JP2010056015A - Display device and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device capable of high definition color display and easy to manufacture, and a method of manufacturing the same. <P>SOLUTION: The display device has a plurality of pixels on a substrate 1 and each pixel is constructed of at least two kinds of sub-pixels that emit light of different wavelength. The sub-pixel has at least an optical path length adjusting layer, a transparent electrode, and an organic electroluminescent layer pinched between an optical half-transmitting reflection layer and an optical reflection layer, and the two kinds of sub-pixels have mutually different thicknesses of their optical path length adjusting layers, and at least one of the optical path length adjusting layers is formed by removing at least the upper layer of a lamination structure by etching after forming a laminate of a plurality of optical transmitting inorganic insulating materials of different composition. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a display device using a light emitting element and a manufacturing method thereof. In particular, the present invention relates to a color display device and a manufacturing method thereof.

  In recent years, instead of a cathode ray tube (CRT), it has been used in a wide field of thin and light flat panel displays, and its use has been extended. This is because personal information terminals such as personal computers and network access compatible mobile phones have been acceleratingly spread with the development of information equipment and infrastructure for service networks centered on the Internet. In addition, the market for flat panel displays has been expanding to home TVs, which have traditionally been exclusive to CRTs.

  Among them, there is an organic electroluminescent element (organic EL element) as a device that has attracted particular attention in recent years. An organic EL element is an element that emits light in response to an electric signal and is configured using an organic compound as a light-emitting substance. Organic EL elements inherently have excellent display characteristics such as a wide viewing angle, high contrast, and high-speed response. In addition, since there is a possibility of realizing thin and light and high-quality display devices from small to large, it has been attracting attention as an element replacing CRT and LCD.

Various 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, in the method of obtaining a desired color by converting the light emitted from the organic EL element with a color conversion film, various improvements have been made, but there are problems such as low conversion efficiency to red.

On the other hand, 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, a first electrode made of a light reflecting material, an organic layer provided with an organic light emitting layer, a light translucent reflecting layer, and a second electrode made of a transparent material are sequentially stacked, and the organic layer becomes a resonance part. In the organic EL element thus formed, an organic EL element configured to satisfy the following formula is known, 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)

  For example, a plurality of organic EL elements are arranged on the same surface of the substrate, an organic light emitting layer and an inorganic compound layer as a spacer are provided between the light reflecting conductive layer and the light reflecting layer, and the first organic EL element portion is the first organic EL element portion. There is disclosed a display device having a configuration in which one inorganic compound layer and a second organic EL element portion are composed of a first inorganic compound layer and a second inorganic compound layer (for example, see Patent Document 1). Specifically, the first inorganic compound layer forms a light reflective electrode (for example, Cr) and is patterned. The second inorganic compound layer is an amorphous transparent conductive metal oxide (for example, ITO). The second inorganic compound layer is patterned by weak acid wet etching (for example, 3.5% by mass of oxalic acid), but the first inorganic compound layer is not etched and only the second inorganic compound is selectively etched.

  In addition, a display device having a microresonator structure in which a conductive spacer is formed on a transparent electrode in order to adjust the optical distance to resonate is disclosed, and the etching rate is 10 times higher than that of the transparent electrode. It is disclosed to use a layer that is twice or more faster (for example, see Patent Document 2). Specifically, as the conductive spacer, amorphous ITO is laminated on the polycrystalline ITO, the amorphous ITO is selectively etched, and further annealed to convert the remaining amorphous ITO into the polycrystalline ITO. To reform. By repeating these steps, the number of stacked layers is changed according to the resonance distance.

However, the display devices using these resonator structures have the following problems.
(1) Since an etching stopper layer is formed, a heterogeneous film formation or an annealing process for crystallinity modification is required, and there are many processes, resulting in poor productivity.
(2) Since the photolithography method and the film formation of the transparent conductive film are alternately repeated, the process is complicated, the risk of dust adhesion increases between different processes, and the yield decreases.
Republished patent WO2005 / 086539 Japanese Patent Laid-Open No. 2005-197011

  An object of the present invention is to provide a display device using a light emitting element and a manufacturing method thereof. In particular, it is to provide a display device capable of high-definition color display and easy to manufacture, and a manufacturing method thereof.

It has been found that the above-mentioned problems of the present invention can be solved by the following means.
<1> A display device including a plurality of pixels on a substrate, each pixel including at least two types of sub-pixels that emit light having different wavelengths, wherein the sub-pixel includes a light transflective layer and a light reflection At least an optical path length adjusting layer, a transparent electrode, and an organic electroluminescent layer sandwiched between layers, and the two sub-pixels have different optical path length adjusting layers, and at least the optical path length adjusting layer One of the display devices is formed by forming a laminated body of a plurality of light-transmitting inorganic insulating materials having different compositions and then removing at least the upper layer of the laminated structure by etching.
<2> The longest optical path length adjustment layer of the at least two types of subpixels is a total lamination of the plurality of light transmissive inorganic insulating materials, and the shortest optical path length adjustment layer is formed of the light transmissive inorganic insulating material. <1> The display device according to <1>, which is a single layer.
<3> The display device according to <1> or <2>, wherein the plurality of light-transmitting inorganic insulating materials have different etching rates from each other, and the etching rate is higher as the upper layer of the stacked structure is formed.
<4> The plurality of light transmissive inorganic insulating materials include at least silicon atoms (Si), Si composition ratios are different in each layer, and the Si composition ratio is smaller as the upper layer of the stacked structure is <1> The display apparatus in any one of <3>.
<5> The at least two types of sub-pixels include a blue pixel, a green pixel, and a red pixel, the optical path length adjustment layer of the blue pixel is the thinnest, and the optical path length adjustment layer of the red pixel is thick. The display device according to any one of <1> to <4>.
<6> The display device according to <5>, further including a white pixel, wherein the white pixel does not include an optical path length adjustment layer.
<7> The display device according to any one of <1> to <6>, wherein the at least two types of subpixels have the same composition of the organic electroluminescent layer and are continuous.
<8> The display device according to <7>, wherein the organic electroluminescent layer is a white light emitting layer.
<9> The method for manufacturing a display device according to any one of <1> to <8>, wherein the manufacturing process of the optical path length adjusting layer of the at least two types of subpixels is at least
1) a step of forming a laminated structure in which light-transmitting inorganic insulating materials whose etching rates are higher as the upper layer are laminated using light-transmitting inorganic insulating materials having different etching rates; and 2) at least an upper layer of the laminated structure is etched. A step of removing by
The thickness of the optical path length adjusting layer is adjusted so that the distance between the light transflective layer and the light reflecting layer becomes an optical distance at which the wavelength of light emitted from the sub-pixel resonates. Device manufacturing method.
<10> The optical path is formed by etching in accordance with the wavelength of light emitted from the sub-pixel after forming a common laminated structure of the light-transmitting inorganic insulating materials of the optical path length adjusting layer of the at least two sub-pixels. The method for producing a display device according to <9>, wherein the thickness of the length adjusting layer is adjusted.
<11> A display device including a plurality of pixels on a substrate, each pixel including at least two types of sub-pixels that emit light having different wavelengths, wherein the sub-pixel includes a light transflective layer and a light reflection At least an optical path length adjustment layer, a transparent electrode, and an organic electroluminescent layer sandwiched between the layers, wherein one of the at least two types of subpixels is a first light-transmitting inorganic insulating material And the other sub-pixel is different from the layer made of the first light-transmitting inorganic insulating material and the first light-transmitting inorganic insulating material laminated thereon. A display device comprising a second optical path length adjusting layer made of a second light-transmitting inorganic insulating material having a composition.
<12> The first light-transmitting inorganic insulating material and the second light-transmitting inorganic insulating material contain at least silicon atoms (Si), Si composition ratios differ in each layer, and the second light-transmitting property <11> The display device according to <11>, wherein the Si composition ratio of the inorganic insulating material is smaller.
<13> The at least two types of subpixels include a blue pixel, a green pixel, and a red pixel, the blue pixel includes the first optical path length adjustment layer, and the green pixel includes the first optical path length adjustment. And the red light pixel includes the first optical path length adjustment layer, the second optical path length adjustment layer, and the first light transmission layer stacked on the first optical path length adjustment layer. A third optical path length adjusting layer made of a third light-transmitting inorganic insulating material having a composition different from that of the conductive inorganic insulating material and the second light-transmitting inorganic insulating material is laminated <11> Or the display apparatus as described in <12>.
<14> The first light-transmitting inorganic insulating material, the second light-transmitting inorganic insulating material, and the third light-transmitting inorganic insulating material contain at least silicon atoms (Si), and the Si composition ratio is It is different in each layer, and the Si composition ratio is smaller in the order of the first light-transmitting inorganic insulating material, the second light-transmitting inorganic insulating material, and the third light-transmitting inorganic insulating material. <13> The display device described in.
<15> The display device according to <13> or <14>, further including a white pixel, wherein the white pixel does not include an optical path length adjustment layer.
<16> The display device according to any one of <11> to <15>, wherein the at least two types of subpixels have the same composition of the organic electroluminescent layer and are continuous.
<17> The display device according to <16>, wherein the organic electroluminescent layer is a white light emitting layer.

  According to the present invention, a display device capable of high-definition color display and easy to manufacture and a manufacturing method thereof are provided. In particular, since the organic electroluminescent layer can be formed in common for all the pixels including the sub-pixels, it is not necessary to paint the organic electroluminescent layer portion separately according to the emission color. Also, for the optical path length adjustment layer, the laminated body forms all the pixels at once and adjusts the thickness of the optical path length adjustment layer only by the etching process, so it is extremely productive and produces a high-definition pattern. Can be easily performed.

  Conventionally, it is necessary to adjust the thickness of the transparent electrode layer or the thickness of the organic electroluminescent layer for each R, G, B pixel to form an optical resonator structure, and the manufacturing process is complicated and high-definition is formed. It was difficult. When the optical resonance distance is adjusted by the thickness of the transparent electrode, the photolithography method and vacuum film formation are alternately performed, so the process time becomes longer, and foreign matters such as dust are attached by moving and transporting materials between these processes. There were concerns about trouble. When the optical resonance distance is adjusted by the thickness of the organic electroluminescent layer, it is necessary to form the organic electroluminescent layer separately for each R, G, and B pixel, and it is difficult to achieve high definition.

Hereinafter, the present invention will be described in more detail.
1. Display Device The 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 are arranged vertically and horizontally on a substrate. Each pixel is composed of at least two types of sub-pixels that emit light having different wavelengths. Preferably, it is composed of three sub-pixels of red (R), green (G), and blue (B). More preferably, it is composed of four color sub-pixels including white pixels (FIG. 2). A full color can be reproduced by independently controlling these sub-pixels and emitting light with independent luminance.

  The at least two types of subpixels include at least an optical path length adjustment layer, a transparent electrode, and an organic electroluminescent layer sandwiched between a light semi-transmissive reflection layer and a light reflection layer, and the at least two types of subpixels are The optical path length adjusting layers have different thicknesses, and at least one of the optical path length adjusting layers is formed by forming a laminated body of a plurality of light transmissive inorganic insulating materials having different compositions, and then removing at least the upper layer of the laminated structure by etching. It is formed by

  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, more preferably an organic electroluminescent element (in the present invention, hereinafter, it may be referred to as “organic EL element”). In the present invention, it may be a top emission type organic EL 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.
On the transparent substrate 1, each of the subpixels has a light semi-transmissive reflective film 2, and on the R subpixel portion, an insulating layer 31 (insulating layer 1) made of a light-transmitting inorganic insulating material is provided. The layer 32 (insulating layer 2) and the insulating layer 33 (insulating 3) are stacked, the G subpixel portion includes the same insulating layer 1 and the insulating layer 2, and the B subpixel portion includes the same. Insulating layer 1 is provided. On top of this, a transparent electrode 4 (first electrode) is patterned on each subpixel. In addition, the organic electroluminescent layer 5 and the light reflecting electrode 6 (second electrode) are provided in common to each subpixel. The light emitted from the organic electroluminescent layer 5 by energization is repeatedly reflected between the light transflective film 2 and the light reflecting electrode 6, passes through the substrate 1, and is emitted to the outside.

  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 light semi-transmissive reflective film 2 and the light reflective electrode 6 in the R sub-pixel portion is made red. By adjusting the thickness of (insulating layer 1 + insulating layer 2 + insulating layer 3) so that the light resonates, only the red component in the white light resonates and is emitted to the outside with high luminance. In the R sub-pixel portion, (insulating layer 1 + insulating layer 2 + insulating layer 3) is an optical path length adjusting layer. Further, in the G sub-pixel portion, the optical distance between the light transflective film 2 and the light reflecting electrode 6 depends on the thickness of (insulating layer 1 + insulating layer 2) so that the green light resonates. By adjusting, only the green component in the white light resonates and is emitted to the outside with high luminance. In the G subpixel portion, (insulating layer 1 + insulating layer 2) is an optical path length adjusting layer. Furthermore, in the B sub-pixel portion, the optical distance between the light transflective film 2 and the light reflecting electrode 6 is adjusted by the thickness of the insulating layer 1 so that the blue light resonates. Only the blue component in the white light resonates and is emitted to the outside with high luminance. In the B subpixel portion, the insulating layer 1 is an optical path length adjusting layer. As described above, in the present invention, in addition to the thickness and refractive index of the organic EL light-emitting layer 5 and the transparent electrode 4 that affect the optical distance of resonance, the insulating layer 1, the insulating layer 2 that forms the optical path length adjusting layer, and By appropriately setting each thickness of the insulating layer 3, the R subpixel unit, the G subpixel unit, and the B subpixel unit can resonate efficiently.

FIG. 4 is a schematic cross-sectional view showing the configuration of one pixel according to another aspect of the present invention.
On the substrate 11, each subpixel has a light reflection film 12 in common, and a transparent electrode 14 (first electrode) is patterned on each subpixel. In addition, an insulating layer 131 (insulating layer 1), an insulating layer 132 (insulating layer 2), and an insulating layer 133 (insulating layer 3) made of a light-transmitting inorganic insulating material are stacked on the R subpixel portion. The G subpixel has the same insulating layer 1 and the insulating layer 2 stacked, and the B subpixel has the same insulating layer 1. In addition, the organic electroluminescent layer 15 and the light transflective electrode 16 (second electrode) are provided in common to each subpixel. The light emitted from the organic electroluminescent layer 15 by energization is repeatedly reflected between the light reflecting film 12 and the light semi-transmissive reflective electrode 16, passes through the light semi-transmissive reflective electrode 16, and is emitted to the outside.
When a white light-emitting organic EL element having an emission spectrum in the entire visible range is used as the organic electroluminescent layer 15, the optical distance between the light reflecting film 12 and the light transflective electrode 16 in the R sub-pixel portion is made red. By adjusting the thickness of (insulating layer 1 + insulating layer 2 + insulating layer 3) so that the light resonates, only the red component in the white light resonates and is emitted to the outside with high luminance. In the R sub-pixel portion, (insulating layer 1 + insulating layer 2 + insulating layer 3) is an optical path length adjusting layer. Further, in the G sub-pixel portion, the optical distance between the light reflecting film 12 and the light transflective electrode 16 depends on the thickness of (insulating layer 1 + insulating layer 2) so that the green light resonates. By adjusting, only the green component in the white light resonates and is emitted to the outside with high luminance. In the G subpixel portion, (insulating layer 1 + insulating layer 2) is an optical path length adjusting layer. Furthermore, in the B sub-pixel portion, the optical distance between the light reflecting film 12 and the light transflective electrode 16 is adjusted by the thickness of the insulating layer 1 so that the blue light resonates. Only the blue component in the white light resonates and is emitted to the outside with high luminance. In the B subpixel portion, the insulating layer 1 is an optical path length adjusting layer.
As described above, in the present invention, in addition to the thickness and refractive index of the organic EL light-emitting layer 15 and the transparent electrode 14 that affect the optical distance of resonance, the insulating layer 1, the insulating layer 2 that forms the optical path length adjusting layer, and By appropriately setting each thickness of the insulating layer 3, the R subpixel unit, the G subpixel unit, and the B subpixel unit can resonate efficiently.

Therefore, according to the present invention, the light emitted from each sub-pixel is a high-saturation light with a high luminance and a narrow spectral distribution, and the emission of light having a wavelength component other than the resonance wavelength from each sub-pixel is suppressed. Therefore, extremely high brightness and high saturation 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, since the optical path length adjusting layer for the R, G, and B sub-pixels is first formed consistently and then the thickness of the G pixel and the B sub-pixel is only adjusted by etching, film formation is performed for each sub-pixel. There is no need to repeat the etching, and further, there is an advantage that a white light emitting material is used as the organic EL light emitting layer, and it can be formed in common with the R, G, B subpixels. Therefore, the manufacturing process is simple, high productivity is obtained, and high definition is easy.

2. Optical path length adjusting layer The optical path length adjusting layer of the present invention is composed of a laminate of a plurality of light-transmitting inorganic insulating materials having different compositions.
Various conventionally known metal oxides, metal nitrides, metal fluorides and the like can be used as the light-transmitting inorganic insulating material used for the optical path length adjusting layer of the present invention.
Specific examples of the metal oxide include MgO, SiO ₂ , Al ₂ O ₃ , Y ₂ O ₃ , and TiO _2. Specific examples of the metal nitride include SiN _x , SiO _x N _y , AlN, and the like. Specific examples of the metal fluoride include MgF ₂ , LiF, AlF ₃ , CaF ₂ , BaF _{2 and the} like. Moreover, these mixtures may be sufficient.

  In the present invention, the optical path length adjusting layer is formed by laminating light-transmitting inorganic insulating materials having different etching rates. On the substrate, a laminated body is formed by laminating a material layer having a low etching rate to a material layer having a low etching rate in order. Since the etching rate is different between the layers, the lower the etching rate, the lower the etching rate. Therefore, when the laminate is first etched under mild conditions, the layer with the fastest etching rate is etched, and the layer below it is etched. Since it functions as a stopper, only the upper layer is selectively etched. Next, when etching is performed under stronger conditions, the lower layer is also etched. In this manner, by stacking materials having different etching rates and sequentially increasing the etching conditions, it is possible to selectively etch one layer at a time from the upper layer.

Examples of combinations of materials having different etching rates include the following examples.
(1) Silicon nitride, a compound having a different bond ratio of silicon atom and nitrogen atom. The higher the Si composition ratio, the slower the etching rate.
(Slow etching rate) Si _x N _{y (x / y = 1.2)} <Si _x N _{y (x / y = 1)} <Si _x N _{y (x / y = 0.75)} (Etching rate is high ₎ )
(2) Silicon oxynitride, a compound having different bond ratios between silicon atoms and oxygen atoms and silicon atoms and nitrogen atoms. The higher the Si composition ratio, the slower the etching rate.
(Slow etching rate) SiO _x N _{y (x / y = 0.6)} <SiO _x N _{y (x / y = 1)} <SiO _x N _{y (x / y = 4)} (High etching rate)
(3) Combination of compounds composed of silicon nitride, silicon oxynitride, and silicon oxide. The higher the Si composition ratio, the slower the etching rate.
(Slow etching rate) SiN _x <SiO _x N _y <SiO _x (High etching rate)

  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 of the R sub-pixel portion is preferably a physical thickness of 150 nm to 350 nm, and more preferably 200 nm to 250 nm. The thickness of the optical path length adjusting layer in the G sub-pixel portion is a physical thickness, preferably 100 nm to 250 nm, and more preferably 150 nm to 200 nm. The thickness of the optical path length adjusting layer in the B subpixel portion is a physical thickness, preferably 50 nm to 200 nm, and more preferably 100 nm to 150 nm.

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.
For example, in the case of the CVD method, the raw material gas is SiN _x , SiO _x N depending on the combination and mixing ratio of silane (SiH ₄ ), nitrous oxide (N ₂ O), ammonia (NH ₃ ), oxygen (O ₂ ). _y, can be generated composition of SiO _x.

<Etching means>
Various conventionally known etching methods can be used as the etching means for the optical path length adjusting layer in the present invention.
For example, in the case of the RIE method (reactive ion etching), anisotropic etching corresponding to the composition of the processed surface can be performed by selecting the reaction gas and the RF output. As the reaction gas, CF ₄ , CHF ₃ , C ₂ F ₆ , C ₃ F ₈ , SF ₆ , NF _{3 and the} like can be used alone or in combination.

  In the present invention, a laminate of a plurality of inorganic insulating materials having different etching rates is selectively etched from the upper layer. For example, when etching the uppermost layer, the etching conditions are the slowest and the uppermost layer is etched, but the lower layer is not etched because the etching rate is slow, and the etching conditions and the material of each layer are substantially set as an etching stopper. Selected.

3. 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.
Moreover, if a luminescent material is white light emission, it may be used individually by 1 type and may use 2 or more types together, and may obtain white light emission. When two or more types are used in combination, the combination of the luminescent color of the luminescent material is not particularly limited, but a combination of a blue luminescent material and a yellow luminescent material, a combination of a blue luminescent material, a green luminescent material and a red luminescent material, etc. Can be mentioned.

  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.
A phosphorescent material may be used alone or in combination of two or more. Further, a fluorescent material and a phosphorescent material may be used at the same time.

  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 The electrode in the present invention may be either the anode or the cathode of the first electrode and the second electrode, but preferably the first electrode is the anode and the second electrode Is the 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 alkaline earth 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.

(application)
The display device of the present invention is applied in a wide range of fields including mobile phone displays, personal digital assistants (PDAs), computer displays, automobile information displays, TV monitors, or general lighting.

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

Example 1
The production method of the present invention will be described with reference to the drawings. 5 and 6 show the stepwise process. The resulting configuration is shown in FIG.
<Figure 5>
Step (1): A light semi-transmissive reflective film 2 (Al, Ag, etc.) is formed on the substrate 1 by a vacuum film forming method.
Step (2): The inorganic insulating layer 1 (Si ₆ N ₅ ) is formed on the light semi-transmissive reflective film by a vacuum film forming method. The flow rates of SiH ₄ gas and NH ₃ gas were adjusted by plasma CVD so that Si atoms and N atoms were combined at 6: 5.
Step (3): An inorganic insulating layer 2 (SiN) is formed on the inorganic insulating layer 1 by a vacuum film forming method. In the same manner as in step (2), the flow rates of SiH ₄ gas and NH ₃ gas were adjusted so that Si atoms and N atoms were combined at 1: 1.
Step (4): An inorganic insulating layer 3 (Si ₃ N ₄ ) is formed on the inorganic insulating layer 2 by a vacuum film forming method. In the same manner as in the step (2), the flow rates of SiH ₄ gas and NH ₃ gas were adjusted so that Si atoms and N atoms were combined at 3: 4.
Step (5): The position of the R pixel is covered with a resist by photolithography, and the resist is opened at the position of the G pixel and the B pixel.
Step (6): The inorganic insulating layer 3 of the G pixel and B pixel in which the resist is opened is removed by fluorine-based dry etching. Here, since the inorganic insulating layer 3 has a higher composition ratio of N to Si than that of the inorganic insulating layer 2, the etching rate is high, and the etching stops on the surface of the inorganic insulating layer 2.

<Fig. 6>
Step (7): The position of the R pixel and the position of the G pixel are covered with a resist by photolithography, and the resist is opened at the position of the B pixel.
Step (8): The inorganic insulating layer 2 of the B pixel in which the resist is opened is removed by fluorine-based dry etching. Here, since the inorganic insulating layer 2 has a higher composition ratio of N to Si than the inorganic insulating layer 1, the etching rate is high, and the etching stops on the surface of the inorganic insulating layer 1.
Step (9): The transparent electrode 4 (ITO, IZO, etc.) that is the first electrode is patterned for each subpixel at each RGB subpixel position on the surface of the inorganic insulating layers 1 to 3 and formed by a vacuum film forming method. To do.
Step (10): The organic electroluminescent layer 5 is formed on the transparent electrode consistently for all three pixels. The organic electroluminescent layer uses white light emission.
Step (11): The light reflecting electrode 6 (Al, Ag, etc.) as the second electrode is formed on the organic electroluminescent layer by a vacuum film forming method.

According to the manufacturing method described above, the process of forming the optical path length adjusting layer of the optical resonator is extremely simpler and more productive than the prior art, and the yield can be increased.
In addition, since the optical path length adjusting layer is manufactured in a process independent of the process of forming the organic EL layer, the organic EL layer can be collectively formed on the entire surface of the light emitting layer, and the organic EL layer can be applied to each subpixel. This eliminates the need to form, simplifies the manufacturing process, increases productivity, and facilitates high definition.
Further, in the production of the optical path length adjusting layer in the present application, the annealing step can be omitted. Inorganic insulating films having different compositions are formed in a continuous film formation environment, and resist formation and etching processes (abbreviated as photolithography processes) by photolithography, in which the optical path length is changed for each pixel, are collectively performed after the film formation. Can do. That is, there is no complexity of repeating the film formation and photolithography processes, and contamination such as dust adhesion in the optical path length adjustment layer can be suppressed.

Example 2
Next, the manufacturing method of the notation apparatus incorporating the top emission type organic EL element shown in FIG. 4 will be described with reference to the drawings. FIG. 7 shows a stepwise process.
Step (1): The light reflecting film 12 (Al, Ag, etc.) is formed on the substrate 11 by a vacuum film forming method.
Step (2): Steps (2) to (8) of Example 1 are formed in the same manner.
Step (3): A transparent electrode 14 (ITO, IZO, etc.), which is the first electrode, is patterned for each subpixel at the RGB subpixel positions on the surfaces of the inorganic insulating films 1 to 3 at the RGB pixel positions, and vacuum is applied. It is formed by a film forming method.
Step (4): The organic electroluminescent layer 15 is formed on the transparent electrode 14 consistently for all three pixels. The organic electroluminescent layer uses white light emission.
Step (5): A light transflective electrode 16 (Al, Ag, etc.) as a second electrode is formed on the organic electroluminescent layer 15 by a vacuum film forming method.

  According to the above manufacturing method, as in the first embodiment, the process of forming the optical path length adjusting layer of the optical resonator is extremely simpler and more productive than the prior art, and the yield can be increased.

It is a conceptual diagram of the pixel arrangement | sequence of a matrix type display apparatus. It is a conceptual diagram which shows the subpixel arrangement | sequence of 1 pixel. It is a schematic sectional drawing of 1 pixel by this invention. It is a schematic sectional drawing of 1 pixel of another aspect by this invention. It is a schematic sectional drawing which shows the manufacturing method of 1 pixel by this invention in process order. FIG. 6 is a schematic cross-sectional view showing a process following the process shown in FIG. It is a schematic sectional drawing which shows the manufacturing method of 1 pixel of another aspect by this invention in process order.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,11: Substrate 2: Light transflective film 31, 131: Insulating layer 1; 32, 132: Insulating layer 2; 33, 133: Insulating layer 3
4, 14: First electrode (transparent electrode)
5, 15: Organic electroluminescent layer 6: Second electrode (light reflecting electrode)
12: Light reflecting film 16: Second electrode (light transflective electrode)

Claims (17)

  A display device comprising a plurality of pixels on a substrate and each pixel comprising at least two types of sub-pixels that emit light having different wavelengths, wherein the sub-pixels are divided into a light transflective layer and a light reflective layer. At least one of the optical path length adjustment layers includes at least an optical path length adjustment layer, a transparent electrode, and an organic electroluminescent layer sandwiched, and the two types of sub-pixels have different optical path length adjustment layers. A display device, which is formed by forming a laminated body of a plurality of light-transmitting inorganic insulating materials having different compositions and then removing at least the upper layer of the laminated structure by etching.   The longest optical path length adjustment layer of the at least two sub-pixels is a laminate of the plurality of light transmissive inorganic insulating materials, and the shortest optical path length adjustment layer is a single layer of the light transmissive inorganic insulating material. The display device according to claim 1, wherein the display device is provided.   3. The display device according to claim 1, wherein the plurality of light-transmitting inorganic insulating materials have different etching rates from each other, and the upper layer of the multilayer structure has a higher etching rate.   The plurality of light-transmitting inorganic insulating materials contain at least silicon atoms (Si), Si composition ratios are different in each layer, and the Si composition ratio is smaller as the upper layer of the laminated structure is. 4. The display device according to any one of 3.   The at least two types of sub-pixels have a blue pixel, a green pixel, and a red pixel, the optical path length adjustment layer of the blue pixel is the thinnest, and the optical path length adjustment layer of the red pixel is thick. The display device according to any one of claims 1 to 4.   The display device according to claim 5, further comprising a white pixel, wherein the white pixel does not have an optical path length adjustment layer.   The display device according to claim 1, wherein the at least two types of subpixels have the same composition of the organic electroluminescent layer and are continuous.   The display device according to claim 7, wherein the organic electroluminescent layer is a white light emitting layer. 9. The method for manufacturing a display device according to claim 1, wherein the manufacturing process of the optical path length adjusting layer of the at least two types of sub-pixels is at least:
1) a step of forming a laminated structure in which light-transmitting inorganic insulating materials whose etching rates are higher as the upper layer are laminated using light-transmitting inorganic insulating materials having different etching rates; and 2) at least an upper layer of the laminated structure is etched. A step of removing by
The thickness of the optical path length adjusting layer is adjusted so that the distance between the light transflective layer and the light reflecting layer becomes an optical distance at which the wavelength of light emitted from the sub-pixel resonates. Device manufacturing method.   The optical path length adjustment layer is formed by etching in accordance with the wavelength of light emitted from the sub-pixels after forming a common laminated structure of light-transmitting inorganic insulating materials of the optical path length adjustment layers of the at least two types of sub-pixels. The method of manufacturing a display device according to claim 9, wherein the thickness of the display device is adjusted.   A display device comprising a plurality of pixels on a substrate and each pixel comprising at least two types of sub-pixels that emit light having different wavelengths, wherein the sub-pixels are divided into a light transflective layer and a light reflective layer. At least an optical path length adjusting layer, a transparent electrode, and an organic electroluminescent layer sandwiched, and one of the at least two types of sub-pixels is made of a first light-transmitting inorganic insulating material. And the other sub-pixel has a layer having a composition different from that of the first light-transmitting inorganic insulating material and the first light-transmitting inorganic insulating material laminated thereon. A display device comprising: a second optical path length adjusting layer made of a light transmissive inorganic insulating material.   The first light-transmitting inorganic insulating material and the second light-transmitting inorganic insulating material contain at least silicon atoms (Si), Si composition ratios are different in each layer, and the second light-transmitting inorganic insulating material The display device according to claim 11, wherein the Si composition ratio is smaller.   The at least two types of sub-pixels include a blue pixel, a green pixel, and a red pixel, the blue pixel includes the first optical path length adjustment layer, and the green pixel includes the first optical path length adjustment layer and the The red pixel has the first optical path length adjustment layer, the second optical path length adjustment layer, and the first light-transmitting inorganic insulation layered thereon. The third optical path length adjusting layer made of a third light transmissive inorganic insulating material having a composition different from that of the material and the second light transmissive inorganic insulating material is laminated. 12. The display device according to 12.   The first light-transmitting inorganic insulating material, the second light-transmitting inorganic insulating material, and the third light-transmitting inorganic insulating material contain at least silicon atoms (Si), and the Si composition ratio differs in each layer. The Si composition ratio is smaller in the order of the first light-transmitting inorganic insulating material, the second light-transmitting inorganic insulating material, and the third light-transmitting inorganic insulating material. The display device described in 1.   The display device according to claim 13, further comprising a white pixel, wherein the white pixel does not have an optical path length adjustment layer.   The display device according to claim 11, wherein the at least two types of subpixels have the same composition of the organic electroluminescent layer and are continuous.   The display device according to claim 16, wherein the organic electroluminescent layer is a white light emitting layer.