KR20050109818A - Organic electroluminescence of top-emission type and fabrication method for the same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic EL device having a top emission system and a method of manufacturing the same, which can improve the reliability of the device by blocking external moisture penetration paths to the planarization film. A unit cell formed of an organic EL layer and a second electrode, and a non-adjacent region adjacent to the active region, as well as an active region formed between the driving TFT and the first electrode and arranged in a matrix form. An organic electroluminescent device having a planarization insulating film extending to a non-active area, comprising: a metal protective layer formed so as to surround an edge portion of the planarization insulating film formed in the non-active area. It is characterized by. Therefore, the long life and reliability of the device can be improved by blocking the external moisture penetration path into the planarization insulating film.

Description

Organic EL device of top emission method and its manufacturing method {Organic Electroluminescence of Top-Emission Type and Fabrication Method for the same}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active matrix organic EL device, and more particularly, to an organic EL device having a top emission system for improving the long life and reliability of the device, and a manufacturing method thereof.

Generally, Active Matrix Organic Electro-Luminescence Device (AMOELD) is divided into AMOELD of Top-Emission Type and AMOELD of Bottom-Emission Type. do.

The pixel portion of the active matrix type organic EL device includes a switching thin film transistor, a driving thin film transistor, a storage capacitor, a pixel electrode, an organic layer, and a common electrode. It is composed of (Cathod).

First, the manufacturing method of the AMOELD of the bottom emission method according to the prior art will be described.

Fig. 1 shows a plan view showing a general active matrix organic EL substrate.

As shown in FIG. 1, a pad unit for electrical connection is provided on a substrate, an active region that is a light emitting region, and a non-active region except for the light emitting region.

FIG. 2 is a partial ("A") cross-sectional view showing a detailed configuration of an organic EL element corresponding to the active region of FIG. 1, wherein a conventional bottom-imposition type organic EL element is shown in the glass substrate 1 as shown in FIG. A semiconductor layer 2 is formed of polycrystalline silicon or the like to be used as an active layer of a thin film transistor on the semiconductor layer 2, and the semiconductor layer 2 is patterned so as to remain only in a predetermined region of the thin film transistor.

Subsequently, the gate insulating film 3 and the gate electrode conductive film are sequentially stacked on the entire surface, and the gate electrode 4 is formed by patterning the conductive film for the gate electrode so as to remain on one region of the patterned semiconductor layer 2. .

The source / drain region 2a of the thin film transistor is implanted and thermally treated by implanting impurities such as boron (B) or phosphorus (P) into the semiconductor layer 2 using the gate electrode 4 as a mask. ) 2b. At this time, the semiconductor layer 2 under the gate electrode 4 to which impurities are not injected is the channel region 2c.

Through the above process, the thin film transistor ("I") having the gate electrode 4 and the source / drain regions 2a and 2b is completed.

Subsequently, a first interlayer insulating film 5 is formed on the entire surface, and the first interlayer insulating film 5 and the gate insulating film 5 are exposed so that the upper surface of the source / drain regions 2a and 2b of the thin film transistor I is exposed. Selectively remove 3) to form contact holes.

Then, the first metal film is formed to a sufficient extent so that the contact hole can be filled, and the first metal film is selectively removed so as to remain only in the contact hole and an area adjacent to the contact hole, and thus source / drain regions 2a and 2b. Forming an electrode line 6 electrically connected to the electrode.

Then, the second interlayer insulating film 7 is formed on the entire surface, and the second interlayer insulating film 7 is selectively removed so that the electrode line 6 connected to the drain region 2b is exposed. A transparent conductive film such as ITO is deposited along the surface.

Subsequently, the transparent conductive film is selectively removed to remain in a predetermined region of the R / G / B light emitting layer to form a pixel electrode (Anode) electrically connected to the electrode line (6).

Then, an insulating film 9 is formed to cover an area between the adjacent pixel electrodes 8 and an edge portion of the pixel electrode 8 adjacent thereto.

Then, an organic material layer 12 such as a hole injection layer, a hole transport layer, an organic light emitting layer, an electron transport layer, an electron injection layer, etc. is sequentially formed, and a metal film such as aluminum is deposited to form a common electrode (Cathod) 15. .

Then, as shown in Figure 1, in order to protect the organic layer 12 from oxygen or moisture by using a sealing cap 17 and a transparent substrate (Seal Cover) 19 using a protective cap bottom-type AMOELD Complete the panel.

That is, the bottom-imitation AMOELD has no planarization film, and since the upper electrode common electrode (aluminum, Al) 15 covers the entire surface, there is almost no oxygen / moisture penetration path.

However, when using multi-TFTs (using multiple TFTs to reduce the deviation between TFTs) or requiring high resolution, the top-emission method is used to solve the aperture ratio problem due to the small pixel pitch of the organic EL device. AMOELD has been used.

Referring to the accompanying drawings, a structure and a manufacturing method of AMOELD of the top-mission method are as follows.

As shown in FIG. 3, a conventional top-mission type AMOELD includes a pad part for electrical connection, an active area that is a light emitting area, and a non-active area except for the light emitting area.

FIG. 4 is a cross-sectional view showing the detailed structure of the organic EL element corresponding to the "B" region of FIG. 3, and FIG. 5 is a cross-sectional view showing the detailed structure of the organic EL element corresponding to the "C" region of FIG.

As shown in FIG. 4, the conventional AMOELD of the conventional top-emission method is similar to the AMOELD of the bottom-emission method. The gate electrode 4 and the semiconductor layer 2 (the source / drain 2a and 2b of the thin film transistor) ), The channel region 2c), and the electrode line 6 are formed in this order.

Then, the planarization insulating layer 21 is formed on the entire surface to planarize the entire surface, and the planarization insulating layer 21 is selectively removed so that the electrode line 6 connected to the drain region 2b is exposed, and then contact holes are formed.

Subsequently, a metal film having a high reflectance and a work function such as Cr, Al, Mo, AgAu, etc. is deposited on the front surface so that the formed contact hole may be filled.

At this time, a metal film is formed in the contact hole so that the metal film is connected to the electrode line 6 under the contact hole.

Subsequently, the metal film is selectively removed so that only the pixel portion remains, thereby forming a pixel electrode 23 electrically connected to the lower drain region 2b through the electrode line 6.

In this case, the planarization insulating layer 21 is formed from the active region to the non-active region, but the pixel electrode 23 is formed along only the active region.

Although not shown, an insulating film is formed to cover a portion of the pixel electrode 23 between the pixel electrodes 23, the hole injection layer and the hole transport layer are deposited as a common organic film, and then a shadow mask is applied. Each of the R / G / B organic light emitting layers.

Subsequently, an organic material layer such as an electron transport layer and an electron injection layer is sequentially formed on the front surface, thereby completing a top emission system AMOELD.

In the conventional top-mission type AMOELD described above, the planarization insulating film 21 is formed as shown in FIG. 3, and then the pixel electrode 23 is formed on the planarizing insulating film 21 according to an active area. A metal reflective film for in-top emission is formed.

However, the organic EL device of the top emission method according to the related art described above has the following problems.

In the organic EL device of the top emission method according to the related art, a planarization insulating film 21 is formed, and then a contact hole is formed to connect the pixel electrode 23 and the TFT through the portion. ), The total area of the? Is larger than that of the pixel electrode 23, so that the outer portion of the planarization insulating layer 21 is exposed as shown in FIG. 5 to form a penetration path of external moisture.

That is, when fabricating the organic EL device of the top emission method, it causes a fatal problem in the device life such as the organic material layer and the electrode are degraded by external moisture.

Accordingly, the present invention has been made to solve the above problems, and the top-mission organic EL device and its fabrication to improve the reliability of the device by blocking the external moisture penetration path to the planarization film at the source The purpose is to provide a method.

The organic EL device of the top emission method according to the present invention for achieving the above object is a unit cell consisting of a driving TFT, a first electrode, an organic EL layer, a second electrode, and the driving TFT and the first electrode. An organic electroluminescence having a planarization insulating layer formed between one electrode and extending to a non-active area adjacent to the active area as well as an active area in which the unit cells are arranged in a matrix; In the device, it is characterized in that a metal protective layer formed so as to surround the edge (Edge) portion of the planarization insulating film formed in the non-active region.

Preferably, the metal protective layer is characterized in that at the same time forming the first electrode.

Preferably, the first electrode and the metal protective layer are made of the same material, and characterized in that it uses one of Cr, Cu, W, Au, Ni, Al, AlNd, Ag, Ti, Ta metal material.

Preferably, the first electrode and the metal protective layer are made of the same material, and an alloy in which at least two or more of Cr, Cu, W, Au, Ni, Al, AlNd, Ag, Ti, and Ta metal materials are mixed. It is characterized by using.

Preferably, the first electrode and the metal protective layer are made of the same material, and are formed of at least two or more of Cr, Cu, W, Au, Ni, Al, AlNd, Ag, Ti, and Ta metal materials. It is characterized by using (Multi-Layer).

In addition, in order to achieve the above object, a method of manufacturing an organic EL device having a top emission method according to the present invention includes unit cells including a driving TFT, a first electrode, an organic EL layer, and a second electrode in a matrix form. In a method of manufacturing an organic light emitting device having an array of active areas, on the substrate on which the driving TFT is formed, not only the active area but also a non-active area adjacent to the active area. Forming an extended planarization insulating film; Forming a first electrode in an active region on the substrate on which the planarization insulating film is formed; Forming a metal passivation layer to surround an edge portion of the planarization insulating layer formed in the non-active region; It is characterized in that it comprises the step of sequentially forming an insulating film, an organic EL layer, and a second electrode on the substrate on which the first electrode is formed.

Preferably, the metal protective layer is formed at the same time when the first electrode is formed.

Preferably, the metal protective layer is formed of the same material as the first electrode, characterized in that simultaneously forming a pattern.

Preferably, the forming of the metal protective layer may be formed to completely or partially surround an edge portion of the planarization insulating layer formed in the non-active region.

Preferably, the insulating film formed on the first electrode is characterized by using an insulator of an inorganic material or an organic material.

Preferably, the inorganic material used as the insulating film is characterized by using any one of SiNx, SiOx.

Preferably, the organic material used as the insulating film is characterized by using any one of polyimide, polyacryl, novolac series.

Other objects, features and advantages of the present invention will become apparent from the following detailed description of embodiments taken in conjunction with the accompanying drawings.

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

6 is a plan view illustrating an organic EL substrate having a top emission method according to the present invention, and FIG. 7 is a cross-sectional view illustrating a detailed structure of an organic EL element corresponding to the active region “D” of FIG. 6. Is a cross-sectional view showing the detailed structure of an organic EL element corresponding to the non-active region " E "

In the organic EL device of the top emission method according to the present invention, a metal protective film 55 is formed so as to surround the pattern outside of the planarization insulating film 51 when the first electrode 53 is formed.

Usually, in the organic EL device of the top-imposition method, the active area is composed of a plurality of unit cells consisting of a driving TFT, a first electrode, an organic EL layer, and a second electrode arranged in a matrix form.

A planarization insulating layer 51 is formed between the driving TFT and the first electrode (pixel electrode), and the planarization insulating layer 51 is formed only in an active region to protect the driving TFT (“I”) from ultraviolet rays. Rather, it is extended to a non-active area adjacent to the active area.

However, when the planarization insulating layer 51 formed as described above is exposed, an input path of external moisture is made.

FIG. 8 is a cross-sectional view of the organic EL element corresponding to the non-active region. As shown in the figure, it is a feature of the present invention to form the outer portion of the planarization insulating film 51 pattern so as to surround the metal protective film 55.

That is, when the metal protection layer 55 is formed at the same time to cover the edge portion of the planarization insulating layer 51 when the first electrode 53 is formed, the water penetration path through the planarization insulating layer 51 can be blocked.

Hereinafter, the structure of the organic EL device of the top emission method according to the present invention will be described in detail.

First, a unit cell forming an active region of an organic EL element includes a driving transistor (“I”), a first electrode 53 serving as a pixel electrode, a second electrode serving as a common electrode (not shown), and an organic EL layer. (Not shown).

At this time, the driving transistor " I " is formed on one region of the glass substrate 1 as shown in Fig. 7, and is composed of a source / drain region 2a and 2b and a channel region 2c. A gate insulating film 3 formed over the layer 22, the entire surface of the glass substrate 1 including the semiconductor layer 22, and a gate electrode formed over the gate insulating film 3 above the channel region 2c. 4) consists of.

A first interlayer insulating film 5 is formed on the driving transistor “I” to open the source region 2a and the drain region 2b. The open portion of the first interlayer insulating film 5 is formed. Electrode lines 6 are formed which are electrically connected to the source / drain regions 2a and 2b via the same.

Then, a second interlayer insulating film 7 is formed on the entire surface, and the second interlayer insulating film 7 is selectively removed to expose the electrode line 6 connected to the drain region 2b, and then the drain region 2b. It is planarized by the planarization insulating film 51 which opens the electrode line 6 electrically connected to it.

The first electrode 53 is formed in the pixel portion on the planarization insulating layer 51, and the first electrode 53 is a drain of the driving transistor “I” through the open portion of the planarization insulating layer 51. It is to be electrically connected to the region 2b.

In addition, the planarization insulating layer 51 extends from the active region consisting of unit cells including the driving transistor " I " and the first electrode 53 to the non-active region.

Then, the metal protective layer 55 surrounding the outermost part of the planarization insulating layer 51 patterned as described above is provided.

That is, FIG. 8 is a cross-sectional view showing the outer portion of the non-active area of the organic EL panel, and the metal protective layer has an edge of the planarization insulating layer 51 to prevent moisture from penetrating into the planarization insulating layer 51 from the outside. It is formed to surround the 55.

Then, an insulating film is formed so that a part of the first electrode 53 is covered between the neighboring first electrodes 53, and then an organic EL layer and a second electrode are sequentially formed on the entire surface thereof.

Referring to FIGS. 7, 9A and 9B, the method of manufacturing the organic EL device of the top emission method according to the present invention will be described in detail as follows.

7 is a cross-sectional view partially showing only the active region of the organic EL panel, and FIGS. 9A and 9B are cross-sectional views partially showing only the non-active region.

 First, as shown in FIG. 7, for use as an active layer of a driving transistor on the glass substrate 1, for example, a semiconductor layer 2 such as a polycrystalline silicon layer is formed and formed only on a driving transistor predetermined region. The semiconductor layer 2 is patterned so as to remain.

In addition, the gate insulating layer 3 and the gate electrode material are sequentially stacked on the entire surface of the structure, and the gate electrode 4 is formed by patterning the gate electrode material so as to remain on one region of the patterned semiconductor layer 2. Form.

Subsequently, an impurity is injected into the semiconductor layer 2 using the gate electrode 4 as a mask and heat-treated to form source / drain regions 2a and 2b of the driving transistor.

Then, the first interlayer insulating film 5 and the gate insulating film 3 are selectively formed so as to form a first interlayer insulating film 5 on the front surface and expose the surfaces of the source / drain regions 2a and 2b of the driving transistor. To form a contact hole.

Subsequently, a first metal film is deposited on the entire surface to fill the contact hole, and the first metal film is selectively removed so as to remain only on the contact hole and an area adjacent to the contact hole. ) To form an electrode line 6 which is electrically connected.

A second interlayer insulating film 7 is formed on the entire surface, and the second interlayer insulating film 7 is selectively removed so that the electrode line 6 connected to the drain region 2b is exposed.

Next, the planarization insulating layer 51 is formed on the entire surface to planarize the entire surface, and then the planarization insulating layer 51 is partially removed to expose the surface of the electrode line 6 connected to the drain region 2b to form a contact hole. do.

When the second metal film is formed on the entire surface, the second metal film is connected to the electrode line 6 under the contact hole. The second metal film is selectively removed to form the first electrode 53 which is a pixel electrode.

An insulating film (not shown) is formed to cover an area between the neighboring first electrodes 53 and an edge portion of the first electrode 53 adjacent thereto.

At this time, the material used as the insulating film is an inorganic or organic insulator, SiNx, SiOx is preferable for the inorganic material, polyimide, polyacryl, novolac-based material is preferable for the organic material.

Looking only at the structure of the non-active region in the organic EL device having the above structure, as shown in Fig. 9A, the glass substrate 1, the gate insulating film 3, the first and second interlayer insulating films 5 and 7 are shown. ) Is formed in order, and then the planarization insulating film 51 is formed.

At this time, the driving transistor " I " and the first electrode 53 are formed only in the active region and are not shown in Fig. 9A.

In addition, after the planarization insulating layer 51 is formed from the active region to the non-active region, a first electrode 53 is formed on the front surface, which surrounds the edge portion of the planarization insulating layer 51 when the first electrode 53 is formed. The metal protective layer 55 is formed (FIG. 9B).

In this case, the metal protective layer 55 uses the same material as the first electrode 53, and any one of Cr, Cu, W, Au, Ni, Al, AlNd, Ag, Ti, and Ta metal materials is used. In addition, an alloy in which two or more of the metal materials are mixed may be used, or a multi-layer formed of two or more materials may be used.

In other words, although the first electrode 53 and the metal protective layer 55 are specified by separate symbols, the first electrode 53 and the metal protective layer 55 of the present invention use the same material, and thus, the first electrode. When the 53 is formed, the first electrode 53 is formed to extend beyond the entire area of the planarization insulating layer 51 to cover the edge portion of the planarization insulating layer 51.

In addition, the metal protection layer 55 may be partially formed without covering the entire outer periphery of the planarization insulating layer 51 so as to connect wires to the pad PAD to apply electricity from the outside.

Although not shown in FIG. 7, the organic EL layer and the second electrode are sequentially stacked on the upper portion where the first electrode 53 is formed, thereby completing the organic EL device of the top emission method according to the present invention.

Accordingly, the present invention extends the first electrode 53 wider than the planarization insulating layer 51 formed from the active region to the non-active region, thereby forming a metal protective layer 55 to surround the pattern outline of the planarization insulating layer 51. It can fundamentally block the external moisture penetration path.

As described above, the organic EL device of the top emission method and a method of manufacturing the same according to the present invention are formed by forming a metal protective layer outside the pattern of the planarization insulating film and blocking the external moisture penetration path to the planarization insulating film. It has the effect of improving long life and reliability.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the embodiments, but should be defined by the claims.

1 is a plan view showing a bottom-imposition type organic EL substrate according to the prior art

FIG. 2 is a cross-sectional view illustrating a detailed structure of an organic EL device corresponding to region “A” of FIG. 1.

3 is a plan view showing a top-mission type organic EL substrate according to the prior art

4 is a cross-sectional view showing a detailed structure of an organic EL element corresponding to area “B” in FIG. 3.

FIG. 5 is a cross-sectional view illustrating a detailed structure of an organic EL device corresponding to region “C” of FIG. 3.

Fig. 6 is a plan view showing a top EL display organic EL substrate according to the present invention.

FIG. 7 is a cross-sectional view illustrating a detailed structure of an organic EL element corresponding to region “D” of FIG. 6.

FIG. 8 is a cross-sectional view illustrating a detailed structure of an organic EL device corresponding to region “E” of FIG. 6.

9A and 9B are sectional views showing the manufacturing process of the organic EL device according to the present invention.

* Explanation of symbols for main parts of the drawings

1: organic substrate 3: gate insulating film

5, 7: interlayer insulation film

51: planarization insulating film 53: first electrode

55: metal protective layer

Claims (12)

A unit cell composed of a driving TFT, a first electrode, an organic EL layer, and a second electrode, A planarization insulating layer formed between the driving TFT and the first electrode and extending not only into an active area in which the unit cells are arranged in a matrix but also to a non-active area adjacent to the active area In the organic electroluminescent device comprising: And a metal protective layer formed so as to surround an edge portion of the planarization insulating film formed in the non-active region. The method of claim 1, And the metal protective layer is formed simultaneously when the first electrode is formed. The method of claim 2, The first electrode and the metal protective layer may be made of the same material, and may include one of Cr, Cu, W, Au, Ni, Al, AlNd, Ag, Ti, and Ta metal materials. Organic EL device. The method of claim 2, The first electrode and the metal protective layer may use the same material, and an alloy including at least two or more of Cr, Cu, W, Au, Ni, Al, AlNd, Ag, Ti, and Ta metal materials may be mixed. The organic electroluminescent element of the top emission system made into. The method of claim 2, The first electrode and the metal protective layer are made of the same material, and are formed of at least two or more of Cr, Cu, W, Au, Ni, Al, AlNd, Ag, Ti, and Ta metal materials. A top-mission organic EL device characterized by using a layer). In the manufacturing method of the organic electroluminescent device having an active area in which the unit cells composed of the driving TFT, the first electrode, the organic EL layer, and the second electrode are arranged in a matrix form, Forming a planarization insulating film on the substrate on which the driving TFT is formed, which extends not only to the active region but also to a non-active region adjacent to the active region; Forming a first electrode in an active region on the substrate on which the planarization insulating film is formed; Forming a metal passivation layer to surround an edge portion of the planarization insulating layer formed in the non-active region; And forming an insulating film, an organic EL layer, and a second electrode in sequence on the substrate on which the first electrode is formed. The method of claim 6, And the metal protective layer is formed simultaneously with the formation of the first electrode. The method of claim 6, And the metal protective layer simultaneously forms a pattern of the same material as that of the first electrode. The method of claim 6, Forming the metal protective layer And an edge portion of the planarization insulating layer formed on the non-active region so as to completely or partially surround the edge portion of the planarization insulating layer. The method of claim 6, The insulating film formed on the first electrode is A method for producing an organic EL device of a top-imposition method, characterized by using an insulator of an inorganic or organic substance. The method of claim 10, The inorganic material used as the insulating film is a method for producing a top-emitting organic EL device, characterized in that any one of SiNx, SiOx. The method of claim 10, The organic material used as the insulating film is a method for manufacturing a top-imposition organic EL device, characterized in that using any one of polyimide, polyacryl, novolac series.