KR20060001749A - Fabricating method of organic electroluminescense display device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an organic light emitting display device. More particularly, the present invention relates to a method of manufacturing an organic electroluminescent display device. The present invention relates to a method of manufacturing an organic light emitting display device.

A method of manufacturing an organic light emitting display device according to the present invention includes forming an insulating film on an insulating substrate including a thin film transistor; Forming a transparent conductive film over the entire surface of the substrate on the insulating film; Coating a photosensitive film on the transparent conductive film; Forming a first photoresist pattern in a light emitting region of the transparent conductive film and a second photoresist pattern having a thickness thinner than a first photoresist pattern in a periphery of the transparent conductive film; Etching the exposed transparent conductive layer by using the first and second photoresist layer patterns to form a first pattern of a light emitting region of the transparent conductive layer and a second pattern of a non-light emitting region which is a periphery of the transparent conductive layer; Modifying the transmittance of the second pattern using the first photoresist pattern as a mask; Removing the first photoresist pattern, and forming a pixel definition layer including an opening and exposing the first pattern; And forming an organic light emitting layer on the first pattern including the opening, and forming an opposite electrode on the substrate including the organic light emitting layer.

Transmittance, transparent conductive film, ion implantation

Description

Fabrication method of organic electroluminescense display device

1 is a schematic diagram illustrating a unit pixel of an organic light emitting display device of an active driving method;

FIG. 2 is a cross-sectional view taken along line II ′ of FIG. 1;

3 is a schematic diagram illustrating a unit pixel of an organic light emitting display device of an active driving method according to an embodiment of the present invention;

4 is a cross-sectional view taken along line II-II 'of FIG. 3;

5A through 5F are cross-sectional views illustrating a method of manufacturing an organic EL device according to an embodiment of the present invention for II-II ′ of FIG. 3.

<Description of reference numerals for main parts of the drawings>

1, 3, 5, 21, 23, 25: metal wires of unit pixel

12, 16, 22, 26: thin film transistor in unit pixel

18, 28, 155, 255: organic light emitting layer

102, 202, 202a, and 202b: transparent electrode layer

120, 220: passivation film

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an organic light emitting display device. More particularly, the present invention relates to a method of manufacturing an organic electroluminescent display device. The present invention relates to a method of manufacturing an organic light emitting display device.

Among the flat panel display devices, the organic light emitting display device has a high response time with a response speed of 1 ms or less, low power consumption, and no self-emission, so there is no problem in viewing angle, and thus it is advantageous as a moving image display medium regardless of the size of the device. . In addition, low-temperature manufacturing is possible, and the manufacturing process is simple based on the existing semiconductor process technology has attracted attention as a next-generation flat panel display device in the future.

The organic light emitting display device is classified into a passive matrix type and an active matrix type according to a driving method.

In the passive driving method, an organic light emitting diode is disposed at a portion where an anode bus line and an anode bus line cross each other, and are driven by a sequential pulse driving (line by line scanning) method. However, due to problems of wiring resistance, power consumption, and driving voltage, it is unsuitable for large display devices to date.

The active driving method uses two or more thin film transistors per organic light emitting diode to control on / off for each unit pixel and saves information using storage capacity, thereby reducing power consumption compared to the passive driving method. In addition, the unit pixel forming process is simpler than the manual driving method, and there is an advantage that a high resolution panel can be manufactured.

1 illustrates a unit pixel of a conventional active driving type organic light emitting display device.

The switching transistor 12, the driving transistor 16, one capacitor 14, and the organic light emitting element 18 are formed in one unit pixel, and light is emitted for each unit pixel of R, G, and B according to a signal. In addition, the wirings of the gate line 3, the data line 1, and the power supply line 5 have a structure connected to each element.

The switching transistor 12 is driven by a scan signal applied to the gate line 3 and transfers a data signal applied to the data line 1 to the driving transistor 16. The driving transistor 16 measures an amount of current flowing through the organic light emitting diode 18 by a data signal transmitted from the switching transistor 12 and a signal transmitted from the power supply line 5, that is, a voltage difference between a gate and a source. Decide In addition, the capacitor 14 stores a data signal transmitted through the switching transistor 12 for one frame.

FIG. 2 is a cross-sectional view of a conventional organic light emitting display device of FIG.

Referring to FIG. 2, an insulating film 120 is formed on an insulating substrate 100 on which a thin film transistor (not shown) is formed, and a pixel electrode 102 for forming an organic light emitting device is formed thereon. The pixel electrode 102 is connected to one of a source / drain electrode (not shown) of the thin film transistor through, for example, a drain electrode and a via hole (not shown) formed in the insulating layer 120. The organic light emitting layer 155 is formed on the pixel electrode 102, and the opposite electrode 165 is formed on the entire surface of the pixel electrode 102 to form an organic light emitting display device.

However, in the conventional organic light emitting display device as described above, the light loss 180 in which the light generated from the organic light emitting layer 155 is spread to the adjacent pixel portion occurs, and the light scattering phenomenon caused by the light loss 180 occurs. . In particular, the optical loss 180 is increased by about 2% as a whole of the pixel and 50% toward the pixel edge portion. Therefore, there is a problem that the linearity of the light emitted from the organic light emitting layer 155 is reduced.

The technical problem to be achieved by the present invention is to solve the problems of the prior art as described above, to provide an organic electroluminescent device which can improve the straightness of the light by preventing the light emitted from the organic light emitting layer to spread to the adjacent pixel portion. There is a purpose.

A method of manufacturing an organic light emitting display device according to the present invention includes forming an insulating film on an insulating substrate including a thin film transistor; Forming a transparent conductive film over the entire surface of the substrate on the insulating film; Coating a photosensitive film on the transparent conductive film; Forming a first photoresist pattern in a light emitting region of the transparent conductive film and a second photoresist pattern having a thickness thinner than a first photoresist pattern in a periphery of the transparent conductive film; Etching the exposed transparent conductive layer using the first and second photoresist layer patterns to form a first pattern of a light emitting region of the transparent conductive layer and a second pattern of a non-light emitting region which is a periphery of the transparent conductive layer; Modifying the transmittance of the second pattern using the first photoresist pattern as a mask; Removing the first photoresist pattern, and forming a pixel definition layer including an opening and exposing the first pattern; And forming an organic light emitting layer on the first pattern including the opening, and forming an opposite electrode on the substrate including the organic light emitting layer.

The first photosensitive film pattern and the second photosensitive film pattern may be formed using the photosensitive film using a halftone mask.

The transparent conductive film is formed of one material selected from the group consisting of ITO, IZO, IO, TO and ZnO.

Deformation of the transmittance of the second pattern is performed by injecting impurities into the second pattern.

The impurity is characterized in that the material selected from the group consisting of argon (Ar), asceic (As), boron (B), phosphorus (P) and hydrogen (H) ions.

The impurity implantation is characterized in that the injection into a high energy source of 40 to 100keV.

The high energy source may be injected one or more times with different injection energy.

The impurity is characterized in that it is injected in the dose amount of 3 × 10 ¹⁵ to 2 × 10 ¹⁶ (ions / cm ² ).

In the step of modifying the transmittance is characterized in that the transmittance is formed to 60% or less.

The insulating film is one selected from a laminated film of SiO 2, SiN x and SiO 2 / SiN x.

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

The following embodiments are provided as examples to sufficiently convey the spirit of the present invention to those skilled in the art. Accordingly, the invention is not limited to the embodiments described below and may be embodied in other forms. In the drawings, lengths, thicknesses, and the like of layers and regions may be exaggerated for convenience. Like numbers refer to like elements throughout.

3 is a schematic diagram illustrating a unit pixel of an organic light emitting display device of an active driving method according to an exemplary embodiment of the present invention.

Referring to FIG. 3, the pixel electrode 202 made of a transparent conductive film is divided into a light emitting region 202a and a region 202b having a low transmittance at the periphery of the light emitting region 202a, and on the light emitting region 202a. The organic light emitting layer 28 is located. The light emitting region 202a refers to a region having a transmittance close to 100%, and the region having a low transmittance 202b refers to a region having a transmittance of about 60% or less. The region 202b having a low transmittance serves to prevent light loss 180 in which light generated from the organic emission layer 28 spreads to an adjacent pixel portion, thereby improving the linearity of the light. Therefore, it is preferable to have a form surrounding the organic light emitting layer 28 in order to further improve the linearity of the emitted light.

4 is a cross-sectional view of an organic electroluminescent device for II-II ′ of FIG. 3 according to an embodiment of the present invention.

Referring to FIG. 4, a transparent insulating substrate 200 having an insulating film, for example, a passivation insulating film 220, is provided. Although the transparent insulating substrate 200 is not shown in the drawing, a process before the passivation insulating film forming process, for example, a thin film transistor forming process is performed in a conventional manner. The passivation film 220 is preferably an inorganic insulating film of one of a laminated film of SiO ₂ , SiNx and SiO ₂ / SiNx. The passivation film 220 is etched to form one of the source / drain electrodes (not shown in the figure) of the thin film transistor, for example, a via hole exposing a drain electrode (not shown in the figure) to be formed in a subsequent process. The pixel electrode is connected to the drain electrode of the thin film transistor.

The transparent conductive film 202 is positioned on the passivation film 220. The transparent conductive film 202 serves as an anode of the organic light emitting diode. The transparent conductive film 202 is positioned on a pixel area, and the light emitting area 202a and the light emitting area 202a of the transparent conductive film 202 are formed. In the periphery, a region 202b having low transmittance is located. Therefore, the region 202b having a low transmittance prevents light generated from the organic light emitting layer 255 from spreading to the adjacent pixel portion, thereby improving the linearity of the light.

The region 202b having low transmittance of the transparent conductive film 202 is formed by modifying the transmittance of the transparent conductive film, which may be formed by injecting impurities with high energy into the transparent conductive film 202, in which case an ion implanter ( impurities such as H, P, B, As, Ar, etc., by using an ion implanter or ion shower, at a high energy of 40 keV to 100 keV and then 3 × 10 ¹⁵ to 2 × 10 ¹⁶ (ions / cm ² ). Inject the dose. The transparent conductive film 202 may be formed of one material selected from the group consisting of ITO, IZO, IO, TO, and ZnO. In addition, the transmittance of the region 202b having low transmittance may be 60% or less.

Next, a pixel definition layer 250 including an opening 240 exposing the emission region 202a is formed on the transparent conductive layer 202.

An organic emission layer 255 is positioned on the emission region 202a in the opening 240, and the counter electrode 265 is formed thereon.

5A through 5F are cross-sectional views illustrating a method of manufacturing an organic light emitting display device according to an exemplary embodiment of the present invention.

Referring to FIG. 5A, an insulating film, for example, a passivation film 220, is formed on an insulating substrate 200 including a thin film transistor (not shown). The passivation film 240 is preferably an inorganic insulating film, one of a laminated film of SiO ₂ , SiNx and SiO ₂ / SiNx. The transparent conductive film 202 is formed on the passivation film 220. The transparent conductive film 202 may be formed of one material selected from the group consisting of ITO, IZO, IO, TO, and ZnO.

Referring to FIG. 5B, a photosensitive film 230 is coated on the transparent conductive film 202. The photoresist film 230 may include one of photoresist, BCB, PI, and acrylic. Next, the photoresist layer 230 is patterned by using a half tone mask 240. In this case, the halftone mask 240 may include a blocking region 241 for completely blocking light corresponding to a light emitting region of the transparent conductive film 202 and a semi-transmissive region for transmitting a portion of light corresponding to a region in which transmittance will be deformed. 242). The remaining portion except for the blocking region 241 and the transflective region 242 is a transmission region that completely transmits light.

Referring to FIG. 5C, when the photoresist layer 230 is patterned using the halftone mask 240, the first pattern 231 and the second pattern 232 of the photoresist layer 230 as shown in FIG. 5C are obtained. The first pattern 231 formed in the light emitting region of the photoresist layer 230 maintains the thickness of the photoresist layer 230 and the second pattern 232 formed in the region where the transmittance is to be modified is the first pattern 231. It has a relatively thin thickness.

Referring to FIG. 5D, when the transparent conductive film 202 is patterned using the photosensitive film 230, only the transparent conductive film remains in the region to which the transmittance is modified, as shown in FIG. 5D, and the transparent conductive film of the light emitting region is formed. The photoresist first pattern 231 remains on the substrate.

Next, when an impurity accelerated to a high energy of 40 keV to 100 keV is injected, the pattern 231 of the photoresist film acts as a mask for ion implantation so that no impurities are injected into the transparent conductive film below the exposed portion, but only to the exposed portion of the transparent conductive film. Impurities are injected. In this case, the impurity implantation process uses an ion injector or an ion shower to convert impurities selected from the group consisting of argon (Ar), asceic (As), boron (B), phosphorus (P) and hydrogen (H) ions into high energy. Inject. It is preferable that the dose amount of the impurity injected is 3 * 10 <^15> -2 * 10 <^16> (ions / cm <^2> ). In this case, the light transmittance of the portion whose transmittance is modified by impurity injection has a transmittance of 60% or less.

In the above, the ion is implanted into the transparent conductive film 202 by a single ion implantation process. However, when ion implantation is performed two or more times at different acceleration voltages, its transmittance is further lowered. In the case where ion implantation is performed a plurality of times, the total dose of impurities to be implanted is the same.

Referring to FIG. 5E, the emission region 202a and the region 202b having low transmittance are formed in the transparent conductive film 202 by the impurity implantation. As the impurities, ie, accelerated ions are implanted into the transparent conductive film, the permeability of the transparent conductive film is lowered due to bombardment caused by ion implantation of oxygen-accelerated impurities contained in the transparent conductive film. Because. That is, the oxygen of the transparent conductive film is released by ion implantation of impurities, so that the metal component ratio of the transparent conductive film is relatively increased, and the transmittance is lowered.

Referring to FIG. 5F, a pixel definition layer 250 including an opening 240 exposing the light emitting region 202a of the transparent conductive film 202 is formed, and the light emitting region 202a including the opening 240 is formed. When the organic light emitting layer 255 is formed and the counter electrode 265 is formed thereon, an organic light emitting display device according to an exemplary embodiment of the present invention is obtained.

As described above, according to the exemplary embodiment of the present invention, light scattering due to light loss is blocked by blocking the path of light emitted from the organic light emitting layer 255 to the adjacent pixel part by the light emitting region 202b of the transparent conductive film 202. Prevent and improve the straightness of light.

The organic light emitting display device according to the present invention can prevent light scattering due to light loss and improve the straightness of the light by changing the transmittance of the periphery of the transparent conductive film to block light from spreading to the adjacent pixel portion in the organic light emitting layer.

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

Claims (10)

Forming an insulating film on an insulating substrate having a thin film transistor; Forming a transparent conductive film over the entire surface of the substrate on the insulating film; Coating a photosensitive film on the transparent conductive film; Forming a first photoresist pattern in a light emitting region of the transparent conductive film and a second photoresist pattern having a thickness thinner than a first photoresist pattern in a periphery of the transparent conductive film; Etching the exposed transparent conductive layer by using the first and second photoresist layer patterns to form a first pattern of a light emitting region of the transparent conductive layer and a second pattern of a non-light emitting region which is a periphery of the transparent conductive layer; Modifying the transmittance of the second pattern using the first photoresist pattern as a mask; Removing the first photoresist pattern, and forming a pixel definition layer including an opening and exposing the first pattern; Forming an organic light emitting layer on the first pattern including the openings, and forming an opposite electrode on the substrate including the organic light emitting layer. The method of claim 1, And forming the first photoresist layer pattern and the second photoresist layer pattern using the photoresist layer using a halftone mask. The method of claim 1, The transparent conductive film is formed of one material selected from the group consisting of ITO, IZO, IO, TO and ZnO. The method of claim 1, And modifying the transmittance of the second pattern is performed by implanting impurities into the second pattern. The method of claim 4, wherein And wherein the impurity is a material selected from the group consisting of argon (Ar), arsenic (As), boron (B), phosphorus (P) and hydrogen (H) ions. The method of claim 4, wherein The impurity implantation is a method of manufacturing an organic light emitting display device, characterized in that for injecting a high energy source of 40 to 100keV. The method of claim 6, The high energy source is a method of manufacturing an organic light emitting display device, characterized in that the implanted at least once with different injection energy. The method of claim 4, wherein And wherein the impurities are implanted at a dose of 3 × 10 ¹⁵ to 2 × 10 ¹⁶ (ions / cm ² ). The method of claim 1, And forming transmittance of 60% or less in the step of modifying the transmittance. The method of claim 1, And the insulating film is one selected from a laminated film of SiO 2, SiN x, and SiO 2 / SiN x.

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