KR100984179B1 - Apparatus and method for imprinting fine structures - Google Patents

Abstract

The present invention relates to an imprint apparatus and method for mass production of a substrate having a fine pattern, comprising: a chamber providing an internal space for performing imprint lithography with a patterned stamp on a photocurable resin coated substrate; Provided is a fine pattern imprint apparatus inserted through a wall of the chamber and comprising a plurality of light transmission windows made of a light transmissive material to irradiate cured light from the outside toward the photocurable resin.

Imprint, photocurable, floodlights.

Description

Fine pattern imprint apparatus and method {APPARATUS AND METHOD FOR IMPRINTING FINE STRUCTURES}

The present invention relates to an imprint apparatus and method for mass production of a substrate on which a fine pattern is formed.

Nano-Imprinting Lithography (NIL) technique is in the spotlight as a method for forming a large amount of fine patterns.

Nano-imprinting lithography (hereinafter referred to as 'imprint') is a pattern of a pre-fabricated mold on a surface of a material having a relatively high strength, as if it is stamped onto another material of low strength, or patterned. After forming a mold having a desired structure shape, a pattern is formed by applying a polymer material into the mold. In the former case, the mold is particularly called a stamp. Such a nanoimprint technique can overcome the problem that the productivity of the micropattern is extremely low, and there is an advantage that the nanoscale micropattern can be mass produced. On the other hand, nanoimprinting lithography is not necessarily applied only to the structure of the nanoscale, but also applied to the structure of the microscale, it can be referred to as a technique for producing a fine pattern.

Referring to FIGS. 1 to 6, a process of forming a fine pattern through a general nanoimprinting lithography technique is as follows.

First, as shown in FIG. 1, the ultraviolet curable resin R is applied to the substrate S thinly. UV curable resin refers to a polymer that hardens when irradiated with ultraviolet rays.

Next, as shown in FIG. 2, the stamp M is placed on the substrate S on which the ultraviolet curable resin R is coated. Here, a predetermined pattern to be formed on the substrate S is embossed on the lower portion of the stamp M. FIG. Therefore, when the stamp M is placed on the substrate S to which the resin R is applied and pressurized, the resin R on the substrate is deformed and the shape corresponding to the pattern formed on the stamp M is the substrate S. Is formed on the phase. Of course, in this step, it may be necessary to align the position of the stamp (M) and the substrate (S) for the exact bonding of the substrate (S) and the stamp (M). In addition, in order to prevent problems such as bubbles being formed between the stamp and the resin, the bonding of the stamp M and the substrate S is performed in a vacuum atmosphere.

In the state where the stamp M and the substrate S are bonded to each other, ultraviolet rays are irradiated from the top of the stamp M by using the ultraviolet lamp L as shown in FIG. 3. At this time, since the stamp (M) is made of an ultraviolet ray transmitting material, the ultraviolet ray passes through the stamp (M) to cure the ultraviolet curable resin (R). Then, the shape corresponding to the pattern shape previously formed in the stamp M is fixed on the substrate.

Next, as shown in FIG. 4, a process of separating the stamp M from the cured resin R is performed. That is, after the ultraviolet curable resin (R) is sufficiently cured by ultraviolet irradiation, the stamp (M) is lifted upward to separate from the resin.

After separating the stamp (M) and the substrate (S), as shown in Figure 5 to remove the unnecessary resin (R) remaining on the upper substrate (S) by a method such as etching to remove the desired The board | substrate S in which the pattern was formed is obtained.

However, in order to improve the accuracy of the pattern formed on the substrate in the imprint lithography technique, the quality of the fine pattern formed by the substrate S and the stamp M is determined by how closely the stamp M and the substrate S are closely adhered to each other. Is determined accordingly. That is, when bubbles exist between the stamp M and the substrate S, the fine patterns formed on the substrate S have a smaller volume and a different shape than the target shape. Therefore, it is required to allow the resin coated on the substrate S to penetrate the shape formed in the stamp M without gap.

To this end, the bonding of the stamp M and the substrate S proceeds inside the chamber, but the bonding is performed while the chamber is kept in a vacuum atmosphere, and the chamber is again mounted while the stamp M and the substrate S are bonded. BACKGROUND ART An imprint apparatus is known that is filled at a high pressure and presses the stamp M and the substrate S to be pressed against each other by gas pressure. That is, the stamp M and the substrate S are pressed under conditions different from atmospheric pressure, and then irradiated with ultraviolet rays toward the resin to cure.

In order to cure the resin, an ultraviolet light source is installed inside the chamber or the compressed stamp M and the substrate S are taken out of the chamber and then hardened by an ultraviolet light source installed outside.

In the former case, the wall of the chamber should be made of a material that can transmit ultraviolet rays. For example, quartz or glass material transmits ultraviolet rays and thus may be selected as the material of the chamber. However, when the wall of the chamber is formed of such a material, not only the self-weight of the chamber is excessively increased, but also quartz and glass have lower toughness than metal materials, so that the structural strength is increased when the inside of the chamber is vacuumed or pressurized above atmospheric pressure. It is a problem.

On the other hand, in the latter case, the stamp M and the substrate S may move together because the resin is not yet hardened in the process of removing the stamp M and the substrate S to the outside of the chamber. That is, the alignment between the stamp M and the substrate S may be disturbed due to the fluidity of the resin, and in this case, the pattern to be formed on the substrate S is deformed, resulting in a defect.

The present invention has been made to solve the above problems, it is an object of the present invention to provide a fine pattern imprint apparatus and method that can partially cure the resin in the chamber even when the imprint proceeds in the chamber.

Other objects, specific advantages and novel features of the invention will become more apparent from the following detailed description and preferred embodiments in conjunction with the accompanying drawings.

In order to achieve the above object, a fine pattern imprint apparatus according to the present invention includes a chamber providing an internal space for performing imprint lithography with a stamp having a pattern formed on a substrate coated with a photocurable resin, and penetrating through a wall of the chamber. And a plurality of light transmission windows made of a light transmissive material so as to be inserted into and irradiated with cured light from the outside toward the photocurable resin. Wherein the chamber includes a first chamber and a second chamber which are operated to be in close contact with or spaced apart from each other and provide the inner space when the chamber is in close contact with each other, the first chuck installed in the first chamber and supporting the stamp; And a second chuck installed in the two chambers and supporting the substrate, wherein the plurality of floodlights are inserted into a wall of the first chamber. The first chuck is preferably a vacuum chuck made of a light transmissive material. Alternatively, the first chuck may be an electrostatic chuck each having through holes formed at positions corresponding to the plurality of light transmission windows.

In the fine pattern imprint apparatus according to the present invention, the plurality of light transmission windows are preferably disposed at positions corresponding to a plurality of points where the pattern of the stamp is not formed. It is preferable that the plurality of light transmitting windows are each made of an optical fiber.

On the other hand, the fine pattern imprint apparatus according to the present invention comprises a chamber providing a space for performing imprint lithography with a stamp on which a pattern is formed on a substrate coated with a photocurable resin, and installed inside the chamber to form the photocurable resin. It comprises a plurality of light sources for irradiating the cured light toward. Wherein the chamber includes a first chamber and a second chamber which are operated to be in close contact with or spaced apart from each other and provide the inner space when the chamber is in close contact with each other, the first chuck installed in the first chamber and supporting the stamp; It is further provided with a second chuck installed in the two chambers for supporting the substrate, wherein the plurality of light sources are preferably installed on the first chuck side surface of the first chamber. The first chuck is preferably a vacuum chuck made of a light transmissive material. Alternatively, the first chuck is preferably an electrostatic chuck each having through holes formed at positions corresponding to the plurality of light sources. Meanwhile, the chamber may include a first chamber and a second chamber which are operated to be in close contact with or spaced apart from each other and provide the inner space when the chamber is in close contact with each other, the first chuck installed in the first chamber and supporting the stamp; The apparatus may further include a second chuck installed in the two chambers to support the substrate, and the plurality of light sources may be installed on the stamp side of the first chuck.

In the fine pattern imprint apparatus according to the present invention, the plurality of light sources are preferably arranged at positions corresponding to a plurality of points where the pattern of the stamp is not formed. The plurality of light sources are preferably fiber lasers, respectively.

The fine pattern imprint method according to the present invention includes a close contact step of closely contacting a substrate on which a photocurable resin is applied and a stamp on which a pattern is formed in a sealed chamber, and irradiating the cured light into the chamber while the chamber is closed. And a preexposure step of curing a part of the photocurable resin, and a main exposure step of curing the remainder of the photocurable resin by irradiating the cured light after releasing the sealed state of the chamber. Here, in the preliminary exposure step, it is preferable to irradiate the cured light from the outside to the inside of the chamber through a plurality of transmission windows inserted through the wall of the chamber. Alternatively, in the preliminary exposure step, the cured light may be irradiated through a plurality of light sources installed inside the chamber. Meanwhile, in the preliminary exposure step, it is preferable to expose each of a plurality of points where the pattern of the stamp is not formed.

According to the present invention, since the cured light irradiated from an external light source can reach the photocurable resin inside the chamber through the light transmission window inserted into the wall of the chamber, the substrate can be cured before being taken out. Alternatively, the photocurable resin may be directly cured by a light source provided inside the chamber. Therefore, the substrate is fixed while being compressed with the stamp, and the alignment is not disturbed between the stamp and the substrate during the process of carrying out the substrate. In addition, since the present invention replaces only a part of the wall of the chamber with a light-transmitting window, or arranges a light source inside the chamber, the photocurable resin inside the chamber can be cured without lowering the structural strength of the chamber.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the fine pattern imprint apparatus according to the present invention.

7 is a cross-sectional view of an embodiment of a fine pattern imprint apparatus according to the present invention.

The chambers 110 and 120 provide an inner space C, and receive the substrate S and the stamp M in the inner space C, respectively. Photocurable resin is apply | coated to the board | substrate S, and the pattern to transfer to the photocurable resin of the board | substrate S is previously formed in the stamp M. As shown in FIG. The stamp M should be made of a light transmissive material, such as quartz or glass, because it should be able to transmit the cured light irradiated to the substrate S side in close contact with the substrate S. Cured light refers to the light of a specific wavelength used for hardening photocurable resin like an ultraviolet-ray or X-ray here.

The chambers 110 and 120 should be able to carry in or take out the substrate S and the stamp M from the outside. In FIG. 7, the chambers 110 and 120 are illustrated in a vertically divided form. That is, the first chamber 110 and the second chamber 120 are operated to be close to or spaced apart from each other, and when the first chamber 110 and the second chamber 120 are in close contact with each other, the substrate S and the stamp M are moved. An inner space C is formed to receive and perform an imprint. When the first chamber 110 and the second chamber 120 are spaced apart from each other, the substrate S and the stamp M are brought in or taken out from the outside. You can do it. The reason for forming the internal space C as described above is to maintain the inside of the chambers 110 and 120 higher or lower than atmospheric pressure. Although not shown, the chambers 110 and 120 may carry in and carry out a substrate or a stamp in addition to a separate chamber in which the first chamber 110 and the second chamber 120 form one chamber 110 and 120. It may be an integrated chamber with a gate installed. Also, in order to support the substrate S and the stamp M in the chambers 110 and 120, and to closely contact or space the substrate S and the stamp M, a first chuck 210 is provided in the first chamber 110 and the second chamber 120. It is preferable that each of the second chucks 220 is provided. The first chuck 210 and the second chuck 220 are plate members arranged to face each other, and are operated by conventional driving means so as to be adjacent to or spaced apart from each other. In addition, the first chuck 210 may support the stamp M, and the second chuck 220 may support the substrate S, respectively. The first chuck 210 may be driven to be relatively close to or spaced apart from the stamp M and the substrate S. Close contact 7 is a state in which the stamp M and the substrate S are already in close contact, the first chuck 210 releases support for the stamp M, and only the second chuck 220 faces the substrate S side. The state of support is shown.

The plurality of floodlights 300 are installed in the chambers 110 and 120. The light transmission window 300 is made of a light transmissive material to allow the cured light to pass therethrough, and is inserted through the walls of the chambers 110 and 120. Each of the floodlights 300 is preferably in the form of a cylinder or a prismatic cylinder, and is manufactured separately from a material such as quartz or glass, and then forms a plurality of through holes in the walls of the chambers 110 and 120, respectively. Can be installed by inserting and fixing. Since the light transmission window 300 exists, when the light source 50 is disposed outside the chambers 110 and 120 to irradiate the cured light, the hardened light passes through the light transmission window 300 and thus inside the chambers 110 and 120. It may enter the inner space (C). When the chambers 110 and 120 are composed of the first chamber 110 and the second chamber 120, each of the floodlights 300 may include a first chamber 110, that is, a first to support the stamp M. The chuck 210 is installed in a chamber installed. In this case, the first chuck 210 is preferably made of a light transmissive material so that the cured light passing through the light transmission window 300 can reach the photocurable resin coated on the substrate S. For example, the first chuck 210 may be configured by a vacuum chuck made of a material such as quartz or glass. Alternatively, the first chuck 210 may be configured as another type of chuck that is difficult to be made of a light transmissive material such as an electrostatic chuck (ESC) or an adhesive chuck. In this case, as shown in FIG. 8, the through-hole 210a is formed in the first chuck 210 at a position corresponding to each of the light-transmitting windows 300, whereby the cured light passing through the light-emitting window 300 is formed. It is preferable to pass through the through hole 210a of the one chuck 210 and pass through the stamp M made of a light-transmissive material to finally reach the photocurable resin.

On the other hand, it is preferable that the several light transmission window 300 is each arrange | positioned at a specific position. Each position of the plurality of light emitting windows 300 will be described with reference to FIG. 9.

9 is a perspective view from below of a stamp of a type commonly used in imprint lithography. As described above, the stamp M is a plate-shaped member made of a light-transmissive material, and one surface of the stamp M is previously formed with a pattern P corresponding to a pattern for forming on a substrate. In addition, an alignment mark (AM) may be formed at the edge to optically check the degree of alignment with the substrate. However, the stamp M is not filled with the pattern P on the surface where the pattern P is formed, and there are extra areas such as an area for displaying the alignment mark AM. It is preferable that the plurality of light-transmitting windows are disposed at positions corresponding to the respective points where the pattern P is not formed in the stamp M. As shown in FIG. That is, as shown in FIG. 7, a plurality of floodlights provided on the wall of the first chamber 110 in a state in which the stamp M is in close contact with the substrate S and supported on the second chuck 220 side. 300 is disposed at positions corresponding to points where the pattern P of the stamp M is not formed, respectively. Similarly, when the first chuck 210 is made of an opaque chuck such as an electrostatic chuck as in the case of FIG. 8, the through holes 210a to be formed in the first chuck 210 also correspond to each light emitting window 300. It must be formed at the position. In this way, the light transmission window 300 is disposed so that the cured light is irradiated only at a specific point, for the subsequent irradiation of the cured light over the entire surface of the substrate S. FIG. When the cured light is irradiated to a part of the photocurable resin two times, the cured light is irradiated twice and the cured light is irradiated twice, and the continuity of the resin structure is broken at the boundary of these parts. This is because the pattern may be deformed by internal stress during curing.

On the other hand, although there is an extra area in the stamp (M) where the pattern (P) is not formed, the area is not wide enough, so that each light transmission window 300 pins the cured light so that the cross-sectional area of the beam is small. It is preferable to transmit in the form of points. Therefore, when each light emitting window 300 is cylindrical, its diameter needs to be narrowed, and in this respect, it is preferable to configure the light transmitting window 300 with a material such as an optical fiber. In addition, it is necessary that the cured light entering the chambers 110 and 120 through the light transmission window 300 is not diffused as much as possible. Therefore, as shown in FIG. 7, one light source 50 such as an ultraviolet lamp may be disposed outside the chambers 110 and 120, but as shown in FIG. 8, one light source (for each light emitting window 300) may be disposed. It is more preferable that the light source 60 be configured such as an ultraviolet laser oscillator having strong straightness.

When the cured light is irradiated to the portion where the pattern P of the stamp M is not formed in this manner, only the photocurable resin of the portion is cured, and the stamp M and the substrate S are fixed by the cured resin. do. Accordingly, as shown in FIG. 11, the first chamber 110 and the second chamber 120 are spaced apart from each other to open the chambers 110 and 120, and the adhesive stamp M and the substrate S are taken out to the outside. In the process of exposing the entire surface of the substrate S with a separate light source 70, relative movement between the stamp M and the substrate S may be minimized.

10 is a cross-sectional view of another embodiment of a fine pattern imprint apparatus according to the present invention.

This embodiment differs from the previous embodiment in that a plurality of light sources 400 are installed inside the chambers 110 and 120. The plurality of light sources 400 are installed inside the chambers 110 and 120 to irradiate the cured light directly toward the photocurable resin applied to the substrate S. The chambers 110 and 120 are composed of a first chamber 110 and a second chamber 120, and a first chuck 210 is installed in the first chamber 110 to support and release the stamp M. In the case where the second chuck 220 is installed in the second chamber 120 to support and release the substrate S, the plurality of light sources 400 may have an inner side surface of the first chamber 110, That is, it is installed on the surface facing the first chuck 210. In this case, the first chuck 210 may be a vacuum chuck made of a light transmissive material, or may be an electrostatic chuck having through-holes 210a (see FIG. 8) formed at points corresponding to each light source 400. In addition, although not shown, each light source 400 may be installed on the surface facing the stamp M of the first chuck 210. In this case, since the cured light irradiated from each light source 400 reaches the stamp M directly without other obstacles, the first chuck 210 does not need to be made of a light transmissive material.

On the other hand, each light source 400 is preferably disposed at a position corresponding to a point where the pattern of the stamp (M) is not formed for the same reason as in the description of each light transmission window of the previous embodiment. In addition, it is preferable that the cured light is irradiated in the form of a beam having a narrow cross section, and it needs to be enough to be referred to as a point light source in comparison with a surface light source. To this end, each light source 400 is preferably made of a fiber laser (Fiber Laser).

12 is a flow chart of one embodiment of a fine pattern imprint method according to the present invention.

First, as shown in FIG. 7, the substrates S and the stamp M are brought into close contact with the inside of the chambers 110 and 120 while the chambers 110 and 120 are sealed to the outside (adhesive step S110). Photocurable resin is coated on one surface of the substrate S, and the stamp M is formed with a pattern corresponding to the pattern to be formed on the substrate S. The substrate S is sandwiched by the photocurable resin. ), So that the pattern of the stamp (M) is transferred to the photocurable resin. In this process, the internal space C inside the chamber may be adjusted higher or lower than atmospheric pressure.

When the substrate (S) and the stamp (M) is in close contact in the close step (S110), the chambers (110, 120) while maintaining the closed state of the chamber (110, 120) in the state that they are located inside the chamber (110, 120) The cured light is irradiated to the inside, and the photocurable resin is first exposed to be cured (preexposure step S120). At this time, it is not necessary to expose the entire photocurable resin, and it is sufficient to partially expose it. Particularly, the portion of the photocurable resin to be exposed in the pre-exposure step S120 is preferably a plurality of points selected from the portions where the pattern P is not formed in the stamp M. Referring to FIG. Since the pattern formed on the stamp M is fine and complex, the area of each of the portions exposed in the pre-exposure step S120 is required to be kept to a minimum. To this end, in the pre-exposure step (S120) it is preferable to project the cured light through the plurality of light transmission window 300 inserted through the walls of the chamber (110, 120). Each light transmission window 300 is made of a light transmissive material, and transmits the cured light irradiated from the light source 50 disposed outside the chamber or the plurality of light sources 60 (see FIG. 8) disposed in each light transmission window 300. To enter the chambers 110 and 120. Alternatively, a plurality of light sources 400 (see FIG. 10) can be directly provided inside the chamber to cure a part of the photocurable resin by the light sources.

When the pre-exposure step S120 is completed, the chambers 110 and 120 are opened, and the cured light is irradiated again to expose the remaining part of the photocurable resin (main exposure step S130). When the chambers 110 and 120 are composed of the first chamber 110 and the second chamber 120, and the light source 50 used in the preliminary exposure step S120 is disposed above the first chamber 110, The first chamber 110 is separated from the second chamber 120 so that the second chamber 120 is completely exposed to the light source 50, and then the light source 50 used in the preexposure step S120 is re-lit. By performing the main exposure step (S130). Alternatively, as shown in FIG. 11, only the substrate S and the stamp M adhered to the outside of the open chambers 110 and 120 to perform the main exposure step S130 as a separate light source 70. It is possible. In particular, in the latter case, mechanical vibration may occur while the substrate S and the stamp M are carried out to perform the main exposure step S130, and some photocurable resins cured in the preliminary exposure step S120 may be Since the (S) and the stamp M are fixed to each other, the alignment state between the substrate S and the stamp M is prevented from being disturbed.

An embodiment of the present invention described above and illustrated in the drawings should not be construed as limiting the technical idea of the present invention. The protection scope of the present invention is limited only by the matters described in the claims, and those skilled in the art can change and change the technical idea of the present invention in various forms. Therefore, such improvements and modifications will fall within the protection scope of the present invention, as will be apparent to those skilled in the art.

1 to 6 are cross-sectional views schematically showing each process of the imprint technique according to the prior art.

9 is a perspective view from below of a stamp of a type commonly used in imprint lithography.

Claims (17)

A chamber providing an internal space for performing imprint lithography with a stamp having a pattern formed on a substrate coated with a photocurable resin, A plurality of light-transmitting windows inserted into the wall of the chamber and made of a light-transmissive material to irradiate cured light from the outside toward the photocurable resin, And the plurality of light transmission windows are disposed at positions corresponding to a plurality of points where the pattern of the stamp is not formed, respectively. The method of claim 1, The chamber includes a first chamber and a second chamber which are operated to be in close contact with or spaced apart from each other and provide the inner space upon close contact with each other. A first chuck installed in the first chamber and supporting the stamp; A second chuck installed in the second chamber and supporting the substrate; And the plurality of floodlights are inserted into a wall of the first chamber. The method of claim 2, wherein the first chuck, A fine pattern imprint apparatus, wherein the vacuum chuck is made of a light transmissive material. The method of claim 2, wherein the first chuck, The fine pattern imprint apparatus, characterized in that the electrostatic chuck each having a through hole formed at a position corresponding to the plurality of light transmission windows. delete The method of claim 1, wherein the plurality of floodlights, A fine pattern imprint apparatus, each comprising an optical fiber. A chamber providing space for performing imprint lithography with a patterned stamp on a substrate coated with a photocurable resin, A plurality of light sources provided inside the chamber and irradiating cured light toward the photocurable resin, And the plurality of light sources are disposed at positions corresponding to a plurality of points where the pattern of the stamp is not formed, respectively. The method of claim 7, wherein The chamber includes a first chamber and a second chamber which are operated to be in close contact with or spaced apart from each other and provide the inner space upon close contact with each other. A first chuck installed in the first chamber and supporting the stamp; A second chuck installed in the second chamber and supporting the substrate; And the plurality of light sources are provided at the first chuck side surface of the first chamber. The method of claim 8, wherein the first chuck, A fine pattern imprint apparatus, wherein the vacuum chuck is made of a light transmissive material. The method of claim 8, wherein the first chuck, The fine pattern imprint apparatus, characterized in that the electrostatic chuck each having a through hole formed in a position corresponding to the plurality of light sources. The method of claim 7, wherein The chamber includes a first chamber and a second chamber which are operated to be in close contact with or spaced apart from each other and provide the inner space upon close contact with each other. A first chuck installed in the first chamber and supporting the stamp; A second chuck installed in the second chamber and supporting the substrate; And the plurality of light sources are provided on the stamp side of the first chuck. delete The method of claim 7, wherein the plurality of light sources, A fine pattern imprint apparatus, each of which is a fiber laser. An adhesion step of closely contacting the substrate on which the photocurable resin is applied to the patterned stamp in the sealed chamber; A preexposure step of curing a part of the photocurable resin by irradiating cured light into the chamber in a state where the chamber is closed; And a main exposure step of curing the rest of the photocurable resin by irradiating cured light after releasing the sealed state of the chamber. The method of claim 14, wherein the pre-exposure step, And irradiating the cured light from the outside into the chamber through a plurality of light-transmitting windows inserted through the wall of the chamber. The method of claim 14, wherein the pre-exposure step, The fine pattern imprint method, characterized in that for irradiating the cured light through a plurality of light sources provided inside the chamber. The method of claim 14, wherein the pre-exposure step, And exposing each of a plurality of points where the pattern of the stamp is not formed.

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