KR100719567B1 - Flat display device and manufacturing method thereof - Google Patents

Abstract

The present invention provides a simple method for blocking diffusion of an impurity metal component from a metal substrate, and is interposed between a metal substrate, a light emitting device provided on one surface of the metal substrate, and the metal substrate and the light emitting device. A flat panel display including a ion doped layer at least one selected from the group consisting of silicon (Si), phosphorus (P), nitrogen (N), antimony (Sb), and arsenic (As) and a method of manufacturing the same will be.

Description

Flat display device and manufacturing method thereof

1 is a circuit diagram of a flat panel display device according to an exemplary embodiment of the present invention.

2 is a cross-sectional view illustrating an example of the PM organic light emitting display device of FIG. 1;

3 to 5 are cross-sectional views illustrating other examples of the PM OLED display of FIG. 1;

6A and 6B are cross-sectional views sequentially illustrating an example of a method of forming a metal substrate having an ion doped layer,

FIG. 7 is a circuit diagram of a flat panel display according to another exemplary embodiment of the present invention, and is a circuit diagram of one pixel of an AM organic light emitting display.

8 is a cross-sectional view illustrating an example of an AM organic light emitting display device of FIG. 7;

9 to 10 are cross-sectional views illustrating other examples of the AM organic light emitting display device of FIG. 8;

11A through 11C are cross-sectional views sequentially illustrating another example of a method of forming a metal substrate having an ion doped layer.

<Explanation of symbols for the main parts of the drawings>

10: metal substrate 11: ion doped layer

12: insulating film 21: first electrode layer

22: organic light emitting layer 23: second electrode layer

30: amorphous silicon film

Prior Art Document 1: US published patent publication US 2004 / 0,087,066

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat panel display and a method for manufacturing the same, and to a flat panel display and a method for manufacturing the same, which can be made flexible using a metal substrate.

In general, a flat panel display such as an organic light emitting display, a TFT-LCD, and the like can be ultra-thin and flexible in view of driving characteristics, and thus many studies have been made.

In order to reduce the thickness and flexibility of the flat panel display device, a flexible substrate is used. As the flexible substrate, a substrate made of a synthetic resin material is generally used. However, since the flat panel display devices have various structures such as an organic film, a thin film transistor layer for driving, an electrode layer, or an alignment film according to their characteristics, a very difficult process condition for forming them is also required. Therefore, when the substrate of the synthetic resin material is used, the substrate is deformed or the thin film layers formed on the substrate are deformed by the above process conditions.

In order to overcome the limitations of the synthetic resin substrate, a technique of using a metal foil as a substrate instead of the synthetic resin substrate has recently been studied.

When the metal foil is used as a substrate, it is sufficient to be used as a top emission type structure, and may be relatively less sensitive to process conditions because a high temperature process such as crystallization of amorphous silicon with polysilicon may be performed.

Prior art document 1 discloses an AM organic electroluminescent display device using a metal foil as a substrate. As can be seen from the disclosed patent, when the metal foil is used as a substrate, the substrate itself is an electrical conductor, so an insulating film must be formed before forming the element on the surface. In the above patent, SiO ₂ , SiNx, SiON, or the like is used as the insulating film.

On the other hand, when the metal foil as described above is used as a substrate, metal components such as Fe, Cr, C, and Mn are diffused and discharged from the metal foil when undergoing a high temperature process of several hundred degrees or more such as silicon crystallization. Such a metal component may penetrate through the insulating film formed on the metal foil surface and may adversely affect the device formed on the insulating film surface.

By the way, in order to block the diffusion of this metal component with the above insulating film, this insulating film should be formed to be 1 micrometer or more thick. In this case, the insulating film is formed too thick on the surface of the metal foil, and the stress due to the thickness acts, thereby causing a defect such as bending of the substrate.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a flat panel display device and a method of manufacturing the same, which can block diffusion of an impurity metal component from a metal substrate by a simple method.

In order to achieve the above object, the present invention is interposed between the metal substrate, the light emitting device provided on one surface of the metal substrate, and the metal substrate and the light emitting device, silicon (Si), phosphorus (P) ), A flat panel display including an ion doped layer at least one selected from the group consisting of nitrogen (N), antimony (Sb), and arsenic (As).

In order to achieve the above object, the present invention also provides a step of preparing a metal substrate, silicon (Si), phosphorus (P), nitrogen (N), antimony (Sb), and arsenic (As) on one surface of the metal substrate And forming a ion doping layer by doping at least one selected from the group consisting of: and forming a light emitting device on one surface of the ion doping layer.

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

1 is a circuit diagram of a flat panel display device according to an exemplary embodiment of the present invention, which is a circuit diagram of a PM organic light emitting display device.

The PM organic light emitting display device is arranged such that a plurality of data lines and a scan line cross each other, and an organic light emitting diode (OLED) is provided at a point where each of them crosses each other. . Each organic light emitting diode OLED is driven according to a scan signal and a data signal.

The PM organic light emitting display device may be implemented on a metal substrate according to the present invention. FIG. 2 is a cross-sectional view of an example thereof.

As shown in FIG. 2, the PM organic light emitting diode display is formed on the metal substrate 10.

The metal substrate 10 may be provided with a metal foil, and stainless steel, Ti, Mo, Invar alloy, Inconel alloy, Kovar alloy, etc. may be used, and stainless steel is more preferable. The metal substrate 10 is preferably cleaned after its surface is planarized. The planarization may be a chemical-mechanical polishing (CMP) method.

As shown in FIG. 2, an ion doped layer 11 is formed on the surface of the metal substrate 10.

The ion doped layer 11 serves to block metal impurities that may diffuse out of the metal substrate 10, and include iron, chromium, nickel, and the like, which may be included in the metal substrate 10. Metal elements such as carbon and manganese may be blocked, and in particular, nickel.

The ion doped layer 11 may be formed by doping ions such as silicon (Si), phosphorus (P), nitrogen (N), antimony (Sb), and arsenic (As) on the metal substrate 10. , Silicon (Si) or phosphorus (P) is more preferred.

The ion doped layer 11 may be obtained by heat treatment after the doping of the ions, as described below. Accordingly, the ions and the elements in the metal substrate 10 form metal silicide on the surface of the metal substrate 10. As a result, compounds such as NiP, NiP ₂ , Ni ₂ P, Ni ₃ P ₃ , Ni ₂ Si, NiSi, and Fe ₃ P are formed. The ion doping layer 11 may prevent the metal element of the metal substrate 10 from diffusing to the upper layer of the metal substrate 10.

The organic light emitting diode OLED is provided on the diffusion barrier 11. The organic light emitting diode OLED includes a first electrode layer 21, an organic light emitting layer 22, and a second electrode layer 23, and an inter-insulating layer is formed between the lines of the first electrode layer 21. The layer 24 may be further interposed, and the first electrode layer 21 and the second electrode layer 23 may be formed in a pattern orthogonal to each other.

The first electrode layer 21 may function as an anode electrode, and the second electrode layer 23 may function as a cathode electrode. Referring to FIG. 1, the first electrode layer 21 may be a data line. (Data), and the second electrode layer 23 may be a scan line. Of course, the polarities of the first electrode layer 21 and the second electrode layer 23 may be reversed.

Since the metal substrate 10 becomes a light reflecting substrate, the present structure is a top emission type. In this case, the second electrode layer 23 may be provided as a transparent electrode. For example, the second electrode layer 23 may be formed of a thin semi-permeable thin film by using a metal such as Mg-Ag. In some cases, the second electrode layer 23 may be formed by depositing transparent ITO on the thin film. The first electrode layer 21 may include ITO, IZO, In 2 O 3, or the like having a high work function.

The first electrode layer 21 and the second electrode layer 23 are not necessarily provided in a stripe pattern orthogonal to each other, and may be patterned in various shapes to achieve predetermined surface emission.

In addition, the first electrode layer 21 and the second electrode layer 23 are not limited to being formed of the above-described materials, and may be formed of a conductive organic material, a conductive paste, or the like.

In addition, although not shown in the drawing, the first electrode layer 21 is a separating layer made of an insulating material in order to obtain a patterning effect of the second electrode layer 23 as an upper electrode. This may be further provided.

The organic light emitting layer 22 may be a low molecular or high molecular organic layer. When the low molecular organic layer is used, a hole injection layer (HIL), a hole transport layer (HTL), and an organic emission layer (EML) may be used. ), An electron transport layer (ETL), an electron injection layer (EIL), or the like, may be formed by stacking a single or a complex structure, and the usable organic material may be copper phthalocyanine (CuPc). , N, N-di (naphthalen-1-yl) -N, N'-diphenyl-benzidine (N, N'-Di (naphthalene-1-yl) -N, N'-diphenyl-benzidine: NPB), Various applications are possible, including tris-8-hydroxyquinoline aluminum (Alq3). These low molecular weight organic layers are formed by the vacuum deposition method.

In the case of the polymer organic layer, the structure may include a hole transporting layer (HTL) and a light emitting layer (EML). In this case, PEDOT is used as the hole transporting layer, and polyvinylvinylene (PPV) and polyfluorene are used as the light emitting layer. Polymer organic materials such as (Polyfluorene) are used and can be formed by screen printing or inkjet printing.

Although not shown in the drawing, the organic light emitting diode OLED is sealed by a separate sealing structure to be blocked from the outside air.

As described above, when the organic light emitting display device is manufactured using the metal substrate 10 having the ion doped layer 11 formed thereon, impurities do not penetrate from the metal substrate 10 even at a high temperature process. It is possible to improve the characteristics and at the same time flexible.

Meanwhile, before forming the organic light emitting diode OLED on the ion doped layer 11 as described above, as shown in FIG. 3, an insulating film 12 may be further formed on the ion doped layer 11. have.

The insulating layer 12 is formed on the thinly formed ion doped layer 11 to compensate for the roughness of the metal substrate 10 and to increase the flatness of the substrate, and may be formed of an organic material and / or an inorganic material. .

As the inorganic substance, SiO 2, SiN x, SiON, Al ₂ O ₃ , TiO ₂ , Ta ₂ O ₅ , HfO ₂ , ZrO ₂ , BST, PZT and the like are possible, and SiO 2, SiNx, SiON and the like are more preferable.

As the organic material, a polymer material can be used. Examples thereof include general general-purpose polymers (PMMA, PS), polymer derivatives having a phenol group, acrylic polymers, imide polymers, arylether polymers, amide polymers, fluorine polymers, and p. Xylene polymers, vinyl alcohol polymers and blends thereof.

The insulating film 12 may also be an inorganic-organic laminated film.

As described above, the insulating film 12 may be formed on the ion doped layer 11 as shown in FIG. 3, and as shown in FIG. 4, the other surface of the metal substrate 10, that is, the metal substrate 10 as seen in the drawing. ) Can also be formed on the lower surface.

In addition, as shown in FIG. 5, the upper and lower surfaces of the metal substrate 10 on which the ion doped layer 11 is formed may be formed. 5 may be particularly useful when the insulating film 12 is formed of an inorganic material. The insulating film 12 formed of the inorganic material stresses the metal substrate 10 so that the metal substrate 10 is formed. In order to prevent bending in one direction, the insulating film 12 is formed on both sides of the metal substrate 10 in the same manner.

Next, a method of forming the ion doped layer 11 as described above will be described.

The surface of the cleaned and / or planarized metal substrate 10 is prepared by the aforementioned ions, namely silicon (Si), phosphorus (P), nitrogen (N), antimony (Sb), and arsenic (As) as shown in FIG. Ions such as), preferably ions such as silicon (Si) and phosphorus (P). At this time, the concentration of the implanted ions are to be 1 × 10 ²⁰ / cm 3 or more. Ions are implanted to a depth within 1 μm from the surface of the metal substrate 10. As the method of doping ions, an ion shower method, an ion implantation method, a diffusion method, or the like can be used.

After ion doping, as shown in Figure 6b, it is heated at 400 ~ 700 ℃. As the heat treatment method, RTA and ELA methods can be used, but Furnace method is more preferable.

In the heat treatment, the ions in the metal substrate 10 getter elements such as Ni, Cr, Fe, etc. in the metal substrate 10 to form metal silicide. For example, when the metal substrate 10 is made of stainless steel (SUS), Ni of SUS is combined with diffusion P from SUS during heat treatment to form compounds such as NiP, NiP ₂ , Ni ₂ P, and Ni ₃ P ₃ . And Si form compounds such as Ni ₂ Si and NiSi. In addition, when phosphorus (P) is injected, the phosphorus binds to Fe to form a compound such as Fe ₃ P. Each formed metal compound serves as a diffusion barrier.

7 illustrates a circuit diagram of one pixel of an AM organic light emitting diode display according to another exemplary embodiment of the present invention.

Referring to FIG. 7, each pixel of an AM organic light emitting diode display according to an exemplary embodiment of the present invention may include a switching TFT M2, at least two thin film transistors of a driving TFT M1, and a storage capacitor. Cst) and an organic light emitting device (OLED).

The switching TFT M2 is turned on / off by a scan signal applied to the scan line Scan to transfer a data signal applied to the data line Data to the storage capacitor Cst and the driving TFT M1. The driving TFT M1 determines the amount of current flowing into the organic light emitting element OLED according to the data signal transmitted through the switching TFT M2. The storage capacitor Cst stores a data signal transmitted through the switching TFT M2 for one frame.

In the circuit diagram according to FIG. 7, the driving TFT M1 and the switching TFT M2 are illustrated as PMOS TFTs, but the present invention is not limited thereto, and at least one of the driving TFT M1 and the switching TFT M2 is not limited thereto. Can be formed of an NMOS TFT, of course. In addition, the number of the thin film transistors and capacitors as described above is not necessarily limited thereto, and of course, a larger number of thin film transistors and capacitors may be provided.

The AM organic light emitting diode display may be implemented on a metal substrate according to the present invention. FIG. 8 is a cross-sectional view of an example thereof.

As shown in FIG. 8, an AM organic light emitting display device is also formed on a metal substrate 10, which is also a metal foil such as stainless steel, Ti, Mo, Invar alloy, as described above. , Inconel alloy, and Kovar alloy, and the like, and preferably provided with stainless steel.

The metal substrate 10 is cleaned and then planarized. The planarization process may use a chemical-mechanical polishing (CMP) method as described above.

As shown in FIG. 8, the ion doped layer 11 is formed on the planarized metal substrate 10. Since the description of the ion doped layer 11 is as described above, a detailed description thereof will be omitted.

After the ion doped layer 11 is formed, the semiconductor active layer 31 of the thin film transistor TFT is formed on the ion doped layer 11. As shown in FIG. 7, the thin film transistor TFT may be a driving TFT M1, but is not limited thereto. When the circuit becomes more complicated, the thin film transistor TFT may be another switching TFT.

The semiconductor active layer 31 may be an inorganic semiconductor or an organic semiconductor.

The inorganic semiconductor may include CdS, GaS, ZnS, CdSe, CaSe, ZnSe, CdTe, SiC, and Si. As in the present invention, in the case of using the metal substrate 10 having the ion doped layer 11, amorphous silicon is formed on the ion doped layer 11, and then subjected to a crystallization process. After forming, it can be patterned and used as the active layer 31. The crystallization of amorphous silicon is solid phase crystallization (SPC), laser crystallization, sequential lateral solidification (SLS), metal induced crystallization, metal induced lateral crystallization Etc. may be used, in addition, various crystallization methods may be used. Since the present invention is a metal substrate 10 even during such crystallization, a high temperature process can be easily applied, and the ion doping layer 11 can block diffusion of an impurity element during a high temperature process.

On the other hand, as the organic semiconductor material, pentacene (tetracene), tetracene (tetracene), anthracene (anthracene), naphthalene (alpha) 6- thiophene, alpha-4-thiophene, perylene (perylene) and Derivatives thereof, rubrene and derivatives thereof, coronene and derivatives thereof, perylene tetracarboxylic diimide and derivatives thereof, perylene tetracarboxylic hydride dianhydride) and derivatives thereof, oligoacenes and derivatives thereof of naphthalene, oligothiophenes and derivatives thereof of alpha-5-thiophene, phthalocyanine and derivatives thereof, with or without metal, naphthalenetetracarboxylic Naphthalene tetracarboxylic diimide and its derivatives, naphthalene tetracarboxylic dianhydride and its derivatives, pyromellitic dianhydride The beads and their derivatives, pyromellitic Pyro tick diimide and its derivatives, conjugated polymer containing thiophene and its derivatives, fluorene and its derivatives and polymer containing fluorene and the like may be used.

After the semiconductor active layer 31 is formed, the gate electrode 33 via the gate insulating film 32 is disposed over the region corresponding to the channel region of the semiconductor active layer 31, and the interlayer insulating film 34 to cover the entire substrate. ) Is formed.

A contact hole 34a is formed in the interlayer insulating film 34, and a source / drain electrode 35 is formed on the interlayer insulating film 34. The source / drain electrode 35 contacts the semiconductor active layer 31 through the contact hole.

The structure of the thin film transistor TFT is not necessarily limited to the embodiment of FIG. 8, and various thin film transistor structures such as a bottom gate structure may be applicable.

After the thin film transistor TFT is formed in this manner, a planarization film 36 is formed to cover the thin film transistor TFT. The planarization film 36 may be formed of a single or organic material and / or an inorganic material, as described above. It may be formed as a composite layer.

Via holes 36a are formed in the planarization film 36, and the first electrode layer 21 of the organic light emitting diode OLED is formed on the planarization film 36. Accordingly, the first electrode layer 21 is connected to any one of the source / drain electrodes 35 of the thin film transistor TFT.

Next, after the pixel definition layer 37 is formed to cover the planarization layer 36 and the first electrode layer 21, the opening 37a is exposed so that a predetermined portion of the first electrode layer 21 is exposed to the pixel definition layer 37. ). Like the planarization layer 36 described above, the pixel definition layer 37 may be formed of a single layer or a composite layer of an organic material and / or an inorganic material, and may be preferably formed of an organic material in order to increase the flatness of the surface. .

The organic light emitting layer 22 and the second electrode layer 23 are sequentially formed on the exposed first electrode layer 21.

Like the above-described PM structure, the first electrode layer 21 may function as an anode electrode, and the second electrode layer 23 may function as a cathode electrode. It may be patterned to correspond to the size of the pixel, and the second electrode layer 23 may be formed to cover all the pixels.

The first electrode layer 21 may be used as a reflective electrode, and after forming a reflective film with Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, or a compound thereof, and the like, ITO, IZO, ZnO, or In 2 O 3 can be formed thereon. In addition, the second electrode layer 24 may be provided as a transparent electrode, and a metal having a small work function, that is, Li, Ca, LiF / Ca, LiF / Al, Al, Mg, and a compound thereof may be formed in the organic light emitting layer 22. After the deposition is directed toward), an auxiliary electrode layer or a bus electrode line may be formed thereon with a material for forming a transparent electrode such as ITO, IZO, ZnO, or In 2 O 3.

The first electrode layer 21 and the second electrode layer 23 are not necessarily formed of the above-described materials, and may be formed of a conductive organic material, a conductive paste, or the like.

Since the organic light emitting layer 22 may have the same PM structure as described above, a detailed description thereof will be omitted.

After the organic light emitting diode OLED is formed in this manner, the upper portion thereof is sealed to block the outside air.

Meanwhile, before forming the thin film transistor TFT and the organic light emitting diode OLED on the ion doped layer 11 as described above, as shown in FIG. 9, the insulating film 12 is formed on the ion doped layer 11. ) Can be further formed.

As described above, the insulating layer 12 may be formed on the ion doped layer 11 as shown in FIG. 9, and as shown in FIG. 10, the other surface of the metal substrate 10, that is, the metal substrate 10 as seen in the drawing. ) Can also be formed on the lower surface. In addition, as shown in FIG. 11, the upper and lower surfaces of the metal substrate 10 on which the ion doped layer 11 is formed may be formed. Since the insulating film 12 is the same as described in the above-described embodiment according to FIGS. 3 to 5, a detailed description thereof will be omitted.

Meanwhile, the ion doped layer 11 may be formed by the method described above with reference to FIGS. 6A and 6B. In the case of an AM organic light emitting display device, the ion doped layer 11 may also be formed by the following method.

First, as shown in FIG. 12A, an amorphous silicon film 30 is formed on one surface of the metal substrate 10. The amorphous silicon film 30 may be deposited to a thickness of about 50 to 500 nm.

Next, as shown in FIG. 12B, ion doping is performed in the direction of the amorphous silicon film 30 in the direction of the amorphous silicon film 30 to 50 nm or less from the interface between the amorphous silicon film 30 and the metal substrate 10. Then, heat treatment is performed to form the ion doped layer 11 as shown in FIG. 12C. Doping ions and conditions are as described above.

After forming the ion doped layer 11 in this manner, the amorphous silicon film 30 is crystallized and then patterned to form the active layer described above.

As described above, when the organic light emitting display device is manufactured using the metal substrate 10 having the ion doped layer 11 formed thereon, impurities do not penetrate from the metal substrate 10 even in a high temperature process such as silicon crystallization. In addition, the characteristics of the light emitting device can be improved and at the same time flexible. In addition, infiltration of impurity elements from the metal substrate 10 can be blocked even in a high temperature process such as an annealing process that is performed after fabrication of the organic light emitting display device or a high temperature environment generated during use. In particular, by allowing the ions to be combined with Ni from the metal substrate 10, it is possible to minimize the diffusion of Ni ions into the insulating film and the active layer of the upper portion, thereby reducing the leakage current in the insulating film of the TFT, the slope below the threshold voltage threshold slop) and gate insulating film characteristics can be improved.

The present invention described above is not necessarily applied only to an organic light emitting display device, but may be applied to various flat panel display devices such as a liquid crystal display, an inorganic electroluminescent display, and an electron emission display.

According to the present invention made as described above, the following effects can be obtained.

First, using a metal substrate, it can be easily applied to high temperature processes.

Second, by applying the ion doping layer to the metal substrate, it is possible to prevent the metal component from being diffused from the metal substrate during the process or in use, thereby preventing degradation of product characteristics.

Third, the ion doped layer can be formed by a simpler method.

Fourth, an ultra-thin and flexible flat panel display can be formed using a metal foil.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and variations can be made therefrom.

Claims (14)

Metal substrates; A light emitting device provided on one surface of the metal substrate; And Interposed between the metal substrate and the light emitting device, the ion doped with at least one selected from the group consisting of silicon (Si), phosphorus (P), nitrogen (N), antimony (Sb), and arsenic (As) And a doping layer. The method of claim 1, The metal substrate includes at least one of iron, chromium, nickel, carbon, and manganese. The method of claim 1, And an insulating film formed between the ion doped layer and the light emitting element or on the other surface of the metal substrate. The method of claim 1, The metal substrate is stainless steel, The doped ions are phosphorus or silicon, And the ion doped layer comprises at least one of NiP, NiP ₂ , Ni ₂ P, Ni ₃ P ₃ , Ni ₂ Si, NiSi, Fe ₃ P, and compounds thereof. The method according to any one of claims 1 to 4, And the light emitting element is an organic electroluminescent element. The method according to any one of claims 1 to 4, And at least one thin film transistor electrically connected to the light emitting device between the light emitting device and the ion doped layer. Preparing a metal substrate; Forming an ion doped layer by doping at least one selected from the group consisting of silicon (Si), phosphorus (P), nitrogen (N), antimony (Sb), and arsenic (As) on one surface of the metal substrate; And And forming a light emitting device on one surface of the ion doped layer. The method of claim 7, wherein Preparing the metal substrate comprises the step of planarizing the surface of the metal substrate. The method of claim 7, wherein And forming an insulating film on one surface of the ion doped layer after the forming of the ion doped layer. The method of claim 7, wherein And forming a semiconductor layer on one surface of the metal substrate before forming the ion doped layer. The method of claim 7, wherein The preparing of the metal substrate may include forming an insulating layer on the other surface of the metal substrate. The method of claim 7, wherein Forming the ion doped layer, And performing heat treatment after the ion doping. The method according to any one of claims 7 to 12, The metal substrate may include at least one of iron, chromium, nickel, carbon, and manganese. The method according to any one of claims 7 to 12, The metal substrate is stainless steel, And the doped ions are phosphorus or silicon.

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