KR20030006225A - Organic electroluminescence device and method for manufacturing the same - Google Patents

Abstract

PURPOSE: An organic EL(Electro-Luminescence) device and a method for fabricating the same are provided to prevent a cross-talk phenomenon and a short-circuit phenomenon between a conductive layer and a cathode electrode between insulating islands by forming a separator having an overhang structure. CONSTITUTION: A plurality of anode electrodes(20) are formed on a transparent substrate(10). An insulating island(25) is arranged on a separator forming portion of the anode electrode(20). A plurality of pixels are formed by depositing sequentially an organic layer(30) and a cathode electrode(40) on an upper surface of an anode electrode between the insulating islands(25). A separator(50) is formed on an upper surface of the insulating island(25). The separator(50) is formed with an upper separator(50b) and a lower separator(50a). The width of the upper separator(50b) is larger than the width of the lower separator(50a). The separator(50) has totally an overhang structure. A conductive layer(42) is formed on the upper separator(50b).

Description

Organic electroluminescent device and method for manufacturing the same {Organic electroluminescence device and method for manufacturing the same}

The present invention relates to an organic electroluminescent device and a method for manufacturing the same, and more particularly to an organic electroluminescent device and a method for manufacturing the same comprising a separator for preventing crosstalk between the cathode electrode and the electrical short.

The organic electroluminescent device has the same response speed as the Cathode Ray Tube (CRT), has a low driving voltage, enables ultra-thin film, and thus is useful as a wall-mounted or portable display device. Since light emission can be obtained, it is also useful as an outdoor display element.

The organic electroluminescent device basically includes a transparent electrode (anode electrode) having a large work function value, an electron related layer, a light emitting layer, a hole related layer, and an electrode having a small work function value (cathode electrode). With reference to Figure 1 looks at the basic structure of such an organic electroluminescent device.

On the transparent substrate 100, a plurality of anode electrodes 200 extending in parallel in one direction are spaced apart from each other. The anode electrode 200 is usually made of ITO. A plurality of organic layers 300, which are substantially orthogonal to the anode electrode 200 and constituting the pixel, are spaced apart from the anode electrode 200. A plurality of cathode electrodes 400 made of aluminum are generally formed on the organic layer 300. A separator 500 is formed between the stacked structures of the organic layer 300 and the cathode layer 400 in order to reduce or prevent crosstalk and electrical short between the adjacent cathode electrodes 400. The separator 500 is formed of an insulating material, and as the height of the separator 500 increases, crosstalk between adjacent cathode electrodes 400 and electrical short circuits can be prevented. Meanwhile, in the organic electroluminescent device having the structure shown in FIG. 1, the organic layer 300 performs all the roles of the electron related layer, the light emitting layer, and the hole related layer. That is, when an appropriate voltage is applied to the anode electrode 200 and the cathode electrode 400, in the organic layer 300, electrons and holes interact with the phonon to generate positive and negative polartons. Recombination produces an exciton under an electric field. The organic layer 300 emits light when the generated excitons return to the ground state.

An organic electroluminescent device comprising a conventionally used separator is shown in FIG. 2. As shown in FIG. 2, an anode electrode 205 made of ITO, which is a transparent conductive material, is formed on the transparent substrate 105, and an insulating island that is spaced apart from each other and is orthogonal to and extends from the anode electrode 205. 255 is formed.

The separator 505 is formed on the insulating island 255. A method of forming the separator 505 will be described. First, a negative type photoresist is applied to the entire surface of the anode electrode 205, and then the negative is formed using a mask (not shown) in which an area where the separator 505 is to be formed is opened. Type photoresist is exposed. However, since the intensity of the light source passing through the mask has a Gaussian distribution, the exposed area decreases as it progresses toward the insulating island 255 in the mask. Since the exposed portion of the negative type photoresist remains after the developing process, the separator 505 formed through the developing process of the negative type photoresist becomes wider as it approaches the insulating island 255 as shown in FIG. 2. It has a negative profile that becomes smaller.

Thereafter, the organic material layer and the cathode electrode material layer are sequentially deposited on the entire surface of the substrate 105 including the separator 505 to form the organic layer 305 and the cathode electrode 405 orthogonal to the anode electrode 205. At the same time, the organic layer 302 and the conductive layer 402 are also formed on the separator 505. Here, the cathode 405 is insulated from the adjacent cathode 405 by the separator 505. Since the separator 505 for insulation between the adjacent cathode electrodes 405 has a negative profile, the conductive layer formed on the cathode electrode 405 formed between the insulation islands 255 and the separator 505 ( Crosstalk with 402 and an electrical short are prevented.

However, when the separator 505 is formed in this manner, the anode 205 and the substrate 105 in which the light transmitted through the photoresist is formed under the negative type photoresist in addition to the incident light in the exposure process of the negative type photoresist. Reflected to produce secondary light, the secondary light also reaches the negative type photoresist. Therefore, since a wider area than the area defined by the mask is exposed to light, the dimension of the separator remaining after the development of the negative type photoresist becomes larger than the design value, which may cause variation in the critical dimension (CD) of the separator. have.

In addition, since the separator 505 is formed entirely of the exposure and development processes of the negative photoresist, the separator formation process lacks a margin. For example, if the light intensity is reduced to increase the angle of the negative profile of the separator, the light does not reach directly above the insulation island 255, or the intensity of the reached light is considerably weak. Of the photoresist may be removed and undercut may occur. On the other hand, if the intensity of the exposure light is increased, the negative profile of the separator 505 is not appropriate, and the cathode electrode 405 and the conductive layer 402 are shorted or crosstalk between them cannot be suppressed. In addition, the shape of the separator 505 is deformed or the separator 505 is formed by a heat treatment process for removing the solvent or gas inside the separator 505 and a heat treatment process at the time of forming the passivation film after the cathode electrode is formed. The surface edge of the negative type photoresist may be broken.

Accordingly, it is an object of the present invention to provide an organic electroluminescent device having a separator that can solve the above problems and a method of manufacturing the same. Another object of the present invention is to provide an organic electroluminescent device and a method of manufacturing the same, which can solve the vulnerability of process margins caused by exposure and development of negative photoresist. It is still another object of the present invention to provide a method for manufacturing an organic electroluminescent device which can accurately and reliably form a separator having an overhang structure.

1 shows a schematic perspective view of a conventional organic electroluminescent device.

2 shows a cross-sectional view of an organic electroluminescent device having a separator according to the prior art.

3 is a cross-sectional view of an organic electroluminescent device having a separator according to the present invention.

4A to 4D are cross-sectional views illustrating steps of manufacturing an organic electroluminescent device having a separator according to the present invention.

In order to achieve the object of the present invention, a transparent substrate, a plurality of anode electrodes formed on the transparent substrate, a plurality of separators formed on a portion of the top surface of the anode electrode, and the anode electrode formed between the plurality of separators sequentially An organic layer and a cathode; each of the plurality of separators includes a lower separator formed on an upper surface of the anode electrode and an upper separator having a width greater than that of the lower separator, and constitutes the upper separator and the lower separator. The material is the same, and the upper separator provides an organic electroluminescent device, which is cured by an electron beam.

The present invention also provides a method of preparing a transparent substrate, forming a plurality of anode electrodes on the transparent substrate, each comprising a lower separator and an upper separator whose width is greater than the width of the lower separator, The lower separator may be made of the same material, and the upper separator may include forming a plurality of separators on one portion of the anode electrode, which are cured by an electron beam, and an organic layer and a cathode electrode on an upper surface of the anode electrode between the plurality of separators. It provides a method of manufacturing an organic electroluminescent device comprising the step of sequentially forming.

The separator may include forming an electron beam curable material layer formed of a material that may be cured by an electron beam on the anode, and forming a mask on the upper surface of the electron beam curable material layer to expose a portion of the electron beam curable material layer. Exposing and developing the electron beam curable material layer on which the mask is formed; irradiating an electron beam to the developed electron beam curable material layer to cure an upper portion of the electron beam curable material layer; and etching the electron beam curable material layer. It is preferably formed by the step of. In addition, the electron beam curable material is preferably a positive type photoresist or a photosensitive spin-on polymer (SOP).

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

3 is a cross-sectional view of an organic electroluminescent device having a separator according to the present invention. As shown in FIG. 3, a plurality of anode electrodes 20 extending in one direction are disposed on the transparent substrate 10 in parallel and spaced apart from each other. If necessary, an insulating island 25 may be formed on a predetermined portion of the anode electrode 20, that is, a portion where a separator is to be formed later, and an upper surface of the anode electrode 20 between the insulating islands 25. The organic layer 30 and the cathode electrode 40 are sequentially formed to form each pixel. And the separator 50 which consists of the upper separator 50b and the lower separator 50a is formed in the upper surface of the insulating island 25. As shown in FIG. Here, the width of the upper separator 50b is larger than the width of the lower separator 50a, so that the separator 50 has an overall overhang structure.

The upper and lower separators 50b and 50a are made of the same material, but are made of a material that can be hardened and hardened by irradiation of an electron beam. As such an electron beam curable material, a positive type photoresist or a photosensitive spin-on polymer (SOP) may be used. As the positive type photoresist, a conventional novolak resin or PMMA type photoresist may be used. As the photosensitive SOP, polyimide may be used. That is, the upper separator 50b is made of the same material as the lower separator 50a but becomes hardened by the electron beam.

The organic layer 32 made of the same material as the organic layer 30 and the conductive layer 42 made of the same material as the cathode electrode 40 are stacked on the upper surface of the upper separator 50b. Since the separator 50 of the present invention has an overhang structure by the upper separator 50b as described above, the cathode electrode 40 between the conductive layer 42 and the insulating island 25 on the separator 50 is formed. Crosstalk and electrical short circuit can be prevented. In addition, since a negative photoresist is not used as a material constituting the upper separator 50b, the dimension of the upper separator 50b is not changed by light reflected and scattered from the transparent substrate 10 and the anode electrode 20. do.

Next, a method of manufacturing a separator according to the present invention will be described with reference to FIGS. 4A to 4D.

Referring to FIG. 4A, preparing a transparent substrate 60, forming a plurality of anode electrodes 70 spaced apart from each other in parallel to the upper surface thereof, and insulating islands 75 at predetermined portions on the anode electrodes 70. The forming step is the same as in the prior art. Here, the anode electrode 70 is preferably made of ITO. Next, while flattening the entire surface of the transparent substrate 60 on which the insulation islands 75 are formed, an electron beam curable material 80 that can be cured by an electron beam is applied. Photosensitive SOP (80: Spin On Polymer) may be used as such a material, and a positive type photoresist may be used.

Subsequently, as shown in FIG. 4B, a mask 90 exposing the upper surface of the SOP 80 aligned with the insulating island 75 is formed on the SOP 80 and exposed to expose the chemical properties of the exposed portion. Transform.

Next, as shown in FIG. 4C, a portion of the SOP 80 defined / exposed by the mask 90 is developed, and then irradiated with an electron beam to form a separator 50 from an electron beam curable material 80 surface. The electron beam is transmitted to a predetermined thickness to form the hardened region 82, while the lower electron beam curable material 80 is not hardened by the electron beam. Here, the thickness of the hardened region 82 may vary depending on the type of material constituting the hardened region, the intensity of the electron beam, the irradiation time, and the like. As described above, before only the upper region of the electron beam curable material 80 is selectively cured, the electron beam curable material 80 may be irradiated to strengthen the electron beam curable material 80. 80) may be changed.

After irradiating the electron beam to form a hardened region 82 having a predetermined hardness, as shown in FIG. 4D, by developing again, the electron beam curable material 80 under the hardened region 82 is etched. 3, the lower separator 50a is formed. Dry etching or wet etching may be used as the etching method, and since the upper portion of the electron beam curable material 80 is cured, an electron beam below the curing region 82 as compared to the curing region 82 when the etching process is performed. Since the etching rate of the curable material 80 is large, the phenomenon that the edge of the curing agent 82 falls during the formation of the lower separator 50a does not occur, and the lower separator 50a having a width smaller than that of the upper separator 50b is removed. Can be formed. Therefore, as shown in FIG. 3, the separator 50 of the overhang structure which consists of the upper separator 50b and the lower separator 50a is completed. After completion of the separator 50, when the organic material layer and the cathode electrode conductive layer are sequentially stacked on the entire surface of the resultant, the sustain electroluminescent element as shown in FIG. 3 is completed.

In summary, since the separator 50 of the present invention has an overhang structure, it is possible to minimize or prevent crosstalk and electrical short between the conductive layer 42 and the cathode electrode 40 formed on the separator 50. Can be.

Further, in the present invention, the separator is not formed using the exposure and development processes of the negative type photoresist, and thus problems such as the weakness of the process margin generated when the separator is formed using the negative type photoresist are not fundamentally generated. Do not.

In addition, since the hardened region 82 functions as an upper separator and also serves as a mask during the etching process for forming the lower separator 50a, a mask for forming the lower separator 50a is not required as described above. This has the advantage of simplifying the process.

Claims (7)

Transparent substrates; A plurality of anode electrodes formed on the transparent substrate; A plurality of separators formed on a portion of an upper surface of the anode electrode; And It includes an organic layer and a cathode electrode sequentially formed on the upper surface of the anode electrode between the plurality of separators, Each of the plurality of separators includes a lower separator formed on an upper surface of the anode electrode and an upper separator having a width greater than that of the lower separator. The material forming the upper separator and the lower separator is the same, and the upper separator is An organic electroluminescent element, which is cured by an electron beam. The organic electroluminescent device according to claim 1, further comprising a conductive layer formed on an upper surface of the separator and made of the same material as the cathode electrode. The organic electroluminescent device according to claim 1, wherein the electron beam curable material is made of a photosensitive spin-on-polymer or a positive type photoresist. Preparing a transparent substrate; Forming a plurality of anode electrodes on the transparent substrate; At one portion of the anode electrode, each of the lower separator and the upper separator whose width is larger than the width of the lower separator is configured, and the upper separator and the lower separator are made of the same material, and the upper separator is cured by an electron beam. Forming a plurality of separators; And And sequentially forming an organic layer and a cathode electrode on an upper surface of the anode electrode between the plurality of separators. The method of claim 4, wherein the forming of the separator comprises: forming an electron beam curable material layer formed of a material that is curable by an electron beam on an entire surface of the substrate on which the anode electrode is formed; Forming a mask on an upper surface of the material layer to expose a portion of the electron beam curable material layer; Exposing and developing the electron beam curable material layer on which the mask is formed; Irradiating an electron beam on the developed electron beam curable material layer to cure an upper portion of the electron beam curable material layer; And And etching the layer of the electron beam curable material. The method of manufacturing an organic electroluminescent device according to claim 4, further comprising an electron beam irradiation step of curing the electron beam curable material as a whole before curing the upper portion of the electron beam curable material using an electron beam. The method of manufacturing an organic electroluminescent device according to claim 4, wherein the separator is made of a photosensitive spin-on polymer or a positive type photoresist.