KR101049218B1 - Micro pattern formation method using applied pressure elimination - Google Patents

Abstract

The present invention relates to a method for forming a fine pattern, a substrate preparation step, a polymer layer forming step of applying a polymer layer on the substrate, a stamp pressing step of pressing the polymer layer using a stamp having a fine pattern, A pressure removing step of removing the pressing force applied to the stamp, a polymer layer curing step of curing the polymer layer, and a stamp separation step of separating the stamp from the polymer layer.

As described above, according to the present invention, a precise fine pattern can be accurately formed by removing the pressing force applied to the stamp and restoring the stamp.

Fine pattern, pressing force, stamp, polymer layer

Description

FINE PATTERN FORMING METHOD USING PRESS AND RELEASE IMPRINT}

The present invention relates to a method of forming a fine pattern, and more particularly to a method of forming a fine pattern comprising the step of removing the pressing force applied to the stamp.

Nano Technology (NT), along with Information Technology (IT) and Biotechnology (BT), is attracting attention as a new paradigm that will lead industrial development in the 21st century.

In addition, nanotechnology is a convergence of various scientific and technological fields such as physics, chemistry, biology, electronics, and materials engineering, overcoming the limitations of existing technologies, and innovating technology in various industries to dramatically improve the quality of human life. It is expected to improve.

Nanotechnology can be divided into a top-down approach and a bottom-up approach depending on the approach. The approach from top to bottom, as can be seen in the history of semiconductor integrated devices that have evolved over the last few decades, has enabled existing microstructure fabrication technologies to further advance to the nanometer scale to continue increasing information storage capacity and information processing speed. It is a technique to do. In contrast, the approach from bottom to top controls materials at the atomic or molecular level, or uses spontaneous nanostructure formation to induce new physical and chemical properties that would not be possible with existing technologies, and use them to create new materials and devices. It is a technique to make.

A representative example of the approach from top to bottom is the optical lithography technique used in existing semiconductor device manufacturing processes. Technological advances of the 20th century, called the information technology revolution, have relied heavily on miniaturization and integration of semiconductor devices, and the key technology of the semiconductor device manufacturing process is optical lithography. However, optical lithography has a disadvantage in that it is difficult to fabricate a pitch of 100 nm or less due to the limitation of the line width of the laser, and thus, there have been many attempts to develop a process using nanoimprint technology.

Nanoimprint technology is a nano device fabrication method introduced by Professor Stephen Chu of Princeton University in the mid-1990s, and is attracting attention as a technology that can compensate for the low productivity of electron beam lithography and the expensive optical lithography equipment.

Nanoimprint technology solves the low productivity problem of electron beam lithography by fabricating a stamp with a nanoscale pattern using electron beam lithography or other methods, imprinting the stamp on a polymer thin film to transfer the nanostructures and using them repeatedly.

However, when imprinting using a stamp, a problem arises in that the fine pattern of the stamp is deformed due to the pressing force. In particular, in order to easily penetrate the photoresist or the like between the fine patterns, a stamp capable of elastic deformation is used. In the case of a stamp capable of elastic deformation, the pattern is deformed and it is difficult to transfer the correct pattern.

As such, when the photoresist is cured while the stamp is deformed, a deformed pattern is formed, thereby preventing a desired function from being exhibited.

The present invention is to provide a fine pattern forming method that can form a precise and precise pattern.

The method for forming a fine pattern according to an embodiment of the present invention includes a substrate preparation step, a polymer layer forming step of applying a polymer layer on the substrate, a stamp pressing step of pressing the polymer layer using a stamp having a fine pattern formed thereon; And a pressing force removing step of removing the pressing force applied to the stamp, a polymer layer curing step of curing the polymer layer, and a stamp separation step of separating the stamp from the polymer layer.

The polymer layer may be formed of a photocurable polymer or a thermosetting polymer, and the fine pattern formed on the stamp may be made of any one material selected from the group consisting of PDMS, PMMA, teflon, and polyurethane.

In addition, the fine pattern may be made of a pitch of nano or micro size, the curing step of the polymer layer may be cured the polymer layer by irradiating ultraviolet light to the polymer layer, the curing step of the polymer layer to the polymer layer Heat may be transferred to cure the polymer layer.

In the polymer layer forming step, the polymer layer is deposited, spin coated, spray coating, dispensing, ink pad coating, or dipping. It may be formed by any one method selected from the group consisting of.

In addition, the stamp pressing step may pressurize the stamp using a pressure roller, and may further include the step of moving the stamp separated in the stamp separation step to the stamp pressing step. Etching and removing the residual polymer layer, wherein the pressing force removing step is to restore the stamp by maintaining until the fine pattern formed on the stamp in the state in which the pressing member installed on the stamp is removed You can.

In the polymer layer curing step, the plurality of substrates may be moved to a curing room to irradiate ultraviolet rays toward the plurality of substrates at once, and the substrates may be installed on a conveyor system and transferred.

According to the present invention, a finer pattern can be formed by removing the pressing force applied to the stamp in the process of forming the fine pattern on the polymer layer and maintaining a predetermined time so that the fine pattern of the stamp can be restored.

In addition, by reducing the non-uniform pressure distribution on the stamp surface, it is possible not only to prevent deformation of the stamp but also to improve the uniformity of the residual layer.

In the present invention, the "fine pattern" refers to a pattern in which the height, pitch, etc. of the pattern have a micro or nano size.

In addition, in the present invention, "on" means to be located above or below the target member, and does not necessarily mean to be located above the gravity direction.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like elements throughout the specification.

1 is a flowchart illustrating a method for forming a fine pattern according to a first embodiment of the present invention, and FIGS. 2A to 2G are flowcharts for describing a method for forming a fine pattern according to a first embodiment of the present invention.

Referring to FIGS. 1 and 2A to 2G, the method for forming a fine pattern according to the present embodiment includes preparing a substrate (S101), a polymer layer forming step (S102) of applying a polymer layer on a substrate, and a polymer layer. Stamp pressing step (S103) to pressurize the stamp, pressing force removal step (S104) for removing the pressing force applied to the stamp, polymer layer curing step (S105) for curing the polymer layer, and stamp separation step (S106).

As shown in FIG. 2A, the substrate 110 is prepared, and a polymer is coated on the substrate 110 to form a polymer layer 120.

The substrate 110 may have a flat plate shape and may be made of a metal such as synthetic resin or aluminum.

The polymer layer 120 may be formed by various methods such as deposition, spin coating, spray coating, dispensing, ink pad coating, dipping, and sputtering. It may be formed and consists of a thermosetting polymer or a photocurable polymer.

When the polymer layer 120 is formed, as shown in FIG. 2B, a stamp 130 having a fine pattern is prepared, and the stamp 130 is brought into close contact with the polymer layer 120 to form the polymer layer 120 using the stamp 130. Pressurize.

The stamp may be made of a polymer such as thermosetting PDMS (polydimethylsiloxane), photocurable PDMS, teflon (teflon), polyurethane (polyurethane), and the like, the micropattern formed portion of the stamp is formed to be elastically changeable.

In the present embodiment, but illustrated as applying a polymer stamp, the present invention is not limited thereto, and may be made of various materials that can be elastically deformed. Thus, the stamp may be made of elastically deformable metal or rock crystal. As a result of pressurizing the bar with a pressure of 1 bar, it can be observed that elastic deformation of tens of nanometers is generated, and deformations of several tens of nanometers act as a large defect in forming nanoscale patterns.

As such, even a stamp made of metal or crystal is deformed during the pressing process, and in particular, when the thickness of the polymer layer is small, the polymer layer may not elastically deform even if the stamp is made of a rigid body, and thus the stamp may be elastic. It may be made of various materials that can be modified.

When pressing the polymer layer 120, a pressing member 140 for pressing the polymer layer 120 is installed on the polymer layer 120 so that the polymer layer can sufficiently penetrate between the fine patterns 135. 120). The micro pattern 135 is deformed by the pressing force. The deformed pattern 125 is transferred to the polymer layer 120 due to the deformed micro pattern 135.

 As shown in FIG. 2D, the pressing member 140 is separated to remove the pressing force applied to the stamp 130. If the state where the pressing force is removed is maintained for a predetermined time, the fine pattern 135 of the stamp 130 is restored to its original shape. When the fine pattern 135 of the stamp 130 is restored, the fine pattern 125 corresponding to the fine pattern 135 formed on the stamp 130 is transferred to the polymer layer 120.

When the fine pattern 125 is restored, as shown in FIG. 2E, ultraviolet rays are irradiated while the stamp 130 is installed to cure the polymer layer 120 made of a photocurable polymer.

The stamp 130 is made of a transparent material so that ultraviolet rays can be sufficiently transmitted to the polymer layer 120. In the present embodiment, the polymer layer 120 is illustrated as being made of a photocurable polymer, but the polymer layer 120 may be made of a thermosetting polymer. When the polymer layer 120 is made of a thermosetting polymer, heat is applied to cure the polymer layer 120.

When the polymer layer 120 is cured, the stamp 130 is separated from the polymer layer 120 as shown in FIG. 2F. When the stamp 130 is separated from the polymer layer 120, as shown in FIG. 2G, the polymer layer 120 that remains unnecessarily is removed using a plasma or the like.

As described above, according to the present exemplary embodiment, the micro pattern 135 of the stamp 130 is removed by removing the pressing force applied to the stamp 130 and maintaining a predetermined time in the process of forming the micro pattern 125 on the polymer layer 120. By allowing it to be restored, a more precise pattern can be formed. In addition, by forming a fine pattern by a lithography method using the stamp 130, it is possible to form a pattern more easily.

FIG. 3A is a photograph of a 50 μm-sized structure manufactured using soft ultraviolet nanoimprinting according to the prior art using an atomic force microscope (AFM), and FIG. 3B illustrates a first embodiment of the present invention. The 50㎛ sized structure was prepared by analyzing the atomic force microscope.

In general, the larger the size, the more severe the deformation of the structure formed on the stamp by pressure. In order to easily analyze the deformation of the stamp, a structure of 50 μm × 50 μm was formed using a PDMS stamp using the method according to the prior art and the method according to the present embodiment, and then analyzed by an atomic force microscope.

Looking at Figure 3a it can be seen that the pattern is severely deformed by the pressing force applied to the stamp, and looking at Figure 3b it can be seen that the pattern is almost completely formed by removing the pressing force, and after curing the pattern, by curing.

As such, according to the prior art, it is difficult to form a precise pattern, whereas according to the present embodiment, a precise pattern can be accurately formed.

On the other hand, when pressing the stamp, the applied pressing force is not uniformly distributed on the surface of the stamp, but the pressure applied to the center and the edge of the contact area is different, and this pressure difference adversely affects the uniformity of the applied liquid polymer. Cause uneven residue layer. However, when the applied pressing force is removed, the non-uniform pressure distribution on the stamp surface is reduced, thereby preventing deformation of the stamp and improving uniformity of the residual residue layer.

4A to 4C are flowcharts illustrating a method of forming a fine pattern according to a second embodiment of the present invention.

The second embodiment is the same as the above-described first embodiment and forming the micropattern 125 on the polymer layer 120 on the substrate 110. After the micropattern 125 is formed, an additional process is performed. Conduct. The duplicate description of the same process is omitted here.

In the second embodiment, the polymer layer 120 is made of photoresist.

When the fine pattern 125 formed of the polymer layer 120 is formed on the substrate 110, the substrate 110 is injected into an oven (not shown) to cure the polymer layer 120, and then, as illustrated in FIG. 4A. As described above, in order to etch the substrate 110, the substrate 110 is placed in a water tank 170 containing the etchant 175. When a predetermined time elapses while the substrate 110 is immersed in the etchant 175, the portion of the exposed substrate 110 is etched without being covered with the polymer layer 120 to form a fine pattern 115 on the substrate 110. do.

When the fine pattern 115 is formed on the substrate 110, as shown in FIG. 4B, the polymer layer 120 remaining on the substrate is removed using a plasma or the like. When the polymer layer 120 is removed, as shown in FIG. 4C, the substrate 110 on which the fine pattern 115 is formed may be obtained.

As such, according to the present exemplary embodiment, the fine patterns 115 may be formed on the substrate 110 itself, and thus the substrate 110 may be applied to various fields, such as fabrication of electronic devices.

5A to 5E are process charts illustrating a method for forming a fine pattern according to a third embodiment of the present invention. The third embodiment provides a method for forming a fine pattern in large quantities.

Referring to FIGS. 5A to 5E, first, the substrate 210 is prepared as shown in FIG. 5A, and the polymer layer 230 is formed on the substrate 210. The polymer layer 230 may be formed by various methods such as deposition and spin coating, and may be made of a thermosetting polymer or a photocurable polymer.

As shown in FIG. 5B, the polymer layer 230 is pressed by using the stamp 240. After the pressing member 250 is installed on the stamp, the pressing member 250 is pushed so that the polymer layer 230 is stamped. It is pressurized to sufficiently penetrate between the fine patterns 245 formed on the 240. At this time, the fine pattern 245 formed on the stamp 240 is deformed by the pressing force, and the fine pattern 235 formed on the polymer layer 230 by the stamp is also deformed.

Pressing the polymer layer 230 is performed within a few seconds. When the polymer layer 230 is sufficiently penetrated between the fine patterns 245, the pressing member 250 is removed as shown in FIG. 5C, and the stamp ( The substrates 210 combined with 250 are moved to the weighting room so that the fine pattern of the stamp is restored.

In this case, when the pressure is removed, in the printing step, the polymer layer 230 is continuously printed using the other stamp 250. Accordingly, the substrates 210 are collected in the weighting room 260.

When all of the fine patterns 245 are restored, the plurality of substrates 210 are moved to the curing room 270 as shown in FIG. 5D, and the polymer layer 230 is irradiated with ultraviolet rays 275 toward the substrates 210. ) Harden.

When the polymer layer 230 is cured, as shown in FIG. 5E, the stamp 240 may be separated to obtain the polymer layer 230 having the fine pattern 235 formed thereon, and the separated stamp 240 may be moved to a pressing step. do.

In this embodiment, since the fine pattern is recovered and cured in large quantities, the polymer layer having the fine pattern can be produced in large quantities.

6 is a schematic process chart for explaining a method for forming a fine pattern according to a fourth embodiment of the present invention, Figures 7a to 7e is a detailed process diagram for explaining a method for forming a fine pattern according to a fourth embodiment of the present invention to be.

The fine pattern forming method according to the present embodiment provides a method of forming a fine pattern in an automated continuous process.

Referring to FIG. 6, in the present embodiment, a pattern is formed in a continuous process while moving the substrate 321 using the conveyor system 310. The conveyor system 310 includes a conveying roller 315 and a belt 312 moved by the conveying roller 315.

As shown in FIG. 7A, the substrate 321 is raised and transported on the conveyor system 310. In the transfer process, the polymer liquid is supplied onto the substrate 321. The polymer liquid is injected onto the substrate 321 by the scanning device 326, and the planarization roller 327 is installed on the substrate 321. The planarization roller 327 is installed adjacent to the substrate 321 on the substrate 321 to serve to flatten the polymer layer 325.

When the polymer layer 325 is formed, as shown in FIG. 7B, the substrate 321 is continuously transferred, and the stamp 341 is pressed onto the polymer layer 325. A plurality of fine patterns 341a are formed in the stamp 341, and are pressed to the polymer layer 325 by the pressure roller 345. The pressure roller 345 presses the stamp 341 so that the polymer layer 325 sufficiently penetrates between the fine patterns 341a of the stamp 341. The pressure of the stamp 341 is applied by the pressing force of the pressure roller 345. The pattern 341a is partially deformed.

When the stamp 341 is pressed using the pressure roller 345 as described above, the polymer layer 325 can easily penetrate between the fine patterns 341a, and minimize the deformation of the stamp 341 to minimize the stamp 341. The time for restoring can be shortened.

When the stamp 341 is completely installed in the polymer layer 325, as shown in FIG. 7C, after the pressing roller 345 is removed, the fine pattern 341a of the stamp 341 is transferred while transferring the substrate 321. To be restored. At this time, the path for transferring the substrate 321 is set long so that the stamp 341 can be sufficiently restored before irradiating ultraviolet rays. When the fine pattern 341a of the stamp 341 is restored, the fine pattern 341a of the stamp 341 is transferred to the polymer layer 325 to form the fine pattern 325a.

As shown in FIG. 7D, when the stamp 341 is completely restored, the stamp 341 is transferred to an ultraviolet irradiation device to cure the polymer layer 325. At this time, the ultraviolet light 350 is irradiated to the polymer layer 325 while the stamp 341 is installed, and the stamp 341 is made of a transparent material so that the ultraviolet light 350 can be easily transmitted to the polymer layer 325. .

When the polymer layer 325 is cured by the irradiation of the ultraviolet light 350, the fine pattern 325a is formed on the polymer layer 325.

As shown in FIG. 7E, the stamp 341 is separated from the polymer layer 325 to complete formation of the fine pattern 325a in the polymer layer 325.

According to this embodiment, it is possible to manufacture a large amount of the structure having a fine pattern on the substrate in a continuous process.

In the above description of the preferred embodiment of the present invention, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to the range of.

1 is a flowchart illustrating a method for forming a fine pattern according to a first embodiment of the present invention.

2A to 2G are flowcharts illustrating a method of forming a fine pattern according to a first embodiment of the present invention.

3A is a photograph showing a fine pattern formed according to the prior art, and FIG. 3B is a photograph showing a fine pattern formed according to the first embodiment of the present invention.

4A to 4C are flowcharts illustrating a method of forming a fine pattern according to a second embodiment of the present invention.

5A to 5E are flowcharts illustrating a method of forming a fine pattern according to a third embodiment of the present invention.

6 is a schematic process diagram illustrating a method for forming a fine pattern according to a fourth embodiment of the present invention.

7A to 7E are detailed process diagrams for describing a method for forming a fine pattern according to a fourth embodiment of the present invention.

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

110: substrate 115: fine pattern

120: polymer layer 130: stamp

140: pressure member 170: water tank

Claims (13)

Substrate preparation step; Forming a polymer layer on the substrate; A stamp pressing step of pressing the polymer layer using a stamp in which a fine pattern is formed and elastically deformable; A pressing force removing step of removing the pressing force applied to the stamp; A polymer layer curing step of curing the polymer layer; And A stamp separation step of separating the stamp from the polymer layer; Including, In the pressing force removing step, after the pressing force is removed, the substrate and the stamp are combined until the restoration of the micro pattern is performed by moving the substrates combined with the stamp to a weighting room so that the micro pattern of the elastically deformed stamp is restored. To form a fine pattern. The method of claim 1, The polymer layer is a fine pattern forming method consisting of a photocurable polymer or a thermosetting polymer. The method of claim 1, The fine pattern formed on the stamp is a fine pattern forming method consisting of any one material selected from the group consisting of polydimethylsiloxane (PDMS), poly methyl meta acrylate (PMMA), teflon, polyurethane. The method of claim 1, The fine pattern is a fine pattern forming method having a nano or micro size pitch. The method of claim 1, The polymer layer curing step of curing the polymer layer by irradiating ultraviolet light to the polymer layer. The method of claim 1, The polymer layer curing step is to transfer heat to the polymer layer to harden the polymer layer forming method. The method of claim 1, In the polymer layer forming step, the polymer layer is formed of deposition, spin coating, spray coating, dispensing, ink pad coating, and dipping. Fine pattern forming method formed by any one method selected from the group. The method of claim 1, The stamp pressing step is a fine pattern forming method for pressing the stamp using a pressure roller. The method of claim 1, The method of claim 1, further comprising moving the stamp separated in the stamp separating step to the stamp pressing step. The method of claim 1, Etching the substrate and removing the residual polymer layer. The method of claim 1, The pressing force removing step is to restore the stamp by maintaining until the restoration of the fine pattern formed on the stamp in a state in which the pressing member installed on the stamp. The method of claim 1, In the curing of the polymer layer, a plurality of substrates are moved to a curing room to irradiate ultraviolet rays toward the plurality of substrates at one time. Substrate preparation step; Forming a polymer layer on the substrate; A stamp pressing step of pressing the polymer layer using a stamp in which a fine pattern is formed and elastically deformable; A pressing force removing step of restoring the stamp by holding the pressing force applied to the stamp until the restoration of the fine pattern; A polymer layer curing step of curing the polymer layer; And A stamp separation step of separating the stamp from the polymer layer; Including, The substrate is installed and transported on a conveyor system, each step is a process for forming a fine pattern continuously on the conveyor system.

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