JP2000200681A - Fine light emitting element and organic el element using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple light source usable for proximity field optics. SOLUTION: On a plane 11 protruded most outwardly from a glass substrate, an organic EL layer 6 and a lower electrode 7, and an upper electrode 5 perpendicular thereto are laminated. The upper electrode 5, the organic EL layer 6 and the lower electrode 7 each has a width W=10 nm. A light source having a fine emission area of 10 nm×10 nm is thus obtained. Since the glass substrate is in a multistage structure, the emission area is easily put close to an object.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fine light emitting device and an organic EL device using the same, and more particularly, to a light source used for near-field optics.

[0002]

2. Description of the Related Art Attention has been focused on optical technology using near-field optics for writing and reading data on a high-density optical disk exceeding the analysis limit of light. Near-field optics refers to the ability to read changes in optical properties smaller than the wavelength of the illuminating light by irradiating light sufficiently close to the object to be read from an opening that is sufficiently smaller than the wavelength of the illuminating light. Things.

A light source used in the near-field optical recording system using near-field optics requires that the aperture be miniaturized and approach an object. In order to satisfy such conditions, as shown in FIG. 15, a probe 61 obtained by etching an optical fiber using an etching solution having a special composition.
Has been proposed. By miniaturizing such a light emission area and bringing the probe 61 closer to the object 63 (about 100 to 200 angstroms), recording and reading at a light wavelength or less can be performed.

[0004] However, the etching method requires very high control. In addition, because of the projection structure, the mechanical strength is low. That is, the light source used in the near-field optical recording system cannot be simply and reliably realized.

An object of the present invention is to solve the above-mentioned problems and to provide a simple light source that can be used for near-field optics.

[0006]

In a fine light emitting device according to the present invention, light is radiated sufficiently close to an object to be read from an opening having a maximum length sufficiently smaller than the wavelength of irradiation light, and the object to be read is illuminated. As a light source for near-field optics that reads changes in the optical properties of an object, the device includes 1) a lower electrode, 2) an organic EL layer located on the lower electrode, and 3) an upper electrode located on the organic EL layer. Used organic EL element. In the organic EL element, a portion where the three layers of the upper electrode, the organic EL layer, and the lower electrode overlap is a light emitting region. Therefore, the overlapping portion is finely processed so that the minimum width of the light emitting region is smaller than the light emission wavelength of the EL element, whereby the light emitting region can be easily used as a light source in the near-field optics.

According to a second aspect of the present invention, in the fine light emitting device according to the first aspect, the lower electrode and the upper electrode are formed orthogonal to each other. Therefore,
An overlapping portion serving as the light emitting region can be easily formed.

According to a third aspect of the present invention, in the fine light emitting device according to claim 1, in the organic EL element, at least one of the upper electrode and the lower electrode is in another region in an intersection region between the lower electrode and the upper electrode. It is characterized in that it is configured to have a narrower portion than that. According to such a configuration, the light emitting region is defined by the narrow portion, and a fine light emitting region can be easily defined.

According to a fourth aspect of the present invention, in the fine light emitting device according to claim 1, the organic EL element has a stripe-shaped pattern in which the lower electrode and the upper electrode are orthogonal to each other. In an intersection region between the organic EL layer and at least one of the upper electrode and the lower electrode, an interface with the organic EL layer is selectively oxidized except for a part thereof. According to this configuration, in the intersecting region between the upper electrode and the lower electrode, the oxidized region of the interface with the organic EL layer becomes an insulating layer, and no electric field is applied. Therefore, it is possible to form a fine light emitting region beyond the limit of lithography. Desirably, by performing this oxidation by pattern exposure using a near field, a finer light emitting region can be obtained.

According to a fifth aspect of the present invention, in the fine light emitting device of the fourth aspect, the minimum width of the region is smaller than the wavelength of light emitted from the organic EL layer.

According to a sixth aspect of the present invention, in the fine light emitting device according to claim 1, the organic EL element comprises a stripe pattern in which the lower electrode and the upper electrode are orthogonal to each other. Are formed in a stripe pattern having an inverted trapezoidal cross-sectional shape in an intersecting region with the lower electrode. According to such a configuration, since the upper electrode has an inverted trapezoidal cross-sectional shape, it is possible to define a fine light-emitting region exceeding the limit of lithography by utilizing the wraparound of etching or the like.

According to a seventh aspect of the present invention, in the fine light emitting device according to claim 1, the organic EL element comprises a stripe pattern in which the lower electrode and the upper electrode are orthogonal to each other. Is characterized in that, in a crossing region with the upper electrode, a region other than the top is formed of a stripe pattern having a trapezoidal cross section covered with an insulating film. According to this configuration, since the lower electrode is formed of a trapezoidal stripe pattern in which a region other than the top portion is covered with an insulating film, fine light emission exceeding the limit of lithography by utilizing the wraparound of etching or the like. An area can be defined.

According to an eighth aspect of the present invention, in the fine light emitting device according to claim 1, the organic EL element has a lower electrode, an organic EL layer located on the lower electrode, and an organic EL layer located on the organic EL layer. And a wavelength of light emitted from the organic EL layer is larger than a length of a short side of the light emitting region. According to such a configuration, even when, for example, a slit-shaped light-emitting region is formed, a slit having a fine width can be obtained, and a stable fine light-emitting element can be obtained.

According to a ninth aspect of the present invention, in the fine light emitting device according to claim 1, the organic EL element has a lower electrode, an organic EL layer located on the lower electrode, and an organic EL layer located on the organic EL layer. An upper electrode formed of a light-shielding conductive film, and a through hole having a diameter smaller than a wavelength of light emitted from the organic EL layer is formed in an intersection region between the lower electrode and the upper electrode. It is characterized by comprising. According to this configuration, since only the through hole constitutes a light extraction region, that is, a light emitting region as an organic EL element, a fine light emitting region defined only by the through hole can be obtained. Further, according to such a configuration, light can be extracted in a state where the light intensity is increased.

According to a tenth aspect of the present invention, in the fine light emitting device according to claim 1, the organic EL element comprises: a lower electrode formed on a substrate; an organic EL layer positioned on the lower electrode; An upper electrode located on the EL layer, and an insulating light-shielding film formed so as to cover the entire surface of the substrate including the upper electrode, wherein the light-shielding mask is provided at an intersection area between the lower electrode and the upper electrode. And a through hole having a diameter smaller than a wavelength of light emitted from the organic EL layer. According to such a configuration, since only the portion of the through hole formed in the insulating light-shielding film constitutes a light extraction region, that is, a light emitting region as an organic EL element, a fine light emitting region defined only by the through hole is obtained. It becomes possible. Further, according to such a configuration, light can be extracted in a state where the light intensity is increased.

According to an eleventh aspect of the present invention, in the fine light emitting device of the tenth aspect, the through hole is formed so that the diameter is larger on the upper electrode side than on the surface side. According to such a configuration, it is possible to form a beam that converges with a diameter smaller than the opening diameter of the through-hole, and it is possible to obtain finer light emission.

According to a twelfth aspect of the present invention, in the fine light emitting device according to the tenth aspect, the through hole is a thin slit, and the width of the slit is larger on the upper electrode side than on the front side. It is characterized by being formed.
According to this configuration, it is possible to form a beam that converges with a width smaller than the opening width of the slit, and it is possible to obtain finer light emission.

According to a thirteenth aspect of the present invention, in the fine light emitting device according to the tenth aspect, the through hole is formed by beam exposure using near-field light. According to such a configuration, finer through holes can be obtained, and finer light emission can be obtained.

According to a fourteenth aspect of the present invention, light having a diameter having a maximum length sufficiently smaller than the wavelength of the illumination light is irradiated sufficiently close to the object to be read, and the change in the optical properties of the object to be read is measured. As a light source for near-field optics to be read, first and second electrodes formed on a substrate, having sharp edges, and formed so that the edges face each other via a fine gap. And an organic EL element having an organic EL layer filled in the gap. According to this configuration, an extremely fine gap can be formed, and the organic EL layer interposed therebetween emits light, so that a highly reliable and fine emission beam can be obtained.

According to a fifteenth aspect of the present invention, in the fine light emitting device according to claim 1, the organic EL device comprises: a lower electrode formed on the substrate; a light emitting layer formed on the lower electrode; An upper electrode formed on the layer and made of an oxygen-permeable material, and a partial region of the light emitting layer is selected by light selective oxidation using light and oxygen reached via the upper electrode. A region where the oxide layer is present constitutes a non-light emitting region, and a minimum width of a light emitting region of the organic EL layer is the same as that of the organic EL layer.
It is characterized by being smaller than the wavelength of the light emitted from the layer. In the organic EL device according to the present invention, the organic EL device includes a lower electrode, an organic EL layer positioned on the lower electrode, and an upper electrode positioned on the organic EL layer. The maximum length of the light emitting region is smaller than the wavelength of the light emitted from. Thereby, a fine light emitting element can be provided.

In the organic EL device according to the present invention,
The lower electrode and the upper electrode are formed orthogonally. Therefore, a fine light emitting device can be provided by reducing the width of the lower electrode and the upper electrode.

That is, according to a sixteenth aspect of the present invention, the organic EL device includes a lower electrode, an organic EL layer positioned on the lower electrode, and an upper electrode positioned on the organic EL layer.
The minimum width of the light emitting region of the L layer is smaller than the wavelength of light emitted from the organic EL layer.

In a seventeenth aspect of the present invention, the organic E
In the L element, the lower electrode and the upper electrode are formed orthogonally. The eighteenth aspect of the present invention
In the above, at least one of the upper electrode and the lower electrode has a portion narrower than the other region in a crossing region between the lower electrode and the upper electrode.

According to a nineteenth aspect of the present invention, in the organic EL device according to the present invention, the lower electrode and the upper electrode are formed in a stripe pattern orthogonal to each other, and the upper electrode and the lower electrode are connected to each other. Is characterized in that at least one of the interface of the upper electrode and the lower electrode with the organic EL layer is selectively oxidized except for a part thereof.

According to a nineteenth aspect of the present invention, in the organic EL device according to claim 16, the minimum width of the region is equal to the organic EL element.
It is characterized by being smaller than the wavelength of light emitted from the L layer.

In a twentieth aspect of the present invention, in the organic EL device according to claim 16, the lower electrode and the upper electrode are formed in a stripe pattern orthogonal to each other, and the upper electrode and the lower electrode are connected to each other. It is characterized in that the intersection area is constituted by a stripe pattern having an inverted trapezoidal cross section.

According to a twenty-second aspect of the present invention, in the organic EL device according to the sixteenth aspect, the lower electrode and the upper electrode are formed in a stripe-shaped pattern orthogonal to each other, and the lower electrode is connected to the upper electrode. In the intersecting region, a region excluding the top is formed of a stripe pattern having a trapezoidal cross section covered with an insulating film.

According to a twenty-third aspect of the present invention, in the organic EL device according to the sixteenth aspect, the device further comprises a lower electrode, an organic EL layer located on the lower electrode, and an upper electrode located on the organic EL layer. The wavelength of light emitted from the organic EL layer is larger than the length of the short side of the light emitting region.

According to a twenty-fourth aspect of the present invention, in the organic EL device according to the sixteenth aspect, the device further comprises a lower electrode, an organic EL layer located on the lower electrode, and an upper electrode located on the organic EL layer. The upper electrode is made of a light-shielding conductive film, and has a through hole having a diameter smaller than a wavelength of light emitted from the organic EL layer in an intersection region between the lower electrode and the upper electrode. Features.

According to a twenty-fifth aspect of the present invention, in the organic EL device according to claim 16, the lower electrode formed on the substrate, the organic EL layer located on the lower electrode, and the organic EL element.
An upper electrode located on the layer, and an insulating light-shielding film formed so as to cover the entire surface of the substrate including the upper electrode, wherein the light-shielding mask is provided at an intersection region between the lower electrode and the upper electrode. And a through hole having a diameter smaller than the wavelength of light emitted from the organic EL layer.

According to a twenty-sixth aspect of the present invention, in the organic EL device according to the sixteenth aspect, the through hole is formed so that the diameter is larger on the upper electrode side than on the surface side.

According to a twenty-seventh aspect of the present invention, in the organic EL device according to the sixteenth aspect, the through hole is a narrow slit, and the width of the slit is formed to be larger on the upper electrode side than on the surface side. It is characterized by having.

According to a twenty-eighth aspect of the present invention, in the organic EL device according to the sixteenth aspect, the through hole is formed by beam exposure using near-field light.

In a twenty-ninth aspect of the present invention, the semiconductor device is formed on a substrate,
A first electrode and a second electrode each having an edge portion having a sharp tip and formed so that the edge portions face each other via a fine gap portion, and an organic EL filled in the gap portion.
And a layer.

In a thirtieth aspect of the present invention, in the organic EL device according to claim 16, a lower electrode formed on the substrate, a light emitting layer formed on the lower electrode, and an oxygen layer formed on the light emitting layer An upper electrode made of a transparent material,
A partial region of the light-emitting layer forms an oxide layer selectively formed by photoselective oxidation using light and oxygen reached via the upper electrode. The existing region forms a non-light emitting region, and a minimum width of the light emitting region of the organic EL layer is smaller than a wavelength of light emitted from the organic EL layer.

The expression “located above” includes not only a case where the layer is formed directly but also a case where another layer is interposed therebetween.

[0037]

Embodiment 1 One embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view of the organic EL element 1, and FIG. 2 is a sectional view taken along line YY of FIG.

In the organic EL device 1, the glass substrate 3
Has a plurality of flat portions 11, 12, and 13, as shown in FIG. A slope 11 is provided between the flat portions 11, 12, and 13.
a and 12a (hereinafter referred to as a multi-section structure). As shown in FIG. 1, the lower electrode 7 includes a lowermost flat portion 13, a slope 12 a, a next flat portion 12, a slope 11 a,
The slope 1 on the opposite side passes through the most protruding flat portion 11.
1a, the next flat portion 12, the slope 12a, and the flat portion 13 are formed.

The upper electrode 5 is also formed over a plurality of flat portions and slopes. The upper electrode 5 is orthogonal to the lower electrode 7.

The laminated structure of the most protruding flat portion 11 will be described with reference to FIG. FIG. 3A is an enlarged view of the XX section. FIG. 3B is an enlarged view of a YY cross section. Thus, the upper electrode 5 serving as the upper electrode and the organic EL layer 6
The lower electrode 7 which is a lower electrode is stacked orthogonally. The width of the upper electrode 5, the organic EL layer 6, and the lower electrode 7 is formed with a fine width W. In the present embodiment, each width W is set to 10 nm. Note that the organic EL layer 6 is formed only with the flat portion 11.

In this embodiment, the intersection of the upper electrode 5, the organic EL layer 6, and the lower electrode 7 is a light emitting region. Therefore, it is possible to obtain a light source in a fine light emitting region of 10 nm * 10 nm. The glass substrate 3 has the multi-stage structure. Therefore, it is easy to bring the light emitting region closer to the target. The upper electrode 5, the organic EL layer 6, and the lower electrode 7 can be formed as a thin film. Accordingly, since irradiation can be performed in a small irradiation area close to the target object, it can be used as a light source in near-field optics.

It is desirable that the upper electrode on the opposite side of the glass substrate be constituted by the upper electrode 5. Since the upper electrode can be made of a thinner material than the lower electrode, it can emit light at a position closer to the object if it is made of a translucent metal, for example, gold (Au).

Next, a method of manufacturing the organic EL device 1 will be described. First, a multi-stage glass substrate 3 shown in FIG. 2 is prepared. In the present embodiment, as the glass substrate 3, the height h1 of the slope 11a is 3 μm, and the flat portion 11 is 20 μm.
It was 0 nm square. The height h1 of the inclined surface 11a is set to 3 μm so that even if an electrode having a thickness of 1 μm is formed on the plane portion 12, it does not protrude from the plane portion 11.

Aluminum is vapor-deposited only in necessary portions using a shadow mask which completely covers the plane portion 12 and the inclined surface 11a of FIG. 1 and has an opening of an electrode pattern formed on the plane 13 and the inclined surface 12a. In this embodiment, aluminum having a thickness of 100 μm is deposited.

Next, a shadow mask is used to cover the fine electrode portions of the flat portion 13 and the flat portion 11 and to form the flat portion 12, the slope 11 a, and the opening of the electrode pattern formed around the flat portion 11. Aluminum is vapor-deposited only in the necessary parts. In this embodiment, aluminum having a thickness of 1 μm is deposited.

Next, a resist is applied on the fine electrode portion of the flat portion 11 and exposed with an electron beam to form a resist 33 having an opening 35 leaving only a necessary portion as shown in FIG. 4A. . Removing the resist by depositing ITO using the resist 33 as a mask (lift-off method)
As a result, the width w1 is formed at the opening 35 of the resist 33.
The lower electrode 7 having a thickness of 10 nm and a thickness of 50 nm is formed. Note that the lower electrode may be a metal layer.

Similarly, a resist is applied on the plane portion 11 and exposed to an electron beam so as to be orthogonal to the lower electrode 7 as shown in FIG.
To form The organic EL layer 6 is laminated thereon. In the present embodiment, a triphenylamine derivative and an aluminum quinoline complex thin film having a thickness of 50 nm are formed at a final vacuum degree of 1 × 10 ⁻⁵ to 1 × 10 ⁻⁷ Torr and a substrate temperature of room temperature before the film formation. , A film was formed by a vacuum deposition method using resistance wire heating.

The organic EL layer is made of anthracene derivative, pyrene derivative, tetracene derivative, stilbene derivative, berylen derivative, quinone derivative, phenanthrene derivative, naphtan derivative, naphthalimide derivative, phthaloberynone derivative, cyclopentadiene derivative, cyanine derivative, other An organic substance that emits strong fluorescence in the visible region may be employed.

Further, a 2 nm-thick indium tin oxide (ITO) thin film is deposited thereon. The ITO thin film may have a thickness enough to transmit light.

As in the case of the lower electrode, the resist 3
By removing 7, a light emitting region having a structure as shown in FIGS. 3A and 3B can be formed.

The fine electrode and the organic EL layer are
The deposition may be performed using a shadow mask 30 having an opening having a width d3 = 10 nm as shown in FIGS. 5A and 5B. That is, the lower electrode may be formed using the shadow mask 30 and rotated by 90 degrees to form the organic EL layer and the upper electrode.

A method of manufacturing the shadow mask 30 will be described with reference to FIG. As shown in FIG.
A silicon oxide film 32 having a thickness of 50 nm is formed on the surface of the silicon substrate 31 of FIG. As shown in FIG. 6B, on the surface on which the silicon oxide film 32 is not formed, the width d1 = 10 μm,
A photoresist 41 having an opening 41a with a length d2 = 15 μm is formed, and only the silicon substrate 31 is etched using the photoresist 41 as a mask. As shown in FIG. 6C, a photoresist 4 is formed on the entire surface of the silicon oxide film 32.
2 is applied and exposed with an electron beam to form a photoresist 42
Opening 42 having a width d3 = 10 nm and a length d4 = 10 nm
a is formed. Using the photoresist 42 as a mask, the silicon oxide film 32 is etched. Photoresist 4
2 is removed to complete the shadow mask 30 as shown in FIGS. 5A and 5B.

When vapor deposition is performed using a shadow mask, it is desirable that the shadow mask be brought into close contact with the glass substrate as much as possible.

When a shadow mask is used,
Instead of using a separate mask in the plane part 11 and in other cases, the shadow mask 30 is configured to cover the plane part 11 to the plane part 13, and the lower electrode, the organic EL layer,
Each of the upper electrodes may be formed by one mask.

Although the organic EL layer has the same width as the upper electrode in the present embodiment, the organic EL layer may be formed on the entire surface.

In the present embodiment, the width of the lower electrode and the upper electrode at the intersection is 10 nm, but the width is not limited to this.

Embodiment 2 Next, a second embodiment of the present invention will be described. In this embodiment, as shown in FIGS. 7A to 7D, after forming a stripe pattern of the lower electrode, laser exposure is performed through a metal mask to evaporate the edge of the pattern to form a thin portion 7S. 7A is a plan view, and FIGS. 7B-D are X1-X1, X2-X2, and YY cross sections, respectively. That is, in the intersecting region between the lower electrode 7 and the upper electrode 5, a part of the lower electrode is configured to have a portion narrower than other regions (W1 <W2). Here, the organic EL layer 6 is formed on the entire surface without patterning. If necessary,
For example, patterning may be performed simultaneously with pattern formation of the upper electrode.

Since the light emitting region is defined by the organic EL layer sandwiched between the lower electrode 7 and the upper electrode 5, according to this configuration, the light emitting region is defined by the narrow portion, It is possible to easily define a fine light emitting region. In addition, only the region that actually contributes to light emission is miniaturized, and the region other than the intersection region, which becomes a power supply portion, is left with the same width, so that it is possible to obtain fine light emission without increasing the wiring resistance.

Further, according to this configuration, not only a single point light source can be used, but also such fine light emitting regions can be arranged in a matrix, so that an array having a large area can be easily formed and a highly reliable array can be obtained. It is possible to form a near-field light in a shape of a circle.

Embodiment 3 Next, a third embodiment of the present invention will be described. In this embodiment, as shown in FIGS. 8A and 8B, a lower electrode 7 is made of a highly doped GaAs layer 7A and an aluminum layer 7A.
B and a two-layer structure, and after forming a stripe pattern,
By oxidizing, the edge portion of the aluminum layer 7B becomes aluminum oxide 7i and becomes an insulating film, and the contact area between the organic EL layer and the lower electrode is substantially reduced. It goes without saying that the organic EL layer 6 and the upper electrode 5 may be formed in the same manner as in the first embodiment. FIG. 8A is a plan view, and FIG. 8B is a view showing its XX section.

With this configuration, it is possible to easily obtain a fine light emitting region. Since the oxidation step for miniaturization does not require the formation of a mask pattern, it can be formed without increasing the number of steps, and a fine light emitting region exceeding the limit of lithography can be obtained. .

In this example, the lower electrode is composed of a two-layer film. However, the lower electrode is composed of a single-layer film of aluminum or the like.
Oxidation may be performed.

Embodiment 4 Next, a fourth embodiment of the present invention will be described. This embodiment is characterized by a method of forming a lower electrode.
As shown in FIG. 9A, the lower electrode is formed in a four-layer structure of a highly doped GaAs layer 7P, a GaAlAs layer 7Q, an AlAs layer 7R, and a GaAs layer 7S.
A fine electrode pattern is formed by mesa etching so as to reach the middle of the lAs layer 7Q. Thereafter, oxidation is performed. Thus, as shown in FIG. 9B, the GaAlAs layer 7Q other than under the GaAs layer becomes an insulating film by oxidation. However, a part of GaAs is oxidized due to the invasion of oxidation, and the region is reduced in size, and a fine light emitting region is formed on the upper portion together with the organic EL layer and the upper electrode formed in the same manner as in the above embodiment.

The GaAs layer 7P and the GaAlA
By controlling the ratio of the thickness of each layer of the s layer 7Q, the AlAs layer 7R, and the GaAs layer 7S and the heat treatment temperature for oxidation, the area ratio of the oxidized region can be adjusted. In this method, since the lower electrode is made of a material which is vulnerable to high temperature, the organic EL layer 6 which can be formed at low temperature is used.
Must be used.

Embodiment 5 Next, a fifth embodiment of the present invention will be described. This embodiment is characterized in that the upper electrode is formed in an inverted trapezoidal shape as shown in FIGS. 10A and 10B. FIG. 10A is a plan view, and FIG. 10B is a view showing the XX section thereof. In this configuration, an inverted trapezoid is formed by causing an overetch in an etching process for forming a pattern of the upper electrode. According to this configuration, since the upper electrode has an inverted trapezoidal cross-sectional shape, an electric field is applied to reduce the area of the light-emitting region that emits light, thereby forming a fine light-emitting region.

It is to be noted that such a light emitting region can be formed into, for example, a slit shape, so that a slit having a fine width can be obtained, and a stable fine light emitting element can be obtained.

Also in this configuration, the organic EL elements may be formed in an array, as in the second embodiment.

Embodiment 6 Next, a sixth embodiment of the present invention will be described. This embodiment uses the upper electrode 1 as shown in FIGS. 11A, 11B and 11C.
Reference numeral 5 denotes a through-hole h having a diameter smaller than the wavelength of light emitted from the organic EL layer in a crossing region between the lower electrode and the upper electrode, which is made of a chromium thin film which is a light-shielding conductive film.
Are formed to define a fine light emitting region. FIG. 11A is a plan view, FIG.
C is a diagram showing a YY cross section thereof.

According to this configuration, only the through hole portion constitutes a light extraction region, that is, a light emitting region as an organic EL element. Therefore, a fine light emitting region defined only by the through hole can be obtained. . Furthermore, according to such a configuration, it is possible to extract light with a high light intensity.

As a modified example, a lower electrode 7 formed on a substrate and an organic EL
Forming an insulating light-shielding mask so as to cover the entire substrate surface including the upper electrode of the ordinary organic EL element formed by the layer 6 and the upper electrode 5 located on the organic EL layer;
A through hole having a diameter smaller than the wavelength of light emitted from the organic EL layer may be formed in a region of the light-shielding mask where the lower electrode and the upper electrode intersect.

According to this configuration, since only the through hole formed in the insulating light-shielding film constitutes a light extraction region, that is, a light emitting region as an organic EL element, fine light emission defined only by the through hole. It is possible to obtain an area. Further, according to such a configuration, light can be extracted in a state where the light intensity is increased.

Embodiment 7 Next, a seventh embodiment of the present invention will be described. In this embodiment, as shown in FIG. 12, the through-hole h2 formed in the light-shielding mask 20 is formed such that the diameter is larger on the upper electrode side than on the surface side. . As for the structure of the organic EL element, the main parts are formed in the same manner as the other embodiments. Here, a state in which it is in close contact with the irradiation target T is shown. Since the light-shielding mask 20 is integrally formed with the organic EL element, the adhesion is improved.

The light-shielding mask 20 may be formed so as to be in close contact with the surface of the organic EL element, or may be formed as a thin film on the element surface by a method such as vapor deposition or sputtering.

According to such a configuration, it is possible to form a beam that converges with a diameter smaller than the opening diameter of the through hole, and it is possible to obtain finer light emission.

The through-hole may be formed by a narrow slit. By forming the width of the slit to be larger on the upper electrode side than on the front side, an effective fine light emitting area can be formed. Becomes possible. Further, by forming this through-hole by beam exposure using near-field light, a finer slit can be obtained.

Embodiment 8 Next, an eighth embodiment of the present invention will be described. In this embodiment, as shown in a plan view in FIG. 13A and a sectional view in FIG. 13B, an organic EL element is formed on a substrate, has edge portions 21e and 22e with sharp tips, and the edge portions are fine. And second electrodes 21 and 22 made of a chromium thin film pattern formed so as to face each other with a wide gap G therebetween.
And an organic EL layer 23 filled in the gap portion.

According to such a configuration, an extremely fine gap G can be formed, and the organic EL layer interposed therebetween emits light, so that a highly reliable and fine emission beam can be obtained. In addition, since it can be formed in a planar shape, higher pattern accuracy can be obtained.

The shapes of the first and second electrodes are as follows:
The present invention is not limited to the shape of this embodiment, and can be appropriately modified.

Embodiment 9 Next, a ninth embodiment of the present invention will be described. In this embodiment, as shown in FIGS. 14A to 14E, the first and second electrodes 71 are formed integrally, and cut by a laser to form a fine gap. The organic EL device is formed by filling the layer 72.

14A is a plan view, FIG. 14B is a sectional view of 14A, 14C is a plan view, FIG. 14D is a sectional view of 14C, and FIG.
E is a sectional view. First, as shown in FIGS. 14A-B,
A chromium thin film pattern 71 is formed on a glass substrate 70. Here, the width of the chromium thin film pattern near the center is reduced.

Next, the chrome thin film pattern 71 is cut along the line C by laser cutting, and divided into a first electrode 71A and a second electrode 71B with a gap G therebetween. This gap G is about 10 nm. Thereafter, the organic EL layer 72 is filled at least in the vicinity of the gap G.

Then, if necessary, a protective film is formed to complete the organic EL device. If necessary, a light-shielding protective film may be formed on this upper layer. Further, it is also possible to form a large number of electrodes on each substrate and form a fine light emitting region in an array.

Embodiment 10 Further, as a tenth embodiment of the present invention, instead of reducing the electrode width in the intersecting region between the upper electrode and the lower electrode, the organic EL layer itself is formed with the non-light emitting region by photoselective oxidation. And the light emitting region may be narrowed.

That is, this organic EL device comprises a lower electrode formed on the substrate, a light emitting layer formed on the lower electrode, and an upper layer formed on the light emitting layer and made of an oxygen-permeable material. An electrode, and a partial region of the light-emitting layer forms an oxide layer selectively formed by light and selective oxidation using light and oxygen reached via the upper electrode, The region where the oxide layer is present constitutes a non-light emitting region, and a minimum width of the light emitting region of the organic EL layer is smaller than a wavelength of light emitted from the organic EL layer.

According to such a configuration, after the EL element is completed, it is possible to narrow the light emitting region immediately before use, and the handling becomes easy.

In this specification, the organic EL layer is
Although a two-layer structure of a triphenylamine derivative and an aluminum quinoline complex thin film is used, for simplicity of description, only one layer is shown in the drawings. The configuration of the organic EL layer is arbitrary, and a three-layer, four-layer, or five-layer multilayer structure may be provided by providing an auxiliary layer that emits light such as an electron transport layer.

In the above embodiment, the organic EL element as a near-field light source has been described. However, the present invention is not necessarily limited to the use as a near-field light source. Needless to say, it can also be used.

[Brief description of the drawings]

FIG. 1 is a plan view of an organic EL device used in a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line YY of FIG.

FIG. 3 is an enlarged view of the vicinity of the uppermost plane portion in FIG. 2;

FIG. 4 is a view showing a shape of a resist.

FIG. 5 is a view showing a shadow mask 30;

FIG. 6 is a view showing a method of forming the shadow mask 30.

FIG. 7 is a view showing an organic EL device according to a second embodiment of the present invention.

FIG. 8 is a view showing an organic EL device according to a third embodiment of the present invention.

FIG. 9 is a view showing an organic EL device according to a fourth embodiment of the present invention.

FIG. 10 is a view showing an organic EL device according to a fifth embodiment of the present invention.

FIG. 11 is a view showing an organic EL device according to a sixth embodiment of the present invention.

FIG. 12 is a view showing an organic EL device according to a seventh embodiment of the present invention.

FIG. 13 is a view showing an organic EL device according to an eighth embodiment of the present invention.

FIG. 14 is a view showing an organic EL device according to a ninth embodiment of the present invention.

FIG. 15 is a diagram showing a shape of a conventional fiber probe.

[Brief description of reference numerals]

 3 Glass substrate 5 Upper electrode 6 Organic EL layer 7 Lower electrode

Claims (13)

[Claims] 1. A near-field optical light source that irradiates light from an opening having a maximum length sufficiently smaller than the wavelength of illumination light and sufficiently close to an object to be read, and reads a change in optical properties of the object to be read. An organic electroluminescence (EL) element comprising: 1) a lower electrode, 2) an organic EL layer located on the lower electrode, and 3) an upper electrode located on the organic EL layer. A fine light emitting device characterized by the following. 2. The fine light emitting device according to claim 1, wherein the organic EL device has the lower electrode and the upper electrode formed orthogonal to each other. 3. The organic EL device according to claim 1, wherein at least one of the upper electrode and the lower electrode has a portion narrower than another region in an intersection region between the lower electrode and the upper electrode. 2. The fine light-emitting device according to claim 1, wherein: 4. The organic EL device according to claim 1, wherein the lower electrode and the upper electrode are formed in a stripe pattern perpendicular to each other, and the upper electrode or the upper electrode is formed in an intersection region between the upper electrode and the lower electrode. 2. The fine light emitting device according to claim 1, wherein an interface between at least one of the lower electrode and the organic EL layer is selectively oxidized except for a part. 5. The fine light emitting device according to claim 4, wherein a minimum width of the region is smaller than a wavelength of light emitted from the organic EL layer. 6. The organic EL device according to claim 1, wherein the lower electrode and the upper electrode are formed in a stripe pattern orthogonal to each other, and the upper electrode has an inverted trapezoidal shape in an intersection region with the lower electrode. 2. The micro light emitting device according to claim 1, wherein the micro light emitting device is configured by a stripe pattern having a cross-sectional shape. 7. The organic EL device, wherein the lower electrode and the upper electrode are formed in a stripe pattern orthogonal to each other, and a region excluding a top portion in a region where the lower electrode intersects with the upper electrode. 2. The fine light emitting device according to claim 1, wherein the light emitting device comprises a stripe pattern having a trapezoidal cross section covered with an insulating film. 8. The organic EL device includes: a lower electrode; an organic EL layer positioned on the lower electrode; and an upper electrode positioned on the organic EL layer, wherein a length of a short side of a light emitting region is increased. 2. The fine light emitting device according to claim 1, wherein a wavelength of light emitted from the organic EL layer is larger than the wavelength. 9. The organic EL device includes: a lower electrode; an organic EL layer located on the lower electrode; and an upper electrode located on the organic EL layer, wherein the upper electrode is a light-shielding conductor. 2. The film according to claim 1, wherein a through hole having a diameter smaller than a wavelength of light emitted from the organic EL layer is provided in an intersection region between the lower electrode and the upper electrode. Fine light emitting element. 10. The organic EL element, wherein: a lower electrode formed on a substrate; an organic EL layer positioned on the lower electrode; an upper electrode positioned on the organic EL layer; An insulating light-shielding film formed so as to cover the entire surface of the substrate including: the light-shielding mask is arranged at an intersection region between the lower electrode and the upper electrode to have a wavelength larger than a wavelength of light emitted from the organic EL layer. 2. The micro light emitting device according to claim 1, comprising a through hole having a small diameter. 11. A near-field optical system that irradiates light having a diameter having a maximum length sufficiently smaller than the wavelength of illumination light sufficiently close to an object to be read, and reads a change in optical properties of the object to be read. First and second light sources are formed on a substrate, have sharp edged edges, and are formed so that the edges face each other via a fine gap.
And an organic EL element comprising: an electrode; and an organic EL layer filled in the gap. 12. The organic EL device, comprising: a lower electrode formed on the substrate; a light emitting layer formed on the lower electrode; and an upper layer formed on the light emitting layer and made of an oxygen-permeable material. An electrode, and a partial region of the light emitting layer forms an oxide layer selectively formed by light selective oxidation using light and oxygen reached via the upper electrode, The region where the oxide layer exists constitutes a non-light emitting region, and a minimum width of a light emitting region of the organic EL layer is smaller than a wavelength of light emitted from the organic EL layer. The micro light emitting device according to the above. A lower electrode, an organic EL layer located on the lower electrode, and an upper electrode located on the organic EL layer, wherein a minimum width of a light emitting region of the organic EL layer is the organic EL layer. An organic EL device having a wavelength smaller than the wavelength of light emitted from the EL layer.