JP6020339B2 - Plasma CVD film forming mask and plasma CVD film forming method - Google Patents

Description

The present invention includes a plasma CVD film formation mask, and relates to a plasma CVD Narumakukata method.

  Organic electroluminescence devices using organic substances (sometimes simply referred to as “organic EL”) are promising for use as solid light-emitting, inexpensive large-area full-color display devices and writing light source arrays. R & D is ongoing. The organic EL element includes a first electrode (anode or cathode) formed on a substrate, an organic compound layer (single layer portion or multilayer portion) containing an organic light emitting material laminated thereon, that is, a light emitting layer, It is a thin film type element having a second electrode (cathode or anode) laminated on the light emitting layer. When a voltage is applied to such an organic EL element, electrons are injected from the cathode into the organic compound layer, and holes are injected from the anode. It is known that light is obtained by releasing energy as light when the electrons and holes recombine in the light emitting layer and the energy level returns from the conduction band to the valence band.

  Thus, since the organic EL element is a thin film type element, when an organic EL panel in which one or a plurality of organic EL elements are formed on a substrate is used as a surface light source such as a backlight, a surface light source. It is possible to easily make the device provided with In addition, when a display device is configured using an organic EL panel in which a predetermined number of organic EL elements as pixels are formed on a substrate as a display panel, the liquid crystal display device has high visibility and no viewing angle dependency. There are advantages that cannot be obtained.

  Organic substances such as organic light emitting materials used in such organic EL elements are vulnerable to moisture, oxygen, etc., and contact with these deteriorates the performance of the organic EL elements. In addition, the characteristics of electrodes are rapidly deteriorated in the atmosphere due to oxidation. In order to prevent these deteriorations, generally, a method of sealing a sealing cap can formed of a metal can, sealing glass, or the like on an element substrate with an adhesive has been proposed. This has a hermetically sealed space, is filled with an inert gas, and is further provided with a hygroscopic material. In this case, since the element surface cathode has a space, the element is not deteriorated by external stress. However, although the organic EL element itself is thin, it has a thickness of the sealing member and a space for disposing the hygroscopic material, and the light emitting element is thick as a whole.

In recent years, the characteristics of being light and difficult to break have been evaluated, and the demand for organic EL elements using a flexible resin substrate is increasing from organic EL elements using glass substrates and sealing members. For an organic EL element using such a flexible resin substrate, a sealing film is formed by forming a silicon nitride film having sealing performance by plasma CVD. Note that, when the sealing film is formed, pattern film formation using a mask is performed. In pattern deposition by plasma CVD, there is no dimensional stability due to the influence of plasma and heat in the process. When a metal mask used for vapor deposition or the like is used, there is a concern about abnormal discharge. In addition, the metal mask is stretched by heat, and gas is entrapped therein to form a film (that is, due to the effect of entering), there is a possibility that the pattern accuracy may be lowered. Furthermore, since it is necessary to use corrosive NF ₃ gas for cleaning, the metal mask is corroded by the gas.

  For this reason, when pattern deposition is performed by plasma CVD, a ceramic mask is generally used instead of a metal mask. However, it is difficult to form a fine mask pattern with a ceramic mask. It is also difficult to reduce the thickness dimension like a metal mask. When the thickness dimension of the mask is large, the film thickness (edge film thickness) of the end portion of the sealing film formed in the vicinity of the opening of the mask becomes thin, and the uniformity of the film thickness of the edge portion decreases. In order to solve these problems, for example, inventions described in Patent Documents 1 and 2 have been proposed.

  In Patent Document 1, a sealing film is formed using a metal mask having a mask main body having a plate thickness of 0.1 mm to 10 mm and an opening edge portion formed thinner than the plate thickness of the mask main body. A method for manufacturing an organic EL device is described.

  Patent Document 2 describes a plasma CVD mask including a metal mask body whose outer shape is formed in a polygon and a ceramic cover disposed on at least one side of the metal mask body. . And in this patent document 2, when forming a thin film by plasma CVD, it forms into a film in the state which has arrange | positioned the ceramic cover in at least one part of the circumference | surroundings of a metal mask, and a metal mask is used at the time of washing | cleaning a metal mask. It is described that the metal mask is cleaned in a state where a ceramic cover is disposed on at least a portion close to the cleaning gas outlet.

JP 2006-59999 A JP 2007-307663 A

  Since the invention described in Patent Document 1 uses a metal mask formed of Invar, Kovar, SUS430, etc., not only abnormal discharge occurs during film formation by plasma CVD, but also bending due to heat during film formation. However, since the film is distorted, there is a problem that the masked portion, that is, the portion where film formation is not desired enters, and the influence is exerted.

In the invention described in Patent Document 2, film formation is performed in a state in which a ceramic cover is disposed on at least a part of the periphery of a metal mask, so that it is difficult not only to form a fine mask pattern but also the mask. Since the thickness dimension cannot be made sufficiently small, the problem that the uniformity of the film thickness at the end of the film formed in the vicinity of the opening of the mask has not been solved. Further, in the invention described in Patent Document 2, a ceramic cover is disposed on at least a portion of the metal mask close to the cleaning gas (NF ₃ gas) outlet when cleaning the metal mask. Since the gas at that time is in contact with the entire surface of the metal mask as well as the portion close to the outlet, the problem that the metal mask is corroded by the gas has not been solved.

The present invention has been made in view of the above problems, and has a plasma CVD film formation mask and a plasma CVD film formation film that have almost no influence of penetration, have high uniformity of the end film thickness, and excellent corrosion resistance to the cleaning gas. it is an object of the present invention to provide a mETHODS.

The object of the present invention is achieved by the following means.
[1] is a plasma CVD film mask for use in forming a film on the surface of the film with a plasma CVD film forming apparatus, a ceramic mask member having a first opening, the first at the same open position the opening has a second opening which opens at the first opening and substantially the same shape on the small aperture size than the opening size of the first opening, are cell la Mick coat, A plasma CVD film-forming mask, comprising: a metal member having a thickness smaller than that of the mask member.
[2] The plasma CVD film forming mask as described in [1], wherein the ceramic coat is an alumina coat.
[3] The plasma CVD film-formation mask according to [1] or [2], wherein the metal member is arranged on the film-formation object side of the mask member .
[4 ] An end of the mask member on the first opening side is opposed to an object to be deposited by the plasma CVD film forming apparatus from one side surface facing the electrode of the plasma CVD film forming apparatus . towards the other side of the plasma CVD film deposition according to any one of the characteristics [1] to [3] an inclination so that the opening size of the first opening portion is reduced it is provided Mask.
[5] The thickness dimension of said metal member is 50 to 500 [mu] m, the thickness of the mask member according to any one of the characteristics [1] to [4] that it is 2~6mm Plasma CVD deposition mask.
[ 6 ] The length dimension from the end on the first opening side of the mask member to the end on the second opening side of the metal member is 1 to 10 mm. plasma CVD deposition mask according to any one of [5].
[7] The plasma CVD deposition mask according to any one of features (1) to (6) to be used for forming the sealing film of an organic electroluminescence device.
[8] The plasma CVD deposition mask according to any one of the characteristics [1] to [7] that film formation performed by a plasma CVD film forming apparatus is Depoappu scheme.
[9] [1] and characterized by forming a sealing film on the surface of the film deposition objects by plasma CVD using a plasma CVD deposition mask according to any one of to [8] A plasma CVD film forming method.
[1 0 ] The plasma CVD film-forming method of [ 9 ], wherein the sealing film is formed by roll-to-roll conveyance .

According to the present invention, it enters effect little, it is possible to provide highly uniform end film thickness, which and excellent corrosion resistance to cleaning gas plasma CVD film formation mask, and a plasma CVD Narumakukata method .

It is the top view which looked at the plasma CVD film-forming mask which concerns on one Embodiment of this invention from the direction where an electrode is arrange | positioned. It is an AA line expanded sectional view of FIG. It is a schematic sectional drawing explaining the structure of the organic EL element which concerns on one Embodiment of this invention. It is a schematic block diagram of the manufacturing apparatus which manufactures an organic EL element.

  Hereinafter, an embodiment of a plasma CVD film forming mask, a plasma CVD film forming method, and an organic electroluminescence element according to the present invention will be described with reference to the drawings as appropriate.

[Plasma for CVD deposition]
The plasma CVD deposition mask (hereinafter simply referred to as a mask) according to the present embodiment forms (forms) a film (layer) on the surface of an object to be deposited by a plasma CVD (Chemical Vapor Deposition) deposition apparatus. In this case, it is used to make the film into a predetermined shape.
Here, the plasma CVD film forming apparatus refers to an apparatus for forming a film by a plasma CVD method. The plasma CVD method refers to a method of forming a film by decomposing a source gas with plasma to generate chemically active radicals and ions and reacting them on a substrate.
In addition, examples of the deposition target include base materials described later, and organic EL panels (organic EL elements) in which an electrode layer, one or more organic EL layers, and the like are formed on the base material.

As shown in FIGS. 1 and 2, the mask 1 includes a mask member 2 and a metal member 3 having a thickness dimension t <b> 3 smaller than the thickness dimension t <b> 2 of the mask member 2.
Among these, the mask member 2 has a first opening 21 formed at a predetermined position and a first non-opening 22 that forms the first opening 21.
In addition, the metal member 3 is opened in the same opening position as the first opening 21 of the mask member 2 in the same shape as the first opening 21 with an opening size smaller than the opening size of the first opening 21. 2 opening 31 and the 2nd non-opening 32 which forms this 2nd opening 31 are provided. In the present invention, the second non-opening portion 32 is ceramic-coated, and the second opening portion 31 formed by the second non-opening portion 32 forms a film formation region (mask pattern) for the film formation target. doing. That is, while the second opening 31 forms a film on a part of the deposition object that can face an electrode (not shown) of the plasma CVD film forming apparatus, the second non-opening 32 causes the plasma to be formed. A film is not formed on a part of the deposition target (masked part) that does not face the electrode of the CVD film forming apparatus. In addition, in FIG. 1, although the 2nd opening part 31 is shown as a simple rectangle, it cannot be overemphasized that it is set as the desired arbitrary shapes and the magnitude | size can be set arbitrarily. A film can be formed in any shape and size.

Thus, the mask 1 has the second opening 31 that opens at the same opening position as the first opening 21 of the mask member 2 with an opening size smaller than the opening size of the first opening 21. Therefore, the mask 1 is not bent or distorted even if it is affected by the heat of plasma CVD when the film is formed in the second opening 31 of the metal member 3. Therefore, there is almost no influence of penetration, and the uniformity of the end film thickness can be increased. Further, since the second non-opening portion 32 of the metal member 3 is ceramic coated, it does not corrode even when it comes into contact with a corrosive cleaning gas such as NF ₃ gas (cleaning gas) used at the time of cleaning. Excellent resistance to corrosion. In addition, since the second non-opening portion 32 of the metal member 3 is ceramic-coated, abnormal discharge when forming a film with a plasma CVD film forming apparatus can be suppressed. The ceramic coat 33 (see FIG. 2) that covers the metal member 3 is preferably formed on the entire surface of the metal member 3. If it does in this way, while being able to improve the corrosion resistance with respect to cleaning gas more, the suppression of abnormal discharge can also be performed.

  The substantially same shape as described above means that the shape may be exactly the same, but it is not necessary. For example, as shown in the cross-sectional view of FIG. 2, a part of the first non-opening portion 22 of the mask member 2 is formed by plasma CVD from one side surface 22a facing the electrode of the plasma CVD film forming apparatus. Even in the case where the second non-opening portion 32 has such an inclination that the opening size of the first opening portion 21 is reduced toward the other side surface 22b facing the film-formed product, It is not necessary to provide an inclination. Further, when the opening shape of the first non-opening portion 22 of the mask member 2 is, for example, a rectangle or a square, the opening shape of the second non-opening portion 32 of the metal member 3 may be a square or a rectangle. In addition, when one side of the first non-opening portion 22 is formed by a straight line, an unevenness may be provided on one side of the second non-opening portion 22 corresponding thereto.

In the present invention, the first non-opening portion 22 of the mask member 2 is a ceramic of alumina, zirconia, or aluminum nitride. That is, the ceramic mask member 2 is preferably used. If the ceramic mask member 2 is used, even if cleaning is performed using corrosive NF ₃ gas, it will not be corroded by the gas. Further, since ceramic is high in hardness and excellent in heat resistance, even when the mask CVD 1 using the ceramic mask member 2 is used and the plasma CVD method is performed by the depot up method, Therefore, the mask member 2 is not bent or distorted. Therefore, the mask member 2 is less likely to cause poor adhesion to the film formation, can reduce the influence of entering, and can prevent the uniformity of the end film thickness from being lowered.

  Note that the deposit-up method is a method in which an electrode is provided below a deposition target and a film is formed on the surface of the deposition target facing downward (this method is also called a face-down method). In the deposition method, since a predetermined space is created between the film formation object and the electrode due to the provision of the electrode below the film formation object, a member is required to hold the film formation object. . Therefore, when the mask 1 using the ceramic mask member 2 is employed as such a member, the mask 1 is not bent or distorted as described above, so that the deposition target is appropriately held. A film having a predetermined shape can be formed.

However, if the mask member 2 is made of ceramic, the hardness is high but brittle fracture is likely to occur. Therefore, the thickness dimension of the end portion 22e of the first non-opening portion 22 is made as small as a metal mask. I can't. Therefore, under the influence of the thickness of the end portion 22e, the uniformity of the end portion film thickness in the vicinity of the end portion 22e is lowered. That is, if the thickness of the end portion 22e is large, a phenomenon such as a gas not flowing smoothly during film formation occurs, and the film thickness of the end portion of the film formed in the vicinity of the end portion 22e becomes thin. Such a phenomenon becomes more prominent as the thickness of the end 22e increases.
If the first non-opening portion 22 of the mask member 2 is made of ceramic, the hardness is high as described above, but brittle fracture is likely. Therefore, if the thickness of the end portion 22e is reduced in order to increase the uniformity of the end portion film thickness, the end portion 22e is likely to be chipped. If the end 22e is chipped, the shape of the film to be formed may be changed.

  Therefore, in the present invention, as described above, the second opening that opens at the same opening position as the first opening 21 and has substantially the same shape as the first opening 21 with an opening size smaller than the opening size of the first opening 21. A thickness dimension t2 of the mask member 2 having an opening 31 and a second non-opening 32 that forms the second opening 31 and ceramic coating the second non-opening 32 (see FIG. 2). The metal member 3 having a smaller thickness dimension t3 (see FIG. 2) is provided. That is, the mask member 2 having the first opening 21 and the first non-opening 22 is used as a rib for supporting the metal member 3 having the second opening 31 and the second non-opening 32.

  Since the metal member 3 is made of metal, it is difficult to brittle fracture, has excellent ductility, and can have a thickness smaller than that of the end portion 22e. Therefore, the uniformity of the end film thickness can be improved for the reason that gas can flow smoothly during film formation.

  The metal member 3 may be formed of, for example, a low thermal expansion member such as 42 alloy, 36 invar, super invar, or inconel. If these metals are used, the thickness dimension can be easily reduced. Although the thickness dimension t3 of the metal member 3 should just be smaller than the mask member 2, it is preferable to set it as 50-500 micrometers, for example. When the thickness dimension t3 of the metal member 3 is within this range, sufficient strength can be ensured, so that the handling property is excellent, and the gas can flow smoothly during film formation. For this reason, the uniformity of the end film thickness can be improved more reliably.

  The thickness t2 of the mask member 2 is preferably 2 to 6 mm, for example. When the thickness dimension t2 of the mask member 2 is within this range, damage during handling is difficult to occur. Further, when the thickness t2 of the mask member 2 is within this range, even when the film is formed by the deposition CVD plasma CVD, it is not bent or distorted by heat or its own weight. It can hold suitably.

  As shown in FIG. 2, an end 22e of the first non-opening 22 on the first opening 21 side is formed by a plasma CVD film forming apparatus from one side surface 22a facing the electrode of the plasma CVD film forming apparatus. It is preferable that the first opening 21 is inclined (tapered) so that the opening dimension of the first opening 21 becomes smaller toward the other side surface 22b facing the film formation target. That is, it is preferable to incline so that the opening dimensions s1 and s2 shown in FIG. 2 have a relationship of s1> s2. In this manner, the gas supplied from the electrode side during film formation flows smoothly toward the film formation object due to the inclination. Therefore, the uniformity of the end film thickness can be further improved. Further, the thickness dimension t2e of the end portion 22e may be set to a thickness that does not cause chipping by taper processing, and is not limited to a specific numerical range.

Returning to FIG. 1, the description will be continued. Since the metal member 3 described above and the ceramic mask member 2 which is a preferred embodiment are made of different materials, they have different thermal expansion coefficients. Accordingly, when these are fixed at predetermined locations using a fixing means such as an adhesive and / or a screw, when the metal member 3 is thermally expanded due to the influence of heat at the time of plasma CVD film formation, the metal member 3 or the mask member 2 may be deformed or damaged. Therefore, the metal member 3 and the mask member 2 do not fix a predetermined portion by the above-described fixing means or the like, for example, as shown in FIG. At the time of plasma CVD film formation, the outer shape of the mask member 2 and the outer shape of the metal member 3 may be set at a predetermined position of the film formation apparatus to form a film. In FIG. 1, the outer shape of the second non-opening portion 31 of the metal member 3 indicated by a broken line is drawn inside the outer shape of the first non-opening portion 21 of the mask member 2 indicated by a solid line. Is made in this manner in relation to drawing, and in practice, it is preferable to match these external shapes as shown in FIG.
If it does in this way, since a predetermined part is not fixed with a fixing means etc., even if it is a case where the metallic member 3 is thermally expanded, it can prevent that this deform | transforms or breaks.

  In addition, although the preferable usage aspect of the mask 1 provided with the metal member 3 and the mask member 2 is as above-mentioned, even if the metal member 3 thermally expands by the influence of the heat | fever at the time of plasma CVD film-forming, this will be damaged. When taking such a means, it is also possible to employ adhesion by an adhesive or fixation by a fixing means such as a screw. As such a fixing method, for example, an adhesive having a viscosity capable of allowing displacement of the metal member 3 due to thermal expansion even after bonding is used, or the strength of the metal member 3 is calculated by numerical analysis or the like. The direction which is easy to thermally expand is calculated | required, One or more long diameter through-holes which lengthened the length along the direction are provided in the arbitrary locations of the metal member 3, and the mask member 2 and the metal member 3 are passed through the said through-hole. And screwing.

  Here, it is preferable that the ceramic coat which coat | covers the metal member 3 is an alumina coat by an atomic layer deposition (Atomic Layer Deposition; ALD) method. Compared with the case where alumina coating is performed by alumina spraying or the like, the temperature at which the ceramic coating is applied can be lowered, so that the metal member 3 can be prevented from being bent by heat.

The ALD method is a method of forming a film by switching the source gas to adsorb one atomic layer at a time on the surface of the adherend (metal member 3 in the present invention) and reacting it. Depending on the reaction activation means, the thermal ALD method and the plasma ALD method can be divided.
The thermal ALD method is a method of forming a film by supplying a gas as a raw material for film formation to the heated metal member 3 without generating plasma.
In the plasma ALD method, in addition to the thermal ALD method, plasma is generated and the reaction is further promoted to form a film. Note that the plasma ALD method can form a denser film with better barrier properties in the low temperature process region than the thermal ALD method. The method of forming a ceramic coat on the metal member 3 is preferably based on the plasma ALD method because it is less likely to be bent by heat and a dense and good barrier property can be formed. Can be used without any problems.

  The metal member 3 has a length dimension s3 from the end portion 22e of the first non-opening portion 22 on the first opening portion 21 side to the end portion 3e of the second non-opening portion 32 on the second opening portion 31 side. It may be 10 mm. When the length dimension s3 is within this range, the gas can flow smoothly during film formation, so that the uniformity of the end film thickness can be improved. Further, since the length dimension s3 is appropriate, the manufacturing is easy, and sufficient strength can be ensured, so that the handling property can be improved. Furthermore, even if it is affected by heat during film formation, the metal member 3 is unlikely to be bent or distorted, so that the influence of entering can be suppressed.

The mask 1 according to the present embodiment described above is opened in substantially the same shape as the first opening 21 with an opening size smaller than the opening size of the first opening 21 at the same opening position as the first opening 21. The second opening portion 31 and the second non-opening portion 32 that forms the second opening portion 31 are provided, and the second non-opening portion 32 is ceramic coated and has a smaller thickness than the mask member 2. (T2> t3, see FIG. 2) The metal member 3 is provided. Therefore, the mask 1 can not only increase the uniformity of the end film thickness of the film formed in the vicinity of the second opening 31 of the metal member 3, but can almost eliminate the influence of entering. Further, since the metal member 3 is ceramic coated, it has corrosion resistance against the cleaning gas. Furthermore, since the metal member 3 is ceramic-coated, abnormal discharge that is likely to occur during plasma CVD film formation can be suppressed. In particular, if a high-hardness ceramic mask member 2 is used, it will not be bent or distorted by heat during plasma CVD film formation, and as described above, film formation is performed by a deposition CVD plasma CVD film formation apparatus. At this time, the film can be formed in a predetermined shape while suitably holding the film formation object.
The mask 1 is not limited to the plasma CVD method, but is a vacuum deposition method, a sputtering method, a reactive sputtering method, a molecular beam epitaxy method, a cluster ion beam method, an ion plating method, a plasma polymerization method, an atmospheric pressure plasma polymerization method, It can also be suitably used in film forming methods such as laser CVD, thermal CVD, and coating.

  In the above description, the case where the film is formed using the mask 1 in the deposition CVD plasma CVD deposition apparatus has been described. However, the deposition CVD plasma deposition apparatus can be suitably used as well. can do. Note that the deposition down method is a method in which an electrode of a film formation apparatus is provided above a film formation object and a film is formed on the surface of the film formation object facing upward (this method is also called a face-up method). Yes.)

[Plasma CVD film forming method and organic EL element]
Next, a plasma CVD film forming method for forming a sealing film on the surface of an object to be formed by plasma CVD using the mask 1 according to the present embodiment will be described. The formation of the sealing film by the plasma CVD method using the mask 1 is suitably applied, for example, when manufacturing an organic EL element by roll-to-roll conveyance. Note that it is preferable to produce an organic EL element by roll-to-roll conveyance because of high productivity.
Hereinafter, the plasma CVD film forming method according to the present embodiment will be described by taking an example of manufacturing an organic EL element as an example. For convenience of explanation, before describing the plasma CVD film forming method in detail, the mask according to the present embodiment will be described. An organic EL element having a sealing film formed using 1 will be described.

(Organic EL device)
As shown in FIG. 3, the organic EL element 10 includes a base material 11, a first electrode layer 12, an organic EL layer 13, and a second electrode layer 14. And the sealing film 15 formed by the plasma CVD method using the mask 1 is provided so that these layers may be sealed. Hereinafter, these layers will be described in order.

(Base material)
The base material 11 is also called a substrate, a transparent substrate, or the like, and is a member that becomes a base of the organic EL element 10. As the base material 11, a synthetic resin having a long belt shape and flexibility, preferably a transparent resin film is used.
Examples of the base material 11 include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene, polypropylene, cellophane (registered trademark), cellulose diacetate, cellulose triacetate (TAC), cellulose acetate butyrate, and cellulose acetate. Cellulose esters such as propionate (CAP), cellulose acetate phthalate, cellulose nitrate or derivatives thereof, polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, poly Ether ketone, polyimide, polyethersulfone (PES), polyphenylene sulfide, polysulfones Cycloolefin resins such as polyetherimide, polyetherketoneimide, polyamide, fluororesin, nylon, polymethylmethacrylate, acrylic or polyarylate, Arton (trade name, manufactured by JSR) or Appel (trade name, manufactured by Mitsui Chemicals) Can be formed.

The base material 11 is preferably formed with a gas barrier film (not shown) that prevents the passage of gas on the surface on which the first electrode layer 12 is formed and / or the back surface thereof. Examples of the gas barrier film include an inorganic film, an organic film, or a hybrid film of both. As a characteristic of the gas barrier film, the water vapor permeability is preferably 0.01 g / m ² · day · atm or less. Furthermore, a high barrier film having an oxygen permeability of 10 ⁻³ ml / m ² / day or less and a water vapor permeability of 10 ⁻⁵ g / m ² / day or less is preferable.

  As a material for forming the gas barrier film, any material may be used as long as it has a function of suppressing intrusion of an element such as moisture or oxygen that causes deterioration of the element. For example, silicon oxide, silicon dioxide, silicon nitride, or the like can be used. Further, in order to improve the brittleness of the film, it is more preferable to have a laminated structure of these inorganic layers and organic material layers. Although there is no restriction | limiting in particular about the lamination | stacking order of an inorganic layer and an organic layer, It is preferable to laminate | stack both alternately several times. The method for forming the gas barrier film is not particularly limited. For example, the vacuum deposition method, the sputtering method, the reactive sputtering method, the molecular beam epitaxy method, the cluster ion beam method, the ion plating method, the plasma polymerization method, the atmospheric pressure plasma polymerization method. A plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used, but an atmospheric pressure plasma polymerization method as described in JP-A-2004-68143 is particularly preferable.

(First electrode layer)
The first electrode layer 12 is connected to a power source and functions as, for example, an anode. As such a first electrode layer 12, a material having a work function (4 eV or more) of a metal, an alloy, an electrically conductive compound and a mixture thereof is preferably used. Specific examples of such electrode materials include metals such as Au, and conductive transparent materials such as CuI, indium tin oxide (ITO), SnO ₂ and ZnO. Alternatively, an amorphous material such as IDIXO (In ₂ O ₃ .ZnO) capable of forming a transparent conductive film may be used. The first electrode layer 12 may be formed by forming a thin film by depositing these electrode materials by a method such as vapor deposition or sputtering, and a pattern having a desired shape may be formed by a photolithography method. (About 100 μm or more), a pattern may be formed through a mask having a desired shape when the electrode material is deposited or sputtered. Or when using the substance which can be apply | coated like an organic electroconductive compound, wet film-forming methods, such as a printing system and a coating system, can also be used. When light emission is extracted from the anode, it is desirable that the transmittance is greater than 10%, and the sheet resistance as the anode is preferably several hundred Ω / □ or less. Further, although the film thickness depends on the material, it is usually selected in the range of 10 to 1000 nm, preferably 10 to 200 nm.

(Second electrode layer)
The second electrode layer 14 is connected to a power source and functions as, for example, a cathode. As such a second electrode layer 14, a material having a work function (less than 4 eV) metal (referred to as an electron injecting metal), an alloy, an electrically conductive compound, and a mixture thereof as an electrode material is used. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al ₂ O ₃ ) Mixtures, indium, lithium / aluminum mixtures, rare earth metals and the like. Among these, from the point of durability against electron injection and oxidation, etc., a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function than this, for example, a magnesium / silver mixture, Suitable are a magnesium / aluminum mixture, a magnesium / indium mixture, an aluminum / aluminum oxide (Al ₂ O ₃ ) mixture, a lithium / aluminum mixture, aluminum and the like. The second electrode layer 14 can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering. Further, the sheet resistance as the second electrode layer 14 is preferably several hundred Ω / □ or less, and the film thickness is usually selected in the range of 10 nm to 5 μm, preferably 50 to 200 nm. In order to transmit the emitted light, if either the anode (first electrode layer 12) or the cathode (second electrode layer 14) of the organic EL element is transparent or translucent, the emission luminance is improved. It is convenient.

  Moreover, after producing the said metal with the film thickness of 1-20 nm in the 2nd electrode layer 14, by producing the electroconductive transparent material quoted by description of the 1st electrode layer 12 on it, it is transparent or half A transparent second electrode layer 14 (cathode) can be produced, and by applying this, both the first electrode layer 12 (anode) and the second electrode layer 14 (cathode) have transparency. An element can be manufactured.

(Organic EL layer)
The organic EL layer 13 includes a light emitting layer (not shown) that emits light by recombination of holes injected from the anode and electrons injected from the cathode. In addition to the light emitting layer, the organic EL layer 13 includes an electron transport layer, a hole transport layer, a hole injection layer (anode buffer layer), an electron injection layer (cathode buffer layer), a hole blocking layer, an electron blocking layer, and the like ( Any of them can be appropriately laminated.

Examples of the configuration of the organic EL layer 13 include the following.
(1) Light emitting layer (2) Hole transport layer / light emitting layer (3) Light emitting layer / electron transport layer (4) Hole transport layer / light emitting layer / electron transport layer (5) Hole transport layer / light emitting layer / positive Hole blocking layer / electron transport layer (6) hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer (7) anode buffer layer / hole transport layer / light emitting layer / hole blocking layer / Electron transport layer / cathode buffer layer (8) hole transport layer / anode buffer layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer (9) anode buffer layer / hole transport layer / light emitting layer / electron Transport layer / cathode buffer layer

(Light emitting layer)
As described above, the light emitting layer is a layer that emits light by recombination of holes injected from the anode and electrons injected from the cathode. The light emitting layer may be a single layer or may be a multilayer using a plurality of light emitting layers. In the case of a multilayer structure, a non-light emitting intermediate layer may be provided between the light emitting layers. In addition, among the layer configurations, an organic compound layer including a light emitting layer can be used as one light emitting unit, and a plurality of light emitting units can be stacked. The plurality of stacked light emitting units may have a non-light emitting intermediate layer between the light emitting units, and the intermediate layer may further include a charge generation layer. When the light emitting layer is multi-layered, it is necessary to dispose a vapor deposition unit and a coating / drying unit according to the number of layers to be stacked.

  The light emitting layer is made of at least one selected from, for example, a blue light emitting layer, a green light emitting layer, and a red light emitting layer. A white element can be manufactured by stacking the blue light emitting layer, the green light emitting layer, and the red light emitting layer. There is no particular limitation on the stacking order when the light emitting layers are stacked. In the present invention, it is preferable that at least one blue light emitting layer is provided at a position closest to the anode in all the light emitting layers. When four or more light emitting layers are provided, for example, blue light emitting layer / green light emitting layer / red light emitting layer / blue light emitting layer, blue light emitting layer / green light emitting layer / red light emitting layer / blue from the order close to the anode. A blue light-emitting layer, a green light-emitting layer, a green light-emitting layer, a red light-emitting layer, a blue light-emitting layer, a green light-emitting layer, and a red light-emitting layer may be stacked in this order. It is preferable for improving luminance stability.

  The total thickness of the light emitting layer is not particularly limited, but is usually selected in the range of 2 nm to 5 μm, preferably 2 to 200 nm in consideration of the uniformity of the film and the voltage required for light emission. Furthermore, it is preferable that it exists in the range of 10-20 nm. A film thickness of 20 nm or less is preferable because it has the effect of improving the stability of the emission color with respect to the driving current as well as the voltage surface. The thickness of each light emitting layer is preferably selected in the range of 2 to 100 nm, and more preferably in the range of 2 to 20 nm. Although there is no restriction | limiting in particular about the film thickness relationship of each light emitting layer of blue, green, and red, It is preferable that the blue light emitting layer (the sum total when there are two or more layers) is the thickest among three light emitting layers.

  The light emitting layer includes at least three layers having different emission spectra, each having an emission maximum wavelength in the range of 430 to 480 nm, 510 to 550 nm, and 600 to 640 nm. If it is three or more layers, there will be no restriction | limiting in particular. When there are more than four layers, there may be a plurality of layers having the same emission spectrum. A layer having an emission maximum wavelength in the range of 430 to 480 nm is referred to as a blue light emitting layer, a layer in the range of 510 to 550 nm is referred to as a green light emitting layer, and a layer in the range of 600 to 640 nm is referred to as a red light emitting layer. Moreover, in the range which maintains the said maximum wavelength, you may mix a several luminescent compound in each light emitting layer. For example, the blue light emitting layer may be used by mixing a blue light emitting compound having a maximum wavelength of 430 to 480 nm and a green light emitting compound having the same wavelength of 510 to 550 nm.

The material (light emitting material) that can be used for the light emitting layer is not particularly limited. For example, Toray Research Center, Inc. The latest trend of flat panel displays The current state of EL displays and the latest technological trends Various materials as described on pages 228 to 332 Can be mentioned.
In addition, in the organic EL element 10 which concerns on this invention, even if it is a low molecular light-emitting material, it can be used conveniently. A low-molecular light-emitting material refers to a light-emitting material having a weight average molecular weight of 5000 or less, preferably 3000 or less, more preferably 2000 or less. In addition, a high-molecular light-emitting material having a weight average molecular weight larger than 5000 can also be suitably used.

  In the light emitting layer constituting the organic EL layer 13 in the organic EL element 10, a known host compound and a known phosphorescent compound (also referred to as a phosphorescent compound) are used to increase the light emission efficiency of the light emitting layer. It is preferable to contain.

  The host compound is a compound contained in the light-emitting layer, the mass ratio in the layer is 20% or more, and the phosphorescence quantum yield of phosphorescence emission is 0.1 at room temperature (25 ° C.). Is defined as less than a compound. The phosphorescence quantum yield is preferably less than 0.01. A plurality of host compounds may be used in combination. By using a plurality of types of host compounds, it is possible to adjust the movement of charges, and the organic EL element can be made highly efficient. In addition, by using a plurality of phosphorescent compounds, it is possible to mix different light emission, thereby obtaining an arbitrary emission color. White light emission is possible by adjusting the kind of phosphorescent compound and the amount of doping, and can also be applied to illumination and backlight.

  As these host compounds, compounds having a hole transporting ability and an electron transporting ability, preventing emission light from being increased in wavelength, and having a high Tg (glass transition temperature) are preferable. Known host compounds include, for example, JP-A Nos. 2001-257076, 2002-308855, 2001-313179, 2002-319491, 2001-357777, and 2002-334786. Gazette, 2002-8860, 2002-334787, 2002-15871, 2002-334788, 2002-43056, 2002-334789, 2002-75645 2002-338579, 2002-105445, 2002-343568, 2002-141173, 2002-352957, 2002-203683, 2002-363227 2002-231453, 2003-3165, 2002-234888, 2003-27048, 2002-255934, 2002-260861, 2002-280183, Examples thereof include compounds described in 2002-299060, 2002-302516, 2002-305083, 2002-305084, 2002-308837 and the like.

  In the case of having a plurality of light emitting layers, it is preferable that 50% by mass or more of the host compound in each layer is the same compound because it is easy to obtain uniform film properties over the entire organic EL layer 13, and further, the host compound It is more preferable that the phosphorescence emission energy of is 2.9 eV or more because it is advantageous in efficiently suppressing energy transfer from the dopant and obtaining high luminance. Phosphorescence emission energy means the peak energy of the 0-0 band of the phosphorescence emission when a host compound is formed as a deposited film with a thickness of 100 nm on a substrate and the photoluminescence is measured.

  The host compound has a phosphorescence emission energy of 2.9 eV or more and a Tg of 90 ° C. or more in consideration of deterioration of the organic EL element 10 over time (decrease in luminance, film property deterioration), market needs as a light source, etc. It is preferable that That is, in order to satisfy both luminance and durability, it is preferable that phosphorescence emission energy is 2.9 eV or more and Tg is 90 ° C. or more. Tg is more preferably 100 ° C. or higher.

  A phosphorescent compound (phosphorescent compound) is a compound in which light emission from an excited triplet is observed, is a compound that emits phosphorescence at room temperature (25 ° C.), and has a phosphorescence quantum yield of 25. The compound is 0.01 or more at ° C. By using it together with the host compound described above, the organic EL device 10 with higher luminous efficiency can be obtained.

  The phosphorescent compound in the present invention preferably has a phosphorescence quantum yield of 0.1 or more. The phosphorescence quantum yield can be measured by the method described in Spectroscopic II, page 398 (1992 edition, Maruzen) of Experimental Chemistry Course 4 of the 4th edition. Although the phosphorescence quantum yield in a solution can be measured using various solvents, the phosphorescence quantum yield used in the present invention only needs to achieve the above phosphorescence quantum yield in any solvent.

  There are two types of light emission of the phosphorescent compound in principle. One is the recombination of the carrier on the host compound to which the carrier is transported to generate an excited state of the host compound, and this energy is transferred to the phosphorescent compound. The energy transfer type is to obtain light emission from the phosphorescent compound by moving to the other, and the other is that the phosphorescent compound becomes a carrier trap, and carrier recombination occurs on the phosphorescent compound, and the phosphorescent compound emits light. Although it is a carrier trap type in which light emission is obtained, in any case, it is a condition that the excited state energy of the phosphorescent compound is lower than the excited state energy of the host compound.

  The phosphorescent compound can be appropriately selected from known compounds used for the light emitting layer of the organic EL element 10. The phosphorescent compound is preferably a complex compound containing a group 8-10 metal in the periodic table of elements, more preferably an iridium compound, an osmium compound, or a platinum compound (platinum complex compound), rare earth Of these, iridium compounds are the most preferred.

  In the present invention, the phosphorescence emission maximum wavelength of the phosphorescent compound is not particularly limited, and can be obtained in principle by selecting a central metal, a ligand, a ligand substituent, and the like. The emission wavelength can be changed.

  The light emission color of the organic EL device 10 of the present invention and the compound according to the present invention is shown in FIG. 4.16 on page 108 of “New Color Science Handbook” (edited by the Japan Color Society, University of Tokyo Press, 1985). It is determined by the color when the result measured with a luminance meter CS-1000 (manufactured by Konica Minolta Optics) is applied to the CIE chromaticity coordinates.

The white element referred to in the present invention means that the chromaticity in the CIE 1931 color system at 1000 cd / m ² is X = 0.33 ± 0.07 when the front luminance at 2 ° viewing angle is measured by the above method. It is in the region of Y = 0.33 ± 0.07.

  The external extraction quantum efficiency at room temperature of light emission of the organic EL device 10 of the present invention is preferably 1% or more, more preferably 5% or more. Here, the external extraction quantum efficiency (%) = the number of photons emitted to the outside of the organic EL element 10 / the number of electrons sent to the organic EL element 10 × 100.

  In addition, a hue improvement filter such as a color filter may be used in combination, or a color conversion filter that converts the emission color from the organic EL element 10 into multiple colors using a phosphor may be used in combination. In the case of using a color conversion filter, the λmax of light emission of the organic EL element 10 is preferably 480 nm or less.

  The organic EL device 10 of the present invention preferably uses the following method in combination in order to efficiently extract light generated in the light emitting layer. Generally, an organic EL element emits light inside a layer having a refractive index higher than that of air (refractive index is about 1.7 to 2.1), and about 15% to 20% of light generated in the light emitting layer. It is said that only the light can be extracted. This is because light incident on the interface (interface between the transparent substrate and air) at an angle θ greater than the critical angle causes total reflection and cannot be taken out of the device, or between the transparent electrode or light emitting layer and the transparent substrate. This is because light is totally reflected between the light and the light is guided through the transparent electrode or the light emitting layer, and as a result, the light escapes in the direction of the side surface of the device.

  As a method for improving the light extraction efficiency, for example, a method of forming irregularities on the surface of the transparent substrate to prevent total reflection at the interface between the transparent substrate and the air (US Pat. No. 4,774,435), A method of improving efficiency by imparting light collecting properties to a substrate (Japanese Patent Laid-Open No. 63-314795), a method of forming a reflective surface on the side surface of an element (Japanese Patent Laid-Open No. 1-220394), a substrate A method of forming an antireflection film by introducing a flat layer having an intermediate refractive index between the base and the light emitter (Japanese Patent Laid-Open No. 62-172691), and a lower refractive index than the substrate between the base and the light emitter A method of introducing a flat layer having a thickness (Japanese Patent Laid-Open No. 2001-202827), and a method of forming a diffraction grating between any one of the substrate, the transparent electrode layer and the light emitting layer (including between the substrate and the outside) -283751).

  In the present invention, these methods can be used in combination with the organic EL element 10, but a method of introducing a flat layer having a lower refractive index than the base material between the base material and the light emitting layer, or a base material, A method of forming a diffraction grating between any layers of the transparent electrode layer and the light emitting layer (including between the substrate and the outside) can be suitably used. In the present invention, by combining these means, it is possible to obtain an element having higher brightness or durability.

  When a low refractive index medium is formed between the transparent electrode and the transparent substrate with a thickness longer than the wavelength of light, the light extracted from the transparent electrode has a higher extraction efficiency to the outside as the refractive index of the medium is lower. . Examples of the low refractive index layer include aerogel, porous silica, magnesium fluoride, and a fluorine-based polymer. Since the refractive index of the transparent substrate is generally about 1.5 to 1.7, the low refractive index layer preferably has a refractive index of about 1.5 or less. Further, it is preferably 1.35 or less. The thickness of the low refractive index medium is preferably at least twice the wavelength in the medium. This is because the effect of the low refractive index layer is diminished when the thickness of the low refractive index medium is about the wavelength of light and the electromagnetic wave that has exuded by evanescent enters the substrate. The method of introducing a diffraction grating into an interface or any medium that causes total reflection is characterized by a high effect of improving light extraction efficiency. This method is generated from the light emitting layer by utilizing the property that the diffraction grating can change the direction of light to a specific direction different from refraction by so-called Bragg diffraction such as first-order diffraction or second-order diffraction. Of the light, the light that cannot go out due to total reflection between layers, etc. is diffracted by introducing a diffraction grating in any layer or medium (inside a transparent substrate or transparent electrode) It tries to take out light. The introduced diffraction grating desirably has a two-dimensional periodic refractive index. This is because light emitted from the light-emitting layer is randomly generated in all directions, so in a general one-dimensional diffraction grating having a periodic refractive index distribution only in a certain direction, only light traveling in a specific direction is diffracted. The light extraction efficiency does not increase so much. However, by making the refractive index distribution a two-dimensional distribution, light traveling in all directions is diffracted, and light extraction efficiency is increased.

  As described above, the position where the diffraction grating is introduced may be in any of the layers or in the medium (in the transparent substrate or in the transparent electrode), but is preferably in the vicinity of the light emitting layer where light is generated. At this time, the period of the diffraction grating is preferably about 1/2 to 3 times the wavelength of light in the medium. The arrangement of the diffraction gratings is preferably two-dimensionally repeated, such as a square lattice, a triangular lattice, or a honeycomb lattice.

  Furthermore, the organic EL element 10 of the present invention is processed so as to provide, for example, a structure on the microlens array on the light extraction side of the base material in order to efficiently extract the light generated in the light emitting layer, or so-called By combining with a condensing sheet, it can condense in a specific direction, for example, a front direction with respect to the element light emitting surface. Thereby, the brightness | luminance in a specific direction can be raised. As an example of the microlens array, quadrangular pyramids having a side of 30 μm and an apex angle of 90 degrees are two-dimensionally arranged on the light extraction side of the substrate. One side is preferably 10 μm to 100 μm. If it becomes smaller than this, the effect of diffraction will generate | occur | produce and color, and if too large, thickness will become thick and is not preferable.

  As the condensing sheet, for example, a sheet that is put into practical use in an LED backlight of a liquid crystal display device can be used. As such a sheet, for example, a brightness enhancement film (BEF) manufactured by Sumitomo 3M Limited can be used. As the shape of the prism sheet, for example, a substrate may be formed with a Δ-shaped stripe having an apex angle of 90 degrees and a pitch of 50 μm, or the apex angle is rounded and the pitch is changed randomly. Other shapes may be used. Moreover, in order to control the light emission angle from a light emitting element, you may use together a light diffusing plate and a film with a condensing sheet. For example, a diffusion film (light-up) manufactured by Kimoto Co., Ltd. can be used.

  The light emitting layer can be formed by a vapor deposition method performed by arranging an arbitrary vapor deposition source in a vacuum film formation chamber. Examples of the vapor deposition method include a sputtering method, a mask vapor deposition method, and a photolithography patterning method. The light emitting layer can also be formed by applying a light emitting layer forming coating solution and drying. As described above, the light emitting layer is a layer that emits light by recombination of electrons and holes injected from the electrode, the electron injection layer, or the hole transport layer. The portion that emits light may be within the layer of the light emitting layer or at the interface between the light emitting layer and the adjacent layer.

  Here, as a wet coating machine for applying the light emitting layer forming coating solution, for example, a die coating method, a screen printing method, a flexographic printing method, an ink jet method, a Mayer bar method, a cap coating method, a spray coating method, a casting method, a roll An applicator used for a coating method, a bar coating method, a gravure coating method, or the like can be used. The use of these wet coaters can be appropriately selected according to the material of the organic compound layer.

(Hole transport layer (hole injection layer, electron blocking layer))
The hole transport layer has a role of moving holes to an effective recombination region and a role of blocking electrons locally as an energy barrier to strengthen light emission. The hole transport layer is made of a hole transport material having a function of transporting holes, and in a broad sense, a hole injection layer and an electron blocking layer are also included in the hole transport layer. The hole transport layer can be provided as a single layer or a plurality of layers. These are described in detail in “Organic EL devices and their forefront of industrialization” (issued on November 30, 1998 by NTS).

  The hole transport material has any of hole injection or transport and electron barrier properties, and may be either organic or inorganic. For example, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, Examples include stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymer oligomers, particularly thiophene oligomers.

  The above-mentioned materials can be used as the hole transport material, but it is preferable to use a porphyrin compound, an aromatic tertiary amine compound and a styrylamine compound, particularly an aromatic tertiary amine compound. Representative examples of aromatic tertiary amine compounds and styrylamine compounds include N, N, N ', N'-tetraphenyl-4,4'-diaminophenyl; N, N'-diphenyl-N, N'- Bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine (TPD); 2,2-bis (4-di-p-tolylaminophenyl) propane; 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane; N, N, N ′, N′-tetra-p-tolyl-4,4′-diaminobiphenyl; 1,1-bis (4-di-p-tolyl) Aminophenyl) -4-phenylcyclohexane; bis (4-dimethylamino-2-methylphenyl) phenylmethane; bis (4-di-p-tolylaminophenyl) phenylmethane; N, N'-diphenyl-N, N ' − (4-methoxyphenyl) -4,4'-diaminobiphenyl; N, N, N ', N'-tetraphenyl-4,4'-diaminodiphenyl ether; 4,4'-bis (diphenylamino) quadriphenyl; N, N, N-tri (p-tolyl) amine; 4- (di-p-tolylamino) -4 '-[4- (di-p-tolylamino) styryl] stilbene; 4-N, N-diphenylamino- (2-diphenylvinyl) benzene; 3-methoxy-4'-N, N-diphenylaminostilbenzene; N-phenylcarbazole, as well as two of those described in US Pat. No. 5,061,569 Having a condensed aromatic ring in the molecule, for example, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-308 4,4 ', 4 "-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine in which three triphenylamine units described in Japanese Patent No. 88 are linked in a starburst type ( MTDATA) and the like.

  Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used. In addition, inorganic compounds such as p-type-Si and p-type-SiC can also be used as the hole injection material and the hole transport material.

  JP-A-11-251067, J. Org. Huang et. al. It is also possible to use so-called p-type hole transport materials as described in the literature (Applied Physics Letters 80 (2002), p. 139). In the present invention, it is preferable to use these materials because a light-emitting element with higher efficiency can be obtained.

  Although there is no restriction | limiting in particular about the film thickness of a positive hole transport layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5-200 nm. This hole transport layer may have a single layer structure composed of one or more of the above materials. Alternatively, a hole transport layer having a high p property doped with impurities can be used. Examples thereof include JP-A-4-297076, JP-A-2000-196140, JP-A-2001-102175, J.A. Appl. Phys. 95, 5773 (2004), and the like. It is preferable to use a hole transport layer having such a high p property because an organic EL element with lower power consumption can be produced.

(Electron transport layer (electron injection layer, hole blocking layer))
The electron transport layer has a role of moving electrons to an effective recombination region and a role of blocking holes as an energy barrier and locally retaining light to enhance light emission. The electron transport layer is made of a material having a function of transporting electrons (electron transport material), and includes an electron injection layer and a hole blocking layer in a broad sense. The electron transport layer can be provided as a single layer or a plurality of layers. These are described in detail in “Organic EL devices and their forefront of industrialization” (issued on November 30, 1998 by NTS).

  Conventionally, it is used for an electron transport layer adjacent to the light-emitting layer on the cathode side when the electron transport material (also serves as a hole blocking material) used for a single electron transport layer or a plurality of electron transport layers are used. Any electron transporting material may be used as long as it has a function of transmitting electrons injected from the cathode to the light emitting layer, and any of known materials can be selected and used as the material. . Examples include nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimides, fluorenylidenemethane derivatives, anthraquinodimethane, anthrone derivatives, and oxadiazole derivatives. Furthermore, in the above oxadiazole derivative, a thiadiazole derivative in which the oxygen atom of the oxadiazole ring is substituted with a sulfur atom, and a quinoxaline derivative having a quinoxaline ring known as an electron-withdrawing group can also be used as a material for the electron transport layer. it can. Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used.

In addition, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (Alq ₃ ), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-quinolinol) Aluminum, tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), etc., and the central metals of these metal complexes are In, Mg Metal complexes replaced with Cu, Ca, Sn, Ga, or Pb can also be used as the material for the electron transport layer.

  In addition, metal-free or metal phthalocyanine, or those having terminal ends substituted with an alkyl group or a sulfonic acid group can be preferably used as the material for the electron transport layer. Further, distyrylpyrazine derivatives exemplified as the material of the light emitting layer can also be used as the material of the electron transport layer, and n-type-Si, n-type-SiC, etc. as well as the hole injection layer and the hole transport layer. These inorganic semiconductors can also be used as a material for the electron transport layer.

The electron transport layer can be formed by thinning the above material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an inkjet method, or an LB method. Although there is no restriction | limiting in particular about the film thickness of an electron carrying layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5-200 nm. The electron transport layer may have a single layer structure composed of one or more of the above materials.
In addition, the electron transport layer can be doped with impurities to increase the n property. Examples thereof include JP-A-4-297076, JP-A-10-270172, JP-A-2000-196140, 2001-102175, J.A. Appl. Phys. 95, 5773 (2004), and the like. Furthermore, in the present invention, the electron transport layer may contain potassium or a potassium compound. As the potassium compound, for example, potassium fluoride can be used. Thus, it is preferable to increase the n property of the electron transport layer because an element with lower power consumption can be manufactured.

  The details of the electron injection layer (cathode buffer layer) are also described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like. Specifically, strontium, aluminum, etc. Metal buffer layer typified by lithium, alkali metal compound buffer layer typified by lithium fluoride, alkaline earth metal compound buffer layer typified by magnesium fluoride, oxide buffer layer typified by aluminum oxide, etc. . The buffer layer (injection layer) is preferably a very thin film, and the film thickness is preferably in the range of 0.1 nm to 5 μm although it depends on the material.

  The hole blocking layer has a function of an electron transport layer in a broad sense. The hole blocking layer is made of a hole blocking material that has a function of transporting electrons but has a very small ability to transport holes, and recombines electrons and holes by blocking holes while transporting electrons. Probability can be improved. The hole blocking layer can be implemented using the one described in the electron transport layer. The hole blocking layer is preferably provided adjacent to the light emitting layer. The film thickness of the hole blocking layer is preferably 3 to 100 nm, more preferably 5 to 30 nm.

(Sealing film)
As shown in FIG. 3, the sealing film 15 is formed in a predetermined shape so as to cover the first electrode layer 12, the organic EL layer 13, and the second electrode layer 14 from the base material 11. Seal.
As described above, the mask 1 according to the present embodiment can be suitably used when the sealing film 15 is formed by a plasma CVD film forming apparatus. Even if it is, it can be used.
For the sealing film 15, it is preferable to use the materials and methods described for the gas barrier film of the substrate 11.

(Manufacturing by roll-to-roll conveyance)
The organic EL element 10 manufactured using the mask 1 according to the present embodiment described above can perform most of the steps by the roll-to-roll conveyance described above. Hereinafter, with reference to FIG. 4, a mode that the organic EL element 10 is manufactured by roll-to-roll conveyance is demonstrated. FIG. 4 is a schematic diagram illustrating a configuration example of a series of manufacturing apparatuses 100 that manufacture organic EL elements.

  The manufacturing apparatus 100 includes an unwinding chamber 110 for unwinding the substrate 11 from a flexible belt-shaped substrate roll 11c (hereinafter simply referred to as “roll 11c”) on which the first electrode layer 12 (anode) is formed, A mechanism that does not cause a positional shift in a direction perpendicular to the transport direction of the base material 11, a transport auxiliary chamber 120 in which a movement distance correction mechanism in the transport direction, and the like are disposed.

  In addition, the manufacturing apparatus 100 is provided with a first film forming chamber 130 for depositing a material constituting each functional layer such as the organic EL layer 13 on the base material 11, and a transport having the same configuration as the transport auxiliary chamber 120. An auxiliary chamber 140 and a second film forming chamber 150 for forming another functional layer on the functional layer formed in the first film forming chamber 130 are provided.

  Furthermore, the manufacturing apparatus 100 seals each functional layer such as the transport auxiliary chamber 160 having the same configuration as the transport auxiliary chambers 120 and 140 and the organic EL layer 13 formed on the substrate 11. And a sealing film forming chamber 170 for forming the film 15.

  In addition, the manufacturing apparatus 100 includes an organic EL sheet 11e (organic EL element 10) obtained by forming a transfer auxiliary chamber 180 having the same configuration as the transfer auxiliary chambers 120, 140, and 160, and a sealing film 15. ) On a roll 11d.

  Here, for simplification of description, the number of chambers in which the functional layers are formed is two chambers, the first deposition chamber 130 and the second deposition chamber 150. However, this can be changed as appropriate according to the number and type of functional layers to be formed. In these chambers, each functional layer is formed by a deposit-up method. Therefore, the sealing film 15 is formed in the sealing film forming chamber 170 by the deposition CVD plasma deposition apparatus 171. In general, it is said that the deposition method is more efficient in the film formation by the plasma CVD method. However, when the film formation is performed by the deposition method, it is necessary to invert the organic EL sheet 11e. . When the reversing mechanism for reversing the organic EL sheet 11e can be provided in the manufacturing apparatus 100, the sealing film 15 is preferably formed by reversing the sheet and depositing down. Here, each of the functional layers is formed by the deposition method without providing such a reversing mechanism, and the sealing film 15 is formed by the deposition method as it is. In the case of roll-to-roll conveyance, it is difficult to install a reversing mechanism for the substrate 11, and it is desirable to form the sealing film 15 as it is after forming each functional layer by the depot up method. .

  In each of the above-described chambers 110 to 190, in this embodiment, the atmosphere is controlled according to the processing performed in the chamber. Specifically, the first film formation chamber 130 and the second film formation chamber 150 in which the functional layer is formed are in a vacuum. Further, the auxiliary transfer chambers 120, 140, 160, and 180 in which the substrate 11 is transferred, the sealing film forming chamber 170, the unwind chamber 110, and the take-up chamber 190 are in vacuum.

  The base material 11 unwound from the roll 11c is changed in the traveling direction by a plurality of rolls and is given an appropriate tension until it is wound around the roll 11d via the respective chambers 110 to 190. The number of installations and installation positions of a plurality of rolls can be arbitrarily set.

  The winding core of the roll 11c provided in the unwinding chamber 110 and the winding core of the roll 11d provided in the winding chamber 190 are not deformed when the substrate 11 is wound up, and the atmosphere is about 100 ° C. Those that do not deform even when exposed are preferred. Further, it is preferable that the winding core does not generate dust when being attached to and detached from the manufacturing apparatus 100 or transferred to the decompression chamber or the like. Furthermore, it is preferable that the part which the base material 11 touches is smooth among the surface parts of a winding core, and specifically, it is preferable that surface roughness Ra is 30 nm or less, and Rt is 100 nm or less. The material of the winding core is preferably glass fiber reinforced plastic or stainless steel.

  Furthermore, in order to prevent the web surface on the core and the back surface of the web overlapping therewith from rubbing against each other at both ends in the axial direction of the winding core of the base material 11, You may give a knurling process (it is also called embossing). This height is preferably about 2 to 50 μm, for example.

  Hereinafter, it demonstrates in order. First, the base material 11 is unwound from a roll 11 c installed in the unwinding chamber 110. As already described, the base material 11 may be subjected to an anode (first electrode layer 12) patterning in advance.

  The base material 11 unwound from the roll 11 c is transferred to the first film forming chamber 130 via the transfer auxiliary chamber 120. Then, the transported base material 11 is stopped at a predetermined position in the first film formation chamber 130, and a functional layer is formed (that is, film formation) in the first film formation chamber 130.

  As shown in FIG. 4, the functional layer is formed at a predetermined position in the first film forming chamber 130 by a vapor deposition source 131 from which a vapor deposition material for forming the functional layer is released, and the vapor deposition source 131 and the base layer. A fine-tunable pattern forming mask 132 (hereinafter referred to as “mask 132”) for forming a functional layer having a desired pattern is disposed between the material 11 and the material 11. Further, a temperature adjustment plate 133 for maintaining the temperature of the base material 11 during vapor deposition is disposed at a position facing the mask 132 with the base material 11 interposed therebetween. The mask 132 may be the mask 1 according to the present embodiment.

  Deposition on the substrate 11 is performed as follows. That is, first, the vapor deposition source 131 is adjusted and maintained so that the vapor deposition material is released at a predetermined vapor deposition rate, and is blocked by a shutter (not shown) or the like so as not to adhere to the base material 11 unintentionally. ing. The substrate 11 is marked with an alignment mark (not shown). The first film forming chamber 130 is provided with a camera (not shown) and the like for reading the mark. Thereby, the base material 11 stops after being conveyed at an arbitrary speed to a predetermined position where the camera can read the alignment mark.

  Next, the alignment mark is read by the camera, and the mask 132 is finely adjusted to match the position of the alignment mark. Thereafter, while the temperature adjustment plate 133 approaches the base material 11 and comes into close contact, the mask 132 also comes close to the base material 11 and stops at a position where it comes into close contact or has a slight gap.

  Then, the shutter of the vapor deposition source 131 is opened, and a functional layer such as the organic EL layer 13 is formed in a pattern on the substrate 11. At this time, the deposition time and the like are controlled so that the determined film thickness is obtained, and the shutter is closed when the determined film thickness is obtained. Thereafter, while the mask 132 is separated from the substrate 11 and returned to the reference position, the temperature adjustment plate 133 is also separated from the substrate 11 and returned to the reference position. Thereafter, the conveyance of the base material 11 is resumed.

  When the transfer is resumed, the substrate 11 is transferred to the second film formation chamber 150 via the transfer auxiliary chamber 140. Then, in the second film formation chamber 150, metal deposition is performed in the same manner as the film formation in the first film formation chamber 130, and a cathode (second electrode layer 14) is formed. That is, a process of forming a cathode is performed on the base material 11.

  As shown in FIG. 4, the cathode is formed at a predetermined position in the second film forming chamber 150 by a vapor deposition source 151 from which a metal material for forming a functional layer is released, and the vapor deposition source 151 and the substrate. 11, a fine-tunable pattern forming mask 152 (hereinafter referred to as “mask 152”) for forming a cathode having a desired pattern is disposed. Further, a temperature adjustment plate 153 for maintaining the temperature of the base material 11 during vapor deposition is disposed at a position facing the mask 152 with the base material 11 interposed therebetween. The mask 152 may be the mask 1 according to this embodiment.

  Thereafter, the base material 11 on which the functional layer and the cathode are formed is sent to the sealing film forming chamber 170 via the auxiliary conveyance chamber 160. In the sealing film forming chamber 170, the sealing film 15 is formed so as to cover the first electrode layer 12, the organic EL layer 13, and the second electrode layer 14 while the substrate 11 is transported. (See FIG. 3).

  As shown in FIG. 4, the sealing film 15 is formed at an electrode 171 of a plasma CVD film forming apparatus for forming the sealing film 15 at a predetermined position in the sealing film forming chamber 170, and this electrode. A finely adjustable pattern forming mask 172 for forming a sealing film 15 having a desired shape between the substrate 171 and the base material 11 (film formation object) on which each functional layer is formed. Hereinafter, “mask 172” is arranged. In addition, a temperature adjustment plate 173 for maintaining the temperature of the base material 11 during film formation is disposed at a position facing the mask 172 with the base material 11 interposed therebetween. The mask 172 is preferably the mask 1 according to the present embodiment. In the following description, a mode in which the mask 1 according to this embodiment is used as the mask 172 will be described.

  The sealing film 15 is formed on the substrate 11 as follows. That is, first, a carrier gas and a raw material gas are mixed and introduced into the reaction field at a predetermined ratio, the base material 11 is heated by the temperature adjustment plate 173, a high frequency is applied by the electrode 171, and the gas is converted into plasma. Then, the sealing film 15 is formed on the substrate 11. Further, the base material 11 is marked with an alignment mark (not shown). In the sealing film forming chamber 170, a camera (not shown) or the like for reading the mark is installed. Thereby, the base material 11 stops after being conveyed at an arbitrary speed to a predetermined position where the camera can read the alignment mark.

  Next, the alignment mark is read by the camera, and the mask 1 (mask 172) is finely adjusted to match the position of the alignment mark. Thereafter, while the temperature adjustment plate 173 approaches the base material 11 and comes into close contact with it, the mask 1 (mask 172) also approaches the base material 11 and stops at a position where it comes into close contact or has a slight gap.

  Then, a voltage is applied to the electrode 171 to start discharging, and the sealing film 15 is formed in a pattern on the substrate 11 as described above. At this time, the film formation time and the like are controlled so that the determined film thickness is obtained, and the discharge and gas supply are interrupted when the determined film thickness is obtained. Thereafter, while the mask 1 is separated from the substrate 11 and returned to the reference position, the temperature adjustment plate 173 is also separated from the substrate 11 and returned to the reference position. Thereafter, the conveyance of the base material 11 is resumed.

  Thus, the organic EL sheet 11e (organic EL element 10) is obtained. Then, the obtained organic EL sheet 11e is conveyed to the winding chamber 190 via the conveyance auxiliary chamber 180 and is wound on the roll 11d. Finally, the organic EL element 10 is obtained by unwinding from the roll 11d as necessary and cutting it into a predetermined size. The organic EL element 10 uses the mask 1 according to this embodiment when forming the sealing film 15.

The mask 1 has a second opening that opens at the same opening position as the first opening 21 of the mask member 2 and has substantially the same shape as the first opening 21 with an opening size smaller than the opening size of the first opening 21. Portion 31 and a second non-opening portion 32 that forms the second opening portion 31, and the thickness of the second non-opening portion 32 is smaller than that of the mask member 2 that is ceramic coated (t2> t3). FIG. 2) A metal member 3 is provided. That is, as described above, the mask 1 supports the mask member 2 having the first opening 21 and the first non-opening 22 and the metal member 3 having the second opening 31 and the second non-opening 32. It is used as a rib. Therefore, the thickness dimension t3 of the metal member 3 can be reduced, and the uniformity of the end portion film thickness in the vicinity of the end portion 3e of the metal member 3 can be increased.
Further, as described above, since the mask member 2 is used as a rib for supporting the metal member 3 having the second opening 31 and the second non-opening 32, it is affected by heat during film formation. However, since it does not bend or distort, the influence of entering can be suppressed.
Furthermore, since the mask 1 uses the ceramic-coated metal member 3, even when the film is formed by a plasma CVD film forming apparatus, abnormal discharge caused by plasma during film formation can be suppressed.
Then, after the organic EL element 10 is manufactured for a predetermined amount or for a predetermined period, the corrosive NF ₃ gas is used in the sealing film forming chamber 170 for maintenance of facilities and prevention of contamination of the organic EL element 10. Although cleaning is performed, since the metal member 3 is ceramic coated, it is not corroded by the NF ₃ gas. Although not shown in the figure, when cleaning with NF ₃ gas, an isolation mechanism is provided to prevent the gas from coming into contact with the substrate 11, and the mask, electrodes, and the like are cleaned.

  In the above description, the case where the organic EL element 10 is manufactured by roll-to-roll conveyance has been described. However, after the organic EL sheet 11e is obtained, the same applies to roll-to-sheet conveyance in which a sheet processing is performed by cutting processing or the like. The organic EL element 10 can be manufactured.

  Next, the content of the present invention will be specifically described with reference to an example that satisfies the requirements of the present invention and in which a desired effect is confirmed, and a comparative example that does not.

  The thickness dimension t2 of the mask member (see FIG. 2), the thickness dimension t3 of the metal member (see FIG. 2), and the end portion of the second non-opening portion of the metal member from the end portion of the first non-opening portion of the mask member. The length dimension s3 (see FIG. 2) up to the conditions shown in Table 1 Plasma CVD film formation masks (hereinafter simply referred to as masks) 1 to 17 were produced. The mask member and the metal member were fabricated so that the outer shape and size were the same. Then, when the film was formed by the plasma CVD film forming apparatus under the conditions described later, the outer shape of the mask member and the outer shape of the metal member were set to be aligned at a predetermined position of the film forming apparatus. In this study, the mask member and the metal member are not fixed by fixing means such as screws.

  No. In each of the masks 1 to 17, the mask member was made of alumina, and the metal member was made of 42 alloy. No. Such metal members other than 1 were alumina coated on the entire surface by the ALD method.

  No. produced under the above conditions. Using the masks according to 1 to 17, a silicon nitride film that can be applied as a sealing film on the surface of the substrate under the following conditions was formed by a deposition CVD plasma CVD apparatus. The substrate used was a long PET film (polyethylene terephthalate film) having a width of 1000 mm and a thickness of 100 μm. The film thickness of the silicon nitride film was 50 nm.

  The silicon nitride film includes an electrode provided to face the substrate, a high-frequency power source that supplies plasma excitation power to the electrode, a bias power source that supplies bias power to a holding member that holds the substrate, A film was formed by a plasma CVD film forming apparatus provided with a gas supply means for supplying a carrier gas and a source gas toward the electrode.

Silane gas (SiH ₄ ), ammonia gas (NH ₃ ), nitrogen gas (N ₂ ), and hydrogen gas (H ₂ ) were used as the film forming gas. The supply amounts of these gases were 100 sccm for silane gas, 200 sccm for ammonia gas, 500 sccm for nitrogen gas, and 500 sccm for hydrogen gas. The film forming pressure was 50 Pa.
The electrode was supplied with 3000 W plasma excitation power at a frequency of 13.5 MHz from a high frequency power source. Further, 500 W bias power was supplied to the holding member from a bias power source. During the film formation, the temperature of the holding member was adjusted to 110 ° C.

  And No. Using the masks according to Nos. 1 to 17, the silicon nitride film formed on the surface of the substrate under the above conditions was evaluated for the uniformity of the end film thickness, the influence of penetration, and the corrosion resistance against the cleaning gas. These evaluations were performed as follows.

(Uniformity of end film thickness)
The edge part of the formed silicon nitride film was measured with a stylus type surface shape measuring device, and the length from the average film thickness to where it was within ± 3% was measured. And the length of 0.15 mm or less was evaluated as good (◯), and the length exceeding 0.15 mm was evaluated as defective (x).

(Intrusion effect)
The edge of the formed silicon nitride film is measured with a stylus type surface shape measuring instrument, and the extent of the edge of the film is below the second non-opening from the end of the second non-opening of the metal member. The length of the film was measured to determine whether the film had entered. And when the length of the film formed by entering under the end of the second non-opening is 0.2 mm or less is good (◯), and the length exceeding 0.2 mm is bad (×) evaluated.

(Corrosion resistance to cleaning gas)
Corrosion resistance to the cleaning gas was evaluated as good when no corrosion was confirmed on the metal member by visual inspection and flowing 500 sccm of NF ₃ gas, and poor when the corrosion was confirmed.

  As shown in Table 1, no. 2, 3, 6, 7, and 14 to 16 were good results in both the uniformity of the end film thickness and the influence of penetration. In contrast, no. 1, 4, 5, 8-13, and 17 resulted in poor end film thickness uniformity and intrusion effects. The corrosion resistance against cleaning gas is No. The masks other than 1 were all good.

1 Mask (Plasma CVD film formation mask)
2 Mask member 21 First opening 22 First non-opening 22e End of first non-opening 3 Metal member 31 Second opening 32 Second non-opening 33 Ceramic coating 3e (Second non-opening) )edge

Claims (10)

A plasma CVD film formation mask used when forming a film on the surface of an object to be formed by a plasma CVD film formation apparatus,
And ceramic mask member having a first opening,
The same opening position and the first opening, a second opening which opens at the first opening and substantially the same shape on the small aperture size than the opening size of the first opening, the cell la Mick coat And a metal member having a thickness dimension smaller than that of the mask member.   The mask for plasma CVD film formation according to claim 1, wherein the ceramic coat is an alumina coat. Wherein the metal member is a plasma CVD film formation mask according to claim 1 or 2, characterized in that arranged on the deposition target object side of the mask member. An end of the mask member on the first opening side is from one side surface facing the electrode of the plasma CVD film forming apparatus to the other side surface facing the film formation film formed by the plasma CVD film forming apparatus . towards a plasma CVD deposition mask according to any one of claims 1 to 3, characterized in that inclined so that the opening size of the first opening portion is reduced is provided. The metal member has a thickness dimension of 50 to 500 μm,
Plasma CVD deposition mask according to any one of claims 1 to 4, wherein the thickness of the mask member is 2 to 6 mm. Any of claims 1-5 in which the length from the end portion of the first opening side to the end portion of the second opening side of said metal member of said mask member is characterized in that it is a 1~10mm plasma CVD deposition mask according to any one of claims. Plasma CVD deposition mask according to any one of claims 1 to 6, characterized in that used for forming the sealing film of an organic electroluminescence device. Plasma CVD deposition mask according to any one of claims 1 to 7, wherein the film formation performed by the plasma CVD film forming apparatus is Depoappu scheme. Plasma CVD film formation, which comprises forming a sealing film on the surface of the film deposition objects by plasma CVD using a plasma CVD deposition mask according to any one of claims 1-8 Method. The plasma CVD film forming method according to claim 9 , wherein the sealing film is formed by roll-to-roll conveyance.

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