JP2010067517A - Patterning method of thin film, electronic material thin film, and organic electroluminescent display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a patterning method of a thin film used for electronic material by a laser ablation processing method, and to provide an electronic material thin film patterned by the laser ablation processing method, and an organic electroluminescent display. <P>SOLUTION: The patterning method of the thin film includes a step of forming a first thin film on a substrate for the electronic material, a first patterning step of processing the first thin film in a larger shape than a predetermined shape by the laser ablation processing method, and a second patterning step of processing the thin film, formed in the first patterning process, in the predetermined shape. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a thin film patterning method by laser ablation processing of a thin film used for an electronic material. Furthermore, the present invention relates to an electronic material thin film patterned by a laser ablation processing method and an organic electroluminescent display device (in the following description, it may be referred to as “organic EL display device”).

  An organic electroluminescent element using a thin film material that emits light by being excited by passing an electric current (may be referred to as “organic EL element” in the following description) is known. Since organic EL devices can emit light with high brightness at low voltages, they have a wide range of potential in a wide range of fields including mobile phone displays, personal digital assistants (PDAs), computer displays, automotive information displays, TV monitors, or general lighting. It has applications and has advantages such as thinning, lightening, miniaturization, and power saving of devices in these fields. For this reason, the expectation as a leading role of the future electronic display market is great.

  In order to use the organic EL element as a display element, patterning of the electrode is indispensable, and in order to perform delicate display, it is necessary that the finely patterned electrode operates normally. To that end, (1) a sufficiently fine electrode pattern and the width of the insulated portion are narrow, (2) the edge portion of the electrode has a sharp shape, and (3) a finely processed portion. Is completely insulated, (4) the micro-machined electrode part is not short-circuited, (5) the performance of the micro-machined electrode is not impaired, and (6) is removed during micro-machining. An important requirement is that it does not affect the underlying part other than the necessary part.

On the other hand, various active-drive full-color display devices using organic EL elements have been proposed.
For example, as means for obtaining three basic colors of red (R), green (G), and blue (B) for full color expression, there are a three-color painting method and a method of combining a color filter with a white organic EL.

  In the three-color coating method, there is a possibility that the efficiency can be improved by preparing materials suitable for three colors as coloring materials and reducing the loss of the circularly polarizing plate. However, since the painting technique is difficult, it is difficult to realize a high-definition display and it is difficult to enlarge the screen.

In the method of obtaining three colors by combining a color filter with a white organic EL element, there are problems that the light emitting efficiency of the white light emitting material itself is low and that the luminance is reduced to about 1/3 by the color filter.
In addition, various improvements have been made in the method of obtaining a desired color by converting the light emitted from the organic EL element using a color conversion film, but there are problems such as low conversion efficiency to red. .

Therefore, a semi-transparent cathode is adopted for the upper electrode, and it is considered to realize high color reproducibility by taking out only light of a specific wavelength outside the organic EL element by the multiple interference effect with the reflective film. Has been. For example, an organic layer configured such that a first electrode made of a light reflecting material, an organic layer having an organic light emitting layer, a translucent reflecting layer, and a second electrode made of a transparent material are sequentially laminated so that the organic layer becomes a resonance part. In the EL element, there is known an organic EL element configured to satisfy the following formula, where λ is the peak wavelength of the spectrum of light to be extracted.
(2L) / λ + Φ / (2π) = m
(L is an optical distance, λ is a wavelength of light to be extracted, m is an integer, Φ is a phase shift, and the optical distance L is a positive minimum value)

  In a display device using these resonator structures, in order to extract red light (R), green light (G), and blue light (B), an anode ( It has been proposed that the thickness of (ITO) is provided by patterning by photolithography corresponding to each R, G, B pixel (see, for example, Patent Document 1). However, this method is complicated because it is manufactured through many steps such as resist coating, baking, exposure, development, etching, and resist stripping. The number of manufacturing processes is large, yield is poor, and there is a problem of increasing costs.

  2. Description of the Related Art Conventionally, as a patterning method for a display EL element, for example, a mask vapor deposition method is known in which a pattern is formed using a mask when an electrode is formed by a method such as vapor deposition. However, in this method, in order to produce a fine pattern, there are problems such as wraparound of the vapor deposition metal, and further, when performing fine patterning, the positional accuracy of the mask setting with respect to the underlying vapor deposition layer is important. Therefore, an advanced mask setting mechanism is required in the vapor deposition apparatus, which causes problems such as a reduction in productivity.

On the other hand, as a simple patterning means, a fine patterning method of an organic EL element by a laser ablation method has been proposed (see, for example, Patent Documents 2 and 3). It is supposed to be used for patterning an ITO film on a glass substrate. However, since the unnecessary part of the film is blown away by laser irradiation for patterning, the blown-off dust may cause a short circuit between the electrodes, or a burr may occur at the end of the pattern, causing a short circuit between the upper and lower electrodes. Concerned about the problem. In normal liquid crystal elements and electronic paper, the distance between electrodes is as wide as several tens of μm to several hundreds of μm, so shorts due to burrs generated by ablation are unlikely to occur. This is because slight burrs at the edges have a large effect. Therefore, it has been difficult to adopt the laser ablation processing method for thin film devices such as organic EL elements because of the technical characteristics.
JP 2007-26849 A JP-A-8-222371 JP-A-9-320760

  The subject of this invention is providing the thin film patterning method by the laser ablation processing method of the thin film used for an electronic material. Furthermore, an electronic material thin film and an organic EL display device patterned by a laser ablation processing method are provided.

The above-described problems of the present invention have been solved by the following means.
<1> A step of forming a first thin film on a substrate for an electronic material, a first patterning step of processing the first thin film into a shape larger than a predetermined shape by a laser ablation method, and the first A thin film patterning method comprising a second patterning step of processing the thin film formed in one patterning step into the predetermined shape.
<2> The thin film patterning method according to <1>, wherein the second patterning step is a processing step by a photolithography method.
<3> A step of forming a first thin film in order on a substrate for an electronic material, a first patterning step of processing the first thin film into a shape larger than a predetermined shape by a laser ablation method, A thin film patterning comprising: a step of forming a second thin film on a pattern formed by the first patterning; and a second patterning step of processing the first thin film into the predetermined shape. Method.
<4> The thin film patterning method according to <3>, wherein the second patterning step is a processing step by a laser ablation processing method.
<5> The thin film patterning method according to <3>, wherein the second patterning step is a processing step by a photolithography method.
<6> An electronic material thin film formed by the thin film patterning method according to any one of <1> to <5>.
<7> An electron having a pattern made of the first thin film formed by the thin film patterning method according to any one of <3> to <5>, and a pattern made of a laminate of the first thin film and the second thin film. Material thin film.
<8> An organic electroluminescent display device having a resonator structure, wherein at least one of the electrodes of the organic electroluminescent display device is formed by the thin film patterning method according to any one of <1> to <5>. An organic electroluminescence display device which is an electrode.
<9> An organic electroluminescent display device having a resonator structure, wherein the organic electroluminescent display device has an insulating layer formed by the thin film patterning method according to any one of <1> to <5>. Organic electroluminescent display device.
<10> The organic electroluminescent display device according to <8> or <9>, which has a white organic electroluminescent layer.

  According to the present invention, there is provided a thin film patterning method by laser ablation processing of a thin film used for an electronic material. Furthermore, an electronic material thin film patterned by a laser ablation processing method and an organic EL display device are provided.

  In the conventional laser ablation processing method, burrs are generated at the end portion of the thin film remaining after ablation, and therefore, an organic EL element composed of a thin layer film causes various troubles. For example, when an electrode of an organic EL element is manufactured, a short circuit occurs between the upper and lower electrodes due to burrs at the end of the electrode, and the element does not emit light. In addition, in the case of an organic EL element including a resonator using the multiple light interference effect, light with different hues is emitted due to uneven thickness, which causes uneven color. On the other hand, in Japanese Patent Application Laid-Open No. 2007-26849, it is described in the text that the film thickness of the ITO electrode is performed by a photolithography method. However, in order to change the film thickness for each pixel, In addition, the number of processes increases, resulting in an increase in cost and a decrease in yield, which is not realistic.

  According to the present invention, there is provided an improved thin film patterning method which solves the problem of burrs generated at the end portion while reducing the number of steps using laser ablation.

Hereinafter, the present invention will be described in more detail.
1. Organic EL Display Device The organic EL display device of the present invention includes a plurality of pixels on a substrate, and each pixel includes at least two types of sub-pixels that emit light having different wavelengths.
As shown in FIG. 1, the display device of the present invention has a matrix type screen panel in which a plurality of pixels 4 are arranged in parallel vertically and horizontally on a substrate 2. Each pixel is composed of at least two types of sub-pixels that emit light having different wavelengths. Preferably, it is composed of sub-pixels of three colors of red (R), green (G), and blue (B) (FIG. 2). A full color can be reproduced by independently controlling these sub-pixels and emitting light with independent luminance.

  The at least two kinds of sub-pixels preferably have at least a white organic electroluminescent layer sandwiched between a light semi-transmissive reflective layer and a light reflective layer, and among the white light components emitted from the white light-emitting layer, A component corresponding to the resonance wavelength determined by the optical distance between the transmissive reflection layer and the light reflection layer is resonated, and is transmitted through the light semi-transmissive reflection layer and emitted to the outside. Accordingly, each sub-pixel portion is formed so as to have an optical distance corresponding to the three colors of R, G, and B.

  A display device using the structure of the present invention can be suitably used for a two-color or full-color display device. Or it can also be set as a B / W display apparatus by mixing 2 colors or 3 colors. Examples of the B / W display device include a display for X-ray photography, and examples of the full-color display device include a home television.

  Preferably, the pixel is a current excitation type light emitting element, and more preferably an organic EL element. In the present invention, it may be a top emission type organic EL element or a bottom emission type organic EL element.

Next, the structure of the display device of the present invention will be specifically described with reference to the drawings.
FIG. 3 is a schematic cross-sectional view showing the configuration of one pixel according to the present invention.
The transparent electrode 3 is disposed on the transparent substrate 1 with the transflective layer 4 interposed therebetween, and the transparent electrode 3 is disposed with a thickness corresponding to each sub-pixel through the transparent insulating film 2. In addition, the organic electroluminescent layer 5 and the light reflecting electrode film 6 are provided in common to each subpixel. The optical distance between the transflective electrode 4 and the light-reflecting electrode film 6 is the distance at which the R light resonates in the R subpixel portion, the distance at which the G light resonates in the G subpixel portion, and the B light in the B subpixel portion. The thickness of the transparent electrode 3 is adjusted to 3a, 3b, 3c so that the resonance distance is obtained (FIG. 4). As another embodiment, as shown in FIG. 5, the transparent substrate 1 has the transflective layer 4, and the transparent insulating film 12 is installed on the transparent substrate 12 with a different thickness. Are arranged in a pattern corresponding to each sub-pixel. On top of that, the organic electroluminescent layer 5 and the light reflecting electrode film 6 are disposed in common to each sub-pixel as in FIG. In this aspect, the optical distance between the transflective electrode 4 and the light reflecting electrode film 6 is the distance at which the R light resonates in the R subpixel portion, the distance at which the G light resonates in the G subpixel portion, and the B subpixel portion. Then, the thickness of the transparent insulating film 12 is set as 12a, 12b, and 12c in a pattern corresponding to the image pixel so that the distance at which the B light resonates.

  When a white light-emitting organic EL element having an emission spectrum in the entire visible range is used as the organic electroluminescent layer 5, the optical distance between the transflective film 4 and the light-reflecting electrode film 6 in the R sub-pixel portion is made red. By adjusting the thickness of the transparent electrode 3 or the thickness of the transparent insulating film 12 so that the light resonates, only the red component in the white light resonates and is emitted to the outside with high luminance. Further, in the G sub-pixel portion, the thickness of the transparent electrode 3 or the transparent insulating film 12 is set so that the optical distance between the transflective film 2 and the light-reflecting electrode film 6 is a distance at which green light resonates. By adjusting the thickness, only the green component in the white light resonates and is emitted to the outside with high luminance. Furthermore, in the B sub-pixel portion, the thickness of the transparent electrode 3 or the transparent insulating film 12 is set so that the optical distance between the transflective film 2 and the light-reflecting electrode film 6 is a distance at which blue light resonates. By adjusting the thickness, only the blue component in the white light resonates and is emitted to the outside with high luminance.

FIG. 6 is a schematic cross-sectional view showing a thin film patterning method according to the present invention.
Step PL-1: Formation of Thin Film First Layer 101 The thin film first layer 101 is formed on the transparent substrate 11 by patterning the thin film first layer 101 wider than a predetermined region (first region).
Step PL-2: Formation of the thin film second layer 102 The thin film first layer 101 is coated on the thin film first layer 101, and the pattern is wider than a predetermined region (second region) of the thin film second layer 102. To form the second thin film layer 102.
PL-3 step: formation of the thin film third layer 103 The thin film first layer 101 and the thin film second layer 102 are covered on the thin film second layer 102, and a predetermined region (second region) of the thin film third layer 103 is further formed. The thin film third layer 103 is formed by patterning wider than the region.
Step PL-4: Second patterning for forming a predetermined region A region wider than a predetermined width of each region is removed by the second patterning. As a result, the first region, the second region, and the third region are separated and formed in a predetermined size.

  The first region is constituted by a stacked body of the thin film first layer 101, the thin film second layer 102, and the thin film third layer 103. The second region is composed of a laminate of the thin film first layer 101 and the thin film second layer 102. The third region is constituted by the thin film third layer 103.

FIG. 7 to FIG. 9 are schematic views showing steps in the case of performing all patterning by a conventional photolithography method. The production of ITO electrodes having different thicknesses will be described as an example.
In order, the substrate cleaning process → ITO first layer formation → photoresist application → baking → mask exposure → photoresist development process → ITO etching process → resist stripping (or alkali dissolution) (FIG. 7) Patterning of the region is performed.
Subsequently, the substrate is cleaned, the second ITO layer is formed, the photoresist is applied, the baking, the mask exposure, the photoresist development process, the ITO etching process, the resist peeling (or alkali dissolution) (FIG. 8). An ITO second layer is patterned and formed on one layer.
Subsequently, the substrate is cleaned, the third ITO layer is formed, the photoresist is applied, the baking is performed, the mask is exposed, the photoresist is developed, the ITO is etched, the resist is stripped (or dissolved in alkali) (FIG. 9). An ITO third layer is further patterned on the second layer. During the ITO third layer patterning, electrical separation of the laminated portion of the ITO third layer and the ITO second layer, and the laminated portion of the ITO third layer, the ITO second layer, and the ITO first layer is also performed simultaneously. Three regions having different thicknesses of ITO are formed electrically independently.

  As described above, when all the layers are patterned by the photolithography method, an extremely large number of steps are necessary. In particular, it is necessary to carry out complicated processing steps of photoresist preparation and application, baking treatment, optical exposure using a mask, resist pattern formation by alkali development, etching treatment, and removal of residual resist for each patterning, Reduces production yield and increases costs.

  FIG. 10 shows a thin film patterning method according to the present invention. The patterning of the ITO electrode will be described as an example. After cleaning the substrate, an ITO electrode is formed (step (2)). First, patterning in the first stage is performed by a laser ablation method (step (3)). The first-stage patterning is formed in a region (wide in the drawing) wider than a predetermined patterning region where the ITO electrode is to be deposited. Next, second-stage patterning is performed by photolithography (steps (4) to (9)). During the second stage patterning, the mask at the time of mask exposure is selected to have a predetermined shape. In the laser ablation process, burrs are generated at the end, but the burrs are removed in the patterning process by the photolithography method. Therefore, the finally obtained pattern has no burrs, has a smooth end, and has a predetermined shape. A pattern having a shape.

FIG. 11 illustrates a method of manufacturing an ITO electrode patterned in three different thicknesses by repeating the steps basically shown in FIG.
The steps (1) to (3) for forming the ITO first layer are the same as those in FIG. 10 and are formed by a laser ablation method. Next, after the substrate cleaning, an ITO second layer is formed by steps (5) to (6). The patterning of the ITO second layer at this stage is formed wider than the predetermined patterning region of the ITO second layer patterning. The ITO second layer is patterned by a laser ablation method. Subsequently, after cleaning the substrate, an ITO third layer is similarly formed (step (8)).
Next, the patterning process by the photolithographic method shown by process (9)-(14) is performed. In the patterning, the mask at the time of mask exposure is selected so that each region has a predetermined shape, and a third region composed of the ITO third layer alone, a laminate of the ITO third layer and the ITO second layer. The second region formed by the first layer and the first region formed of a laminate of the ITO third layer, the ITO second layer, and the ITO first layer are each formed in a predetermined shape. In each laser ablation process, burrs are generated at the end, but the burrs are removed in the patterning process by the photolithography method, so that the finally obtained pattern has no burrs and the end shape is smooth. .

FIG. 13 shows another embodiment of the present invention, in which both the first-stage patterning formed wider than a predetermined size and the second-stage patterning formed to a predetermined size are performed by the laser ablation method. Is.
The shape symbol representing the predetermined area shown in the figure is an image for explanation and does not exist as a structure.
After the ITO first layer is formed, it is patterned by a laser ablation method so as to be wider than a predetermined region (wide in the drawing) (step (3)). After the cleaning, an ITO second layer is formed (step (5)). Thereafter, similarly to the ITO first layer, patterning is performed by a laser ablation method so as to be wider than a predetermined region (wide in the drawing) (step (6)). After the cleaning, an ITO third layer is formed (step (8)).
Next, the patterning process by the laser ablation method shown by process (9) is performed. The patterning step by the laser ablation method shown in step (9) is patterning in which each region forms a predetermined shape, and a mask is selected so as to have a predetermined shape. As a result, the third region composed of the ITO third layer alone, the second region formed from the laminate of the ITO third layer and the ITO second layer, the ITO third layer, the ITO second layer, and the ITO second layer Each of the first regions formed of a single layer stack is formed in a predetermined shape. The burrs at the end of the laser ablation process that are wider than the predetermined shape are removed by patterning the final predetermined shape. Even if the laser ablation process is performed a plurality of times, the end-shaped burrs are kept to a minimum, so that the occurrence of troubles such as electrical short-circuits can be suppressed even if this method is used for the organic EL element.

  On the other hand, FIG. 14 shows a comparative mode in which each patterning step is formed by an ablation method in which each region has a predetermined size (width). That is, the ITO first layer patterning step (3), the ITO second layer patterning step (6), and the ITO third layer patterning step (9) are all performed at a predetermined size (width) by the laser ablation method. Formed with. In this case, since the burrs generated in the laser ablation process are integrated, the burrs formed in the finally formed patterning are, in particular, the first ITO layer, the second ITO layer, and the third ITO layer. In the first region, it becomes very large. Therefore, when applied to an organic EL element, there is a concern that problems such as an electrical short circuit may occur.

As described above, according to the present invention, thin layers having different thicknesses can be easily formed by patterning with a small number of manufacturing steps. Patterning by the laser ablation method is a technique conventionally used for mass production of electrode substrates, but has a basic problem that burrs are generated at the blown ends. In a normal liquid crystal element or electronic paper, the electrodes are separated from each other by several tens of μm to several hundreds of μm. Therefore, short-circuit due to burrs generated by ablation hardly occurs and has not been a problem. However, since the gap between the electrodes of the organic EL element is several hundreds of nanometers, which is three digits or more, blown dust and burrs cause a short circuit between the electrodes. Therefore, the laser ablation method is currently difficult to employ for ultra-thin devices such as organic EL elements.
According to the present invention, the laser ablation method is used, but the occurrence of burrs is minimized, the number of manufacturing steps is small, and the characteristics that are simple can be fully exhibited.
The thin layer patterns having different thicknesses obtained by the present invention can be preferably used particularly for an organic EL display device having a resonator structure. For example, the resonance distance can be adjusted by changing the thickness of a transparent electrode such as ITO. Alternatively, the resonant distance can be adjusted by installing insulating layers having different thicknesses as the transparent optical path length adjusting layer.
By introducing the resonator structure, the light emitted from each sub-pixel of the display device is high-saturation light with high brightness and narrow spectral distribution, and light of wavelength components other than the resonance wavelength is emitted from each sub-pixel. Is suppressed, so that extremely bright and highly saturated light can be obtained. Furthermore, the light of one pixel obtained by mixing the light components from these subpixels also has high luminance and high saturation.
In addition, using a white light emitting material as the organic EL light emitting layer, the R, G, B subpixels have an advantage that the organic EL light emitting layer, the reflective layer, and the like can be formed in common. Therefore, the manufacturing process of the notation device is further simplified, high productivity is obtained, and high definition is easy.

2. Laser ablation processing method The laser ablation processing method used in the present invention is a phenomenon in which, when a laser beam is irradiated on the surface of a solid material, the material that absorbed the laser energy is scattered as a fragment having a large energy, that is, a laser ablation phenomenon. It is a method of applying fine processing.

  As the conditions in the laser ablation method of the present invention, the method described in paragraphs (0016) to (0022) of JP-A-8-222371 can be applied.

3. Optical path length adjusting layer It is preferable to use an optical path length adjusting layer as a thin layer having a different thickness in the present invention.
The optical path length adjusting layer is not particularly limited as long as it is a transparent insulating layer material, and may be any of inorganic substances (SiO ₂ , SiON, SiN, ITO, IZO, etc.) and organic substances (polycarbonate, polyacrylate, silicone resin, etc.).
As the inorganic insulating material used for the optical path length adjusting layer in the present invention, various conventionally known metal oxides, metal nitrides, metal fluorides and the like can be used.
Specific examples of the metal _{oxides, MgO, SiO, SiO 2,} Al 2 O 3, GeO, NiO, CaO, BaO, Fe 2 O 3, Y 2 O 3, TiO 2 and the like, metal nitrides Specific examples include SiN _x , SiN _x O _{y and the} like, and specific examples of the metal fluoride include MgF ₂ , LiF, AlF ₃ , CaF _{2 and the} like. Moreover, these mixtures may be sufficient.

  As the material for the optical path length adjusting layer in the present invention, an organic compound can also be used, and a film-forming polymer is preferably used. Examples of the film-forming polymer include polycarbonate, polyacrylate, silicone resin, polyvinyl butyral, and the like.

  The thickness of the optical path length adjusting layer is adjusted so that each subpixel has an optical distance at which light of a predetermined wavelength can resonate efficiently. Therefore, the optical distance to resonate is determined by the refractive index of the material sandwiched between the reflective film and the semi-transmissive reflective film, its composition, and thickness, and is not determined by the optical path length adjusting layer. Considering the configuration of a generally used organic EL light emitting layer, the thickness of the optical path length adjusting layer is preferably 1 nm to 1000 nm, more preferably 10 nm to 500 nm, and still more preferably 10 nm to 200 nm in terms of physical thickness.

  The method for forming the optical path length adjusting layer is not particularly limited. For example, vacuum deposition, sputtering, reactive sputtering, MBE (molecular beam epitaxy), cluster ion beam, ion plating, plasma polymerization (High frequency excitation ion plating method), plasma CVD method, laser CVD method, thermal CVD method, gas source CVD method, coating method, printing method, or transfer method can be applied.

4). Organic electroluminescent device The organic electroluminescent device according to the present invention includes conventionally known organic compound layers such as a hole transport layer, an electron transport layer, a block layer, an electron injection layer, and a hole injection layer in addition to the light emitting layer. You may have.

Details will be described below.
1) Layer structure <Electrode>
At least one of the pair of electrodes of the organic electroluminescent element in the present invention is a transparent electrode, and the other is a back electrode. The back electrode may be transparent or non-transparent.
<Configuration of organic compound layer>
There is no restriction | limiting in particular as a layer structure of the said organic compound layer, Although it can select suitably according to the use and objective of an organic electroluminescent element, It is formed on the said transparent electrode or the said back electrode. preferable. In this case, the organic compound layer is formed on the front surface or one surface on the transparent electrode or the back electrode.
There is no restriction | limiting in particular about the shape of a organic compound layer, a magnitude | size, thickness, etc., According to the objective, it can select suitably.

Specific examples of the layer configuration include the following, but the present invention is not limited to these configurations.
Anode / hole transport layer / light emitting layer / electron transport layer / cathode,
Anode / hole transport layer / light emitting layer / block layer / electron transport layer / cathode,
Anode / hole transport layer / light emitting layer / block layer / electron transport layer / electron injection layer / cathode,
Anode / hole injection layer / hole transport layer / light emitting layer / block layer / electron transport layer / cathode,
Anode / hole injection layer / hole transport layer / light emitting layer / block layer / electron transport layer / electron injection layer / cathode.

Each layer will be described in detail below.
2) Hole transport layer The hole transport layer used in the present invention contains a hole transport material. The hole transport material is not particularly limited as long as it has either a function of transporting holes or a function of blocking electrons injected from the cathode. As the hole transport material used in the present invention, any of a low molecular hole transport material and a polymer hole transport material can be used.
Specific examples of the hole transport material used in the present invention include the following materials.

Carbazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives , Aromatic tertiary amine compounds, styrylamine compounds, aromatic dimethylidene compounds, porphyrin compounds, polysilane compounds, poly (N-vinylcarbazole) derivatives, aniline copolymers, thiophene oligomers, polythiophenes, etc. And polymer compounds such as conductive polymer oligomers, polythiophene derivatives, polyphenylene derivatives, polyphenylene vinylene derivatives, and polyfluorene derivatives.
These may be used alone or in combination of two or more.

  The thickness of the hole transport layer is preferably 10 nm to 400 nm, and more preferably 50 nm to 200 nm.

3) Hole injection layer In the present invention, a hole injection layer can be provided between the hole transport layer and the anode.
The hole injection layer is a layer that facilitates injection of holes from the anode into the hole transport layer, and specifically, a material having a small ionization potential is preferably used among the hole transport materials. For example, a phthalocyanine compound, a porphyrin compound, a starburst type triarylamine compound, etc. can be mentioned, It can use suitably.
The thickness of the hole injection layer is preferably 1 nm to 300 nm.

4) Light emitting layer The light emitting layer used in the present invention contains at least one kind of light emitting material, and may contain a hole transport material, an electron transport material, and a host material as necessary.
The light emitting material used in the present invention is not particularly limited, and either a fluorescent light emitting material or a phosphorescent light emitting material can be used. A phosphorescent material is preferred from the viewpoint of luminous efficiency.

  Examples of fluorescent light-emitting materials include benzoxazole derivatives, benzimidazole derivatives, benzothiazole derivatives, styrylbenzene derivatives, polyphenyl derivatives, diphenylbutadiene derivatives, tetraphenylbutadiene derivatives, naphthalimide derivatives, coumarin derivatives, perylene derivatives, perinone derivatives, oxalates. Diazole derivatives, aldazine derivatives, pyralidine derivatives, cyclopentadiene derivatives, bisstyrylanthracene derivatives, quinacridone derivatives, pyrrolopyridine derivatives, thiadiazolopyridine derivatives, styrylamine derivatives, aromatic dimethylidene compounds, 8-quinolinol derivative metal complexes and rare earths Various metal complexes represented by complexes, polythiophene derivatives, polyphenylene derivatives, polyphenylene vinylene derivatives, and poly Polymeric compounds such as fluorene derivatives. These can be used alone or in combination of two or more.

  Although it does not specifically limit as a phosphorescence-emitting material, An ortho metalated metal complex or a porphyrin metal complex is preferable.

  The ortho-metalated metal complex includes, for example, Akio Yamamoto, “Organic Metal Chemistry: Fundamentals and Applications”, pages 150 to 232; Yersin's “Photochemistry and Photophysics of Coordination Compounds”, pages 71-77, pages 135-146, Springer-Verlag (published in 1987), etc. The use of the orthometalated metal complex as a light emitting material in the light emitting layer is advantageous in terms of high luminance and excellent light emission efficiency.

  There are various ligands that form the ortho-metalated metal complex, which are also described in the above documents. Among them, preferred ligands include 2-phenylpyridine derivatives, 7,8- Examples include benzoquinoline derivatives, 2- (2-thienyl) pyridine derivatives, 2- (1-naphthyl) pyridine derivatives, and 2-phenylquinoline derivatives. These derivatives may have a substituent if necessary. The orthometalated metal complex may have other ligands in addition to the above ligands.

The orthometalated metal complex used in the present invention can be obtained from Inorg Chem. 1991, 30, 1685, 1988, 27, 3464, 1994, 33, 545, Inorg. Chim. Acta, 1991, No. 181, page 245; Organomet. Chem. 1987, No. 335, 293, J. Am. Am. Chem. Soc. It can be synthesized by various known techniques such as 1985, No. 107, page 1431.
Among the ortho-metalated complexes, compounds that emit light from triplet excitons can be suitably used in the present invention from the viewpoint of improving luminous efficiency.

  Of the porphyrin metal complexes, a porphyrin platinum complex is preferred.

  Moreover, a luminescent material may be used individually by 1 type, if white light emission is obtained, and may use 2 or more types together. The combination of the luminescent color of the luminescent material when two or more are used in combination is not particularly limited, but the blue luminescent material and the yellow luminescent material are used together, the blue luminescent material, the green luminescent material and the red luminescent material are used together, etc. Can be mentioned.

  The host material is a material having a function of causing energy transfer from the excited state to the fluorescent light-emitting material or the phosphorescent light-emitting material, and as a result, causing the fluorescent light-emitting material or the phosphorescent light-emitting material to emit light.

The host material is not particularly limited as long as it is a compound capable of transferring exciton energy to the light emitting material, and can be appropriately selected according to the purpose. Specifically, a carbazole derivative, a triazole derivative, an oxazole derivative, Oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aromatic Tertiary amine compounds, styrylamine compounds, aromatic dimethylidene compounds, porphyrin compounds, anthraquinodimethane derivatives, anthrone derivatives, diphenylquinone derivatives, thiopi Dioxide derivatives, carbodiimide derivatives, fluorenylidenemethane derivatives, distyrylpyrazine derivatives, heterocyclic tetracarboxylic anhydrides such as naphthaleneperylene, phthalocyanine derivatives, metal complexes of 8-quinolinol derivatives, metal phthalocyanines, benzoxazoles and benzothiazoles Various metal complexes represented by metal complexes as ligands, polysilane compounds, poly (N-vinylcarbazole) derivatives, aniline copolymers, thiophene oligomers, conductive polymer oligomers such as polythiophene, polythiophene derivatives, polyphenylene derivatives , Polymer compounds such as polyphenylene vinylene derivatives and polyfluorene derivatives. These compounds may be used individually by 1 type, and may use 2 or more types together.
As content in the light emitting layer of a host material, 0 mass%-99.9 mass% are preferable, More preferably, they are 0 mass%-99.0 mass%.

5) Block layer In this invention, a block layer can be provided between a light emitting layer and an electron carrying layer. The block layer is a layer that suppresses the diffusion of excitons generated in the light emitting layer, and also a layer that suppresses holes from penetrating to the cathode side.

  The material used for the block layer is not particularly limited as long as it is a material that can receive electrons from the electron transport layer and pass the electrons to the light emitting layer, and a general electron transport material can be used. For example, the following materials can be mentioned. Triazole derivatives, oxazole derivatives, oxadiazol derivatives, fluorenone derivatives, anthraquinodimethane derivatives, anthrone derivatives, diphenylquinone derivatives, thiopyrandioxide derivatives, carbodiimide derivatives, fluorenylidenemethane derivatives, distyrylpyrazine derivatives , Metal complexes of heterocyclic tetracarboxylic anhydrides such as naphthaleneperylene, phthalocyanine derivatives, 8-quinolinol derivatives and metal complexes having metal phthalocyanine, benzoxazole and benzothiazol as ligands Polymers such as complexes, aniline copolymers, conductive polymer oligomers such as thiophene oligomers and polythiophenes, polythiophene derivatives, polyphenylene derivatives, polyphenylene vinylene derivatives, and polyfluorene derivatives Mention may be made of the compound. These may be used individually by 1 type and may use 2 or more types together.

6) Electron transport layer In the present invention, an electron transport layer containing an electron transport material can be provided.
The electron transport material is not limited as long as it has either a function of transporting electrons or a function of blocking holes injected from the anode, and is mentioned when explaining the block layer. A suitable electron transport material can be used.
The thickness of the electron transport layer is preferably 10 nm to 200 nm, and more preferably 20 nm to 80 nm.

  When the thickness exceeds 1000 nm, the driving voltage may increase. When the thickness is less than 10 nm, the light emission efficiency of the light emitting device may be extremely lowered, which is not preferable.

7) Electron Injection Layer In the present invention, an electron injection layer can be provided between the electron transport layer and the cathode.
The electron injection layer is a layer that facilitates injection of electrons from the cathode into the electron transport layer. Specifically, lithium salts such as lithium fluoride, lithium chloride, and lithium bromide, sodium fluoride, sodium chloride, fluoride An alkali metal salt such as cesium, an insulating metal oxide such as lithium oxide, aluminum oxide, indium oxide, or magnesium oxide can be suitably used.
The thickness of the electron injection layer is preferably 0.1 nm to 5 nm.

8) Substrate The material of the substrate used in the present invention is preferably a material that does not transmit moisture or a material with extremely low moisture permeability, and does not scatter or attenuate light emitted from the organic compound layer. Material is preferred. Specific examples include, for example, YSZ (zirconia stabilized yttrium), inorganic materials such as glass, polyethylene terephthalate, polybutylene terephthalate, polyester such as polyethylene naphthalate, polystyrene, polycarbonate, Examples thereof include organic materials such as polyethersulfone, polyarylate, allyl diglycol carbonate, polyimide, polycycloolefin, norbornene resin, and synthetic resin such as poly (chlorotrifluoroethylene).
In the case of the said organic material, it is preferable that it is excellent in heat resistance, dimensional stability, solvent resistance, electrical insulation, workability, low air permeability, or low hygroscopicity. These materials may be used alone or in combination of two or more.

  There is no restriction | limiting in particular about the shape of a board | substrate, a structure, a magnitude | size, It can select suitably according to the use, purpose, etc. of a light emitting element. Generally, the shape is a plate shape. The structure may be a single layer structure, a laminated structure, may be formed of a single member, or may be formed of two or more members.

  The substrate may be colorless and transparent, or may be colored and transparent, but is preferably colorless and transparent in that it does not scatter or attenuate light emitted from the light emitting layer.

The substrate is preferably provided with a moisture permeation preventing layer (gas barrier layer) on the front surface or the back surface (on the transparent electrode side). As the material for the moisture permeation preventive layer (gas barrier layer), inorganic materials such as silicon nitride and silicon oxide are preferably used. The moisture permeation preventing layer (gas barrier layer) can be formed by, for example, a high frequency sputtering method.
The substrate may be further provided with a hard coat layer, an undercoat layer, and the like as required.

9) Electrode In the present invention, the first electrode and the second electrode may be either an anode or a cathode, but preferably the first electrode is an anode and the second electrode is a cathode. .

<Anode>
The anode used in the present invention is usually only required to have a function as an anode for supplying holes to the organic compound layer, and the shape, structure, size and the like are not particularly limited, and the light emitting device Depending on the use and purpose, it can be appropriately selected from known electrodes.

  As a material for the anode, for example, a metal, an alloy, a metal oxide, an organic conductive compound, or a mixture thereof can be preferably cited. A material having a work function of 4.0 eV or more is preferable. Specific examples include semiconductive metals such as tin oxide doped with antimony and fluorine (ATO, FTO), tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), and zinc indium oxide (IZO). Metals such as oxides, gold, silver, chromium and nickel, and mixtures or laminates of these metals and conductive metal oxides, inorganic conductive materials such as copper iodide and copper sulfide, polyaniline, polythiophene, polypyrrole Organic conductive materials such as copper, and laminates of these with ITO.

  The anode is, for example, a printing method, a wet method such as a coating method, a physical method such as a vacuum deposition method, a sputtering method, or an ion plating method, or a chemical method such as a CVD or a plasma CVD method. Can be formed on the substrate in accordance with a method appropriately selected in consideration of suitability. For example, when ITO is selected as the anode material, the anode can be formed according to a direct current or high frequency sputtering method, a vacuum deposition method, an ion plating method, or the like. Moreover, when selecting an organic electroconductive compound as a material of an anode, it can carry out according to the wet film forming method.

  There is no restriction | limiting in particular as a formation position in the said light emitting element of an anode, Although it can select suitably according to the use and objective of this light emitting element, It is preferable to form on the said board | substrate. In this case, the anode may be formed on the entire one surface of the substrate or a part thereof.

  The patterning of the anode may be performed by chemical etching such as photolithography, or may be performed by physical etching using a laser or the like, or may be performed by vacuum deposition or sputtering by overlapping a mask. Etc., or may be performed by a lift-off method or a printing method.

The thickness of the anode can be appropriately selected depending on the material and cannot be generally defined, but is usually 10 nm to 50 μm, and preferably 50 nm to 20 μm.
The resistance value of the anode is preferably 10 ³ Ω / □ or less, and more preferably 10 ² Ω / □ or less.
The anode may be colorless and transparent or colored and transparent. In order to extract light emitted from the anode side, the transmittance is preferably 60% or more, and more preferably 70% or more. This transmittance can be measured according to a known method using a spectrophotometer.

  The anode is described in detail in the book “New Development of Transparent Electrode Film”, published by CMC (1999), supervised by Yutaka Sawada, and these can be applied to the present invention. When using a plastic substrate having low heat resistance, an anode formed using ITO or IZO at a low temperature of 150 ° C. or lower is preferable.

<Cathode>
The cathode that can be used in the present invention is usually only required to have a function as a cathode for injecting electrons into the organic compound layer, and there is no particular limitation on the shape, structure, size, etc. According to the use and purpose of the element, it can be appropriately selected from known electrodes.

  Examples of the material for the cathode include metals, alloys, metal oxides, electrically conductive compounds, and mixtures thereof, and those having a work function of 4.5 eV or less are preferable. Specific examples include alkali metals (for example, Li, Na, K, or Cs), alkaline earth metals (for example, Mg, Ca, etc.), gold, silver, lead, aluminum, sodium-potassium alloys, lithium-aluminum alloys, Examples thereof include magnesium-silver alloys, rare earth metals such as indium and ytterbium. These may be used alone, but from the viewpoint of achieving both stability and electron injection properties, two or more of them can be suitably used in combination.

  Among these, alkali metals and alkalinity metals are preferable from the viewpoint of electron injection properties, and materials mainly composed of aluminum are preferable from the viewpoint of excellent storage stability. The material mainly composed of aluminum is aluminum alone, or an alloy or mixture of aluminum and 0.01% by mass to 10% by mass of alkali metal or alkaline earth metal (for example, lithium-aluminum alloy, magnesium-aluminum alloy, etc. ).

  The cathode materials are described in detail in JP-A-2-15595 and JP-A-5-121172, and these can be applied to the present invention.

There is no restriction | limiting in particular in the formation method of a cathode, It can carry out according to a well-known method. For example, a printing method, a wet method such as a coating method, a physical method such as a vacuum deposition method, a sputtering method, or an ion plating method, a chemical method such as a CVD method or a plasma CVD method, etc. It can be formed on the substrate according to a method appropriately selected in consideration of suitability.
For example, when a metal or the like is selected as the material of the cathode, one or more of them can be simultaneously or sequentially performed according to a sputtering method or the like.

  The patterning of the cathode may be performed by chemical etching such as photolithography, or may be performed by physical etching using a laser or the like, or vacuum deposition or sputtering is performed with a mask overlapped. It may be performed by a lift-off method or a printing method.

There is no restriction | limiting in particular as a formation position in the organic electroluminescent element of a cathode, Although it can select suitably according to the use and objective of this light emitting element, forming in an organic compound layer is preferable. In this case, the cathode may be formed on the entire organic compound layer or a part thereof.
Further, a dielectric layer made of the alkali metal or the alkaline earth metal fluoride may be inserted between the cathode and the organic compound layer with a thickness of 0.1 nm to 5 nm.

The thickness of the cathode can be appropriately selected depending on the material and cannot be generally defined, but is usually 10 nm to 5 μm, and preferably 50 nm to 1 μm.
The cathode may be transparent or opaque. The transparent cathode can be formed by forming the cathode material into a thin film with a thickness of 1 nm to 10 nm and further laminating the transparent conductive material such as ITO or IZO.

10) Protective layer In this invention, the whole organic EL element may be protected by the protective layer.
As a material contained in the protective layer, any material may be used as long as it has a function of preventing materials that promote device deterioration such as moisture and oxygen from entering the device.
Specific examples thereof include metals such as In, Sn, Pb, Au, Cu, Ag, Al, Ti, and Ni, MgO, SiO, SiO ₂ , Al ₂ O ₃ , GeO, NiO, CaO, BaO, and Fe ₂ O. ₃ , metal oxides such as Y ₂ O ₃ , TiO ₂ , metal nitrides such as SiN _x , SiN _x O _y , metal fluorides such as MgF ₂ , LiF, AlF ₃ , CaF ₂ , polyethylene, polypropylene, polymethyl Monomer mixture containing methacrylate, polyimide, polyurea, polytetrafluoroethylene, polychlorotrifluoroethylene, polydichlorodifluoroethylene, copolymer of chlorotrifluoroethylene and dichlorodifluoroethylene, tetrafluoroethylene and at least one comonomer Copolymer obtained by copolymerization, cyclic in the copolymer main chain Examples thereof include a fluorine-containing copolymer having a structure, a water-absorbing substance having a water absorption of 1% or more, and a moisture-proof substance having a water absorption of 0.1% or less.

  The method for forming the protective layer is not particularly limited, and for example, vacuum deposition, sputtering, reactive sputtering, MBE (molecular beam epitaxy), cluster ion beam, ion plating, plasma polymerization (high frequency) Excited ion plating method), plasma CVD method, laser CVD method, thermal CVD method, gas source CVD method, coating method, printing method, or transfer method can be applied.

11) Sealing Furthermore, the organic electroluminescent element in this invention may seal the whole element using a sealing container.
Further, a moisture absorbent or an inert liquid may be sealed in a space between the sealing container and the light emitting element.
Although it does not specifically limit as a moisture absorber, For example, barium oxide, sodium oxide, potassium oxide, calcium oxide, sodium sulfate, calcium sulfate, magnesium sulfate, phosphorus pentoxide, calcium chloride, magnesium chloride, copper chloride Cesium fluoride, niobium fluoride, calcium bromide, vanadium bromide, molecular sieve, zeolite, magnesium oxide, and the like. The inert liquid is not particularly limited, and examples thereof include paraffins, liquid paraffins, fluorinated solvents such as perfluoroalkane, perfluoroamine, and perfluoroether, chlorinated solvents, and silicone oils. Can be mentioned.

12) Device Manufacturing Method Each layer constituting the device of the present invention is formed by a dry film forming method such as vapor deposition or sputtering, dipping, spin coating, dip coating, casting, die coating, or roll. The film can be suitably formed by any of wet film forming methods such as a Lucorte method, a Bar coat method, and a gravure coat method.
Of these, the dry method is preferred from the viewpoint of luminous efficiency and durability. In the case of the wet film forming method, the remaining coating solvent is not preferable because the light emitting layer is damaged.
Particularly preferred is a resistance heating vacuum deposition method. The resistance heating type vacuum vapor deposition method is advantageous because it can efficiently heat only the substance to be evaporated by heating under vacuum, and the element is not exposed to high temperature, and is therefore less damaged.

  Vacuum deposition is a method in which a deposition material is heated, vaporized or sublimated in a vacuumed container, and is attached to the surface of an object to be deposited placed at a slightly separated position to form a thin film. Heating is performed by a method such as resistance heating, electron beam, high-frequency induction, or laser depending on the type of vapor deposition material or deposition target. Of these, film formation at the lowest temperature is a resistance heating type vacuum vapor deposition method, and a material with a high sublimation point cannot be formed, but a material with a low sublimation point causes thermal damage to the material to be deposited. Film formation can be performed in almost no state.

The sealing film material in the present invention can be formed by resistance heating type vacuum deposition.
Conventionally used sealing agents such as silicon oxide have a high sublimation point and cannot be deposited by resistance heating. In addition, the vacuum deposition method such as ion plating generally described in known examples has an evaporation source part of several thousand degrees Celsius, so the material to be deposited is thermally affected and altered. Therefore, it is not suitable as a method for producing a sealing film of an organic EL element that is particularly susceptible to heat and ultraviolet rays.

13) Driving method The organic electroluminescent element in the present invention applies a direct current (which may include an alternating current component as necessary) voltage (usually 2 to 15 volts) or a direct current between the anode and the cathode. Thus, light emission can be obtained.

  The driving method of the organic electroluminescence device in the present invention is described in JP-A-2-148687, JP-A-6-301355, JP-A-5-29080, JP-A-7-134558, JP-A-8-234585, and JP-A-8-2441047. The driving method described in each publication, Japanese Patent No. 2784615, US Pat. Nos. 5,828,429, 6023308, and the like can be applied.

(Use)
The use of the organic EL device of the present invention is not particularly limited, but can be applied to a wide display field such as a mobile phone display, a personal digital assistant (PDA), a computer display, an automobile information display, or a TV monitor.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

Comparative Example 1
This is an example in which an ITO film having a thickness of two types is formed on a glass substrate and patterned into a strip shape having a width of 2.0 mm by a conventional patterning method of an ITO film by a photolithography method. In order, it consists of the following 16 steps.

(1) Substrate cleaning (2) ITO first layer sputtering (3) Resist coating (4) Resist baking (5) Mask exposure (6) Resist development (7) Exposed ITO etching (8) Resist stripping (9) Substrate cleaning (10) ITO second layer sputtering (11) Resist coating (12) Resist baking (13) Mask exposure (14) Resist development (15) Exposed ITO etching (16) Resist stripping

  The thin film patterning method comprises a number of processes, is complicated, has a low production yield, and increases costs.

Comparative Example 2
In this example, laser ablation is used instead of patterning by photolithography in Comparative Example 1. In order, it consists of the following steps.

(1) Substrate cleaning (2) ITO first layer sputtering (3) Laser ablation (4) Substrate cleaning (5) ITO second layer sputtering (6) Laser ablation

  In this patterning method, burrs are generated at the end of the pattern, and when the ITO film is used as an anode and an organic EL layer is formed thereon, an electrical short circuit occurs between the anode and the cathode, and normal light emission cannot be obtained. . As for the frequency of short-circuiting, burrs due to ablation are particularly noticeable at the end of the portion where a plurality of ITO electrodes are stacked.

Example 1
In Comparative Example 2, the first step patterning of the ITO first layer is patterned by a laser ablation method to a width of 2.2 mm, and the second step patterning is changed to a photolithography method and patterned into a strip shape having a width of 2.0 mm. Is an example of

(1) Substrate cleaning (2) ITO sputtering (3) Resist coating (solubilization by laser irradiation)
(4) Resist baking (5) The resist is removed by laser ablation method and patterned to a width of 2.2 mm. (6) Resist development (of the ablation residue, the laser-irradiated end is dissolved, and a burr is about 0.1 mm wide. Remaining)
(7) Exposed ITO edge portion etching process (burrs are dissolved and removed)
(8) Resist stripping

  In the above process, the burrs at the end of the ITO are dissolved and removed by the etching process. Therefore, when the organic EL layer is formed using the obtained ITO as an electrode, there is no burrs and normal light emission is obtained. In addition, according to the thin film patterning method, a resist mask is formed by a laser ablation process, so that a metal mask for exposure is not required, so that the cost can be further simplified.

Example 2
As shown in FIGS. 11 and 12, an example is shown in which three types of ITO films are formed on a glass substrate and patterned into a strip shape having a width of 2.0 mm. A thin film in which the patterning in the first stage and the second stage is performed by laser ablation with a width (2.2 mm) wider than a predetermined region, and the patterning in the third stage is performed by a photolithography method to a predetermined width (2.0 mm). Patterning method. It consists of the following steps in order.

(1) Substrate cleaning (2) ITO first layer sputtering (3) Patterning by laser ablation (patterning to 2.2 mm width)
(4) Substrate cleaning (5) ITO second layer sputtering (6) Patterning by laser ablation (patterning to 2.2 mm width)
(7) Substrate cleaning (8) ITO third layer sputtering (9) Resist application (10) Resist bake (11) Mask exposure (patterning to 2.0 mm width)
(12) Resist development (13) Exposed ITO etching (14) Resist stripping

  Compared to Comparative Example 2, there is no burr at the patterned end, and even when the ITO film is used as an anode and an organic EL layer is formed thereon, an electrical short circuit between the anode and the cathode is not caused. Normal luminescence is obtained.

Comparative Example 3
The following white light-emitting organic EL device was produced on a substrate with an ITO film.
After the substrate was cleaned and subjected to oxygen plasma treatment, it was put into a vacuum deposition apparatus to uniformly form the following white light-emitting organic EL layer.

F4-TCNQ (tetrafluorotetracyanoquinodimethane) is added to 4,4 ′, 4 ″ -tris (2-naphthylphenylamino) triphenylamine (abbreviated as 2-TNATA) and 2-TNATA. Co-evaporation was performed so that the content was 0% by mass. The film thickness was 50 nm.
N, N′-dinaphthyl-N, N′-diphenyl- [1,1′-biphenyl] -4,4′-diamine (abbreviated as α-NPD) was formed to a thickness of 10 nm.
15 mass% of luminescent material A, 0.13 mass% of luminescent material B, and 0.13 mass% of luminescent material C with respect to 1,3-bis (carbazol-9-yl) benzene (abbreviated as mCP) and mCP Co-evaporation was performed in four ways so that The film thickness was 30 nm.
Bis- (2-methyl-8-quinolinolate) -4- (phenylphenolate) aluminum (abbreviated as BAlq) was formed. The thickness was 40 nm.
LiF was 0.5 nm thick to form an electron injection layer.
A metal electrode (Al, 100 nm) was formed.

  The light emitting material A emitted light in the blue region, the light emitting material B emitted light in the green region, and the light emitting material C emitted light in the red region, whereby white light emission was obtained. The obtained device emitted white light at all light emitting positions. In addition, since this device does not sharpen the emission spectrum due to multiple interference, the RGB emission spectra overlap, and there are problems that efficiency is difficult to separate and color filter design is difficult to separate with good color purity. all right.

Example 3
An Ag vapor deposition film was formed to a thickness of 20 nm on the entire surface of a 0.2 mm thick polyethylene naphthalate substrate, and a SiO2 film was further formed to a thickness of 20 nm by sputtering. Three types of ITO electrodes were formed on this substrate by the method of Example 2. The sputtering thickness of the ITO first layer was 56 nm, the second layer was 33 nm, and the third layer was 48 nm. Thereby, the board | substrate provided with the transflective layer by the Ag thin film on the board | substrate, and the ITO electrode with the film thickness of 48 nm, 81 nm, and 137 nm was obtained.
The same organic EL element as Comparative Example 3 was produced on the above substrate.

  Since the resonance wavelength of the obtained device is adjusted by the thickness of the ITO electrode, the emission color is separated without a color filter. In the case of the device having the 48-nm-thick ITO electrode, blue light-emission and the 81-nm-thick ITO electrode are used. The element having green light emission, and the element having a 137 nm ITO electrode emitted red light. Since the front intensity is enhanced by multiple interference, the front intensity is higher than the RGB peak intensity of the element of Comparative Example 3, and the color filter is easy to design because the peaks are separated. I understood.

  The structures of the compounds used in the examples are shown below.

(Resonance distance)
When the light reflecting layer is an Al film having a thickness of 100 nm and the semi-transmissive and semi-reflecting layer is a silver thin film having a thickness of 20 nm, the optical distance to resonate is estimated as follows for each color.
When it is desired to intensify light of wavelength λ, the optical distance may be adjusted so that m in the following expression becomes an integer. Here, n is the refractive index of the layer through which light passes, and φ is the amount of phase shift of light in the reflective layer. When a plurality of layers having different refractive indexes are stacked, the 2nd portion may be set to 2 (n ₁ * d ₁ + n ₂ * d ₂ +...).
2nd / λ + φ / 2π = m
When φ of the above formula is obtained by experiment and an optical distance (a transflective semi-reflective layer-reflective interlayer distance, in terms of organic film) that strengthens 460 nm, 520 nm, and 620 nm is obtained, it is as follows.

Optical distance for resonating blue (460 nm): 203 nm ± 135 nm (203 nm, 338 nm, 473 nm, ----)
Optical distance for resonating green (520 nm): 242 nm ± 153 nm (242 nm, 395 nm, 548 nm, ----)
Optical distance for resonating red (620 nm): 308 nm ± 182 nm (126 nm, 308 nm, 490 nm, ----)

  In the element of Example 3, the optical distances (in terms of organic film) of the elements having ITO electrode thicknesses of 48 nm, 81 nm, and 137 nm are as follows. As described above, the optical distances intensify blue, green, and red, respectively. Since it corresponds to the film thickness, monochromatic light can be extracted using a white element.

-Optical distance in terms of organic film of an element with an ITO electrode of 48 nm:
SiO ₂ (20 * 1.45 / 1.7) + ITO (48 * 2.0 / 1.7) + OLED (130) at 203 nm
-Optical distance in terms of organic film of an element having an ITO electrode of 81 nm:
242 nm for SiO ₂ (20 * 1.45 / 1.7) + ITO (81 * 2.0 / 1.7) + OLED (130)
-Optical distance in terms of organic film of an element having an ITO electrode of 137 nm:
308 nm for SiO ₂ (20 * 1.45 / 1.7) + ITO (137 * 2.0 / 1.7) + OLED (130)

  Note that, for example, there is a condition in which blue and red are intensified at the same time as the optical distance. Therefore, a configuration in which an unnecessary peak is removed by using a color filter is more preferable. Moreover, although the example which isolate | separated a white element into RGB using multiple interference was described in the Example, it is more preferable to set it as the WRGB pixel structure which added original white as a pixel.

It is a conceptual diagram of the pixel arrangement | sequence of an active matrix type display apparatus. It is a conceptual diagram which shows the subpixel arrangement | sequence of 1 pixel. It is a schematic sectional drawing which shows the subpixel arrangement | sequence of 1 pixel. It is a schematic sectional drawing which shows the aspect of the transparent electrode which comprises the resonator in the subpixel arrangement | sequence of 1 pixel. It is a schematic sectional drawing which shows the aspect of the transparent insulating film which comprises the resonator in the subpixel arrangement | sequence of 1 pixel. It is a schematic sectional drawing which shows the process of forming the thin film layer from which thickness differs by this invention. It is a schematic sectional drawing which shows a part of process of forming the several thin film layer from which thickness differs by the conventional photolithographic method. It is a schematic sectional drawing which shows another part of the process of forming several thin film layers from which thickness differs by the conventional photolithographic method. It is a schematic sectional drawing which shows another part of the process of forming the several thin film layer from which thickness differs by the conventional photolithographic method. It is a schematic sectional drawing which shows the process of forming the thin film layer by this invention. It is a schematic sectional drawing which shows a part of process of forming the several thin film layer from which thickness differs by this invention. It is a schematic sectional drawing which shows another part of the process of forming the several thin film layer from which thickness differs by this invention. It is a schematic sectional drawing which shows a part of process of forming several thin film layers from which thickness differs by the conventional ablation method. It is a schematic sectional drawing which shows another part of the process of forming the several thin film layer from which thickness differs by the conventional ablation method.

Claims (10)

  A step of forming a first thin film on a substrate for an electronic material, a first patterning step of processing the first thin film into a shape larger than a predetermined shape by a laser ablation method, and the first patterning A thin film patterning method comprising a second patterning step of processing the thin film formed in the step into the predetermined shape.   The thin film patterning method according to claim 1, wherein the second patterning step is a processing step by a photolithography method.   A step of forming a first thin film on a substrate for an electronic material in order, a first patterning step of processing the first thin film into a shape larger than a predetermined shape by a laser ablation method, the first Forming a second thin film on the pattern formed by the patterning, and a second patterning step of processing a portion having the first thin film and the second thin film stacked into the predetermined shape. A method for patterning a thin film.   The thin film patterning method according to claim 3, wherein the second patterning step is a processing step by a laser ablation processing method.   The thin film patterning method according to claim 3, wherein the second patterning step is a processing step by a photolithography method.   An electronic material thin film formed by the thin film patterning method according to claim 1.   An electronic material having a pattern made of a first thin film formed by the thin film patterning method according to any one of claims 3 to 5, and a pattern made of a laminate of the first thin film and the second thin film. Thin film.   It is an organic electroluminescent display apparatus which has a resonator structure, Comprising: At least one of the electrodes of this organic electroluminescent display apparatus was formed by the thin film patterning method of any one of Claims 1-5. Organic electroluminescent display device which is an electrode.   6. An organic electroluminescent display device having a resonator structure, wherein the organic electroluminescent display device has an insulating layer formed by the thin film patterning method according to claim 1. Electroluminescent display device.   The organic electroluminescent display device according to claim 8, comprising a white organic electroluminescent layer.