KR20050078279A - Method for forming micro-pattern by using polymer mold - Google Patents

Abstract

The present invention is to enable the formation of a fine pattern of a low molecular organic material or a metal on the substrate through a technique of selectively peeling and remaining a thin film formed on the substrate using a polymer mold. Unlike the conventional method of forming a fine pattern on a substrate in such a way that an organic material or a metal thin film is not formed on an undesired portion by using a polymer mold having an arbitrary pattern of an embossed portion and an intaglio portion, a low molecular organic material or The micro pattern of the thin film on the substrate is contacted on the substrate on which the metal thin film is formed in close contact with each other, the heat treatment process is performed at a glass transition temperature or lower, and then only the low molecular organic material or the metal material contacting the embossed portion of the polymer mold is selectively peeled off. Formation, greatly improving product productivity and reliability It can be enhanced by, and, it is possible to realize a significant reduction of production accordingly not only highly effective in large size and miniaturization of the display it is possible to fundamentally prevent the shadow effect cost.

Description

Micro pattern formation method using polymer mold {METHOD FOR FORMING MICRO-PATTERN BY USING POLYMER MOLD}

The present invention relates to a semiconductor device, and more particularly to a fine pattern forming technique suitable for forming a fine pattern of a thin film on a substrate using a polymer mold.

As is well known, polymer or low-molecular organic materials in the field of electronic materials have been steadily studied to replace current inorganic materials, and the possibility is gradually being realized.

Meanwhile, in the manufacture of organic light-emitting diodes and other organic devices, which are closest to industrialization, traditional shadow mask methods are used to pattern organic materials or metal cathodes. This traditional method uses a shadow mask to prevent the formation of organic or metal thin films on unwanted portions.

However, such a traditional shadow mask method has a problem that it is difficult to manufacture a mask as the size of the pattern becomes smaller (a limitation problem in making a mask), and the ratio of the error for the pattern is inevitably increased due to the shadow effect. Has disadvantages.

In addition, the traditional shadow mask method has a problem that it is difficult to keep the distance between the shadow mask and the substrate as a whole as the size of the display increases, and to solve this problem, the thickness of the mask must be thickened. Another problem is that the resolution becomes low.

Therefore, the traditional shadow mask method inevitably entails a problem that the manufacturing cost increases rapidly as the display becomes larger and smaller.

Meanwhile, in polymer light-emitting diodes, in addition to the conventional spin-coating or ink-jet printing methods for patterning polymer materials, patterning methods using polymer molds such as PDMS are available. It is being tried.

Among the above methods, patterning using a polymer mold such as PDMS requires a temperature higher than the glass transition temperature (T _g ) of the polymer or a solvent, and these methods cannot be used for the patterning of low molecular organic materials. There was no. In other words, excessive temperature above the glass transition temperature may crystallize the low molecular weight organic material and use of the solvent may damage or dissolve the low molecular weight organic material.

The present invention is to solve the above problems of the prior art, by using a technique of selectively peeling and remaining a low molecular organic thin film formed on the substrate using a polymer mold can form a fine pattern of the low molecular organic material on the substrate The purpose is to provide a method.

Another object of the present invention is to provide a method for forming a fine pattern of metal on a substrate through a technique of selectively peeling and remaining a metal thin film formed on the substrate using a polymer mold.

The present invention according to one embodiment for achieving the above object is a method of forming a fine pattern on a substrate using a polymer mold having an arbitrary pattern of an embossed portion and an intaglio portion, a low molecular organic thin film on the substrate Forming a surface of the polymer mold by closely contacting the patterned surface of the polymer mold with the thin film of organic polymer, and performing a heat treatment at a predetermined temperature and pressure. A method of forming a fine pattern using a polymer mold, the method including forming a fine pattern of a low molecular organic material on the substrate by selectively peeling only the low molecular organic thin film adhered to a portion thereof.

According to another aspect of the present invention, there is provided a method of forming a fine pattern on a substrate using a polymer mold having an arbitrary pattern of an embossed portion and an intaglio portion, forming a metal thin film on an organic substrate. And performing a heat treatment process at a predetermined temperature and unpressurized process condition after closely contacting the pattern surface of the polymer mold on the metal thin film, and removing the polymer mold to the embossed portion. A method of forming a fine pattern using a polymer mold, the method including forming a fine pattern of a metal on the organic substrate by selectively peeling only the adhered metal thin film from the organic substrate.

The above and other objects and various advantages of the present invention will become more apparent from the preferred embodiments of the present invention described below with reference to the accompanying drawings by those skilled in the art.

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

First, a key technical aspect of the present invention is that unlike the aforementioned conventional method of forming a fine pattern on a substrate in such a manner that an organic material or a metal thin film is not formed in an unwanted portion by using a shadow mask, A low molecular organic material or metal material contacting an embossed part of the polymer mold after the polymer mold having an arbitrary pattern of the intaglio parts is brought into close contact with the low molecular organic material or the substrate on which the metal thin film is formed, and the heat treatment is performed at a glass transition temperature or lower. By forming the fine pattern of the thin film on the substrate in a manner of selectively peeling only, it is easy to achieve the object of the present invention through this technical means.

As is well known, one of the reasons that the PDMS mold is mainly used to mold the micropatterned polymer material is because the surface energy is low and the polymer material does not stick well and is not reactive and thus does not form a bond with the polymer material. Therefore, after the polymer thin film was formed, the polymer could not be molded without applying a temperature higher than the glass transition temperature.

On the other hand, in the patterning of small molecule organics, if the PDMS mold is contacted with the surface of the organic thin film and removed after a certain time while applying a suitable temperature below the glass transition temperature, the organic material in the portion where the PDMS mold is in contact with the substrate It is possible to form a desired pattern on the substrate away from (peeled out) from the present invention. In the present invention, the thin film of the target thin film on the substrate can be selectively peeled off and left on the substrate by using the principle. Form a pattern.

1A to 1C are process flowcharts illustrating a process of forming a fine pattern on a substrate using a polymer mold according to a preferred embodiment of the present invention.

Referring to FIG. 1A, a polymer mold 106 having an arbitrary pattern of an embossed portion 106a and an intaglio portion 106b is prepared, and a substrate (eg, indium-tin) is performed by performing a process such as vacuum deposition. An oxide substrate, etc.) to form a low molecular weight organic thin film 104. Here, the polymer mold 106 is a fully cured mold.

Subsequently, as shown in FIG. 1B, the patterned surface of the polymer mold 106 is brought into close contact with the low molecular weight organic thin film 104, whereby only the embossed portion 106a of the polymer mold 106 has a low molecular weight organic thin film 104. Is selectively contacted).

Next, an annealing process is performed for a predetermined time at a temperature condition lower than the glass transition temperature of NPB, for example, a temperature range of about 95 ° C to 110 ° C, for example, about 90 ° C. . Here, the heat treatment process is performed to increase the adhesive force at the interface between the embossed portion 106a of the polymer mold 106 and the low molecular organic thin film 104 in contact therewith, and the heat treatment is performed at a temperature below the glass transition temperature. The reason for carrying out the process is to prevent the low molecular organics from thermal damage (such as alteration or alteration of properties).

Subsequently, the polymer mold 106 is removed from the substrate 102, wherein the low molecular weight organic thin film 104b which is in contact with the embossed portion 106a of the polymer mold 106 is the embossed portion 106a of the polymer mold 106. Adhered to the substrate 102 and peeled from the substrate 102, the low molecular weight organic thin film in the portion opposite to the intaglio portion 106b but not the embossed portion 106a is left on the substrate 102 as it is. As shown in FIG. 1C, the fine pattern 104a of the target low molecular weight organic material is completed on the substrate 102.

That is, according to the present invention, a fine pattern of a target low molecular organic material, for example, a fine pattern of several millimeters to 1 micron or less is formed on a substrate through a polymer mold having an arbitrary pattern and a simple heat treatment process. can do.

On the other hand, in the preferred embodiment of the present invention has been described as to form a fine pattern of a low molecular organic material having a target pattern on the substrate, the present invention is not necessarily limited to this, the low molecular weight through substantially the same to similar process Not only the fine pattern of the organic material but also the fine pattern of the metal may be formed on the organic substrate.

In addition, the method for forming a fine pattern using the polymer mold according to the present invention may also be patterned on a flexible substrate which is impossible in a conventional exposure process. Therefore, the method of forming a fine pattern according to the present invention can be applied not only to an organic light emitting device but also to an organic electronic device such as an organic thin-film transistor or an organic laser. to be.

Furthermore, in the preferred embodiment of the present invention, the use of a polymer mold for patterning has been described as an example, but the present invention is not necessarily limited thereto, and an elastomer polymer mold may be used.

Next, the inventors of the present invention conducted an experiment for forming a fine pattern of low molecular weight organic material on the substrate according to the method of the present invention, the results are as shown in Figs.

2 is an indium-tin oxide substrate of NPB (4,4'-bis [N-1-napthyl-N-phenyl-amino] biphenyl) used as a hole transporting material of an organic light emitting diode according to a preferred embodiment of the present invention. Figure 3 is a photograph of the result of patterning using a PDMS mold after vacuum deposition on, Figure 3 is a NPB thin film deposited on an indium-tin oxide substrate and then patterned using a PDMS mold, Alq3, a green light emitting material, an insulating film It is a light emission photograph of the organic light emitting element produced by sequentially depositing LiF and Al thin films which are cathodes.

That is, the inventors of the present invention perform an experiment in which the method of forming a micropattern according to the present invention is applied to an organic light emitting device, that is, after cleaning the indium-tin oxide substrate and transferring it to a glove box to deposit an NPB thin film, The PDMS mold was patterned according to the present invention. Subsequent processes were performed to sequentially deposit Alq3, a green light emitting material, LiF, an insulating film, and a thin Al film, a cathode. As a result, FIGS. 2 and FIG. As shown in FIG. 3, it can be seen that the organic light emitting device manufactured through the simplified process emits light normally.

4A and 4B are SEM and AFM images of a low molecular organic pattern formed on a substrate according to an experimental example of the present invention.

That is, FIG. 4A is an SEM image of line patterns having various sizes, where a dark part is an organic material remaining and a bright part is an organic material removed to expose a substrate.

In addition, Figure 4b shows an AFM image of the line pattern formed on the substrate through an experimental example of the present invention, it can be seen that the shadow effect does not occur at all, that is, the pattern is formed with a nearly vertical angle .

In the experimental example of the present invention, NPB, which is a low molecular organic material, was tested. However, the present invention is not limited thereto, and NPB (N, N'-bis) -N, N'-bis is not limited thereto. (phenyl) benzidine), TPD (N, N'- bis (3-methylphenyl) -N, N'- bis (phenyl) benzidine), Alq3 (tris (8-hydroxyquinoline) aluminum), DPVBi (4, 4 '- bis (2, 2 -diphenylvinyl) biphenyl), BCzVBi (4, 4 '-bis (9-ethyl-3-carbazovinylene)-1, 1'-biphenyl), DCM2 (4-(dicyanomethylene)-2-methyl-6 -(julolidin-4-yl-vinyl)-4H-pyran), MTDATA (4, 4 ', 4 "-tris (N-3-methylphenyl-N-phenyl-amino) triphenylamine), Rubrene (5, 6, 11 It is, of course, applicable to low molecular weight organic materials such as 12-tetraphenylnaphthacene) and copper phthalocyanine (CuPC).

Therefore, the method for forming a fine pattern according to the present invention selectively removes a low molecular organic material or a metal thin film from a substrate (or an organic substrate) by using a polymer mold (PDMS mold or a polymer elastomer mold) rather than the conventional shadow mask method ( Forming a desired pattern on the substrate (or the organic substrate) in a manner of peeling), thereby forming a desired pattern without damaging the fine pattern of the low molecular organic material or the metal formed on the substrate. This can greatly increase the productivity and reliability of the product.

In addition, the method for forming a fine pattern according to the present invention is very effective for large-sized and miniaturized displays, as well as a significant reduction in manufacturing cost, since the shadow effect due to the use of the shadow mask does not occur at the source. have.

Furthermore, in the conventional polymer patterning using PDMS, the aspect ratio of the PDMS mold affects the patterning. For example, in the case of very fine patterns of 100 nm or less, when the aspect ratio is 1 or more, PDMS due to technical limitations, etc. The problem arises that it becomes impossible to manufacture the mold, but in the present invention, only the contact of the PDMS mold is an issue, so even if the PDMS mold has an aspect ratio of 1 or less, a pattern (low molecular weight organic pattern, metal pattern, etc.) can be formed. Therefore, according to the present invention, a PDMS mold having an aspect ratio of 1 or less may be easily manufactured to form a very fine low molecular organic pattern or a metal pattern of 100 nm or less on a substrate.

That is, since the present invention adopts a method of selectively peeling low-molecular organic material or metal of the thin film by contacting the PDMS mold, the step (that is, the step between the embossed portion and the intaglio portion of the PDMS mold) may be very small, and thus has a PDMS mold having a fine pattern. Another advantage is that it is very easy to manufacture.

As described above, according to the present invention, unlike the aforementioned conventional method of forming a fine pattern on a substrate in such a way that an organic material or a metal thin film is not formed in an unwanted portion by using a shadow mask, the embossed portion and the intaglio Only the low molecular organic material or the metal material contacting the embossed part of the polymer mold after the polymer mold having an arbitrary pattern of parts is brought into close contact with the low molecular organic material or the substrate on which the metal thin film is formed, and the heat treatment process is performed at or below the glass transition temperature. By forming a fine pattern of the thin film on the substrate in a method of selectively peeling off, it is possible to significantly increase the productivity and reliability of the product, and also to block the shadow effect at the source, which is very effective for the enlargement and miniaturization of the display. Significant production costs Which can realize the savings.

1A to 1C are process flowcharts illustrating a process of forming a fine pattern of a low molecular organic material on a substrate using a polymer mold according to a preferred embodiment of the present invention;

2 is an indium-tin oxide substrate of NPB (4,4'-bis [N-1-napthyl-N-phenyl-amino] biphenyl) used as a hole transporting material of an organic light emitting diode according to a preferred embodiment of the present invention. Photographed after vacuum deposition on the patterned pattern using PDMS mold,

3 is a NPB thin film deposited on an indium-tin oxide substrate and patterned using a PDMS mold, and light emission of an organic light emitting device manufactured by sequentially depositing a green light emitting material Alq3, an insulating film LiF, and an Al thin film as a cathode. Picture,

4A and 4B are SEM and AFM images of a low molecular organic pattern formed on a substrate according to an experimental example of the present invention.

<Description of the code | symbol about the principal part of drawing>

102 substrate 104 low molecular weight organic thin film

106: polymer mold 106a: embossed portion

106b: engraving

Claims (8)

A method of forming a fine pattern on a substrate using a polymer mold having an arbitrary pattern of an embossed portion and an engraved portion, Forming a low molecular weight organic thin film on the substrate; Performing a heat treatment process on the pattern surface of the polymer mold in close contact with the low molecular organic material thin film and then performing a heat treatment process at a predetermined temperature and unpressurized process conditions; Removing the polymer mold and selectively peeling only the low molecular weight organic material thin film adhered to the embossed portion from the substrate, thereby forming a fine pattern of low molecular weight organic material on the substrate Fine pattern forming method using a polymer mold comprising a. The method of claim 1, The temperature condition is a fine pattern forming method using a polymer mold, characterized in that it has a temperature range at least lower than the glass transition temperature. The method of claim 1, The polymer mold is a fine pattern forming method using a polymer mold, characterized in that the PDMS mold or a polymer elastomer mold. The method according to any one of claims 1 to 3, The polymer mold is a fine pattern forming method using a polymer mold, characterized in that the cured mold. A method of forming a fine pattern on a substrate using a polymer mold having an arbitrary pattern of an embossed portion and an engraved portion, Forming a metal thin film on the organic substrate, Contacting the pattern surface of the polymer mold with the metal thin film in close contact with each other and then performing a heat treatment process at a predetermined temperature and unpressurized process condition; Removing the polymer mold to selectively peel only the metal thin film adhered to the embossed portion from the organic substrate, thereby forming a fine pattern of a metal on the organic substrate Fine pattern forming method using a polymer mold comprising a. The method of claim 5, The temperature condition is a fine pattern forming method using a polymer mold, characterized in that it has a temperature range at least lower than the glass transition temperature. The method of claim 5, The polymer mold is a fine pattern forming method using a polymer mold, characterized in that the PDMS mold or a polymer elastomer mold. The method according to any one of claims 5 to 7, The polymer mold is a fine pattern forming method using a polymer mold, characterized in that the cured mold.