KR20050028567A - Active matrix organic electroluminescence device employing double buffer layer and method of fabricating the same - Google Patents

Abstract

An active matrix organic electroluminescence device having double buffer layers and a fabrication method thereof are provided to cover a substrate of the rest areas except an opening area when the first buffer layer patterns are formed, in order to passivate a defect generated from a crystal grain boundary of an active layer, thereby improving electrical features and substrate uniformity. A substrate(100) consists of pixel unit areas(b1,b2) having the opening unit area(b2) and a circuit unit area(a). At least one pixel active layer pattern(450) and at least one circuit active layer pattern(455) are located in the other pixel unit area(b1) except the opening unit area(b2) and the circuit unit area(a), respectively. The first buffer layer patterns(250) are interposed between the active layer patterns(450,455) and the substrate(100), and cover the substrate(100) except the opening area(b2) by containing hydrogen. The second buffer layer(300) covers the whole surface of the substrate(100) including the first buffer layer patterns(250).

Description

Active matrix organic electroluminescent device employing double buffer layer and method of fabricating the same

The present invention relates to an organic electroluminescence device and a method of manufacturing the same, and more particularly, to an active matrix organic electroluminescent device and a method of manufacturing the same.

An active matrix organic light emitting display device requires an active matrix substrate, in which a thin film transistor (hereinafter referred to as TFT) for controlling a current applied to the pixel electrode is disposed in a matrix area of the substrate. .

The TFT is divided into a polycrystalline silicon TFT and an amorphous silicon TFT, which has a carrier mobility higher than that of amorphous silicon, thereby enabling the implementation of an organic light emitting display device having a high resolution. In addition, the high carrier mobility of the polycrystalline silicon makes it possible to simultaneously form not only the pixel portion but also the driving circuit portion in the active matrix substrate. This makes it possible to reduce the actual use of the driving circuit chip.

However, the polycrystalline silicon has a defect in each crystal grain boundary, which causes a decrease in electrical properties such as carrier mobility of TFTs, threshold voltages, and non-uniformity of the electrical properties in the substrate.

In order to solve this problem, US Pat. No. 6,365,935 uses a hydrogen ion implantation process to form a hydrogen-rich region on a substrate under the polycrystalline silicon layer, and conducts a heat treatment process to diffuse the hydrogen into the polycrystalline silicon layer. Compensates for defects at the boundary of silicon crystal grains. However, injecting hydrogen ions into the substrate may cause substrate defects due to ion implantation.

SUMMARY OF THE INVENTION The present invention has been made in an effort to solve the above-described problems of the prior art, and provides an organic light emitting display device and a method of manufacturing the same, in which defects in crystal grain boundaries of polycrystalline silicon can be compensated for.

In order to achieve the above technical problem, the present invention provides an active matrix organic light emitting display device. The organic light emitting display device includes a pixel portion region having an opening region and a substrate having a circuit portion region, at least one pixel active layer pattern and at least one circuit active layer respectively positioned on the pixel portion region except the opening region and the circuit portion region. A pattern, interposed between the active layer patterns and the substrate, a first buffer layer pattern containing hydrogen covering at least the substrate except for the opening region, and interposed between the active layer patterns and the first buffer layer pattern. And a second buffer layer covering the entire surface of the substrate including the buffer layer pattern.

Preferably, the second buffer layer is a silicon oxide film.

The first buffer layer pattern may be a silicon nitride layer (SiNx) or a silicon oxynitride layer (SiON). More preferably, the silicon nitride film or silicon oxynitride film is a film formed by PECVD.

The first buffer layer pattern may cover only the substrate under the active layer patterns among the substrates of the remaining regions except at least the opening region.

The second buffer layer may be located only on the first buffer layer pattern.

In order to achieve the above technical problem, the present invention provides a method of manufacturing an active matrix organic light emitting display device. The manufacturing method provides a substrate having a pixel portion region having an opening region and a circuit portion region, forming a first buffer layer pattern containing hydrogen at least exposing the opening region on the substrate, and forming the first buffer layer pattern. Forming a second buffer layer on the substrate, and forming at least one pixel active layer pattern and at least one circuit active layer pattern on the pixel portion region excluding the opening region and the second buffer layer of the circuit portion region, respectively.

The manufacturing method further includes heat treating the substrate on which the active layer patterns are formed.

The second buffer layer is preferably formed of a silicon oxide film.

The first buffer layer pattern may be formed using a silicon nitride film or a silicon oxynitride film. More preferably, the silicon nitride film or silicon oxynitride film is formed using PECVD.

In order to achieve the above technical problem, the present invention provides another method of manufacturing an active matrix organic light emitting display device. The other manufacturing method provides a substrate having a pixel portion region having an opening region and a circuit portion region, forming a first buffer layer containing hydrogen on the entire surface of the substrate, and forming a second buffer layer on the first buffer layer. And forming an active layer on the second buffer layer, and patterning the active layer, the second buffer layer, and the first buffer layer in order using one etching mask, thereby forming the active layer, the pixel region except for the opening region, and the circuit region. Each forming at least one pixel active layer pattern and at least one circuit active layer pattern.

The other manufacturing method may further include heat treating the substrate on which the active layer patterns are formed.

The second buffer layer is preferably formed of a silicon oxide film.

The first buffer layer is preferably formed using a silicon nitride film or a silicon oxynitride film. More preferably, the silicon nitride film or silicon oxynitride film is formed using PECVD.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings in order to describe the present invention in more detail. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms.

1A and 1B are cross-sectional views illustrating a method of manufacturing an active matrix organic light emitting display device according to a first embodiment of the present invention.

Referring to FIG. 1A, a substrate 100 having a circuit portion region a and pixel portion regions b1 and b2 is provided. The pixel portion regions b1 and b2 include an opening region b2 and a pixel portion region excluding the opening region b2, that is, the pixel thin film transistor region b1. The opening region b2 is a region in which light is emitted by the pixel electrode formed in a subsequent process, and the pixel thin film transistor region b1 is at least one pixel thin film for controlling a current applied to the pixel electrode. This is the region where the transistor is formed. In addition, the circuit portion region (a) is a region in which at least one circuit thin film transistor for a driving circuit is formed.

A first buffer layer containing hydrogen is formed on the entire surface of the provided substrate 100. The first buffer layer is preferably formed of a silicon nitride film (SiNx) or a silicon oxynitride film (SiON). The silicon nitride film or silicon oxynitride film is a film containing a large amount of hydrogen, and is preferably formed using PECVD to enrich the hydrogen content in the silicon nitride film or the silicon oxynitride film. Moreover, it is preferable to form the thickness about 1000 kPa.

Subsequently, the first buffer layer is etched using a first photoresist pattern (not shown) to expose at least the opening region b2, that is, at least the substrate covering the remaining regions except for the opening region b2. 1 buffer layer pattern 250 is formed. The first buffer layer pattern 250 may be formed to cover only the circuit portion region a. The first buffer layer, in particular, the silicon nitride layer or the silicon oxynitride layer has a high refractive index and a low light transmittance, which may affect light efficiency and color coordinates of the organic light emitting diode when light is emitted through the first buffer layer. When the organic light emitting diode is a bottom emission type emitting light through the opening region b2 of the substrate, the first buffer layer pattern exposing the opening region b2 by removing the first buffer layer on the opening region b2. By forming 250, an organic light emitting display device having no influence on light efficiency and color coordinates can be manufactured.

The second buffer layer 300 is formed on the entire surface of the substrate including the first buffer layer pattern 250. The second buffer layer 300 is a film capable of blocking impurities flowing out of the substrate 100 and facilitating adhesion to an active layer formed in a subsequent process. The second buffer layer 300 may be formed of a silicon oxide film. . The silicon oxide film is preferably formed to a thickness of about 3000 kPa using CVD.

Subsequently, at least one pixel active layer pattern 450 and at least one circuit active layer pattern 455 are formed on the pixel thin film transistor region b1 and the circuit portion region a, respectively. The active layer patterns 450 and 455 may be formed of polysilicon formed by crystallizing amorphous silicon.

Referring to FIG. 1B, the gate patterns 650 may be formed by forming a gate insulating layer 500 on the active layer patterns 450 and 455 and forming gate patterns 650 on the gate insulating layer 500. ) The active layers on both sides are exposed. Subsequently, source and drain regions 450a and 455a are formed by implanting a dopant into the exposed active layers using the gate pattern 650 as a mask. As a result, at least one pixel thin film transistor and a circuit thin film transistor are formed on the pixel thin film transistor region b1 and the circuit portion region a, respectively.

Subsequently, an interlayer insulating film 700 covering the entire surface of the substrate including the thin film transistors is formed, and a source and drain electrode 750 contacting the source and drain regions 450a and 455a are formed in the interlayer insulating film 700. do. After the protective film 800 is formed on the entire surface of the substrate including the source and drain electrodes 750, the substrate is heat-treated. The heat treatment serves to activate the dopant implanted in the active layer patterns 450 and 455, and the hydrogen contained in the first buffer layer pattern 250 to be diffused into the active layer patterns 450 and 455. Makes it easy. As described above, hydrogen diffused into the active layer patterns 450 and 455 may passivate defects such as dangling bonds at crystal grain boundaries of polycrystalline silicon constituting the active layer. In addition to improving the electrical characteristics of the thin film transistor, it is possible to improve the uniformity in the substrate of the electrical characteristics.

2A and 2B are cross-sectional views illustrating a method of manufacturing an active matrix organic light emitting display device according to a second embodiment of the present invention. Unlike the first embodiment, the present embodiment is characterized in that the first buffer layer pattern is located only below the active layer patterns.

Referring to FIG. 2A, a substrate 100 having a circuit portion region a and pixel portion regions b1 and b2 is provided. The pixel portion regions b1 and b2 include an opening region b2 and a pixel portion region excluding the opening region b2, that is, the pixel thin film transistor region b1. The first buffer layer 200, the second buffer layer 300, and the active layer 400 containing hydrogen are sequentially formed on the substrate 100.

 Referring to FIG. 2B, the pixel thin film transistor region b1 and the circuit part are sequentially etched by sequentially etching the active layer 400, the second buffer layer 300, and the first buffer layer 200 using one etching mask. At least one pixel active layer pattern 450 and at least one circuit active layer pattern 455 are formed on the region a. A second buffer layer pattern 350 and a first buffer layer pattern 250 are sequentially stacked below the active layer patterns 450 and 455. Thus, the first buffer layer pattern 250 covers only the substrate under the active layer patterns 450 and 455, and the second buffer layer pattern 350 is positioned only on the first buffer layer pattern 250.

Next, a gate insulating film 500 is formed on the substrate on which the active layer pattern 450 is formed. The process after formation of the gate insulating film 500 is the same as that of the first embodiment described above.

As described above, according to the present invention, by forming a first buffer layer pattern containing hydrogen on the substrate to cover the substrate of the remaining region except at least the opening region, the crystal of the active layer formed on the first buffer layer pattern By passivating the defects appearing at the grain boundary, the electrical properties of the thin film transistor and the uniformity of the electrical properties in the substrate can be improved, and the organic light emitting device can be fabricated without affecting the light efficiency and color coordinates by the first buffer layer. Can be.

1A and 1B are cross-sectional views illustrating a method of manufacturing an active matrix organic light emitting display device according to a first embodiment of the present invention.

2A and 2B are cross-sectional views illustrating a method of manufacturing an active matrix organic light emitting display device according to a second embodiment of the present invention.

(Explanation of symbols for main parts of drawing)

100 substrate 250 first buffer layer pattern

300: second buffer layer 450: active layer

Claims (16)

A substrate having a pixel portion region having an opening region and a circuit portion region; At least one pixel active layer pattern and at least one circuit active layer pattern respectively positioned on the pixel region and the circuit region except the opening region; A first buffer layer pattern interposed between the active layer patterns and the substrate and containing hydrogen covering at least the substrate except for the opening region; And And a second buffer layer interposed between the active layer patterns and the first buffer layer pattern and covering the entire surface of the substrate including the first buffer layer pattern. The method of claim 1, And the second buffer layer is a silicon oxide film. The method of claim 1, The first buffer layer pattern is a silicon nitride layer (SiNx) or a silicon oxynitride layer (SiON). The method of claim 3, wherein The silicon nitride film or silicon oxynitride film is an organic light emitting device formed by PECVD. The method of claim 1, The first buffer layer pattern is An organic light emitting diode covering only the substrate under the active layer patterns among the substrates in the remaining region except at least the opening region. The method of claim 1, The second buffer layer is an organic light emitting device positioned only on the first buffer layer pattern. Providing a substrate having a pixel portion region having an opening region and a circuit portion region; Forming a first buffer layer pattern containing hydrogen at least exposing the opening region on the substrate; Forming a second buffer layer on the first buffer layer pattern; And forming at least one pixel active layer pattern and at least one circuit active layer pattern on the pixel portion region other than the opening region and the second buffer layer of the circuit portion region, respectively. The method of claim 7, wherein The method of manufacturing an organic light emitting display device further comprising heat treating the substrate on which the active layer patterns are formed. The method of claim 7, wherein The second buffer layer is formed of a silicon oxide film organic light emitting device manufacturing method. The method of claim 7, wherein The first buffer layer pattern is formed using a silicon nitride film or a silicon oxynitride film. The method of claim 10, The silicon nitride film or silicon oxynitride film is formed using PECVD method of manufacturing an organic light emitting device. Providing a substrate having a pixel portion region having an opening region and a circuit portion region; Forming a first buffer layer containing hydrogen on the entire surface of the substrate; Forming a second buffer layer on the first buffer layer; Forming an active layer on the second buffer layer; By patterning the active layer, the second buffer layer, and the first buffer layer in sequence using one etching mask, at least one pixel active layer pattern and at least one circuit on the pixel portion region and the circuit portion region except the opening region, respectively. An organic electroluminescent device manufacturing method comprising forming an active layer pattern. The method of claim 12, The method of manufacturing an organic light emitting display device further comprising heat treating the substrate on which the active layer patterns are formed. The method of claim 12, The second buffer layer is formed of a silicon oxide film organic light emitting device manufacturing method. The method of claim 12, The first buffer layer is formed using a silicon nitride film or a silicon oxynitride film. The method of claim 12, The silicon nitride film or silicon oxynitride film is formed using PECVD method of manufacturing an organic light emitting device.