a crosslinkable polydimethylsiloxane (PDMS) elastomer is preferably employed as the material. 
     The plurality of protrusions  61  can be patterned all over the casting mold  60  by a conventionally-known method. Preferably, the plurality of protrusions  61  are directly patterned on the casting mold  60  by thermal nano-imprinting or UV nano-imprinting. 
     In the step of impregnating the casting mold  60  with an acidic liquid, the casting mold  60  can be entirely immersed in the acidic liquid. Alternatively, only the plurality of protrusions  61  can be immersed in the acidic liquid. Immersion time can be adjusted as appropriate in accordance with, for example, an immersion speed of a liquid, a size of the casting mold  60 , and the like. Such immersion time is for approximately several hours. 
     A pressure under which the casting mold  60  is pressed against the metal plate  50  is preferably adjusted as appropriate while measuring a length of a part of the plurality of protrusions  61  which part intrudes into the metal plate  50 . This makes it possible to produce a vapor deposition mask  10  having a plurality of structural elements  13  each having a given length. 
     The plurality of apertures  12  can be formed in the metal plate  50  by etching, laser irradiation, or the like. Note, however, that such processes can damage the plurality of structural elements  13 . 
     In view of the damage, it is possible to restrain the damage of the plurality of structural elements  13  caused in the step (aperture forming step) of forming the apertures  12 , by carrying out the step (fine-irregularities structure forming step) of forming the fine-irregularities structure  14 , so that the vapor deposition mask  10  is produced, with respect to the apertures in the metal plate  50  in which the apertures are formed in advance by carrying out the step of forming the apertures in the metal plate  50 . 
     Note that the method of producing the vapor deposition mask  10  is not limited to the above method. Alternatively, the vapor deposition mask  10  can be produced by carrying out the step of forming the plurality of apertures  12  (aperture forming step) with respect to the metal plate  50  on which the plurality of structural elements  13  have already been formed in the step of forming the fine-irregularities structure  14  with respect to the metal plate  50  (fine-irregularities structure forming step). 
     A vapor deposition mask  10  made of a resin can be produced by employing a resin plate instead of the metal plate  50 . In a case where the vapor deposition mask  10  made of resin is to be produced, the plurality of structural elements  13  can be formed on a surface of the resin plate by carrying out thermal nano-imprinting or UV nano-imprinting with respect to the resin plate. 
     Variation 1 of Vapor Deposition Device  1   
       FIG. 7  is a lateral view illustrating Variation 1 of the vapor deposition device  1  in accordance with Embodiment 1. 
     A vapor deposition device  1  in accordance with Variation 1 includes (i) a mask frame  15  which supports an edge part of a vapor deposition mask  10 , (ii) a mask trestle  71  on which the mask frame  15  can be placed, and (iii) a mask-lifting mechanism  70  which can lift up and down the mask trestle  71  (see  FIG. 7 ). 
     The mask frame  15 , the mask trestle  71 , and the mask-lifting mechanism  70  constitute a holding member which (i) holds the vapor deposition mask  10  and (ii) lifts up and down the vapor deposition mask  10 . 
     With the above configuration, it is possible for a fine-irregularities structure  14  to be in close contact with a vapor deposition surface of a film formation target substrate  30 , by lifting up the vapor deposition mask  10  toward the film formation target substrate  30  in a state where the vapor deposition mask  10  and the film formation target substrate  30  faces each other. 
     Note that the mask-lifting mechanism  70  is not particularly limited, provided that it can lift up and down the mask trestle  71 . Alternatively, the mask-lifting mechanism  70  can be configured to (i) lift up and down a mask holder, including the mask trestle  71 , with use of an actuator or (ii) lift up and down such a mask holder by winding up and down a wiring connected to the mask holder. Note that the mask holder  41  illustrated in (a) of  FIG. 2  can be employed as the above mask holder. Furthermore, the mask-lifting mechanism  70  can include the rotation mechanism  45  illustrated in (a) of  FIG. 2 . 
     Variation  2  of Vapor Deposition Device  1   
       FIG. 8  is a lateral view illustrating Variation 2 of the vapor deposition device  1  in accordance with Embodiment 1. 
     A vapor deposition device  1  in accordance with Variation 2 includes (i) a presser plate  80  which is a plate member provided on a film formation target substrate  30  attracted to a vapor deposition mask  10  and (ii) a presser-lifting mechanism  81  which can lift up and down the presser plate  80  so as to apply a load to the film formation target substrate  30  (see  FIG. 8 ). 
     The presser plate  80  and the presser-lifting mechanism  81  constitute a presser member which (i) causes the vapor deposition mask  10  and the film formation target substrate  30  to be in closer contact with each other and (ii) prevents a positional displacement of the film formation target substrate  30 . 
     This makes it possible to prevent a positional displacement of the vapor deposition mask  10  to the film formation target substrate  30  in the vapor deposition step. 
     Note that the presser-lifting mechanism  81  can be configured to (i) lift up and down the presser plate  80  with use of an actuator or (ii) lift up and down the presser plate  80  by winding up and down a wiring connected to the presser plate  80 . 
     Embodiment 2 
     The following description will discuss Embodiment 2 of the present invention with reference to  FIG. 9 . Note that, for convenience, any member of Embodiment 2 that is identical in function to a corresponding member described in Embodiment 1 is given an identical reference numeral, and descriptions of such members are omitted. 
       FIG. 9  is a plan view illustrating a vapor deposition mask  110  and a film formation target substrate  30  in accordance with Embodiment 2 in a state where the vapor deposition mask  110  is caused to face the film formation target substrate  30 . 
     The vapor deposition mask  110  is identical in configuration to the vapor deposition mask  10  in accordance with Embodiment 1, except that it has, on the surface (contact surface) which faces the film formation target substrate  30 , a structural element removal area  111  in which no fine-irregularities structure  14  is provided (see  FIG. 9 ). 
     The structural element removal area  111  is provided around an edge part of the contact surface of the vapor deposition mask  110 . More specifically, the structural element removal area  111  is provided (around a circumferential edge part) so that it surrounds an outer circumference of the film formation target substrate  30 , when viewed from above, in a state where the vapor deposition mask  110  and the film formation target substrate  30  are in close contact with each other. 
       FIG. 9  illustrates an example where the structural element removal area  111  has a four-sided frame shape. Note, however, that the shape of the structural element removal area  111  is not limited as such. Alternatively, the structural element removal area  111  can have (i) a one-sided linear shape or (ii) a non-continuous block (banded) shape. 
     In a case where the intermolecular force is excessive which acts on the film formation target substrate  30  and the vapor deposition mask  110 , it becomes difficult to peel off the vapor deposition mask  110  from the film formation target substrate  30  after a vapor deposition film is formed. To address such a problem, according to Embodiment 2, the structural element removal area  111  is provided in the edge part (circumferential edge part), of the vapor deposition mask  110 , which is away from a group of mask aperture areas  11  of the vapor deposition mask  110 . This causes a reduction in the adhesion of the film formation target substrate  30  to the vapor deposition mask  110 , and consequently allows the vapor deposition mask  110  to be easily peeled off from the film formation target substrate  30 . 
     With the configuration, mechanical force is applied, in a direction perpendicular to the contact surface, to an edge part of the vapor deposition mask  110  or the film formation target substrate  30  when the vapor deposition mask  110  is away from the film formation target substrate  30 . This allows force to be applied, in an oblique direction, to the structural elements  13  via the structural element removal area  111 . This makes it possible to easily separate the vapor deposition mask  110  from the film formation target substrate  30 . 
     It is preferable that force is applied to an area where no structural element  13  is provided, when the vapor deposition mask  110  is to be away from the film formation target substrate  30 . This makes it possible for the vapor deposition mask  110  to be more easily separated from the film formation target substrate  30 . 
     As has been discussed, according to Embodiment 2, (i) the fine-irregularities structure  14  is provided around the plurality of apertures  12 , of the vapor deposition mask  110 , which are involved in accuracy of the pattern of a vapor deposition film, so that the vapor deposition mask  110  is prevented from being raised around the plurality of apertures  12  and (ii) the intermolecular force is reduced in a part (edge part of the vapor deposition mask  110 ) which is not involved in accuracy of the pattern of the vapor deposition film. This makes it possible (i) for the vapor deposition mask  110  to be securely in close contact with the film formation target substrate  30  and (ii) for the vapor deposition mask  110  to be easily separated from the film formation target substrate  30 . 
     As with the vapor deposition mask  10  in accordance with Embodiment 1, the fine-irregularities structure  14  is provided around the plurality of apertures  12 . This makes it possible for the vapor deposition mask  110  to be securely in close contact with the film formation target substrate  30  around the plurality of apertures  12 . The vapor deposition mask  110  in accordance with Embodiment 2 can therefore be prevented from being raised around the plurality of apertures  12 . 
     It is further possible for the vapor deposition mask  110  to be easily separated from the film formation target substrate  30 , by applying the force to the structural element removal area  111 . 
     Since the structural element removal area  111  is provided in the edge part of the contact surface, which makes contact with the film formation target substrate  30 , it is possible for the vapor deposition mask  110  and the film formation target substrate  30  to be securely in close contact with each other and for the vapor deposition mask  110  to be partially away from the film formation target substrate  30 . 
     Embodiment 3 
     The following description will discuss Embodiment 3 of the present invention with reference to (a) and (b) of  FIG. 10 . Note that, for convenience, any member of Embodiment 3 that is identical in function to a corresponding member described in Embodiments 1 and 2 is given an identical reference numeral, and descriptions of such members are omitted. 
     (a) of  FIG. 10  is a plan view illustrating a vapor deposition mask  210  and a film formation target substrate  30  in accordance with Embodiment 3 in a state where the vapor deposition mask  210  is caused to face the film formation target substrate  30 . (b) of  FIG. 10  is a cross-sectional view taken along a line A-A of (a) of  FIG. 10 . 
     The vapor deposition mask  210  is identical in configuration to the vapor deposition masks  10  and  110  in accordance with respective Embodiments 1 and 2, except that (i) it has, on a contact surface where the vapor deposition mask  210  makes contact with the film formation target substrate  30 , a structural element removal area  211  in which the fine-irregularities structure  14  is not provided and (ii) it has, in the structural element removal area  211 , suction holes  216  via which vacuum-attraction is caused (see (a) of  FIG. 10 ). 
     Note that the suction holes  216  of the vapor deposition mask  210  are provided so as to extend in a mask frame  215  (see (b) of  FIG. 10 ). 
     This makes it possible for the film formation target substrate  30  to be attracted to the vapor deposition mask  210 , via the suction holes  216 , by vacuum-attraction. Since the film formation target substrate  30  is also attracted to an area in which no fine-irregularities structure  14  is provided, the film formation target substrate  30  and the vapor deposition mask  210  can be in close contact with each other. 
     Embodiment 4 
     The following description will discuss Embodiment 4 of the present invention with reference to  FIG. 11  through (a) and (b) of  FIG. 13 . Note that, for convenience, any member of Embodiment 4 that is identical in function to a corresponding member described in Embodiments 1 through 3 is given an identical reference numeral, and descriptions of such members are omitted. 
       FIG. 11  is a perspective view illustrating a configuration of a main part of a vapor deposition device  301  in accordance with Embodiment 4. 
       FIG. 12  is a lateral view illustrating a vapor deposition mask  310  in accordance with Embodiment 4. 
     The vapor deposition mask  310  included in the vapor deposition device  301  in accordance with Embodiment 4 is identical in configuration to the vapor deposition masks  10 ,  110 , and  210  in accordance with respective Embodiments 1 through 3, except that it includes a mask body  16  having a laminated structure which includes a resin layer  310 A and a metal layer  310 B (see  FIG. 11  and  FIG. 12 ). The vapor deposition mask  310  and the film formation target substrate  30  are in contact with each other via the resin layer  310 A of the vapor deposition mask  310 . A fine-irregularities structure  14  is provided on the resin layer  310 A. 
     A conventional metal vapor deposition mask is hard to reduce in thickness to several tens of micrometers or smaller. This makes it difficult to form apertures with high accuracy. Furthermore, a conventional resin vapor deposition mask is easy to twist and bend. This makes it difficult to form a vapor deposition film in an intended location in the vapor deposition step. 
     In contrast, (i) the vapor deposition mask  310  is composed of the resin layer  310 A and the metal layer  310 B and (ii) the metal layer  310 B has a function of supporting the resin layer  310 A. This makes it possible to (i) form, by using the resin layer  310 A, a vapor deposition pattern with high definition and (ii) prevent, by using the metal layer  310 B, the vapor deposition mask  310  from twisting and bending. 
     Furthermore, by causing the resin layer  310 A to serve as the contact surface which makes contact with the film formation target substrate  30 , it is possible to easily and accurately form, by printing or the like, the fine-irregularities structure  14  on the resin layer  310 A. 
     (a) of  FIG. 13  is a plan view illustrating another example of the vapor deposition mask  310  in accordance with Embodiment 4. (b) of  FIG. 13  is a cross-sectional view taken along a line B-B of (a) of  FIG. 13 . 
     In a case where the vapor deposition mask  310  in accordance with Embodiment 4 employs the metal layer  310 B merely as a member for supporting the resin layer  310 A, the metal layer  310 B can be formed, at given intervals, in a linear manner on a rear surface of the resin layer  310 A (see (b) of  FIG. 13 ). 
     Embodiment 5 
     The following description will discuss Embodiment 5 of the present invention with reference to  FIGS. 14 and 15 . Note that, for convenience, any member of Embodiment 5 that is identical in function to a corresponding member described in Embodiments 1 through 4 is given an identical reference numeral, and descriptions of such members are omitted. 
       FIG. 14  is a perspective view illustrating a configuration of a main part of a vapor deposition device  401  in accordance with Embodiment 5. 
       FIG. 15  is a lateral view illustrating the configuration of the main part of the vapor deposition device  401  in accordance with Embodiment 5. 
     The vapor deposition device  401  is identical in configuration to the vapor deposition devices  1  and  301  in accordance with Embodiments 1 through 4, except that it includes a magnet plate  90  (magnetically-attracting member) which is provided, during vapor deposition, so as to face a vapor deposition mask  410  via a film formation target substrate  30  (see  FIG. 14 ). 
     As with the vapor deposition mask  310  in accordance with Embodiment 4, (i) the vapor deposition mask  410  included in the vapor deposition device  401  in accordance with Embodiment 5 includes a resin layer  410 A and a metal layer  410 B and (ii) a fine-irregularities structure  14  is provided on the resin layer  410 A (see  FIGS. 14 and 15 ). 
     Since (i) the vapor deposition mask  410  includes the metal layer  410 B and (ii) the magnet plate  90  is provided on a rear surface of the film formation target substrate  30 , magnetic force acts on the metal layer  410 B. This causes the vapor deposition mask  410  to be attracted, and consequently allows an improvement in adhesion of the vapor deposition mask  410  to the film formation target substrate  30 . 
     Because of the fine-irregularities structure  14  provided on the resin layer  410 A, the vapor deposition mask  410  and the film formation target substrate  30  can be in close contact with each other by intermolecular force. It is possible that the film formation target substrate  30  and the vapor deposition mask  410  are more securely in close contact with each other, because the film formation target substrate  30  and the vapor deposition mask  410  are thus in close contact with each other by both of (i) the intermolecular force caused by the fine-irregularities structure  14  and (ii) the magnetic force caused by the magnet plate  90 . 
     Main Points 
     A vapor deposition mask ( 10 ,  110 ,  210 ,  310 ,  410 ) in accordance with a first aspect of the present invention is a vapor deposition mask having a plurality of apertures ( 12 ) used to form a vapor deposition material ( 22 ) on a film formation target substrate ( 30 ), the vapor deposition mask including: a fine-irregularities structure ( 14 ), provided on a contact surface of the vapor deposition mask, which is configured to attract, by van der Waals force, the film formation target substrate so as to surround the plurality of the apertures, the contact surface making contact with the film formation target substrate. 
     With the above configuration, it is possible for the vapor deposition mask and the film formation target substrate to be in close contact with each other even in a case where the vapor deposition mask is bending or a foreign matter is adhering to the vapor deposition mask, because the film formation target substrate is attracted to the vapor deposition mask by van der Waals force caused by the fine-irregularities structure. 
     The fine-irregularities structure which is provided so as to surround the plurality of apertures makes it possible for the vapor deposition mask and the film formation target substrate to be in close contact with each other around the plurality of apertures. 
     This makes it possible to prevent a mask from being raised around the plurality of apertures, which is a most important point to prevent (i) color mixture and/or (ii) uneven luminescence in a single pixel. It is therefore possible to provide a vapor deposition mask which allows a vapor deposition pattern to be formed with high definition. 
     The vapor deposition mask in accordance with a second aspect of the present invention can be configured such that, in the first aspect of the present invention, the vapor deposition mask has a laminated structure which includes a metal layer ( 310 B) and a resin layer ( 310 A), the resin layer serving as the contact surface. 
     According to the above configuration, by causing the resin layer to serve as the contact surface, it is possible to easily and accurately form, by printing or the like, the fine-irregularities structure on the contact surface. Furthermore, the above configuration makes it possible to form, by using the resin layer, a vapor deposition pattern with high definition and (ii) prevent, by using the metal layer, the vapor deposition mask from twisting and bending. 
     The vapor deposition mask in accordance with a third aspect of the present invention can be configured such that, in the first or second aspect of the present invention, the following inequality is satisfied: 
         W/ 102&lt; F 0× S&lt;Y×S  
 
     where W indicates a mass of the film formation target substrate, F0 indicates van der Waals force acting on the fine-irregularities structure per unit surface area, S indicates a total area of the fine-irregularities structure, and Y indicates a tensile strength of the vapor deposition mask. 
     According to the above configuration, by forming the fine-irregularities structure whose F 0 ×S satisfies the above inequality, it is possible for the vapor deposition mask and the film formation target substrate to be securely in close contact with each other and (ii) for the vapor deposition mask to be away from the film formation target substrate without causing the vapor deposition mask to be damaged due to stress, which occurs when the vapor deposition mask is to be separated from the film formation target substrate. 
     The vapor deposition mask in accordance with a fourth aspect of the present invention can be configured such that, in any one of the first through third aspects of the present invention, the fine-irregularities structure is provided across the contact area in which the contact surface makes contact with the film formation target substrate. 
     The above configuration makes it possible for the vapor deposition mask and the film formation target substrate to be in close contact with each other, by using van der Waals force, across the contact area in which the vapor deposition mask makes contact with the film formation target substrate. It is therefore possible to that the vapor deposition mask and the film formation target substrate are sufficiently in close contact with each other across the contact area. 
     The vapor deposition mask in accordance with a fifth aspect of the present invention can be configured such that, in any one of the first through third aspects of the present invention, an area (structural element removal area  211 ), where no fine-irregularities structure is provided, is secured in an edge part of the contact surface. 
     The above configuration makes it possible to prevent a mask from being raised around the plurality of apertures, which is a most important point to prevent (i) color mixture and/or (ii) uneven luminescence in a single pixel. Furthermore, it is possible for the vapor deposition mask to be easily separated from the film formation target substrate by applying force to an area in which no fine-irregularities structure is provided. Note that, normally, bending of the vapor deposition mask due to its own weight is large at its center part and is comparatively small at its edge part. 
     Since the area, in which no fine-irregularities structure is provided, is provided in the edge part of the contact surface which makes contact with the film formation target substrate, it is possible for the vapor deposition mask and the film formation target substrate to be securely in close contact with each other and for the vapor deposition mask to be partially away from the film formation target substrate. 
     The vapor deposition mask in accordance with a sixth aspect of the present invention can be configured to further have, in the fifth aspect of the present invention, the area has a suction hole ( 216 ) for vacuum-attraction. 
     The above configuration makes it possible for the vapor deposition mask and the film formation target substrate to be in close contact with each other by causing vacuum-attraction via the suction hole. This makes it possible, to a certain extent, for the vapor deposition mask and the film formation target substrate to be in close contact with each other also in an area in which no fine-irregularities structure is provided. It is therefore possible to prevent the vapor deposition mask from being comprehensively raised above the film formation target substrate. 
     A vapor deposition device ( 1 ,  301 ,  401 ) in accordance with a seventh aspect of the present invention can include: a vapor deposition mask in accordance with any one of the first through sixths aspect of the present invention; and a vapor deposition source ( 20 ) configured to deposit the vapor deposition material on the film formation target substrate via the plurality of apertures of the vapor deposition mask. 
     According to the above configuration, the vapor deposition mask is provided so that it is possible to form a vapor deposition pattern with high definition. 
     The vapor deposition device in accordance with an eighth aspect of the present invention can be configured to further include, in the seventh aspect of the present invention, a holding member configured to hold the vapor deposition mask, the holding member including a lifting mechanism ( 70 ) configured to lift up and down the vapor deposition mask. 
     According to the above configuration, the lifting mechanism which lifts up and down the vapor deposition mask makes it possible for the fine-irregularities structure to more securely follow a surface shape of the film formation target substrate. 
     The vapor deposition device in accordance with a ninth aspect of the present invention can be configured to further include, in the seventh or eighth aspect of the present invention, a presser member (presser plate  80 , presser-lifting mechanism  81 ) configured to press, from above the film formation target substrate, the film formation target substrate which has been attracted to the vapor deposition mask. 
     The above configuration makes it possible to prevent a substrate from displacement while a film is being formed in the vapor deposition step. 
     The vapor deposition device in accordance with a tenth aspect of the present invention can be configured such that, in the seventh or eighth aspect of the present invention, the vapor deposition mask has a metal layer, the vapor deposition device further including: a magnetically-attracting member (magnet plate  90 ) provided so as to face the vapor deposition mask via the film formation target substrate which has been attracted to the vapor deposition mask, the magnetically-attracting member attracting the metal layer by magnetic force. 
     It is possible that the film formation target substrate and the vapor deposition mask to be more securely in close contact with each other, because the film formation target substrate and the vapor deposition mask are in contact with each other by both of (i) van der Waals force caused by the fine-irregularities structure and (ii) the magnetic force. 
     A method of producing a vapor deposition mask in accordance with an eleventh aspect of the present invention can be a method of producing a vapor deposition mask, the vapor deposition mask having a plurality of apertures used to form a vapor deposition material on a film formation target substrate, the vapor deposition mask including: a fine-irregularities structure, provided on a contact surface of the vapor deposition mask, which is configured to attract, by van der Waals force, the film formation target substrate so as to surround the plurality of the apertures, the contact surface making contact with the film formation target substrate, the method including the steps of: (a) forming the plurality of apertures in the vapor deposition mask; and (b) forming the fine-irregularities structure on the contact surface. 
     The above method makes it possible to provide a vapor deposition mask which allows a vapor deposition pattern to be formed with high definition. 
     The method of producing a vapor deposition mask in accordance with a twelfth aspect of the present invention can be configured such that, in the eleventh aspect of the present invention, a metal (metal plate  50 ) serves as the contact surface; and in the step (b), a casting mold ( 60 ), impregnated with a liquid which corrodes or dissolves the metal, is brought into contact with the contact surface so that a pattern of the casting mold is transferred to a surface of the metal. 
     The above method makes it possible for the fine-irregularities structure to be easily formed on the contact surface, of the vapor deposition mask, which makes contact with the film formation target substrate, in a case where the contact surface is made of metal. 
     A method of producing a vapor deposition mask in accordance with a thirteenth aspect of the present invention can be configured such that, in the eleventh aspect of the present invention, a resin serves as the contact surface; and in the step (b), the fine-irregularities structure is printed on the contact surface. 
     The above method makes it possible for the fine-irregularities structure to be easily formed on the contact surface, of the vapor deposition mask, which makes contact with the film formation target substrate, in a case where the contact surface is made of resin. 
     A vapor deposition method in accordance with a fourteenth aspect of the present invention can be a vapor deposition method of forming a film, having a given pattern, on a film formation target substrate, the method including the steps of: (a) bringing the film formation target substrate into contact with a vapor deposition mask in accordance with any one of the first through sixth aspects of the present invention so as to attract the film formation target substrate to the vapor deposition mask; and (b) depositing the vapor deposition material on the film formation target substrate via the plurality of apertures of the vapor deposition mask. 
     With the above vapor deposition method, it is possible for the vapor deposition mask and the film formation target substrate to be in close contact with each other in the step (a) even in a case where the vapor deposition mask is bending or a foreign matter is adhering to the vapor deposition mask, because the film formation target substrate is attracted to the vapor deposition mask by van der Waals force caused by the fine-irregularities structure. 
     The fine-irregularities structure which is provided so as to surround the plurality of apertures makes it possible for the vapor deposition mask and the film formation target substrate to be in close contact with each other around the plurality of apertures. 
     This makes it possible to prevent, in the step (b), a mask from being raised around the plurality of apertures, which is a most important point to prevent (i) color mixture and/or (ii) uneven luminescence in a single pixel. The above vapor deposition method therefore makes it possible to form a vapor deposition pattern with high definition. 
     The present invention is not limited to the embodiments, but can be altered by a skilled person in the art within the scope of the claims. An embodiment derived from a proper combination of technical means each disclosed in a different embodiment is also encompassed in the technical scope of the present invention. Further, it is possible to form a new technical feature by combining the technical means disclosed in the respective embodiments. 
     INDUSTRIAL APPLICABILITY 
     The present invention is suitably applicable to production of, for example, (i) an organic EL element, (ii) an inorganic EL element, (iii) an organic EL display device including the organic EL element, and (iv) an inorganic EL display device including the inorganic EL element. 
     REFERENCE SIGNS LIST 
     
         
           1 ,  301 ,  401 : Vapor deposition device 
           10 ,  210 ,  310 ,  410 : Vapor deposition mask 
           11 : Mask aperture area 
           12 : Aperture 
           14 : Fine-irregularities structure 
           15 ,  215 : Mask frame (holding member) 
           16 : Mask body 
           20 : Vapor deposition source 
           30 : Film formation target substrate 
           50 : Metal plate 
           60 : Casting mold 
           70 : Mask-lifting mechanism (lifting mechanism) 
           71 : Mask trestle (holding member) 
           80 : Presser plate (presser member) 
           81 : Presser-lifting mechanism (presser member) 
           90 : Magnet plate (magnetically-attracting member) 
           111 ,  211 : Structural element removal area (area in which no fine-irregularities structure is provided) 
           216 : Suction hole 
           310 A,  410 A: Resin layer 
           310 B,  410 B: Metal layer