JP7454934B2 - Vapor deposition mask and its manufacturing method - Google Patents

Description

One embodiment of the present invention relates to a deposition mask. In particular, one embodiment of the present invention relates to a tapered vapor deposition mask and a method for manufacturing the same.

Examples of flat panel display devices include liquid crystal display devices and organic EL (electroluminescence) display devices. These display devices are structures in which thin films containing various materials such as insulators, semiconductors, and conductors are laminated on a substrate. By appropriately patterning and connecting these thin films, a function as a display device is realized.

Methods for forming thin films are broadly classified into gas phase methods, liquid phase methods, and solid phase methods. Gas phase methods are classified into physical vapor phase methods and chemical vapor phase methods. A vapor deposition method is known as a typical example of a physical vapor phase method. The simplest vapor deposition method is the vacuum vapor deposition method. The vacuum evaporation method sublimates or evaporates the material by heating the material under high vacuum to generate vapor of the material (hereinafter, these are generally referred to as vaporization). In a region for depositing this material (hereinafter referred to as a vapor deposition region), the vaporized material is solidified and deposited to obtain a thin film of the material. Vacuum deposition is performed using a mask (deposition mask) so that a thin film is selectively formed in the deposition area and no material is deposited in other areas (hereinafter referred to as non-deposition areas). (See Patent Documents 1 and 2).

JP2009-87840A JP2013-209710A

Patent Document 1 and Patent Document 2 disclose a vapor deposition mask in which a vapor deposition region is formed of a thin film. In order to ensure a margin in the vapor deposition process, the vapor deposition mask preferably has a tapered shape when viewed from the vapor deposition source side. In order to form a vapor deposition mask into a tapered shape, it is necessary to add a taper angle to the resist pattern used when producing the vapor deposition mask. However, it is difficult to process a resist pattern into a tapered shape using a photomask.

An object of one embodiment of the present invention is to provide a vapor deposition mask for vapor deposition having a tapered shape and a method for manufacturing the same.

A vapor deposition mask according to an embodiment of the present invention includes a thin film-like mask body provided with a plurality of openings, and each of the plurality of openings extends from a first surface to a second surface of the mask body by a thickness thereof. The side wall between the first surface and the second surface of each of the plurality of openings has a tapered portion of 45° or more and 85° or less.

A method for manufacturing a vapor deposition mask according to an embodiment of the present invention includes preparing a substrate, applying a photoresist on a first surface of the substrate, and coating a part of the photoresist with a first wavelength and the first wavelength. irradiate the photoresist with light having a different second wavelength and remove the exposed portion of the photoresist to form a resist pattern on the first surface of the substrate; The method includes forming a metal layer in areas exposed from the pattern, removing the resist pattern, and removing the substrate.

FIG. 1 is a top view of a vapor deposition apparatus according to an embodiment of the present invention. FIG. 1 is a side view of a vapor deposition apparatus according to an embodiment of the present invention. 1 is a cross-sectional view of a deposition source according to an embodiment of the present invention. It is a top view of the vapor deposition mask concerning one embodiment of the present invention. FIG. 1 is an enlarged view of a vapor deposition mask according to an embodiment of the present invention. FIG. 1 is a cross-sectional view of a vapor deposition mask according to an embodiment of the present invention. FIG. 1 is a cross-sectional view of a vapor deposition mask according to an embodiment of the present invention. FIG. 1 is an enlarged cross-sectional view of a vapor deposition mask according to an embodiment of the present invention. 1 is a cross-sectional view showing a method for manufacturing a vapor deposition mask according to an embodiment of the present invention. 1 is a cross-sectional view showing a method for manufacturing a vapor deposition mask according to an embodiment of the present invention. 1 is a plan view showing a method for manufacturing a vapor deposition mask according to an embodiment of the present invention. 1 is a cross-sectional view showing a method for manufacturing a vapor deposition mask according to an embodiment of the present invention. 1 is a cross-sectional view showing a method for manufacturing a vapor deposition mask according to an embodiment of the present invention. 1 is a cross-sectional view showing a method for manufacturing a vapor deposition mask according to an embodiment of the present invention. 1 is a cross-sectional view showing a method for manufacturing a vapor deposition mask according to an embodiment of the present invention. It is a top view showing the manufacturing method of the vapor deposition mask concerning one embodiment of the present invention. FIG. 3 is a SEM cross-sectional view of a resist pattern. FIG. 3 is a SEM cross-sectional view of a resist pattern. FIG. 3 is a SEM cross-sectional view of a resist pattern. FIG. 3 is a SEM cross-sectional view of a resist pattern. FIG. 3 is a SEM cross-sectional view of a resist pattern. FIG. 3 is a SEM cross-sectional view of a resist pattern. FIG. 3 is a SEM cross-sectional view of a resist pattern. FIG. 3 is a SEM cross-sectional view of a resist pattern. FIG. 1 is a top view of a display device according to an embodiment of the present invention. 1 is a cross-sectional view of a display device according to an embodiment of the present invention. 1 is a cross-sectional view of a display device according to an embodiment of the present invention. 1 is a cross-sectional view of a display device according to an embodiment of the present invention. 1 is a cross-sectional view of a display device according to an embodiment of the present invention. 1 is a cross-sectional view of a display device according to an embodiment of the present invention. 1 is a cross-sectional view of a display device according to an embodiment of the present invention. 1 is a cross-sectional view of a display device according to an embodiment of the present invention.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. However, the present invention can be implemented in various forms without departing from the scope thereof, and should not be construed as being limited to the contents described in the embodiments exemplified below.

In order to make the explanation clearer, the drawings may schematically represent the width, thickness, shape, etc. of each part compared to the actual aspect. However, the examples shown in the drawings are merely examples and do not limit the interpretation of the present invention. In this specification and each figure, structures that are the same as or similar to those described above with respect to the existing figures are denoted by the same reference numerals, and detailed description thereof may be omitted.

In the present invention, when a plurality of films are formed by etching or irradiating one film with light, these films may have different functions and roles. However, these multiple films originate from films formed as the same layer in the same process, and have the same layer structure and the same material. Therefore, these multiple films are defined as existing in the same layer.

In this specification and the claims, when expressing an aspect in which a structure is arranged on top of another structure, the term "on" simply refers to the structure of a structure unless otherwise specified. There are two cases: when another structure is placed directly above a structure so as to be in contact with the body, and when another structure is placed above a structure via another structure. It is defined as including both.

<First embodiment>
A vapor deposition mask, a method for manufacturing the vapor deposition mask, and a vapor deposition apparatus using the vapor deposition mask according to an embodiment of the present invention will be described with reference to FIGS. 1 to 23.

[Configuration of vapor deposition apparatus 10]
The configuration of a vapor deposition apparatus 10 according to an embodiment of the present invention will be described using FIGS. 1 to 3. The vapor deposition apparatus 10 includes a plurality of chambers having various functions. The example shown below is an example showing one vapor deposition chamber 100 among a plurality of chambers. FIG. 1 is a top view of a vapor deposition apparatus according to an embodiment of the present invention. FIG. 2 is a side view of a vapor deposition apparatus according to an embodiment of the present invention.

As shown in FIG. 1, the deposition chamber 100 is separated from adjacent chambers by a load lock door 102. The deposition chamber 100 can maintain the interior of the deposition chamber 100 in a high vacuum and reduced pressure state or in a state filled with an inert gas such as nitrogen or argon. Therefore, a pressure reducing device, a gas suction/exhaust mechanism, etc. (not shown) are connected to the deposition chamber 100.

The vapor deposition chamber 100 has a configuration capable of accommodating an object on which a vapor deposition film is to be formed. An example in which a plate-shaped deposition target substrate 104 is used as the object will be described below. As shown in FIGS. 1 and 2, an evaporation source 112 is placed below the substrate 104 to be evaporated. The evaporation source 112 has a generally rectangular shape and is arranged along one side of the substrate 104 to be evaporated. Such a vapor deposition source 112 is called a linear source type. When a linear source type evaporation source 112 is used, the evaporation chamber 100 has a configuration in which the evaporation target substrate 104 and the evaporation source 112 move relative to each other. FIG. 1 shows an example in which the deposition source 112 is fixed and the deposition target substrate 104 moves over it.

The deposition source 112 is filled with the material to be deposited. The vapor deposition source 112 has a heating section 122 (see FIG. 3 described later) that heats the material. When the material is heated by the heating unit 122 of the evaporation source 112, the heated material is vaporized and flows from the evaporation source 112 toward the substrate 104 to be evaporated as vapor. When the vapor of the material reaches the surface of the substrate 104 to be evaporated, the vapor is cooled and solidified, and the material is deposited on the surface of the substrate 104 to be evaporated. In this way, a thin film of the material is formed on the deposition target substrate 104 (in FIG. 2, on the lower surface of the deposition target substrate 104).

As shown in FIG. 2, the vapor deposition chamber 100 further includes a holder 108 for holding the substrate to be vapor deposited 104 and a vapor deposition mask 300 for vapor deposition, a moving mechanism 110 for moving the holder 108, a shutter 114, and the like. The holder 108 maintains the mutual positional relationship of the deposition target substrate 104 and the deposition mask 300. The moving mechanism 110 moves the deposition target substrate 104 and the deposition mask 300 over the deposition source 112 . The shutter 114 is movably provided above the deposition source 112. By moving the shutter 114 above the deposition source 112, the shutter 114 blocks the vapor of the material heated by the deposition source 112. By moving the shutter 114 to a position where it does not overlap the deposition source 112, the vapor of the material reaches the deposition target substrate 104 without being blocked by the shutter 114. Opening and closing of the shutter 114 is controlled by a control device (not shown).

In the example shown in FIG. 1, a linear source type evaporation source 112 is shown, but the evaporation source 112 is not limited to the above shape and can have any shape. For example, the shape of the evaporation source 112 may be a so-called point source shape in which the material used for evaporation is selectively placed at and near the center of gravity of the substrate 104 to be evaporated. In the case of a point source type, the relative positions of the deposition target substrate 104 and the deposition source 112 may be fixed, and a mechanism for rotating the deposition target substrate 104 may be provided in the deposition chamber 100. Further, in the examples shown in FIGS. 1 and 2, a horizontal vapor deposition apparatus is shown in which the substrate is arranged so that the main surface of the substrate is parallel to the horizontal direction, but the vapor deposition mask 300 is It can also be used in a vertical vapor deposition apparatus in which the substrate is arranged perpendicular to the substrate.

FIG. 3 is a cross-sectional view of a deposition source according to an embodiment of the present invention. The vapor deposition source 112 includes a storage container 120, a heating section 122, a vapor deposition holder 124, a mesh metal plate 128, and a pair of guide plates 132.

The storage container 120 is a member that holds the material to be deposited. As the storage container 120, a member such as a crucible can be used, for example. The storage container 120 is removably held inside the heating section 122. The storage container 120 can include metals such as tungsten, tantalum, molybdenum, titanium, and nickel, or alloys thereof. Alternatively, the storage container 120 may include an inorganic insulator such as alumina, boron nitride, or zirconium oxide.

The heating unit 122 is removably held inside the deposition holder 124. The heating unit 122 is configured to heat the storage container 120 using a resistance heating method. Specifically, the heating section 122 includes a heater 126. By energizing the heater 126, the heating unit 122 is heated, and the material in the storage container 120 is heated and vaporized. The vaporized material is emitted to the outside of the storage container 120 through the opening 130 of the storage container 120. The mesh metal plate 128 arranged to cover the opening 130 suppresses the bumped material from being discharged outside the storage container 120 . The heating unit 122 and the deposition holder 124 may include the same material as the storage container 120.

A pair of guide plates 132 are provided above the vapor deposition source 112. At least a portion of the guide plate 132 is inclined with respect to the side surface or the vertical direction of the storage container 120. The angle at which the vapor of the material spreads (hereinafter referred to as the injection angle) is controlled by the inclination of the guide plate 132, and the direction of flight of the vapor can be given directivity. The emission angle is determined by the angle θe (in degrees) formed by the two guide plates 132. The angle θe is appropriately adjusted depending on the size of the deposition target substrate 104 and the distance between the deposition source 112 and the deposition target substrate 104. The angle θe is, for example, 40° or more and 80° or less, 50° or more and 70° or less, and typically 60°. The surfaces formed by the inclined surfaces of the guide plate 132 are critical surfaces 160a and 160b. The vapor of the material flies in the space substantially sandwiched between the critical surfaces 160a and 160b. Although not shown, if the deposition source 112 is a point source, the guide plate 132 may be a part of the surface of a cone.

The material to be deposited can be selected from a variety of materials and can be either organic or inorganic. As the organic compound, for example, a luminescent material or a carrier-transporting organic compound can be used. As the inorganic compound, metals, alloys thereof, metal oxides, etc. can be used. Film formation may be performed by filling one storage container 120 with a plurality of materials. Although not shown, the deposition chamber 100 may be configured using a plurality of deposition sources so that different materials can be heated simultaneously.

[Configuration of vapor deposition mask 300]
The configuration of a vapor deposition mask 300 according to an embodiment of the present invention will be described using FIGS. 4 to 8. FIG. 4 is a top view of a deposition mask according to an embodiment of the present invention. The vapor deposition mask 300 includes a thin film mask body 310, a holding frame 330, and a first connection member 350. A plurality of panel areas 315 are arranged in the mask body 310. Each panel region 315 is provided with a plurality of openings 311 that penetrate from the upper surface (first surface) to the lower surface (second surface) of the mask main body 310 in the thickness direction in accordance with the pixel pitch of the display device. There is. The area other than the opening 311 of the mask body 310 is referred to as a non-opening area. A non-aperture surrounds each aperture 311. Note that the thickness of the mask body 310 may be 1 μm or more and 30 μm or less.

During vapor deposition, the evaporation mask 300 and the evaporation target substrate 104 are aligned so that the evaporation region and the opening 311 on the evaporation target substrate 104 overlap, and the non-evaporation region and the non-opening on the evaporation target substrate 104 overlap. The material vapor passes through the opening 311 and the material is deposited on the deposition area of the deposition target substrate 104 .

(Configuration of mask body 310)
FIG. 5 is a partially enlarged view of the mask body 310, and is a plan view of the mask body 310 viewed from the lower surface (second surface) 310b side of the mask body 310. The upper surface (first surface) 310a and lower surface (second surface) 310b of the mask main body 310 will be described later. FIG. 6 is a sectional view taken along line BB' shown in FIG.

The mask main body 310 is a thin film vapor deposition mask. The mask body 310 is made of metal such as copper (Cu), aluminum (Al), invar (Fe-Ni alloy), nickel, and nickel-cobalt alloy. As described above, the plurality of panel regions 315 arranged in the mask main body 310 are each provided with a plurality of openings 311 that penetrate from the upper surface (first surface) 310a to the lower surface (second surface) 310b of the mask main body 310. It is being

Each of the plurality of openings 311 has a tapered portion. In each of the plurality of openings 311, the area a1 of the opening end on the first surface 310a side of the opening 311 and the area a2 of the opening end on the second surface 310b side are different, and the relationship a1<a2 is satisfied. Here, the upper surface (first surface) 310a of the mask body 310 is a surface facing the deposition target substrate 104, and the lower surface (second surface) 310b is a surface facing the evaporation source 112. That is, the opening end of each of the plurality of openings 311 becomes wider from the first surface 310a side toward the second surface 310b side. The angle (hereinafter referred to as taper angle) θt between the plane including the lower surface (second surface) 310b and the inner wall of the opening 311 is 45° or more and 85° or less, and preferably 60° or more and 70° or less.

In the present embodiment, each of the plurality of openings 311 provided in the mask main body 310 has a tapered shape, and the area a1 of the opening end on the first surface 310a side facing the deposition target substrate 104 is opposite to the deposition source 112. This area is smaller than the area a2 of the opening end on the second surface 310b side. Thereby, when the material vaporized from the evaporation source 112 adheres to the deposition target substrate 104 to form a thin film layer, a margin between the pixel pitches can be more reliably secured.

(Configuration of holding frame 330)
Referring again to FIG. 4, the configuration of the holding frame 330 will be described. The holding frame 330 is provided around the mask body 310. The first connecting member 350 is provided between the mask main body 310 and the holding frame 330 and connects the mask main body 310 and the holding frame 330. The first outer edge 353 of the first connection member 350 in the area in contact with the holding frame 330 is arranged on the outer periphery of the second outer edge 313 of the mask body 310 in the area in contact with the first connection member 350. That is, in plan view, the mask main body 310 and the holding frame 330 do not overlap. However, the positional relationship between the mask main body 310 and the holding frame 330 is not limited to this, and the mask main body 310 and the holding frame 330 may overlap in plan view.

FIG. 7 is a cross-sectional view of a vapor deposition mask according to an embodiment of the present invention. The cross-sectional view shown in FIG. 7 is a cross-sectional view taken along line A-A' in FIG. 4. As shown in FIG. 7, the first connection member 350 is provided above the mask body 310 and along the edge of the mask body 310. The first connecting member 350 protrudes from the end of the mask body 310 toward the outside of the mask body 310.

The holding frame 330 is provided further above the upper surface of the mask body 310. That is, in the vertical direction, the lower end (lower surface 331) of the holding frame 330 is provided above the upper end of the mask main body 310. Further, the holding frame 330 is provided further outside the second outer edge 313 of the mask main body 310. In other words, the holding frame 330 is provided outside the mask body 310 in the horizontal direction. Note that the above-mentioned vertical direction is a direction perpendicular to the main surface of the mask body 310. The horizontal direction is a direction parallel to the main surface of the mask body 310.

The first connecting member 350 is in contact with the side surface 335 of the holding frame 330. On the other hand, the first connecting member 350 is not provided on the upper surface 333 and lower surface 331 of the holding frame 330. The first connecting member 350 is in contact with the side surface 335 of the holding frame 330 from the lower end to the upper end. However, the first connecting member 350 may be in contact with the upper surface 333 and lower surface 331 of the holding frame 330.

The holding frame 330 may have a laminated structure including a first layer 360 and a second layer 370. The second layer 370 is provided above the first layer 360. The first layer 360 is closer to the mask body 310 than the second layer 370.

FIG. 8 shows an enlarged view of the area surrounded by the dotted line in FIG. The first connecting member 350 is in contact with a side surface 365 of the first layer 360 and a side surface 375 of the second layer 370. The first connecting member 350 is provided not only on the side surfaces 365 and 375 but also in a region where the first layer 360 and the second layer 370 face each other. That is, the first connecting member 350 is in contact with a portion of the lower surface 371 of the second layer 370. In other words, the first connecting member 350 is inserted vertically below the second layer 370. The first connecting member 350 is inserted into a plurality of openings 317 provided near the second outer edge 313 of the mask body 310.

An adhesive layer 500 is provided between the first layer 360 and the second layer 370. In other words, the first layer 360 and the second layer 370 are connected by the adhesive layer 500. In plan view, the pattern of the adhesive layer 500 is approximately the same as the pattern of the second layer 370. However, the pattern of the adhesive layer 500 is located slightly inside the pattern of the second layer 370. In other words, a portion of the lower surface of the second layer 370 is exposed from the adhesive layer 500. In FIG. 8 , a region of the lower surface 371 of the second layer 370 that is exposed from the adhesive layer 500 is in contact with the first connecting member 350 .

The configuration of the holding frame 330 according to this embodiment is not limited to the configuration described above, and may have any configuration that can hold the mask main body 310.

[Method for manufacturing vapor deposition mask 300]
A method for manufacturing a vapor deposition mask 300 according to an embodiment of the present invention will be described using FIGS. 9 to 16. 9 to 15 are cross-sectional views showing a method for manufacturing a deposition mask according to an embodiment of the present invention. FIG. 16 is a plan view showing a method for manufacturing a deposition mask according to an embodiment of the present invention. In particular, a method for manufacturing the mask body 310 of the vapor deposition mask 300 will be described below.

As shown in FIG. 9, a substrate 901 is prepared. The substrate 901 may be, for example, a SUS substrate. Next, as shown in FIG. 10, a photoresist 1001 is applied on one surface of the substrate 901. In this embodiment, a negative resist is used as the photoresist 1001.

Next, as shown in FIG. 11, the photoresist 1001 is exposed. At this time, a direct drawing device is used that directly draws light from a light source onto the photoresist 1001 without using a mask. A high-pressure mercury lamp is used as a light source for exposure. The light used for exposure is light with a mixed wavelength including a first wavelength and a second wavelength different from the first wavelength. Here, the first wavelength is the i-line (wavelength 365 nm), and the second wavelength is the h-line (wavelength 405 nm). The transmittance of the photoresist 1001 to the second wavelength is higher than the transmittance of the photoresist to the first wavelength. The mixing ratio of the first wavelength and the second wavelength in the mixed wavelength is preferably 3:1 to 3:2. By adjusting the mixing ratio of the first wavelength and the second wavelength in the mixed wavelength, the taper shape of the resist pattern described later can be adjusted.

Next, as shown in FIG. 12, development is performed to remove unexposed portions of the photoresist 1001 to form a resist pattern 1201. FIG. 13 is an enlarged view of the portion surrounded by the dotted line in FIG. 12. Each of the resist patterns 1201 has a tapered portion whose cross-sectional area horizontal to the surface of the substrate 901 decreases toward the surface of the substrate 901. The angle θr between the surface of the substrate 901 and the side wall of the resist pattern 1201 is 45° or more and 85° or less, and preferably 60° or more and 70° or less. The angle θr can be adjusted by adjusting the mixing ratio of the first wavelength and the second wavelength when exposing the photoresist 1001.

Specifically, the i-ray having the first wavelength hardens the surface side of the photoresist 1001, that is, the exposed surface side. On the other hand, the h-ray having the second wavelength hardens the back side of the photoresist 1001, that is, the substrate 901 side. In other words, the surface area of the resist pattern 1201 on the front side, that is, on the exposure side, depends on the intensity of the first wavelength. On the other hand, the surface area on the back side of the resist pattern 1201, that is, on the substrate 901 side, depends on the intensity of the second wavelength. The angle θr between the surface of the substrate 901 and the side wall of the resist pattern 1201 is determined by the surface area on the back side of the resist pattern 1201, that is, on the substrate 901 side. That is, the angle θr depends on the mixing ratio of the first wavelength and the second wavelength in the mixed wavelength.

Next, as shown in FIG. 14, a metal layer is formed on the substrate 901 by electrolytic plating (or electroforming plating). The metal layer 1401 may include, for example, invar (Fe--Ni alloy). In this case, a mixed solution of a solution containing a nickel compound and a solution containing an iron compound can be used as the plating solution. For example, a mixed solution of a solution containing nickel sulfamate or nickel bromide and a solution containing ferrous sulfamate may be used. The plating solution may contain various additives. Note that the metal contained in the metal layer 1401 is not limited to the nickel-iron alloy, and may be nickel, nickel-cobalt alloy, copper (Cu), aluminum (Al), or the like. The thickness of the metal layer 1401 may be between 3 μm and 20 μm.

Next, as shown in FIG. 15, the resist pattern 1201 is removed from the substrate 901. The spaces from which each resist pattern 1201 is removed correspond to the openings 311 of the mask body 310. For example, the resist pattern 1201 can be removed using an alkaline stripping solution such as an aqueous sodium hydroxide solution or an aqueous potassium hydroxide solution. Each of the plurality of openings 311 has a tapered portion in which the area of the opening end increases toward the front surface of the substrate 901. Finally, the metal layer 1401 and the substrate 901 can be separated to form a mask body 310 having a plurality of openings 311, as shown in FIG.

A holding frame 330 is formed separately from the mask body 310. The vapor deposition mask 300 can be manufactured by attaching the mask body 310 to the holding frame 330. A detailed explanation of the process of forming the holding frame 330 will be omitted here, but since the holding frame 330 is thicker than the mask main body 310, as shown in FIG. 7 and FIG. It may also be formed as a laminate. In addition, since the holding frame 330 is required to have high flatness, when using rolled material, a structure such as stacking plates of approximately 1/2 of the desired thickness back to back to offset the warping of the rolled material is required. is preferred.

In this embodiment, the angle θr between the surface of the substrate 901 and the sidewall of the resist pattern 1201 depends on the mixing ratio of the first wavelength and the second wavelength of the light used to expose the photoresist 1001. Here, the angle θr between the surface of the substrate 901 and the sidewall of the resist pattern 1201 corresponds to the taper angle θt of the opening 311 of the mask body 310. Therefore, by adjusting the mixing ratio of the first wavelength and second wavelength of the light used to expose the photoresist 1001, the taper angle θt of the opening 311 can be controlled more precisely. When forming a thin film, by using the vapor deposition mask 300 according to this embodiment as a vapor deposition mask in the vapor deposition process, a margin between pixel pitches can be ensured.

17 to 23 are SEM cross-sectional views of resist patterns after exposing the photoresist to light including a first wavelength and a second wavelength. Table 1 below shows the mixing ratio of the first wavelength and second wavelength of the light used for exposing the photoresist, and the angle θr between the surface of the substrate and the sidewall of the resist pattern, which corresponds to the taper angle θt of the aperture. .

As shown in FIGS. 17 to 19, when exposing a photoresist, if the light does not contain the second wavelength (h line), the surface side of the photoresist, that is, the exposed side ( Even if the hardening of the photoresist (the upper side of the resist pattern shown in FIG. The width at the bottom of the is insufficient. Further, as shown in FIG. 20, when the mixing ratio of the first wavelength and the second wavelength in the mixed wavelength is 3:0.5, although the angle θr is 45° or more, Since the side (lower side of the resist pattern shown in FIG. 20) is insufficiently cured, the width of the lower side of the resist pattern is insufficient.

On the other hand, as shown in FIGS. 21 to 23, when the mixing ratio of the first wavelength and the second wavelength in the mixed wavelength is 3:1 to 3:2, the angle θr is 50° or more, and The side, that is, the substrate side (the lower side of the resist pattern shown in FIGS. 21 to 23) is sufficiently cured, and is suitable as a resist pattern when manufacturing the mask body 310 of the vapor deposition mask 300 according to the present embodiment. be.

<Second embodiment>
Hereinafter, a method for manufacturing a display device using a thin film forming method using a vapor deposition mask 300 will be described with reference to FIGS. 24 to 32. As the display device 200 according to the second embodiment, a method for manufacturing an organic EL display device in which a plurality of pixels each having an organic light emitting element (hereinafter referred to as a light emitting element) are formed on an insulating substrate 202 will be described. Note that redundant explanations of the contents described in the first embodiment will be omitted.

FIG. 24 is a top view of a display device according to an embodiment of the present invention. The display device 200 has an insulating substrate 202, on which a plurality of pixels 204 and a drive circuit 206 (gate side drive circuit 206a, source side drive circuit 206b) for driving the pixels 204 are provided. The insulating substrate 202 is, for example, a glass substrate or a resin substrate. A plurality of pixels 204 are arranged periodically, and a display area 205 is defined by these pixels. As described later, each pixel 204 is provided with a light emitting element 260.

The drive circuit 206 is arranged in a peripheral area around the display area 205. Various wiring (not shown) formed of a patterned conductive film extends from the display area 205 and the drive circuit 206 to one side of the insulating substrate 202 and is exposed to the surface near the end of the insulating substrate 202. Terminal 207 is formed. These terminals 207 are electrically connected to a flexible printed circuit board (FPC) (not shown). Various signals for driving the display device 200 are input to the drive circuit 206 and the pixels 204 via the terminal 207. Although not shown, a drive IC having an integrated circuit may be further mounted together with the drive circuit 206 or in place of a part thereof.

FIG. 25 is a schematic cross-sectional view of two adjacent pixels 204 (204a and 204b). A pixel circuit is formed in each pixel 204. The configuration of the pixel circuit is arbitrary, and FIG. 25 shows a drive transistor 210, a storage capacitor 230, an additional capacitor 250, and a light emitting element 260.

Each element included in the pixel circuit is provided on the insulating substrate 202 with an undercoat 208 interposed therebetween. The drive transistor 210 includes a semiconductor film 212, a gate insulating film 214, a gate electrode 216, a source electrode 220, and a drain electrode 222. The gate electrode 216 is arranged to intersect at least a portion of the semiconductor film 212 with the gate insulating film 214 interposed therebetween. The semiconductor film 212 has a drain region 212a, a source region 212b, and a channel 212c. The channel 212c is a region where the semiconductor film 212 and the gate electrode 216 overlap. Channel 212c is provided between drain region 212a and source region 212b.

The capacitor electrode 232 is present in the same layer as the gate electrode 216 and overlaps the drain region 212a with the gate insulating film 214 interposed therebetween. An interlayer insulating film 218 is provided on the gate electrode 216 and the capacitor electrode 232. Openings reaching the source region 212b and drain region 212a are formed in the interlayer insulating film 218 and the gate insulating film 214, respectively. A source electrode 220 and a drain electrode 222 are arranged inside these openings. Drain electrode 222 overlaps capacitor electrode 232 with interlayer insulating film 218 interposed therebetween. A storage capacitor 230 is formed by the drain region 212a, the capacitor electrode 232, and the gate insulating film 214 between them, as well as the capacitor electrode 232, the drain electrode 222, and the interlayer insulating film 218 between them.

A planarization film 240 is provided on the drive transistor 210 and the storage capacitor 230. The planarization film 240 has an opening that reaches the drain electrode 222. A connection electrode 242 covering this opening and a part of the upper surface of the planarization film 240 is provided so as to be in contact with the drain electrode 222 . An additional capacitance electrode 252 is provided on the planarization film 240. A capacitor insulating film 254 is provided to cover the connection electrode 242 and the additional capacitor electrode 252. The capacitor insulating film 254 exposes a part of the connection electrode 242 in the opening of the planarization film 240. Thereby, the pixel electrode 262 and drain electrode 222 of the light emitting element 260 are electrically connected via the connection electrode 242. An opening 256 is provided in the capacitive insulating film 254. The partition wall 258 provided on the capacitive insulating film 254 and the planarization film 240 are in contact with each other through the opening 256. With this configuration, impurities in the planarization film 240 can be removed through the opening 256, and the reliability of the pixel circuit and the light emitting element 260 can be improved. Note that the formation of the connection electrode 242 and the opening 256 is optional.

A pixel electrode 262 is provided on the capacitor insulating film 254 so as to cover the connection electrode 242 and the additional capacitor electrode 252. The capacitor insulating film 254 is provided between the additional capacitor electrode 252 and the pixel electrode 262. This structure constitutes the additional capacitor 250. The pixel electrode 262 is shared by the additional capacitor 250 and the light emitting element 260. A partition wall 258 is provided above the pixel electrode 262 to cover an end of the pixel electrode 262. The structure from the insulating substrate 202 and undercoat 208 to the partition wall 258 is sometimes referred to as an array substrate. The array substrate can be manufactured by applying known materials and methods, so a description thereof will be omitted.

[Configuration of light emitting element 260]
As shown in FIG. 25, the light emitting element 260 includes a pixel electrode 262, an EL layer 264, and a counter electrode 272. The EL layer 264 and the counter electrode 272 are provided to cover the pixel electrode 262 and the partition wall 258. In the example shown in FIG. 25, the EL layer 264 includes a hole injection/transport layer 266, a light emitting layer 268 (light emitting layers 268a, 268b), and an electron injection/transport layer 270. The hole injection/transport layer 266 and the electron injection/transport layer 270 are provided in common to the plurality of pixels 204 and are shared by the plurality of pixels 204. Similarly, counter electrode 272 covers and is shared by multiple pixels 204 . On the other hand, the light emitting layer 268 is provided individually for each pixel 204.

Known structures and materials can be used for the pixel electrode 262, the counter electrode 272, and the EL layer 264. For example, the EL layer 264 may have various functional layers such as a hole blocking layer, an electron blocking layer, and an exciton blocking layer in addition to the above structure.

The structure of the EL layer 264 may be the same among a plurality of pixels 204, or a portion of the structure may be different between adjacent pixels 204. For example, the pixels 204 may be configured such that the structure or material of the light emitting layer 268 is different between adjacent pixels 204, and the other layers have the same structure.

[Method for forming light emitting element 260]
The EL layer 264 and the counter electrode 272 can be formed using the vapor deposition masks of the first and second embodiments. A method for forming the EL layer 264 and the counter electrode 272 will be described below with reference to FIGS. 26 to 32. In these figures, an EL layer 264 and a counter electrode 272 are formed on the partition wall 258 and the pixel electrode 262. However, when evaporating the EL layer 264 and the counter electrode 272, the evaporation source 112 is placed under the insulating substrate 202, and the insulating substrate 202 is placed so that the evaporation region faces the evaporation source 112. In other words, the partition walls 258 and the pixel electrodes 262 are arranged closer to the evaporation source 112 than the insulating substrate 202 is.

As shown in FIGS. 26 and 27, a hole injection/transport layer 266 is formed on the array substrate using a vapor deposition method. Since the hole injection/transport layer 266 is shared by all pixels 204, the deposition mask 300 used for vapor deposition of the hole injection/transport layer 266 has one opening 311 that overlaps the entire display area 205. Although details are omitted, the vapor deposition mask 300 is placed between the array substrate and the vapor deposition source 112 so that the opening 311 overlaps with the display area 205, and the material contained in the hole injection/transport layer 266 is vaporized in the vapor deposition source 112. As a result, a hole injection/transport layer 266 is formed.

Next, a light emitting layer 268 is formed on the hole injection/transport layer 266. When full-color display is performed, a plurality of pixels 204a that emit red light, pixels 204b that emit blue light, and pixels 204c that emit green light are arranged in the display area 205. Note that the pixels 204a, 204b, and 204c are simply referred to as pixels 204 unless otherwise distinguished. When the pixels 204 are arranged in a matrix, the pixels 204 that emit light of different colors are usually arranged periodically in order. The light emitting layer 268 is formed in different steps for each emitted color. For example, when forming a pixel 204a that emits red light, as shown in FIG. 300 are placed.

In this way, the vapor deposition mask 300 provided with the opening 311 is placed so that the lower surface 148 is closer to the insulating substrate 202 than the upper surface 150 at the position where the opening 311 overlaps with the pixel 204a and the non-opening portion overlaps with other pixels 204b and 204c. The materials of the light-emitting layer 268a are deposited on the pixel 204a (FIGS. 28 and 29). As a result, a light emitting layer 268a is selectively formed on the pixel electrode 262 of the pixel 204a (FIG. 30). In addition, in FIG. 31, the vapor deposition mask 300 (mask body 310) is arranged so as to be in contact with the hole injection/transport layer 266 during vapor deposition, but the vapor deposition mask 300 may be arranged so as to be in contact with the partition wall 258, or It may be placed apart from the partition wall 258 and the hole injection/transport layer 266.

Next, a light emitting layer 268b is formed similarly to the formation of the light emitting layer 268a. As shown in FIGS. 31 and 32, the vapor deposition mask 300 is placed at a position where the opening 311 overlaps with the pixel 204b and the non-opening portion overlaps with the other pixels 204a and 204c, so that the lower surface 148 is closer to the insulating substrate 202 than the upper surface 150. The material of the light emitting layer 268b is deposited on the pixel 204b (FIG. 31). As a result, a light emitting layer 268b is selectively formed on the pixel electrode 262 of the pixel 204b (FIG. 32). The formation of the light emitting layer 268c on the pixel 204c is also performed in a similar manner.

Next, an electron injection/transport layer 270 and a counter electrode 272 are formed. Since the electron injection/transport layer 270 and the counter electrode 272 are shared by all pixels 204, they can be formed using the same vapor deposition mask 300 used for vapor deposition of the hole injection/transport layer 266. Thereby, the structure shown in FIG. 25 can be obtained. Although not shown, an optical adjustment layer and a polarizing plate for adjusting light from the light emitting layer 268, a protective film for protecting the light emitting element 260, and a counter substrate may be provided on the counter electrode 272.

The embodiments described above as embodiments of the present invention can be implemented in appropriate combinations as long as they do not contradict each other. Furthermore, the present invention also applies to those in which a person skilled in the art appropriately adds, deletes, or changes the design of components based on the vapor deposition mask of each embodiment, or adds, omit, or changes conditions in steps. As long as it has the gist, it is within the scope of the present invention.

In this specification, an EL display device is mainly illustrated as an example of a display device, but the present invention may be applied to other display devices as other application examples. Further, it can be applied to any size from small to medium size to large size without particular limitation.

10: Vapor deposition device, 100: Vapor deposition chamber, 102: Load lock door, 104: Vapor deposition target substrate, 108: Holder, 110: Movement mechanism, 112: Vapor deposition source, 114: Shutter, 120: Storage container, 122: Heating section, 124: Vapor deposition holder, 126: Heater, 128: Metal plate, 130: Opening, 132: Guide plate, 148: Lower surface, 150: Upper surface, 160: Critical surface, 200: Display device, 202: Insulating substrate, 204: Pixel , 205: display area, 206: drive circuit, 207: terminal, 208: undercoat, 210: drive transistor, 212: semiconductor film, 212a: drain region, 212b: source region, 212c: channel, 214: gate insulating film, 216: Gate electrode, 218: Interlayer insulating film, 220: Source electrode, 222: Drain electrode, 230: Storage capacitor, 232: Capacitor electrode, 240: Flattening film, 242: Connection electrode, 250: Additional capacitor, 252: Addition capacitive electrode, 254: capacitive insulating film, 256: opening, 258: partition wall, 260: light emitting element, 262: pixel electrode, 264: EL layer, 266: hole injection/transport layer, 268: light emitting layer, 270: electron injection/ transport layer, 272: counter electrode, 300: vapor deposition mask, 310: mask body, 311, 317: opening, 313: second outer edge, 315: panel region, 330: holding frame, 331, 361, 371: lower surface, 333, 363, 373: Top surface, 335, 365, 375: Side surface, 350: First connection member, 353: First outer edge, 360: First layer, 367A: Recess, 370: Second layer, 377: Through hole, 378: Inner wall, 379: Gap, 901: Substrate, 1001: Photoresist, 1201: Resist pattern, 1401: Metal layer

Claims (11)

Equipped with a thin film-like mask body with multiple openings,
Each of the plurality of openings penetrates from the first surface to the second surface of the mask main body in the thickness direction,
A side wall between the first surface and the second surface of each of the plurality of openings has an overall tapered shape,
A vapor deposition mask , wherein the taper angle of the tapered shape is 60° or more and 70° or less . The vapor deposition mask according to claim 1, wherein the film thickness of the thin film mask body is 10 μm or less. further comprising a holding frame surrounding the thin film-like mask body,
The vapor deposition mask according to claim 1, wherein the holding frame and the thin film mask body are connected via a connecting member. 4. The vapor deposition mask according to claim 3, wherein the outer shape of the thin film mask main body is smaller than the opening of the holding frame in plan view. Prepare the substrate,
applying a photoresist on the first side of the substrate;
irradiating a portion of the photoresist with light including a first wavelength and a second wavelength different from the first wavelength;
forming a resist pattern by removing a portion of the photoresist except for the exposed portion;
forming a metal layer on the first surface of the substrate in a region exposed from the resist pattern;
removing the resist pattern;
removing the substrate;
including;
The metal layer after removing the resist pattern has an opening corresponding to the resist pattern,
The side wall of the opening has an overall tapered shape,
The method for manufacturing a vapor deposition mask , wherein the taper angle of the tapered shape is 60° or more and 70° or less . 6. The method of manufacturing a vapor deposition mask according to claim 5 , wherein the first wavelength is 365 nm and the second wavelength is 405 nm. The method for manufacturing a vapor deposition mask according to claim 5 , wherein the ratio of the first wavelength and the second wavelength in the light is 3:1 to 3:2. 6. The method for manufacturing a vapor deposition mask according to claim 5 , wherein at least a portion of the resist pattern has a tapered shape. The method for manufacturing a vapor deposition mask according to claim 8 , wherein the taper angle of the tapered shape is 60° or more and 70° or less. 9. The method for manufacturing a vapor deposition mask according to claim 8 , wherein the at least part of the resist pattern has a tapered shape whose cross-sectional area is smaller than that of the substrate. 6. The method for manufacturing a vapor deposition mask according to claim 5 , wherein the metal layer is formed by electroforming using the first surface of the substrate as a conductor.

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