KR100560795B1 - OLED panel and fabricating method of the same - Google Patents

Abstract

The present invention relates to an organic light emitting display device and a method of manufacturing the same, and more particularly, to an organic light emitting display device having a capacitor having a different capacitance for each pixel, and a method of manufacturing the same. A substrate having R, G, and B unit pixel regions; R, G, and B organic light emitting diodes respectively disposed on the R, G, and B unit pixel areas; Provided are an organic light emitting display device including R, G, and B capacitors electrically connected to the R, G, and B organic light emitting elements, and having different dielectric film thicknesses, and a method of manufacturing the same.

Halftone Mask, Capacitor, Organic Light Emitting Display

Description

Organic light emitting display device and manufacturing method thereof {OLED panel and fabricating method of the same}

1 is a circuit diagram of R, G, and B unit pixels;

2A through 2C are cross-sectional views illustrating forming capacitors of respective unit pixels of the organic light emitting display device according to the exemplary embodiment of the present invention.

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

10a, 10b, 10c: data line, 20: gate line

30a, 30b, 30c: power supply line,

40a, 40b, 40c: switching thin film transistors,

50a, 50b, 50c: driving thin film transistor,

60a, 60b, 60c: capacitor, 70a, 70b, 70c: organic light emitting device,

100: substrate

125a, 125b, 125c: capacitor lower electrode,

130: dielectric film, 135, 135a: photosensitive film,

145a, 145b, 145c: capacitor upper electrode

200: halftone mask

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic light emitting display device and a method of manufacturing the same, and more particularly, to an organic light emitting display device having a capacitor having different capacitance for each pixel and a method of manufacturing the same.

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 that 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 one or more thin film transistors per organic light emitting diode to control on / off for each unit pixel and stores information by 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.

In the active driving method, various elements and wirings including a thin film transistor form a driving circuit unit for driving R, G, and B unit pixels.

1 shows a circuit diagram for R, G, and B unit pixels. Referring to the drawings, switching transistors 40a, 40b, 40c, driving transistors 50a, 50b, 50c, and capacitors 60a, 60b, 60c for each of the R, G, and B light emitting elements 70a, 70b, and 70c. ) Are connected. In addition, wirings of the power supply lines 30a, 30b, and 30c, the gate line 20, and the data lines 10a, 10b, and 10c are configured. Therefore, the size of the light emitting area is limited due to the elements and the wirings except for the light emitting device.

Particularly, in the case of the capacitor, since the dielectric film is formed of the same material as the insulating film of the thin film transistor, there is a limitation in the type and thickness of the dielectric film and thus the capacitance. In addition, since the area of the capacitor is limited by securing the aperture ratio, it is difficult to implement capacitance having an appropriate capacitance for each pixel of R, G, and B for implementing white balance.

In order to solve the above problems, the present invention provides an organic light emitting display device having a capacitor having an appropriate capacity for each unit pixel by forming a capacitor dielectric layer thickness different for each R, G, and B unit without adding a process, and a method of manufacturing the same. The purpose is to provide.

In order to achieve the above object, the present invention, the substrate having a R, G, and B unit pixel region; R, G, and B organic light emitting diodes respectively disposed on the R, G, and B unit pixel areas; The present invention provides an organic light emitting display device including R, G, and B capacitors electrically connected to the R, G, and B organic light emitting diodes, and having different dielectric film thicknesses.

The capacitor connected to the organic light emitting diode having the lowest luminous efficiency among the organic light emitting diodes may include the thinnest dielectric layer among the capacitors.

The organic light emitting device having the lowest luminous efficiency may be B.

In addition, in order to achieve the above object, the present invention, R, G, and B lower electrodes are formed on a substrate, a dielectric film having a different thickness on the lower electrode, and an upper electrode on the dielectric film Forming an R, G, and B capacitor, and forming R, G, and B organic light emitting elements electrically connected to the R, G, and B capacitors, respectively. To provide.

The dielectric films having different thicknesses may be formed using halftone masks.

The capacitor connected to the organic light emitting diode having the lowest luminous efficiency among the organic light emitting diodes may form the thinnest dielectric film among the capacitors.

The organic light emitting device having the lowest luminous efficiency may be B.

The dielectric film may be formed using one selected from the group consisting of a silicon oxide film (SiO 2), a silicon nitride film (SiN x), and a silicon oxynitride film (SiO x N y).

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.

2C illustrates a capacitor and a thin film transistor of an organic light emitting display device according to an exemplary embodiment of the present invention.

Referring to the drawings, thin film transistors and capacitors are positioned in each unit pixel region on a substrate 100 having R, G, and B unit pixel regions A, B, and C. Referring to FIG. The semiconductor layers 110a, 110b, and 110c are positioned in each of the regions A, B, and C, and the gate insulating layer 115 is positioned thereon. Gate electrodes 120a, 120b and 120c are positioned on the gate insulating layer, and capacitor lower electrodes 125a, 125b and 125c formed simultaneously with the gate electrode are positioned. A buffer layer may be located between the substrate 100 and the semiconductor layers 110a, 110b, and 110c. In addition, each capacitor and the thin film transistors are connected to R, G, and B organic light emitting devices (not shown) respectively positioned on the R, G, and B unit pixel regions A, B, and C. Each is electrically connected.

The capacitor dielectric layer 130, which is an interlayer insulating layer of the thin film transistors, is disposed on the gate electrodes 120a, 120b, and 120c and the capacitor lower electrodes 125a, 125b, and 125c. The capacitor connected to the organic light emitting device having the lowest luminous efficiency among the organic light emitting devices may include the thinnest dielectric layer Tc among the capacitors, and the organic light emitting device having the lowest luminous efficiency may be B. FIG.

Source and drain electrodes 140a, 140b, 140c, 140d, 140e, and 140f are positioned on the dielectric layer 130, and capacitor upper electrodes 145a, 145b, and 145c simultaneously formed with the source and drain electrodes are formed. Located.

In contrast, the capacitor lower electrode may include the semiconductor layers 110a, 110b and 110c, the gate electrodes 120a, 120b and 120c, and the source / drain electrodes 140a and 140b of the thin film transistor positioned in the organic light emitting display device. 140c, 140d, 140e, and 140f) may be formed simultaneously. The capacitor dielectric layer may include a gate insulating layer 115, an interlayer insulating layer 130, an inorganic protective layer (not shown), and a planarization layer (not shown) of the thin film transistor positioned in the organic light emitting display device. The capacitor upper electrode may be formed at the same time, simultaneously with the gate electrode 120a, 120b, 120c, the source / drain electrodes 140a, 140b, 140c, 140d, 140e, 140f, and the pixel electrode (not shown). Can be formed.

2A to 2C illustrate a method of forming capacitors and thin film transistors of an organic light emitting display device according to an exemplary embodiment of the present invention.

Referring to FIG. 2A, semiconductor layers 110a, 100b, and 110c of thin film transistors are formed on a substrate 100 having R, G, and B unit pixel regions A, B, and C. Referring to FIG. A buffer layer may be formed between the substrate 100 and the semiconductor layers 110a, 100b, and 110c.

A gate insulating film 115 is formed on the formed semiconductor layers 110a, 100b, and 110c, and a conductive film is stacked thereon. The conductive layer is patterned to simultaneously form gate electrodes 120a, 120b and 120c and capacitor lower electrodes 125a, 125b and 125c of the thin film transistors.

A capacitor dielectric layer 130, which is an interlayer insulating layer of thin film transistors, is formed on the gate electrodes 120a, 120b, and 120c and the capacitor lower electrodes 125a, 125b, and 125c. The capacitor dielectric layer 120 may be formed using one or more selected from the group consisting of a silicon oxide layer (SiO 2), a silicon nitride layer (SiNx), and a silicon nitride oxide layer (SiNxOy).

The photoresist layer 135 is formed on the capacitor dielectric layer 120. The halftone mask 200 is exposed on the substrate on which the photosensitive film 135 is formed. The halftone mask 200 is divided into regions 200a, 200b, and 200c having different degrees of light transmission during exposure according to R, G, and B unit pixel regions A, B, and C. FIG.

Referring to FIG. 2B, the photoresist film 135a is formed to have a different thickness for each unit pixel area after the exposure using the halftone mask 200. In addition, an etching mask for forming the source / drain electrode contact hole may also be formed. Therefore, when the photoresist layer 135a is etched at a constant etching rate, the insulating layer 130 under the photoresist layer is etched to have a different thickness according to the thickness of the photoresist layer, and a dielectric film having a different thickness for each capacitor of each pixel of R, G, and B units. And the source / drain contact holes of each thin film transistor.

Referring to FIG. 2C, the capacitor dielectric layer of each unit pixel region is formed to have different thicknesses Ta, Tb, and Tc due to the above process. The capacitor dielectric layer may have a thickness of Tc ≦ Tb ≦ Ta.

 The capacitor connected to the organic light emitting device having the lowest luminous efficiency among the unit pixels of the organic light emitting display device may have the thinnest dielectric layer thickness Ta of the capacitors. In addition, the organic light emitting device having the lowest luminous efficiency may be a B pixel region. Therefore, due to the simple process using a halftone mask, the capacitor of each unit pixel may have a dielectric film of an appropriate thickness without the addition of a process, and thus, the capacitance of an appropriate value regardless of the type of dielectric film and the capacitor area of each unit pixel. It can have Therefore, the white balance characteristic of the display device can also be improved.

The conductive film is stacked on the capacitor dielectric layer 130 and then patterned to simultaneously form the source / drain electrodes 140a, 140b, 140c, 140d, 140e, and 140f and the capacitor upper electrodes 145a, 145b, and 145c of the thin film transistors. do. The formed thin film transistors and capacitors are electrically connected to R, G, and B organic light emitting devices (not shown), respectively, positioned on the R, G, and B unit pixel areas, respectively. A display device is formed.

In contrast, the capacitor lower electrode may include the semiconductor layers 110a, 110b and 110c, the gate electrodes 120a, 120b and 120c, and the source / drain electrodes 140a and 140b of the thin film transistor positioned in the organic light emitting display device. 140c, 140d, 140e, 140f) can be formed at the same time. The capacitor dielectric layer may include a gate insulating layer 115, an interlayer insulating layer 130, an inorganic protective layer (not shown), and a planarization layer (not shown) of the thin film transistor positioned in the organic light emitting display device. The capacitor upper electrode can be formed simultaneously with the gate electrode 120a, 120b, 120c, the source / drain electrodes 140a, 140b, 140c, 140d, 140e, 140f, and the pixel electrode (not shown). Can be formed.

Each capacitor in the R, G, and B unit pixel regions of the organic light emitting display device according to the present invention has a feature that the capacitance of each unit pixel can be adjusted by a simple process due to the dielectric film thickness control using a halftone mask.

Accordingly, the unit pixel with low luminous efficiency may control the current flowing in the unit pixel by adjusting capacitance characteristics, thereby forming an organic light emitting display device having improved white balance.

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 (8)

A substrate having R, G, and B unit pixel regions; R, G, and B organic light emitting diodes respectively disposed on the R, G, and B unit pixel areas; An organic light emitting display device comprising R, G, and B capacitors electrically connected to the R, G, and B organic light emitting elements, respectively, and having different dielectric film thicknesses. The method of claim 1, And a capacitor connected to the organic light emitting diode having the lowest luminous efficiency among the organic light emitting diodes includes the thinnest dielectric layer among the capacitors. The method of claim 2, The organic light emitting display device having the lowest luminous efficiency is B. Forming R, G, and B lower electrodes on the substrate, Forming dielectric films having different thicknesses on the lower electrode; Forming an upper electrode on the dielectric layer to form R, G, and B capacitors, And forming R, G, and B organic light emitting devices that are electrically connected to the R, G, and B capacitors, respectively. The method of claim 4, wherein And forming a dielectric film having different thicknesses using a halftone mask. The method of claim 4, wherein And a capacitor connected to the organic light emitting diode having the lowest luminous efficiency among the organic light emitting diodes forms the thinnest dielectric film among the capacitors. The method of claim 6, The organic light emitting device having the lowest luminous efficiency is B. A method of manufacturing an organic light emitting display device. The method of claim 4, wherein The dielectric layer is formed using one selected from the group consisting of a silicon oxide film (SiO 2), a silicon nitride film (SiN x), and a silicon oxynitride film (SiO x N y).

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