TWI671433B - Method for manufacturing organic light emitting display device - Google Patents

Abstract

A method for manufacturing an organic light emitting display device is disclosed. The method includes: a) forming a gate electrode on a substrate; b) forming a gate insulating layer on a substrate including the gate electrode; c) forming an active layer on the gate insulating layer D) forming an insulating layer on the active layer; e) forming a source electrode and a drain electrode in contact with the active layer on the insulating layer; f) forming a protective layer on the insulating layer to cover the source electrode and the drain electrode And g) forming an organic light-emitting element electrically connected to one of the source electrode and the drain electrode, wherein step a) includes forming an aluminum, molybdenum, or silver metal layer or a laminate thereof, and comprising 50 to 70 wt.% Phosphoric acid, 2 to 15 wt.% Nitric acid, 5 to 20 wt.% Acetic acid, 0.1 to 5 wt.% P-toluenesulfonic acid, and water as a balanced etchant composition etches the metal layer to form a gate electrode, thereby together It is possible to form a metal layer of the gate electrode and the pixel electrode by etching to achieve an excellent etching effect, and to manufacture an organic light emitting display device with improved process efficiency.

Description

Method for manufacturing organic light emitting display device

The present invention relates to a method of manufacturing an organic light emitting display device.

Generally speaking, flat display devices can be classified into light emitting type and light receiving type devices. The light emitting type device may include, for example, a flat cathode ray tube, a plasma display panel, an electric field light emitting device, a light emitting diode, or the like. The light receiving type device may include, for example, a liquid crystal display. Among these, the electric field light emitting device has several advantages, such as a wide viewing angle, excellent contrast, and a high response rate, and thus attracts public attention as a next-generation display device.

Such an electric field light emitting device is classified into an inorganic electric field light emitting device and an organic electric field light emitting device according to a material forming the light emitting layer.

Among these, the organic electric field light emitting device is a self-emission type display that electrically excites a fluorescent organic compound to emit light. The device can be driven at a low voltage, can be easily manufactured in a thin thickness, and can have a wide viewing angle and a high response rate, thereby attracting the attention of the public as a next-generation display that can overcome the problems of conventional liquid crystal displays.

The organic electric field light emitting device may include an anode electrode, a cathode electrode, and a light emitting layer made of an organic material therebetween. For organic electric field light-emitting devices, since positive and negative voltages are applied to these electrodes, respectively, holes injected from the anode electrode pass through the hole transport layer and move to the light-emitting layer, and electrons provided from the cathode electrode pass through the electron transport layer, And it moves to the light-emitting layer, and then these electrons and holes combine again in the light-emitting layer to generate excitons.

When the exciton changes from the excited state to the ground state, the phosphor molecules in the light emitting layer emit light to generate an image. In the case of a full-color organic electric field light-emitting device, pixels of three colors of red (R), green (G), and blue (B) are provided to obtain a full-color image.

Meanwhile, a thin film transistor (hereinafter referred to as a TFT) used in a flat display device such as an electric field light emitting device, a liquid crystal display, or the like is typically used as a switching device that controls the operation of each pixel and a driving device that drives the pixels. . This type of thin film transistor includes a semiconductor active layer having a drain region and a source region doped on a substrate with a high concentration of impurities, a channel region formed between the drain region and the source region, and a semiconductor active layer. A gate insulating film, and a gate electrode formed on top of a channel region in the active layer.

For example, Korean Patent Registration No. 10-1174881 discloses an organic light emitting display and a manufacturing method thereof. However, this patent may not fundamentally solve the above problems.

Therefore, an object of the present invention is to provide a method for manufacturing an organic light emitting display device using an etchant composition usable in forming a gate electrode and a pixel electrode.

The above object of the present invention will be achieved by the following features:

(1) A method for manufacturing an organic light emitting display device, comprising: a) forming a gate electrode on a substrate; b) forming a gate insulating layer on a substrate including the gate electrode; c) on the gate insulating layer Forming an active layer; d) forming an insulating layer on the active layer; e) forming a source and a drain electrode in contact with the active layer on the insulating layer; f) forming a passivation layer on the insulating layer to cover the source electrode and the drain electrode; And g) forming an organic light emitting element electrically connected to one of the source electrode and the drain electrode, wherein step a) includes forming an aluminum, molybdenum or silver metal layer or a laminate layer thereof, and using 70 wt.% Phosphoric acid, 2 to 15 wt.% Nitric acid, 5 to 20 wt.% Acetic acid, 0.1 to 5 wt.% P-toluenesulfonic acid, and water as a balanced etchant composition to etch this metal layer to form a gate Electrode.

(2) According to the method of (1) above, the aluminum metal layer is an aluminum layer, or includes aluminum and from La, Mg, Zn, In, Ca, Te, Sr, Cr, Co, Mo, Nb, Ta, W, Ni , Nd, Sn, Fe, Si, Ti, Pt and an alloy layer of at least one metal selected from C.

(3) According to the method of (1) above, the molybdenum metal layer is a molybdenum layer or an alloy layer including molybdenum and at least one metal selected from Ti, Ta, Cr, Ni, Nd, In, and Al.

(4) The method according to the above (1), the silver metal layer is a silver layer or includes silver, An alloy layer of at least one metal selected from Nd, Sn, Fe, Si, Ti, Pt, Pd, and Cu.

(5) The method according to the above (1), the step of forming an organic light emitting element includes: forming a first electrode electrically connected to one of the source electrode and the drain electrode; forming an organic layer on the first electrode; and A second electrode is formed on the organic layer.

(6) According to the method of (5) above, the first electrode is a conductive material layer formed by forming an aluminum, molybdenum or silver metal layer, a metal oxide layer or a laminate thereof on the passivation layer, and including 50 to 70 wt. % Phosphoric acid, 2 to 15 wt.% Nitric acid, 5 to 20 wt.% Acetic acid, 0.1 to 5 wt.% P-toluenesulfonic acid, and water are formed by etching the conductive material layer as a balanced etchant composition.

(7) According to the method of (6) above, the metal oxide layer is indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium zinc tin oxide (IZTO), or cadmium tin oxide. (CTO) or indium gallium zinc oxide (IGZO) layer.

According to a method for manufacturing an organic light emitting display device, it is possible to etch the metal layers forming the gate electrode and the pixel electrode together to achieve an excellent etching effect. Further, compared with the conventional method of using the respective etchant composition separately, it is possible to simplify the entire manufacturing process and reduce the process cost, thereby realizing the production of an organic light emitting display device with improved process efficiency.

The invention discloses a method for manufacturing an organic light-emitting display device, including: a) forming a gate electrode on a substrate; b) forming a gate insulating layer on a substrate including the gate electrode; c) forming an active layer on the gate insulating layer D) forming an insulating layer on the active layer; e) forming a source electrode and a drain electrode in contact with the active layer on the insulating layer; f) forming a passivation layer on the insulating layer to cover the source electrode and the drain electrode; And g) forming an organic light emitting element that is electrically connected to one of the source electrode and the drain electrode, wherein step a) includes forming an aluminum, molybdenum, or silver metal layer or a laminate thereof, and comprising 50 to 70 wt.% Phosphoric acid, 2 to 15 wt.% Nitric acid, 5 to 20 wt.% Acetic acid, 0.1 to 5 wt.% P-toluenesulfonic acid, and water as a balanced etchant composition etches the metal layer to form a gate electrode, thereby It is possible to etch the metal layers forming the gate electrode and the pixel electrode to achieve an excellent etching effect, and to manufacture an organic light emitting display device with improved process efficiency.

Hereinafter, a method of manufacturing an organic light emitting display device according to a specific embodiment of the present invention will be described in detail.

First, a) forming a gate electrode on a substrate.

Such substrates can be made using silicon (Si), glass, or organic materials. When silicon (Si) is used as the substrate, an insulating layer (not shown) may be further formed on the surface of the substrate through a thermal oxidation process.

A conductive material layer such as a metal or a conductive metal oxide is formed on the substrate, and then the conductive material layer is etched to form a gate electrode.

According to a specific embodiment of the present invention, the conductive material layer may include, for example, an aluminum metal layer, a molybdenum metal layer, a silver metal layer, or a laminate thereof.

In the present disclosure, the aluminum metal layer refers to an aluminum layer or an aluminum alloy layer. The aluminum alloy layer used herein may include, for example, an alloy layer including aluminum and another metal, Al-X (X is from La, Mg, Zn, In, Ca, Te, Sr, Cr, Co, Mo, Nb, Ta, W, Ni, Nd, Sn, Fe, Si, Ti, Pt, and at least one metal selected from C). When an Al-X alloy layer is used as the aluminum metal layer, some process problems of the hill-lock phenomenon due to the heat of aluminum may be advantageously avoided.

The molybdenum metal layer refers to a molybdenum layer or a molybdenum alloy layer and serves as a buffer for battery reactions between thin layers. The molybdenum alloy layer may be formed by alloying molybdenum as a main composition and at least one metal selected from a metal group consisting of Ti, Ta, Cr, Ni, Nd, In, and Al.

The silver metal layer refers to a silver layer or a silver alloy layer. The silver alloy layer can be made of, for example, silver as a main composition and from La, Mg, Zn, In, Ca, Te, Sr, Cr, Co, Mo, Nb, Ta, W, Ni, Nd, Sn, Fe, At least one metal selected from a metal group consisting of Si, Ti, Pt, Pd, and Cu is alloyed. Considering the degree of surface adhesion of reflection and deposition in the visible wavelength range, a silver alloy including both Pd and Cu is preferably used.

The metal layer may be etched with an etchant composition including phosphoric acid, nitric acid, acetic acid, and p-toluenesulfonic acid to form a gate electrode.

In the etchant composition according to the present invention, phosphoric acid is the main oxidant for oxidizing the metal layer.

The content of phosphoric acid is not particularly limited but may include, for example, an amount of 50 to 70 wt.% Based on the total weight of the composition. If the content is less than 50 wt.%, Etching may not be performed sufficiently due to lack of etching ability. If its content exceeds 70 wt.%, The metal may be over-etched and the area of the remaining metal layer becomes small, so it cannot play the role of an electrode.

Nitric acid is a secondary oxidant and functions to control the etch rate and reduce the taper angle.

The content of nitric acid is not particularly limited but may include, for example, an amount of 2 to 15 wt.%, Preferably 3 to 8 wt.%, Based on the total weight of the composition. If its content is less than 2 wt.%, The rate of etching the metal layer may be reduced and residues of the silver metal layer may be generated to cause dark spot defects. When its content exceeds 15 wt.%, The etching rate may increase, making it difficult to control the process stage.

Acetic acid is a buffer that controls the reaction rate and the like, and can control the degradation rate of nitric acid. Acetic acid typically plays a role in reducing the rate of degradation.

The content of acetic acid is not particularly limited but may include, for example, an amount of 5 to 20 wt.% And preferably 5 to 15 wt.% Of the total weight of the composition. If its content is less than 5wt.%, The metal layer may not be etched smoothly, thereby reducing Low etching uniformity. When its content exceeds 20 wt.%, Foaming may occur and the silver metal layer may not be etched smoothly.

P-toluenesulfonic acid plays a role of improving the uniformity of the first electrode and the gate electrode, and acts as an etching inhibitor for the molybdenum metal layer and an etching control agent for the silver metal layer.

The content of p-toluenesulfonic acid is not particularly limited but may include, for example, an amount of 0.1 to 5 wt.% Based on the total weight of the composition. If its content is less than 0.1 wt.%, The etching uniformity of the silver metal layer may be reduced and spots may occur. When its content exceeds 5 wt.%, The silver metal layer may retain a residue and cause the occurrence of dark spot defects.

The etchant composition according to the present invention can be prepared according to specific needs by appropriately using the above-mentioned composition and then adding water thereto to control the overall structural composition. That is, water is the balance of the overall composition. Preferably, the overall structural composition needs to be controlled so that the above-mentioned composition components are all included in the above-mentioned content range, respectively.

The type of water is not particularly limited, but deionized water is preferably used, and more preferably, deionized distilled water for a semiconductor process having a specific resistivity of 18 MΩ.cm or higher is used.

Next, b) forming a gate insulating layer on the substrate including the gate electrode.

An insulating material may be applied to a substrate including a gate electrode to form a gate insulating layer, and then the gate insulating layer is patterned.

The insulating material is not particularly limited but may include any typical insulating material known in the related art. For example, silicon oxide, tantalum oxide, aluminum oxide, or the like can be used. These materials may be used alone or in combination of two or more of them.

Next, c) forming an active layer on the gate insulating layer.

A semiconductor substance may be applied to a gate insulating layer corresponding to a gate electrode by a deposition process to form an active layer, wherein a deposition process such as physical vapor deposition (PVD), chemical vapor deposition (CVD), atomic layer deposition (ALD) Or something like that, then pattern the active layer.

The active layer may include a source / drain region doped with n-type or p-type impurities, and a channel region connecting the source region and the drain region.

The semiconductor substance usable herein may include, for example, an inorganic semiconductor, an organic semiconductor, an oxide semiconductor, and the like, and may be used alone or in combination of two or more thereof.

Specific examples of the inorganic semiconductor may include CdS, GaS, ZnS, CdSe, CaSe, ZnSe, CdTe, SiC, Si, or the like, which may be used alone or in combination of two or more of them.

Specific examples of the organic semiconductor may include; polythiophene and its derivatives, polyparaphenylene vinylene and its derivatives, polyparaphenylene and its derivatives, polyfluorene and its derivatives, polythiophene Polythiophene vinylene and its derivatives and polythiophene heterocyclic aromatic copolymers and their derivatives. Further, the low molecules include, for example, oligoacene and its derivatives of pentacene, fused tetrabenzene, and naphthalene, α-6-thiophene, α-5-thiophene, and oligothiophene and their derivatives. Derivatives, phthalocyanin and its derivatives with / without metal, pyromellitic dianhydride or pyromellitic diimide and its derivatives, perylene tetracarboxylic acid dianhydride) or perylene tetracarboxylic diimide and its derivatives.

A specific example of the oxide semiconductor may include at least one element selected from the group consisting of gallium (Ga), phosphorus (In), zinc (Zn) and tin (Sn), and oxygen. For example, the active layer may be a ZnO, ZnGaO, ZnInO, GaInO, GaSnO, ZnSnO, InSnO, HfInZnO, ZnGaInO, etc., and preferably a GI-ZO layer [a (In2O3) b (Ga2O3) c (ZnO) layer] (Where a, b, and c are 0, b 0, c> 0).

Next, d) forming an insulating layer on the active layer.

The insulating layer is a channel provided in particular to protect the active layer. The insulating layer may be designed to cover the entire active layer except for the areas contacting the source electrode and the drain electrode, however, it is not necessarily limited to this, and the insulating layer may be formed only on the top of the channel.

The insulating layer may also function as an anti-etching layer (etch stop layer).

An insulating material may be applied within the above range to form an insulating layer, and then the insulating layer is patterned.

Next, e) forming a source electrode and a drain electrode in contact with the active layer on the insulating layer.

The source electrode and the drain electrode can be formed by forming a contact hole at a portion corresponding to a portion, and then forming a conductive material layer on the insulating layer and etching the conductive material layer. In this portion, the active layer and the source electrode And the drain electrode.

The conductive material layer may be an aluminum metal layer, a molybdenum metal layer, a silver metal layer, or a laminate thereof. The conductive material layer may be etched using the above-mentioned etchant composition according to the present invention to form a source electrode and a drain electrode.

According to a specific embodiment of the present invention, in the above-mentioned etching process, an intermediate portion of each of the source electrode and the drain electrode may be etched and removed, that is, a portion corresponding to an edge portion of the gate electrode At the inclined portion.

Therefore, the source electrode may include a first source electrode and a second source electrode that are separately formed. Here, the first source electrode is formed on the top of the active layer, and the second source electrode is formed on a portion where the active layer is not formed. In this regard, the first and second source electrodes are each formed in a flat shape without an inclined portion. Similarly, the first drain electrode is formed on the top of the active layer, and the second drain electrode is formed on a portion where the active layer is not formed. In this regard, the first and second drain electrodes are each formed in a flat shape without an inclined portion.

Thereafter, both the third source electrode and the third drain electrode are formed during a first electrode formation period to be described below. In this regard, a third source electrode is formed to connect the first and second source electrodes, and a third drain electrode is formed to connect the first and second drain electrodes.

Therefore, after the inclined portions of the source / drain electrodes are removed, these electrodes are connected via an indium tin oxide (ITO) electrode or the like, so that malfunctions caused by the inclined portions can be avoided, thereby reducing device defects.

Specific structures and effects achieved according to the above specific embodiments of the present invention are described in Korean Patent Registration No. 1178881, the contents of which are incorporated herein by reference.

F) forming a passivation layer on the insulating layer to cover the source electrode and the drain electrode.

G) forming an organic light emitting element electrically connected to one of the source electrode and the drain electrode.

An organic light emitting element can be prepared by forming a first electrode connected to one of a source electrode and a drain electrode; forming an organic layer on the first electrode; and forming a second electrode on the organic layer.

The first electrode may be formed by forming a contact hole on a passivation layer at a portion where the first electrode is connected to one of the source electrode and the drain electrode, and then forming a conductive material layer on the passivation layer and etching the conductive material layer. .

The conductive material layer may include, for example, an aluminum metal layer, a molybdenum metal layer, a silver metal layer, a metal oxide layer, or a laminate thereof. Etching this layer using the etchant composition according to the present invention can form a first electrode.

The metal oxide layer may be, for example, indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium zinc tin oxide (IZTO), cadmium tin oxide (CTO), or indium gallium zinc oxide IGZO layer, and preferably an indium tin oxide layer or an indium gallium zinc oxide layer, but is not limited thereto.

A pixel definition layer made of an insulating material may be further formed on the passivation layer to cover the first electrode. In this case, a portion of a pixel definition layer (hereinafter referred to as a PDL) in which the first electrode and the organic layer are connected to each other may be patterned to form a hole.

More specifically, a PDL is provided to cover an edge of the first electrode. This PDL has a role of defining a light emitting area, and increasing an edge interval between the first electrode and the second electrode to prevent electric fields from being concentrated on the edge portion of the first electrode, thereby preventing a short circuit between the first and second electrodes.

Subsequently, an organic layer is formed on the first electrode.

The organic layer may be provided with a hole injection transport layer, a light emitting layer, an electron injection transport layer, and the like, which are all or selectively laminated. However, a light emitting layer must be provided.

Further, a second electrode is formed on the organic layer.

A first electrode is provided to be patterned for each pixel.

In the case of a front-emission type structure for achieving an image in the direction of the second electrode, the first electrode may be provided as a reflective electrode. To this end, a reflective layer made of an alloy of Al, Ag, or the like is provided.

When the first electrode is used as the anode electrode, a layer made of a metal oxide having a high work function (absolute value) such as ITO, IZO, ZnO, or the like is included. When the first electrode is used as the cathode electrode, a highly conductive metal having a low work function (absolute value) such as Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, or the like is used. Therefore, the above-mentioned reflective layer is unnecessary in this case.

A second electrode may be provided as the light-transmissive electrode. To this end, a transflective reflective layer formed as a thin layer using Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, or the like may be included. Otherwise, a light-transmissive metal oxide such as ITO, IZO, ZnO, etc. may be included. When the first electrode is used as the anode, the second electrode becomes the cathode. On the other hand, when the first electrode is used as the cathode, the second electrode becomes the anode.

A protective layer may be further formed on the second electrode, and glass may be used for sealing.

Hereinafter, preferred specific embodiments are proposed to describe the present invention more specifically. However, the following examples are only provided to illustrate the present invention, and it will be apparent to those skilled in the relevant art that various changes and modifications within the scope and spirit of the present invention are possible. Such changes and modifications are appropriately included in the appendix In the scope of patent application.

Examples and Comparative Examples

(1) Preparation of an etchant composition

Etchant compositions were prepared having different structural compositions and contents described in Table 1 below, and including water as a balance.

(2) the formation of wires

1) Gate electrode

A Mo / Al / Mo metal layer is formed on a glass substrate by a deposition method, and each of the above-mentioned etchant compositions is used to etch the formed metal layer to form a gate electrode.

2) First electrode

A gate electrode, a source electrode, and a drain electrode are formed on a glass substrate, and then a passivation layer is formed thereon. After that, a ITO / APC (AgPdCu) / ITO laminated structure is formed on the passivation layer, and each of the above-mentioned etchant compositions is etched to form a first electrode. Here, a hole is formed in the passivation layer to connect the drain electrode and the first electrode, thereby smoothly transmitting an electronic signal.

Experimental example: Evaluation of etching characteristics

The scanning electrode microscope (SEM) was used to observe the gate electrode and the first electrode in each of the organic light-emitting display devices manufactured according to the methods described in the above examples and comparative examples, and the etching characteristics were evaluated according to the following criteria, and the results are listed In Table 2 below.

<Side Etching>

○: (gate electrode) is less than 1.3 μm

(Pixel electrode) less than 0.5μm

△: (gate electrode) 1.3 μm or more but less than 1.6 μm

(Pixel electrode) 0.5 μm or more but less than 1.0 μm

X: (gate electrode) 1.6 μm or higher

(Pixel electrode) 1.0 μm or more

<Taper angle>

○: 30 ° or more but less than 50 °

△: 50 ° or more but less than 70 °

X: below 30 ° or 70 ° or higher

Referring to Table 2 above, the gate electrode in the organic light-emitting display device manufactured according to the method described in Example 1 has reduced side etching and shows an excellent taper angle. As such, the first electrode has reduced side etching and appears to be free of residues.

However, regarding the organic light-emitting display devices manufactured according to the methods described in Comparative Examples 1 to 8, the gate electrode and the first electrode have deteriorated etching characteristics, and thus exhibit low utility in electrical wiring.

Claims (6)

A method for manufacturing an organic light emitting display device includes: a) forming a gate electrode on a substrate; b) forming a gate insulating layer on the substrate including the gate electrode; c) insulating the gate electrode Forming an active layer on the layer; d) forming an insulating layer on the active layer; e) forming a source electrode and a drain electrode in contact with the active layer on the insulating layer; f) on the insulating layer Forming a protective layer to cover the source electrode and the drain electrode; and g) forming an organic light emitting element electrically connected to one of the source electrode and the drain electrode, wherein step a) includes forming a silver A metal layer, or a laminate of aluminum, molybdenum, and silver metal layers, and a layer comprising 50 to 70 wt.% Phosphoric acid, 2 to 15 wt.% Nitric acid, 5 to 20 wt.% Acetic acid, and 0.1 to 5 wt.% Paratoluene Sulfuric acid and water serve as a balanced etchant composition to etch the metal layer to form the gate electrode, wherein the silver metal layer is a silver layer, or includes silver and from La, Mg, Zn, In, Ca, Te , Sr, Cr, Co, Mo, Nb, Ta, W, Ni, Nd, Sn, Fe, Si, Ti, Pt, Pd and Cu A layer of metal alloy. The method as described in item 1 of the scope of patent application, wherein the aluminum metal layer is an aluminum layer, or includes aluminum and from La, Mg, Zn, In, Ca, Te, Sr, Cr, Co, Mo, Nb, An alloy layer of at least one metal selected from Ta, W, Ni, Nd, Sn, Fe, Si, Ti, Pt, and C. The method as described in claim 1, wherein the molybdenum metal layer is a molybdenum layer, or an alloy including molybdenum and at least one metal selected from Ti, Ta, Cr, Ni, Nd, In, and Al Floor. The method as described in item 1 of the patent application scope, wherein the step of forming the organic light emitting element includes: forming a first electrode electrically connected to one of the source electrode and the drain electrode; Forming an organic layer on the electrode; and forming a second electrode on the organic layer. The method as described in item 4 of the scope of patent application, wherein the first electrode is a conductive material layer formed on the protective layer as an aluminum, molybdenum or silver metal layer, a metal oxide layer or a laminate thereof. And etching the composition with an etchant composition comprising 50 to 70 wt.% Phosphoric acid, 2 to 15 wt.% Nitric acid, 5 to 20 wt.% Acetic acid, 0.1 to 5 wt.% P-toluenesulfonic acid and water as a balance. A conductive material layer is formed. The method as described in item 5 of the application, wherein the metal oxide layer is an indium tin oxide (ITO), an indium zinc oxide (IZO), zinc oxide (ZnO), indium zinc tin oxide ( IZTO), a cadmium tin oxide (CTO) or an indium gallium zinc oxide (IGZO) layer.