KR20040039791A - Structure of OELD(Organic Electro Luminescence Display) and Methode of fabricating the same - Google Patents

Abstract

PURPOSE: A structure of an organic electro-luminescence display panel and a fabricating method thereof are provided to form finely an even part of a reflective plate by performing a fabrication process without using an additional mask. CONSTITUTION: A structure of an organic electro-luminescence display panel includes a substrate(300), an active layer(310), a gate insulating layer(320), a gate electrode, an interlayer dielectric, a source electrode(351), a drain electrode(355), a multi-uneven part, a pixel part, a reflective plate(357), and a bottom electrode(370). The active layer(310) is formed on a TFT part of the substrate(300). The gate electrode is formed on the gate insulating layer(320). The source electrode(351) and the drain electrode(355) are formed on the interlayer dielectric. A multiple lower-uneven part is formed on the pixel part. The reflective plate(357) and the bottom electrode(370) are formed with a multi-uneven structure by the multiple lower-uneven parts. The multi-uneven structure includes two or more uneven parts of a first uneven part, a second uneven part, and a third uneven part. The first uneven part is formed with a polysilicon pattern. The second uneven part is formed with a gate pattern. The third uneven part is formed with a contact hole pattern.

Description

Structure of organic electroluminescent display and manufacturing method thereof {Structure of OELD (Organic Electro Luminescence Display) and Method of fabricating the same}

The present invention relates to a structure and a method of manufacturing the organic light emitting display device, and more particularly, to a structure of a top-emitting organic light emitting display device having a high reflection efficiency by forming multiple irregularities without additional masks and a method of manufacturing the same. It is about.

In general, an organic light emitting display (OELD) is characterized in that electrons and holes form electron-hole pairs in a semiconductor or carriers are excited to a higher energy state and then fall back into a stabilized equilibrium state. Use the phenomenon that light is generated through the process.

Hereinafter, a conventional technology will be described with reference to the accompanying drawings.

1 is a cross-sectional view of an organic light emitting diode display using a conventional reflector.

Referring to FIG. 1, a buffer layer 110 is formed on a substrate 100. Amorphous silicon is deposited on the buffer layer 110 and crystallized to form a polysilicon film. Then, the polysilicon layer is patterned to form the active layer 120. Thereafter, a gate insulating layer 130 is deposited on the substrate 100.

A gate metal is deposited on the gate insulating layer 130, and the gate metal is patterned to form a gate electrode 140 on the gate insulating layer 130 on the active layer 120. The source region 121 and the drain region 125 are formed using the gate electrode 140 as a mask by doping impurities of a predetermined conductivity type. A region not doped with impurities between the source region 121 and the drain region 125 serves as the channel region 123.

An oxide layer is deposited on the substrate 100 to form an interlayer insulating layer 150, and the contact hole 151 exposing a portion of the source region 121 and the drain region 125 by photo etching the interlayer insulating layer 150. , 155).

After depositing a conductive material on the interlayer insulating layer 150 including the contact holes 151 and 155, the conductive material is patterned to be connected to the source region 121 through the contact hole 151. And a drain electrode 185 connected to the drain region 125 through the contact hole 155. At the same time, a planar reflector 187 is formed in the pixel portion B to reflect light emitted from the light emitting layer in the opposite direction.

The passivation layer 190 is deposited on the substrate 100 on which the source / drain electrodes 181 and 185 are formed, and either of the source electrode 181 or the drain electrode 185 is formed on the passivation layer, for example, a drain electrode ( A via hole 195 is formed that exposes a portion of 185. This is to connect the lower electrode and the drain electrode to be formed in a subsequent process.

After depositing a lower electrode material on the passivation layer 190 including the via hole 195, the lower electrode is patterned to form a lower electrode 210 connected to the drain electrode 185 through the via hole 195. do.

Although not shown in the drawings, a planarization film is formed on the substrate 100 on which the lower electrode 210 is formed, and then an opening for exposing the lower electrode 210 is formed. A light emitting layer connected to the lower electrode 210 in the opening is formed. The upper electrode is formed by depositing a conductive material on the substrate on which the emission layer is formed.

However, the reflection plate of the conventional organic light emitting display device is formed in a plane, which causes a problem of low reflection efficiency.

Therefore, in order to compensate for the problem that the planar reflector is inferior in reflection efficiency, as shown in FIG. 2, a reflector formed with a plurality of recesses to collect light incident from the light emitting layer is introduced.

FIG. 2 is a cross-sectional view of an organic light emitting diode display using a reflective plate in which a recess is formed.

Referring to FIG. 2, the recess is formed by depositing a photosensitive resin 160, such as a photoresist, on a top surface of the substrate 100 before forming a reflective plate, and then patterning a mask on the top surface of the photosensitive resin 160. To align to the exposure process. Thereafter, the photosensitive resin 160 is developed using a developer, put into a heating furnace, and heat treated at a high temperature to form concavities and convexities that form concave portions. When the concave portion is formed by the heat treatment as described above, the overcoat layer 170 is laminated on the upper portion.

The photosensitive resin 160 and the overcoat layer 170 are deposited by spin coating with strict thickness control.

Next, the reflective plate 187 having the recess is formed by depositing the reflective plate 187 on the overcoat layer 170 through sputtering.

The via hole 205 is formed by depositing and patterning the planarization layer 200 on the substrate 100 on which the reflective plate 187 is formed. Then, the lower electrode material is deposited and patterned on the planarization layer 200 to form the lower electrode 210.

Lastly, although not shown in the drawing, a light emitting layer is formed on the lower electrode 210 and an upper electrode is formed by a conventional method of manufacturing an organic light emitting display device, thereby manufacturing an organic light emitting display device having a reflective plate.

However, in the organic light emitting display device having the recessed portion of the reflecting plate, there is a burden on additional processes such as masking and developing the photosensitive resin PR and additional work such as high temperature heat treatment when the recessed portion is formed. do. In addition, problems such as substrate deformation due to high temperature heat treatment occur. In addition, when the irregularities for forming the recesses in the reflecting plate are formed in any one of the layers, the interval between the irregularities is limited due to process limitations, and thus there is a problem in that the irregularities cannot be formed below a predetermined interval.

An object of the present invention is to solve the above problems of the prior art, and to provide a top-emitting organic electroluminescent display device and a method of manufacturing the same by forming multiple unevenness without additional mask to increase the reflection efficiency.

1 to 2 are cross-sectional views illustrating a method of manufacturing a top-emitting organic light emitting display device using a conventional reflector.

3A to 3C are cross-sectional views illustrating respective processes for explaining a method of manufacturing a top-emitting organic electroluminescent display device according to an embodiment of the present invention.

4A to 4C are diagrams illustrating a patterning method of a lower structure according to an embodiment of the present invention.

(Explanation of symbols for the main parts of the drawing)

300; A substrate 310; Active layer

311; Source region 313; Channel area

315; Drain region 317; Polysilicon pattern

320; A gate insulating film 331; Gate electrode

335; Gate pattern 340; Interlayer insulation film

341, 345, 347; Contact hole 351; Source electrode

355; Drain electrode 357; Reflector

360; Planarization film 361; Via Hall

370; Lower electrode A; TFT section

B; Pixel part

In order to achieve the above object of the present invention, the present invention includes an active layer, a gate electrode formed on the gate insulating film, a source / drain electrode formed on the interlayer insulating film in the TFT portion on the substrate, the pixel portion has a plurality of lower unevenness, A reflection plate and a lower electrode formed of a multi-concave-convex structure by the lower concave-convex, wherein the multi-concave-convex of the lower structure includes a first concave-convex formed of a polysilicon pattern simultaneously with the formation of an active layer; Second unevenness formed in a gate pattern simultaneously with forming a gate electrode on the gate insulating film; An organic light emitting display device including at least two uneven structures having at least two lower structures among third unevennesses formed in a contact hole pattern in an interlayer insulating layer is provided.

In the present invention, it is preferable that the reflecting plate formed of the multi-concave-convex structure has a concave lens type or convex lens type in order to increase the reflection efficiency of light emitted from the light emitting layer. In addition, when forming the first, second, and third unevenness, the uneven pattern may form the structure into a square, a circle, an oval or a polygon, and may form the unevenness in the same shape or different shapes. have.

In addition, the present invention comprises the steps of forming an active layer on a substrate; Forming a gate electrode on the gate oxide film on the substrate; Patterning an interlayer insulating film on the substrate to form a contact hole exposing a portion of the source / drain region of the active layer; Forming a source / drain electrode on the TFT portion on the substrate, and simultaneously forming a reflecting plate on the pixel portion; Depositing a planarization film on the substrate on which the source / drain electrodes are formed; Patterning the planarization layer to form a via hole exposing a portion of the drain electrode; And forming a lower electrode connected to the drain electrode through the via hole, wherein a plurality of irregularities are formed under the reflective plate of the pixel portion, wherein the multiple irregularities form an active layer, a gate electrode, and a contact hole. A method of manufacturing an organic light emitting display device that is simultaneously formed at least two or more times in a step is provided.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention.

3A to 3C are cross-sectional views illustrating respective processes for explaining a method of manufacturing a top-emitting organic electroluminescent display device according to an exemplary embodiment of the present invention.

4A to 4C are diagrams illustrating a pattern method of a lower structure according to an embodiment of the present invention.

Referring to FIG. 3A, a polysilicon film is formed by crystallizing amorphous silicon on a substrate 300 through a crystallization method such as conventional Solid Phase Crystallization (SPC) or Eximer Laser Annealing (ELA). Then, the polysilicon layer is patterned using a mask to form the active layer 310 on the TFT portion A, and the polysilicon pattern 317 is also applied to the pixel portion B as shown in FIG. 4A. To form the first unevenness.

Then, a gate insulating film 320 made of SiO ₂ or the like is formed on the substrate 300 having the first unevenness. A gate metal is deposited on the gate insulating layer 320 and patterned to form a gate electrode 331 in the TFT portion A. Referring to FIG. At the same time, as shown in FIG. 4B, the gate pattern 335 is formed in a region between the neighboring polysilicon patterns 317 of the pixel portion B to form second unevenness.

The source / drain regions 311 and 315 are formed by doping impurities having a predetermined conductivity type in the active layer 310 of the TFT portion A using the gate electrode 331 as a mask. A region not doped with impurities between the source / drain regions 311 and 315 serves as a channel region 313.

Referring to FIG. 3B, a contact hole for depositing an interlayer insulating film 340 on the substrate 300 on which the second unevenness is formed and exposing a portion of the source / drain regions 311 and 315 of the TFT portion A may be formed. 341, 345 are formed. In this case, in the pixel portion B, a contact hole pattern 347 exposing a part of the gate insulating layer 320 in a region between the polysilicon pattern 317 and the gate pattern 335 adjacent to each other in the interlayer insulating layer 340. ) At the same time. As shown in FIG. 4C, the contact hole 347 of the pixel portion B serves as third unevenness.

Figure 3b shows an embodiment of the cross-sectional structure of the first to third unevenness of the present invention. The first, second and third unevennesses are unevennesses of the lower structure for giving multiple unevennesses to the reflecting plate formed in a subsequent process. In the present invention, the second unevenness formed by the gate pattern 335 is formed in the space between the first unevenness formed by the polysilicon pattern 317, and the contact hole pattern 347 is formed in the space between the first and second unevenness. By forming the third concave-convex formed in the form of is not limited to the process limit and can reduce the interval between each concave-convex, it is possible to increase the reflection efficiency of the reflector formed in the subsequent process.

In addition, when the first, second, and third unevenness is formed, the uneven pattern may form the structure into a rectangle, a circle, an oval or a polygon, and may form the unevenness in the same shape or different shapes. . This is to increase the brightness of the organic light emitting display device by causing constructive interference of light reflected by the reflecting plate having multiple unevennesses formed in a subsequent process. Therefore, in forming the first, second, and third uneven patterns, it is preferable to optimize the combination of each uneven pattern in consideration of the interference phenomenon of light.

A conductive material is deposited on the substrate 300 on which the third unevenness is formed. The conductive material is made of any one of aluminum (Al), chromium (Cr), molybdenum (Mo), tungsten (W), titanium (Ti), tantalum (Ta) or alloys thereof.

In addition, the conductive material is patterned using a mask, and the TFT portion A is connected to the source region 311 through the contact hole 341 and the drain region through the contact hole 345. The drain electrode 355 is formed at the same time as the 315 is connected to the lower electrode formed in a subsequent process. The source / drain electrodes 351 and 355 are formed, and at the same time, a highly efficient reflector 357 is formed in the pixel portion B. The reflective plate 357 of the pixel portion B is made of the conductive material, and is formed in the form of irregularities by the first, second, and third irregularities in the lower portion. In addition, the reflecting plate 357 is formed by the first, second, and third irregularities to form a concave lens type or a convex lens type reflector 357 in order to increase the reflection efficiency of the light emitted from the light emitting layer formed in a subsequent step. desirable.

Referring to FIG. 3C, the planarization layer 360 is deposited on the substrate 300 provided with the reflective plate 357. Thereafter, the planarization layer 360 is dry-etched to form a via hole 361 exposing any one of the source / drain electrodes 351 and 355, for example, a part of the drain electrode 355. At this time, the planarization film 360 usually deposits at least 0.5 µm of the insulator, or uses a non-photosensitive photoresist with the insulator of 0.5 µm or less.

Next, after depositing a lower electrode material on the planarization layer 360 on which the via holes 361 are formed, the lower electrode 370 connected to the drain electrode 355 through the via holes 361 is photo-etched. Form.

Thereafter, although not shown in the drawings, an organic light emitting display is formed by forming a light emitting layer on the lower electrode 370 and then forming an upper electrode on the substrate 300 by a conventional method of manufacturing an organic light emitting display device. Manufacture the device.

The multiple concavities and convexities formed in the present invention form concavities and convexities of at least two or more substructures in a previous process of forming the reflecting plate. When the reflector is formed of the conductive material used for the source / drain electrodes as in the exemplary embodiment of the present invention, all the irregularities are formed in the polysilicon pattern, the gate pattern, and the contact hole forming process to form multiple unevennesses on the reflector. . Alternatively, irregularities may be formed only in the polysilicon pattern and the gate pattern, the polysilicon pattern and the contact hole, and the gate pattern and the contact hole forming process to form multiple irregularities in the reflector.

As described above, according to the present invention, dense unevenness of the reflector may be formed while the existing normal process is performed without adding a mask. In addition, since multiple irregularities are formed on the reflecting plate by repeatedly giving irregularities to regions between neighboring irregularities of different layers, the process width can be obtained by limiting the line width when forming the irregularities of the upper or lower layer. In addition, it is possible to increase the reflection efficiency through various combinations of irregularities of the reflector lower structure.

While the foregoing has been described with reference to preferred embodiments of the present invention, those skilled in the art will be able to variously modify and change the present invention without departing from the spirit and scope of the invention as set forth in the claims below. It will be appreciated.

Claims (3)

An active layer, a gate electrode formed on the gate insulating film, and a source / drain electrode formed on the interlayer insulating film, and the pixel portion includes a plurality of lower unevenness, and a reflector and a lower electrode formed of a multi-uneven structure by the lower unevenness. Including; Multiple irregularities of the substructure First unevenness formed of a polysilicon pattern simultaneously with the formation of the active layer; Second unevenness formed in a gate pattern simultaneously with forming a gate electrode on the gate insulating film; Among the third unevenness formed in the form of a contact hole pattern in the interlayer insulating film An organic light emitting display device comprising at least two uneven structures of at least two substructures. The method of claim 1, The first, second, and third uneven patterns may be rectangular, circular, elliptical, or polygonal, and the uneven patterns may have the same shape or different shapes. Forming an active layer on the substrate; Forming a gate electrode on the gate oxide film on the substrate; Patterning an interlayer insulating film on the substrate to form a contact hole exposing a portion of the source / drain region of the active layer; Forming a source / drain electrode on the TFT portion on the substrate, and simultaneously forming a reflecting plate on the pixel portion; Depositing a planarization film on the substrate on which the source / drain electrodes are formed; Patterning the planarization layer to form a via hole exposing a portion of the drain electrode; And forming a lower electrode connected to the drain electrode through the via hole. The lower part of the reflector of the pixel portion is formed with irregularities of multiple structures, The multi-concave-convex is formed at the same time at least two or more of the steps of forming the active layer, the gate electrode and the contact hole.