KR100843553B1 - Patterning Method Of Organic materials Of Organic Electric Device and Organic Thin Film Transistor and Organic Electronic Emitting Device - Google Patents

Abstract

The present invention relates to a method for patterning an organic material layer of an organic electronic device, and an organic thin film transistor and an organic electroluminescent device fabricated using the method.

The organic material layer patterning method of the present organic electronic device includes applying a first photoresist on a substrate, heat treating the applied first photoresist, exposing the first photoresist to the entire surface, and Depositing a metal thin film on the resist, forming a second photoresist on the metal thin film, heat treating the applied second photoresist, and masking a desired pattern on the heat treated second photoresist Forming a light source, exposing the second photoresist on a mask, developing a first photoresist and the second photoresist, and forming an organic electronic device on the patterned substrate and the second photoresist. Forming a layer of an organic material to be used in the process, forming a protective film on the surface of the organic material layer, and a lift-off method. Comprising the step of removing the registry, in the step of developing the first photoresist, and a second photoresist is characterized by developing using a developing solution capable of developing the first photoresist, and the second photoresist at the same time.

Accordingly, by using a photoresist having a multi-layered structure, deformation during the process can be prevented, and a lift-off method can be used even after forming a protective film protecting the organic material layer of the organic electronic device, and thus the organic material layer of the organic electronic device. Fine patterning can be carried out without changing the properties of.

Organic material layer of organic electronic device, first photoresist, second photoresist, organic thin film transistor, organic electroluminescent device

Description

A method of patterning an organic material layer of an organic electronic device, and an organic thin film transistor and an organic electroluminescent device fabricated using the method.

1A and 1B are enlarged cross-sectional views of a region of a photoresist for use in a conventional lift-off process.

2A to 2I are side cross-sectional views of a process of patterning an organic material layer of an organic electronic device according to the present invention.

3 is a step-by-step manufacturing block diagram showing the manufacturing process of Figures 2a to 2i.

4 is a photograph of a photoresist having a multilayer structure according to the present invention.

** Description of the main parts of the drawing **

210: substrate 220 first photoresist

230: metal thin film 240: second photoresist

240a: overhang area h: overhang height

w: overhang depression width 250: mask

260: organic material layer 270: protective film

The present invention relates to an organic material layer patterning method of an organic electronic device and an organic thin film transistor and an organic electroluminescent device fabricated using the method, and more particularly, by performing a lift-off process using a photoresist having a multilayer structure. The present invention relates to an organic material layer patterning method of an organic electronic device that enables fine patterning without changing characteristics of an organic material layer, and to an organic thin film transistor and an organic electroluminescent device fabricated using the method.

The organic material used in the organic material layer is composed of elements such as carbon, oxygen, and hydrogen, unlike silicon and gallium-based inorganic materials, and has electrical characteristics similar to those of inorganic materials. Organic electronic devices based on organic materials have advantages such as low cost, low power consumption, large area, and eco-friendliness. Electronic devices and components using inorganic materials include a process of patterning inorganic materials to ensure functionality. Organic electronic devices and components based on organic materials must also include a patterning process to ensure the functionality of each device. Patterning methods for inorganic and organic materials include etching processes (wet etching methods, dry etching methods, etc.), selective coating processes (inkjet, printing, etc.), selective deposition processes, and self-aligned processes. have.

In general, in order to pattern an organic material using an etching process among various patterning methods, a lithography process defining a patterning region is used. Lithography processes can be classified into optical lithography, radiation lithography, and the like, and photoresist sensitive to light is used in the lithography process.

However, since the photoresist is an organic material, chemical stability may be degraded when the photoresist is applied on the organic material to be patterned. In other words, in fabricating an organic electronic device based on an organic material, when a conventional inorganic electronic device manufacturing process is applied to a fine patterning process of an organic material, chemical stability is poor and a desired pattern cannot be formed. There is this. In particular, in the case of performing a dry etching process after applying the photoresist, it is not easy to control the etching depth due to the lack of selectivity between the photoresist as an organic material and the organic material layer to be patterned. In addition, since the photoresist is applied on an organic material, there is a problem that the characteristics of the organic electronic device are drastically reduced after forming the pattern.

In order to solve the above problems, a photo-masking process including an exposure step, a development step, and an etching step may include a lift-off in which a fine pattern may be formed without the etching step and including only the exposure step and the development step. ) Method is used.

1A and 1B are enlarged cross-sectional views of a region of a photoresist for use in a conventional lift-off process. Referring to FIGS. 1A and 1B, FIG. 1A discloses a photoresist 101 in which a reverse slope occurs, that is, an inverted trapezoidal shape in which the upper width is wider than the lower width and a protruding overhang 101a are formed. 1b discloses a photoresist 102 having an overhang 102a in which a portion of the upper region protrudes like an eave.

However, the photoresist used in the lift-off process is limited in kind due to chemical stability problems, so that it is not easy to form an organic material layer. In addition, when the organic material layer is formed on the photoresist, the shape of the photoresist may be damaged depending on the deposition thickness of the organic material layer. Furthermore, there is a disadvantage that the shape of the photoresist may be damaged even when the protective film is formed on the organic material layer.

SUMMARY OF THE INVENTION The present invention is an invention devised to solve the above problems, and an object of the present invention is to form a photoresist in multiple layers so that the organic material of the organic electronic device can be finely patterned without changing the properties of the organic electronic device. To provide a material layer patterning method and an organic thin film transistor and an organic electroluminescent device fabricated using the method.

In order to achieve the above and other objects, according to one aspect of the present invention, a method for patterning an organic material layer of an organic electronic device includes applying a first photoresist on a substrate, and applying the first photoresist applied to the substrate. Heat treatment, exposing the first photoresist to the entire surface, depositing a metal thin film on the first photoresist, forming a second photoresist on the metal thin film, and applying the coating. Heat treating the second photoresist; forming a mask according to a desired pattern on the heat treated second photoresist; exposing the second photoresist on the mask; Developing the resist and the second photoresist, and for use in an organic electronic device on the patterned substrate and the second photoresist. Forming a base material layer, forming a protective film on the surface of the organic material layer, and removing the first and second photoresist by a lift-off method, wherein the first photoresist and the first In the developing of the second photoresist, the first photoresist and the second photoresist may be developed using a developer capable of simultaneously developing the photoresist.
In a preferred embodiment, the first photoresist and the second photoresist are developed to form an overhang. The thickness of the overhang is controllable using at least one of the thickness of the second photoresist and the metal thin film. Recess width of the overhang is 0.1㎛ ~ 30㎛, The depression width of the overhang is controlled using at least one of the thickness of the metal thin film, the exposure time and the development time of the first photoresist.

delete

delete

The heat treatment of the first photoresist is performed at a temperature equal to or higher than the heat treatment temperature of the second photoresist. The heat treatment temperature of the second photoresist is 80 ~ 150 ℃ . In the step of depositing the metal thin film, the thickness of the metal thin film is 1 ~ 10Å. In the depositing of the metal thin film, the metal thin film is formed using aluminum.

On the other hand, according to another aspect of the present invention, the present invention provides an organic thin film transistor manufactured using the organic material layer patterning method of the organic electronic device according to any one of claims 1 to 11.

According to yet another aspect of the present invention, the present invention provides an organic electroluminescent device fabricated using the organic material layer patterning method of the organic electronic device according to any one of claims 1 to 11.

Hereinafter, a patterning method of an organic electronic device according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2A to 2I are side cross-sectional views illustrating a process of patterning an organic material layer of an organic electronic device according to the present invention, and FIG. 3 is a step-by-step manufacturing block diagram illustrating the manufacturing process of FIGS. 2A to 2I.

Referring to FIGS. 2A, 2B, and 3, first, a substrate 210 is prepared, and a first photoresist 220 is coated on the prepared substrate 210 (S305). The substrate 210 selects and uses a type (eg, a transparent substrate) suitable for a type and shape (eg, an organic thin film transistor, an organic electroluminescent device, etc.) of the organic electronic device to be manufactured. After applying the first photoresist 220, a heat treatment process is performed to activate the deposited first photoresist 220 (S310). In the next process, the first photoresist 220 is exposed to the entire surface without a mask (lithography, S315). The exposure may use various methods such as optical lithography and radiation lithography. In this embodiment, the exposure process is performed using ultraviolet (UV) light.

Referring to FIG. 2C, the metal thin film 230 is formed on the first photoresist 220 exposed to the entire surface (S320). The metal thin film 230 may be formed of a material capable of etching the first photoresist 220 with a developer capable of etching the first photoresist 220. In general, since the developer capable of etching the first photoresist 220 is a basic solution, an etchable metal is used for the basic solution. In the present embodiment, the metal thin film 230 is formed using aluminum (Al) etched in the basic solution.

The metal thin film 230 may control the thickness of the metal thin film 230 according to a deposition rate, a deposition time, and the like, and may be deposited to a thickness less affecting a second photoresist (not shown) to be formed on the metal thin film 230. It is preferable. In general, the etching rate of the metal thin film 230 by the developer is relatively slow compared to the photoresist developing speed, and when the thickness of the metal thin film 230 becomes thick, the time taken to etch the metal thin film 230 becomes longer and the upper portion is increased. Since the second photoresist to be formed in the can be etched too much, in consideration of this, the metal thin film 230 is deposited to a thickness of about 1 ~ 10Å.

2D and 2E, the second photoresist 240 is coated on the metal thin film 230 (S325). In general, the first and second photoresists 220 and 240 are compounds that exhibit a sensitive reaction to light, and are positive photosensitive agents in which a portion of light is soluble in a developer and a negative photosensitive agent in which a portion of light is insoluble in a developer. Since it can be divided and marketed in various ways by manufacturers, it can be appropriately selected and used in accordance with the characteristics of the organic electronic device manufactured these materials.

After applying the second photoresist 240, the second photoresist 240 is heat-treated (S330). Meanwhile, the second photoresist 240 is heat treated at a temperature lower than or equal to the heat treatment temperature of the first photoresist 220. This is because when the heat treatment temperature of the second photoresist 220 is higher than the heat treatment temperature of the first photoresist 240, the first photoresist 220 may be deformed during the heat treatment of the second photoresist 240. . In this embodiment, the second photoresist 240 is heat-treated in the range of 80 to 150 ° C. After the heat treatment is performed, a mask 250 is formed on the second photoresist 240 (S335). After the mask 250 is formed, the second photoresist 240 is exposed according to the formed mask 250 pattern (S340).

Referring to FIG. 2F, after exposing the second photoresist 240, the first photoresist 220 and the second photoresist 240 are developed (S345). The first and second photoresists 220 and 240 may be simultaneously developed using the same developer. When the first photoresist 220 and the second photoresist 240 are developed, an overhang 240a is formed. The height h of the overhang 240a can be controlled according to the thickness of the second photoresist 240, and the thickness of the metal thin film 230 also affects the height h of the overhang 240a. Can give The depression width w of the overhang 240a may be controlled by the exposure time of the first photoresist 220, the stack thickness and the development time of the metal thin film 130, and the exposure time of the first photoresist 220. In order to increase the thickness, or to deposit the metal thin film 230 thickly, or to increase the development time of the metal thin film 230, the depression width w of the overhang 240a may be controlled to a depth of 0.1 μm to 30 μm. Specifically, when the exposure time of the first photoresist 220 is longer, the development of the first photoresist 220 is faster, and when the thickness of the metal thin film 230 is thicker, the developer is used to uniformly etch the metal thin film 230. When the exposure time is increased, and when the development time of the metal thin film 230 is longer, the first photoresist 220 is excessively developed, the recessed width w of the first photoresist 220 may be deepened. have.

Referring to FIG. 2G, after the first and second photoresists 220 and 240 are patterned to have an overhang through a developing process, the patterned second photoresist 250 and the exposed substrate 210 are formed. The organic material layer 260 to be used for the organic electronic device is deposited on the surface (S350). Referring to FIG. 2H, a passivation layer 270 is formed on the organic material layer 260 (S355). After the protective film 270 is formed, referring to FIG. 2I, a lift-off process is performed using the protective film 270 as a mask (S360). Through the above process steps, the organic material layer 260 to be used for the organic electronic device and the passivation layer 270 formed on the organic material layer 260 remain on the substrate 210.

4 is a photograph of a photoresist having a multilayer structure according to the present invention. Referring to FIG. 4, in FIG. 4, photoresist 220 and 240 having a multi-layer structure are disclosed on a substrate 210 and formed by the development of the first photoresist 220 and the second photoresist 240. It can be seen that the overhang 240a is disclosed. As described above, by forming the photoresist 220 and 240 having a multi-layer structure, damage to the photoresist may be prevented by a lift-off process, and thus, a characteristic change of the organic material layer used in the organic electronic device may be prevented.

The organic material layer patterning method of the organic electronic device described above, specifically, a method of laminating a photoresist having a multilayer structure, forming an overhang using the same, and then patterning the organic material layer using a lift-off process (FIGS. 2i and 3), the organic material layer of the organic thin film transistor can be patterned, and the characteristics of the organic material layer used in the organic electroluminescent device and the organic electroluminescent display or a protective film thereon may be changed. It can be finely patterned without. Furthermore, the patterning method can be used for patterning the organic material layer / inorganic material layer used in the organic thin film transistor, the organic electroluminescent device and the organic electroluminescent display.

Although the technical spirit of the present invention has been described in detail according to the above-described preferred embodiment, the embodiment is for the purpose of description and not of limitation, and those skilled in the art will appreciate that various changes within the scope of the technical idea of the present invention. It will be appreciated that embodiments are possible.

As described above, according to the above, the present invention can improve the chemical stability compared to the case of applying to the conventional inorganic electronic material process by using a lift-off process in the process of fine patterning the organic material layer of the organic electronic device, Even after forming a desired pattern, the characteristics of the organic material layer are not deteriorated.

In addition, the present invention by forming a photoresist used in the lift-off process in a multi-layer structure, it is possible to prevent the deformation during the process, even after forming a protective film to protect the organic material layer to perform fine patterning without changing the characteristics of the organic material layer can do.

Claims (13)

Applying a first photoresist on the substrate, Heat treating the applied first photoresist; Exposing the entire surface of the first photoresist; Depositing a metal thin film on the first photoresist; Forming a second photoresist on the metal thin film; Heat treating the applied second photoresist; Forming a mask according to a desired pattern on the heat treated second photoresist; Exposing the second photoresist on the mask; Developing the first photoresist and the second photoresist; Forming an organic material layer for use in an organic electronic device on the patterned substrate and the second photoresist; Forming a protective film on the surface of the organic material layer, and Removing the first and second photoresist by a lift-off method Including but not limited to: In the developing of the first photoresist and the second photoresist, Developing using a developer capable of developing the first photoresist and the second photoresist simultaneously The organic material layer patterning method of the organic electronic device. delete The method of claim 1, The developer is an organic material layer patterning method of the organic electronic device is a basic solution. The method of claim 1, In the developing of the first photoresist and the second photoresist, And forming an overhang protruding to one side from the first photoresist pattern side in the second photoresist. The method of claim 4, wherein And the thickness of the overhang is controllable using at least one of the thickness of the second photoresist and the metal thin film. The method of claim 4, wherein The overhang recessed width is 0.1 μm to 30 μm. The organic material layer patterning method of the organic electronic device. The method of claim 6, The method of patterning the organic material layer of the organic electronic device to control the depression width of the overhang by using at least one of the thickness of the metal thin film, the exposure time and the development time of the first photoresist. The method of claim 1, And heat treating the first photoresist at a temperature equal to or higher than the heat treatment temperature of the second photoresist. The method of claim 8, The heat treatment temperature of the second photoresist is 80 ~ 150 ℃ organic material layer patterning method of an organic electronic device. The method of claim 1, The thickness of the metal thin film in the step of depositing the metal thin film organic material layer patterning method of the organic electronic device. The method of claim 10, In the depositing the metal thin film, the organic material patterning method of forming the metal thin film using aluminum. Claim 1, 3, 4, 5, 6, 7, 8, 9, 10, and 11 of the organic electronic device according to any one of the An organic thin film transistor manufactured by using an organic material layer patterning method. Claim 1, 3, 4, 5, 6, 7, 8, 9, 10, and 11 of the organic electronic device according to any one of the An organic electroluminescent device fabricated using an organic material layer patterning method.

Images