KR101974575B1 - Manufacturing method for microscopic multi-slope sturcutre using synchrotron x-ray - Google Patents

Abstract

The present invention relates to a production method of a subminiature multi-slope structure, which comprises: a mask production step of producing a flexible X-ray mask; a photosensitive layer forming step of forming a photosensitive layer on a curved flexible substrate; a mask disposing step of disposing the X-ray mask in close contact with the photosensitive layer; a photosensitive layer pattern forming step of selectively exposing and developing the photosensitive layer by scanning the synchrotron X-ray; and a substrate deforming step of deforming the flexible substrate to change an inclination angle of the photosensitive layer pattern.

Description

TECHNICAL FIELD [0001] The present invention relates to a method of manufacturing a micro multi-slope structure using a synchrotron X-

The present invention relates to a method of manufacturing an ultra-small structure, and more particularly, to a process technology for fabricating various types of ultra-small structures on a three-dimensional substrate having a curved surface rather than a two-dimensional substrate.

Currently, various ultra-small processing technologies are being researched and developed. Micro-machining, stero lithography, MEMS (micro-electro-machining), micro-machining (micro-machining) based lithography-based technology.

New fabrication techniques are required to overcome the limitations of the geometry of a two-dimensional structure implemented by conventional micro-fabrication techniques. Techniques such as microstereography lithography or 3-D printing have excellent shape flexibility but do not show high productivity until now. Lithographic-based process technology and precise replica molding technology based on this technology can ensure high productivity.

Most of the lithography techniques used in the fabrication of microstructures use ultraviolet light sources, and there are restrictions on the shape of the two-dimensional structure. Techniques such as oblique lithography, photoresist reflow, back exposure lithography, and gray-scale lithography have been developed to overcome these limitations.

However, these techniques are still constrained in the shape of the structure that can be implemented. Further, in some cases, it is necessary to manufacture an additional apparatus for progressing the related process, or an exposure mask in which difficulty in fabrication occurs.

An object of the present invention is to provide a method of manufacturing a micro multi-level inclined structure capable of manufacturing various types of micro-structures on a three-dimensional substrate having a curved surface rather than a two-dimensional substrate using a synchrotron X-ray.

A method of fabricating a microlithographic multiple inclined structure according to an embodiment of the present invention includes the steps of fabricating a flexible X-ray mask, forming a photosensitive layer on a curved flexible substrate, A photosensitive layer pattern forming step of selectively exposing the photosensitive layer by scanning with a synchrotron X-ray to develop the photosensitive layer pattern; and a substrate deforming step of deforming the flexible substrate to change the inclination angle of the photosensitive layer pattern .

In the mask making step, the x-ray mask may include a flexible support and an x-ray shield layer formed on the support.

In the photosensitive layer forming step, the flexible substrate can form a convex or concave single curved surface. On the other hand, in the photosensitive layer forming step, the flexible substrate can form multiple curved surfaces composed of a combination of a plurality of curved surfaces in which at least one of a curvature radius and a curvature direction is different.

In the substrate deforming step, the flexible substrate can be deformed flat. On the other hand, in the substrate deforming step, the flexible substrate may be deformed to a different curved surface in at least one of the photosensitive layer forming step, the curvature radius and the curvature direction.

According to another embodiment of the present invention, there is provided a method of manufacturing a micro multi-tilted structure, comprising the steps of: stretching a stretchable substrate; stretching the stretched substrate; forming a photosensitive layer on the stretched stretchable substrate; A photosensitive layer pattern forming step of selectively exposing the photosensitive layer by a synchrotron X-ray scan to develop the photosensitive layer pattern; a step of changing the interval and the inclination angle of the photosensitive layer pattern by the tensile force release and deformation of the stretchable substrate; .

The stretchable substrate may be a flexible substrate, and may be brought into close contact with a curved substrate support in the substrate stretching step to maintain a curved shape. The stretchable substrate can form a single convex or concave curved surface. On the other hand, the flexible substrate can form multiple curved surfaces composed of a combination of a plurality of curved surfaces in which at least one of a curvature radius and a curvature direction is different.

In the mask placement step, the X-ray mask may be made of a flexible mask and disposed closely to the photosensitive layer, or may be made of a hard mask and positioned at a distance from the photosensitive layer.

In the substrate deformation step, the stretchable substrate can be deformed flat. On the other hand, in the substrate deforming step, at least one of the curvature radius and the curvature direction may be changed to another curved surface at the photosensitive layer forming step and the stretchable substrate.

According to the present invention, it is possible to easily manufacture a tiny multi-tilt structure having a high degree of freedom in shape, and the manufactured tiny multi-tilt structure can be applied to various fields. For example, the technology provided by the present invention can be applied to ultra-precision molds of a curved or cylindrical shape, optical devices based on micro / nano patterns having different slopes in the same substrate, and wettability control surface structures according to directions have.

FIG. 1 is a process flow diagram illustrating a method of manufacturing a micro multi-level gradient structure according to a first embodiment of the present invention.
Fig. 2 is a configuration diagram showing the flexible substrate, the photosensitive layer, and the X-ray mask shown in Fig.
3 is a configuration diagram showing a modified example of the flexible board shown in Fig.
4 is a schematic cross-sectional view showing the flexible substrate and the photosensitive layer pattern of the fourth step shown in FIG.
5 is a schematic cross-sectional view showing the flexible substrate and the photosensitive layer pattern of the fifth step shown in FIG.
6 is a schematic cross-sectional view showing a modified example of the flexible substrate and the photosensitive layer pattern shown in Fig.
FIG. 7 is a flowchart illustrating a method of manufacturing a micro multi-level gradient structure according to a second embodiment of the present invention.
Fig. 8 is a configuration diagram showing the flexible substrate, the photosensitive layer, and the X-ray mask shown in Fig. 7;
9 is a configuration diagram showing a modified example of the X-ray mask shown in FIG.
10 is a schematic cross-sectional view showing the stretchable substrate and the photosensitive layer pattern of the ninth and tenth steps shown in Fig.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art to which the present invention pertains. The present invention may be embodied in many different forms and is not limited to the embodiments described herein.

FIG. 1 is a process flow diagram illustrating a method of manufacturing a micro multi-level gradient structure according to a first embodiment of the present invention.

Referring to FIG. 1, a method of manufacturing a micro multi-level gradient structure according to a first embodiment includes a first step S10 of producing a flexible X-ray mask, a second step S20 of forming a photosensitive layer on a curved flexible substrate, A fourth step (S40) of forming a photosensitive layer pattern by selectively exposing and developing the photosensitive layer to form a photosensitive layer pattern, a fifth step (S30) of deforming the flexible substrate, Step S50.

Fig. 2 is a configuration diagram showing the flexible substrate, the photosensitive layer, and the X-ray mask shown in Fig.

Referring to FIGS. 1 and 2, in the first step S10, the X-ray mask 30 has flexibility to easily bend. The X-ray mask 30 may include a transparent and flexible support 31 and an X-ray shielding layer 32 formed on one side of the support 31. The support 31 may be a transparent plastic film such as polyimide. The x-ray shielding layer 32 is a thick metal layer that absorbs x-rays, and may include, for example, gold (Au).

A thin metal layer (not shown) may be positioned between the x-ray shielding layers 32 to expose the surface of the support 31 or allow x-ray transmission. In FIG. 2, the x-ray shielding layer 32 of the stripe pattern is shown as an example, but the shape of the x-ray shielding layer 32 is not limited to the illustrated example.

In the second step S20, the photosensitive layer 20 is formed on the curved flexible substrate 10. The flexible substrate 10 can be a thin flexible plastic film that can easily bend and can maintain a curved shape by the substrate support 15 located at the rear side. The photosensitive layer 20 may be formed to have a predetermined thickness on the curved surface of the flexible substrate 10 and have substantially the same curved shape as the flexible substrate 10.

The flexible substrate 10 may form a convex or concave curved surface toward the x-ray source 40, or may form multiple curved surfaces combining two or more curved surfaces. In FIG. 2, the flexible substrate 10 having a single curved surface convex toward the X-ray source 40 is shown as an example. 3 is a configuration diagram showing a modified example of the flexible board shown in Fig.

Referring to FIG. 3, the flexible board 10a can form a curved surface concave toward the X-ray light source. On the other hand, the flexible board 10b may be formed of a combination of a plurality of curved surfaces in which at least one of the curvature radius and the curvature direction (the direction in which the curvature center is located) is different. The shapes of the flexible boards 10, 10a, 10b are not limited to the examples shown in Figs.

Referring again to FIGS. 1 and 2, in the third step S30, the X-ray mask 30 is bent in accordance with the curved shape of the flexible substrate 10, and is disposed in close contact with the photosensitive layer 20. By using the flexible X-ray mask 30, the pattern of the X-ray mask 30 can be precisely transferred to the photosensitive layer 20 formed on the flexible substrate 10 having various curved shapes.

In the fourth step S40, the X-ray source 40 operates to discharge the synchrotron X-rays toward the X-ray mask 30. [ The X-ray source 40 may be a rod-shaped light source that is parallel to one side of the X-ray mask 30, and may be exposed by a scanning method while being moved by the transfer unit 45.

Some of the synchrotron X-rays emitted from the X-ray source 40 are absorbed by the X-ray shielding layer 32, and the remainder passes through the X-ray mask 30 to reach the photosensitive layer 20. Synchrotron X-rays have very short wavelengths compared to ultraviolet rays, have strong linearity and high luminance. The photosensitive layer 20 is partially exposed and developed by the X-ray mask 30 to become a photosensitive layer pattern.

4 is a schematic cross-sectional view showing the flexible substrate and the photosensitive layer pattern of the fourth step shown in FIG.

2 and 4, when the photosensitive layer 20 is of a positive type, the portion of the photosensitive layer 20 irradiated with X-rays is removed by the developing solution to form the photosensitive layer pattern 50. In this case, the photosensitive layer pattern 50 has the same shape as the X-ray shielding layer 32 of the X-ray mask 30.

On the other hand, when the photosensitive layer 20 is of a negative type, the portion of the photosensitive layer 20 not exposed to X-rays is removed by the developing solution to form the photosensitive layer pattern 50. In this case, the photosensitive layer pattern 50 has the same shape as the portion of the X-ray mask 30 other than the X-ray shielding layer 32. In the fourth step S40, the side surfaces of the photosensitive layer pattern 50 are all parallel.

5 is a schematic cross-sectional view showing the flexible substrate and the photosensitive layer pattern of the fifth step shown in FIG.

5, in the fifth step S50, the flexible substrate 10 is deformed and the photosensitive layer pattern 50 located on the deformed flexible substrate 10 is deformed slightly And have different inclination angles. That is, the photosensitive layer pattern 50 of the fifth step S50 forms the ultra-small multi-gradient structure.

In the fifth step S50, the flexible substrate 10 may be flatly deformed, or at least one of the curvature radius and the curvature direction may be deformed to a different curved surface in the second to fourth steps S20, S30, and S40 have. 5 shows a case where the flexible substrate 10 is flatly deformed after forming the photosensitive layer pattern 50 in a convex curved surface.

5, the side surface of the photosensitive layer pattern 50 located at the center of the flexible substrate 10 is substantially perpendicular to the surface of the flexible substrate 10, while the side surface of the photosensitive layer pattern 50 located at the peripheral portion is substantially perpendicular to the surface of the flexible substrate 10, Has an inclined angle inclined toward the central portion. At this time, as the photosensitive layer pattern 50 located far from the center of the flexible board 10, the side inclination angle becomes larger.

6 is a schematic cross-sectional view showing a modified example of the flexible substrate and the photosensitive layer pattern shown in Fig. 6 shows a case where the flexible substrate 10 is flatly deformed after forming the photosensitive layer pattern 50 in a concave curved surface.

6, the side surface of the photosensitive layer pattern 50 located at the center of the flexible substrate 10 is substantially perpendicular to the surface of the flexible substrate 10, while the side surface of the photosensitive layer pattern 50 located at the peripheral portion is substantially perpendicular to the surface of the flexible substrate 10, Has an inclined angle inclined toward the peripheral portion. At this time, as the photosensitive layer pattern 50 located far from the center of the flexible board 10, the side inclination angle becomes larger.

According to the manufacturing method of the first embodiment, it is possible to precisely fabricate a micro multi-level gradient structure having various gradients on the flexible substrate 10. The tiny multi-tilted structure can be used as a mold in a high-precision mold system, and a precise replica molding technique can be implemented using a high-precision mold system.

FIG. 7 is a flowchart illustrating a method of manufacturing a micro multi-level gradient structure according to a second embodiment of the present invention.

Referring to FIG. 7, the method for fabricating the micro multi inclined structure of the second embodiment includes a sixth step S60 of stretching the stretchable substrate, a seventh step S70 of forming a photosensitive layer on the stretched stretchable substrate, (S80) of arranging an X-ray mask in front of the photosensitive layer, a ninth step (S90) of forming a photosensitive layer pattern by selectively exposing and developing the photosensitive layer, a step of releasing and deforming the stretchable substrate 10 (S100).

Fig. 8 is a configuration diagram showing the flexible substrate, the photosensitive layer, and the X-ray mask shown in Fig. 7;

Referring to FIGS. 7 and 8, in the sixth step S60, the stretchable substrate 60 has elasticity stretching in at least one direction and is stretched in at least one direction by an external force. The stretchable substrate 60 may be a flexible substrate and may be in close contact with a curved substrate support 15 in a state of being stretched by an external force to maintain a curved shape.

The substrate support 15 and the elastic substrate 60 brought into close contact with the substrate support 15 can form a convex or concave single curved surface toward the x-ray source 40, and a plurality of curved surfaces having at least one of a curvature radius and a curvature direction different from each other Multiple curved surfaces can be formed. 8 shows an example in which the substrate support 15 and the flexible substrate 60 form a single curved surface convex toward the x-ray source 40. [

In the seventh step S70, the photosensitive layer 20 is formed on the stretchable substrate 60. When the flexible substrate 60 is flat, the photosensitive layer 20 is formed flat. When the flexible substrate 60 forms a curved surface, the photosensitive layer 20 has substantially the same curved shape as the flexible substrate 60.

In the eighth step S80, an X-ray mask 30 is disposed in front of the photosensitive layer 20. The X-ray mask 30 may be the same flexible mask as that of the first embodiment, or may be a rigid mask that does not bend. The flexible X-ray mask 30 is bent in accordance with the curved shape of the flexible substrate 60 and is disposed in close contact with the photosensitive layer 20.

9 is a configuration diagram showing a modified example of the X-ray mask shown in FIG. 9, the X-ray mask 30a may include a hard support 31a such as glass and an X-ray shielding layer 32 formed on one side of the support 31a. The solid x-ray mask 30a is disposed in front of the photosensitive layer 20 at a distance from the photosensitive layer 20.

In a conventional lithography process using ultraviolet rays, the straightness is low and there is no gap between the photosensitive layer and the exposure mask due to the ultraviolet characteristics that cause diffraction phenomena. If a gap is provided between the photosensitive layer and the exposure mask, the pattern of the exposure mask can not be transferred precisely to the photosensitive layer while the ultraviolet ray passing through the exposure mask causes the diffraction phenomenon.

However, in the manufacturing method of the second embodiment, a gap may be provided between the photosensitive layer 20 and the X-ray mask 30a. The synchrotron X-ray has a very short wavelength compared to ultraviolet rays, so it has little diffraction and is excellent in straightness. Therefore, even if a gap is provided between the photosensitive layer 20 and the X-ray mask 30a, the pattern of the X-ray mask 30a can be accurately transferred to the photosensitive layer 20. [

10 is a schematic cross-sectional view showing the stretchable substrate and the photosensitive layer pattern of the ninth and tenth steps shown in Fig.

Referring to FIG. 10, in the ninth step S90, the photosensitive layer 20 is selectively exposed and developed by a synchrotron X-ray scan to become a photosensitive layer pattern 50. In the ninth step S90, the photosensitive layer pattern 50 may be positioned with a first interval G1 of an inter-micrometer scale (less than 1 탆 and less than 1,000 탆).

In the tenth step, the stretchable substrate 60 is deformed to have a shape different from that in the seventh to ninth steps (S70, S80, S90). Accordingly, the photosensitive layer patterns 50 have mutually different inclination angles depending on their positions as the intervals between the photosensitive layer patterns 50 are reduced and the angles are slightly changed. That is, the photosensitive layer pattern 50 of the tenth step forms a micro multi-gradient structure.

At this time, the stretchable substrate 60 may be deformed flatly, or at least one of the curvature radius and the curvature direction may be changed to another curved surface in the seventh to ninth steps (S70, S80, S90). In FIG. 10, a case where the stretchable substrate 60 is curved to be flat and deformed after the photosensitive layer pattern 50 is formed is shown as an example.

The photosensitive layer pattern 50 of the tenth step S100 is located at a second gap G2 smaller than the first gap G1 by releasing the tension of the stretchable substrate 60. [ The second gap G2 may belong to a micrometer scale smaller than the first gap G1 or may belong to a nanometer scale (less than 1 nm and less than 1,000 nm).

According to the manufacturing method of the second embodiment, it is possible to easily realize the ultra-small multi-tilting structure having the nanometer-scale interval by using the flexible substrate 60. The gap of the nanometer scale can be used as a channel of a fluid delivery system such as a micro fluidic device, and a precise flow rate control technique can be implemented by using this.

According to the first and second embodiments described above, it is possible to easily manufacture a micro-inclined structure having a high degree of freedom in shape, and can be applied to various fields. For example, the technology provided by the present invention can be applied to ultra-precision molds of a curved or cylindrical shape, optical devices based on micro / nano patterns having different slopes in the same substrate, and wettability control surface structures according to directions have.

Further, the technology provided by the present invention can be utilized in various fields such as precision optical elements, microfluidic devices, precision molds for plastic and powder injection molding, and micro / nano composites.

Although the technology using high-energy synchrotron X-rays is mainly limited to the basic science field, the precision processing technology provided by the present invention can be a key link between the advanced basic research field and the actual production / manufacturing industry, It is a technology that can fuse the phenomenon.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Of course.

10: flexible substrate 20: photosensitive layer
30: X-ray mask 31: Support
32: X-ray shielding layer 40: X-ray light source
45: transfer part 50: photosensitive layer pattern
60: stretchable substrate

Claims (13)

A mask manufacturing step of fabricating an X-ray mask having an X-ray shielding layer formed on a flexible support;
A photosensitive layer forming step of bringing the flexible substrate into close contact with the substrate support having at least one curved surface and forming a photosensitive layer on the flexible substrate;
A mask disposing step of closely placing the X-ray mask on the photosensitive layer;
Forming a photosensitive layer pattern by selectively exposing and developing the photosensitive layer by scanning a synchrotron X-ray; And
And a substrate deforming step of separating the substrate support and the flexible substrate and transforming the flexible substrate into one of several other shapes than the substrate support,
Wherein the photosensitive layer pattern is a multiple inclined structure having different inclination angles depending on positions in the substrate deforming step. delete The method according to claim 1,
Wherein in the photosensitive layer forming step, the flexible substrate forms a convex or concave single curved surface. The method according to claim 1,
Wherein the flexible substrate forms multiple curved surfaces composed of a combination of a plurality of curved surfaces having at least one of a curvature radius and a curvature direction different from each other in the photosensitive layer forming step. The method according to claim 3 or 4,
Wherein in the substrate deformation step, the flexible substrate is flatly deformed. The method according to claim 3 or 4,
Wherein, in the step of deforming the substrate, at least one of the curvature radius and the curvature direction is deformed to a different curved surface at the photosensitive layer forming step, the flexible substrate, and the flexible substrate. A substrate tensioning step of stretching an elastic substrate having elasticity and flexibility in at least one direction;
A photosensitive layer forming step of forming a photosensitive layer on the stretched substrate which is stretched;
Disposing an X-ray mask in front of the photosensitive layer;
A photosensitive layer pattern forming step of selectively exposing and developing the photosensitive layer by a synchrotron X-ray scan; And
And a substrate deforming step of releasing a tensile force of the elastic substrate and deforming the elastic substrate into one of various shapes other than that at the time of forming the photosensitive layer pattern,
Wherein the photosensitive layer patterns in the substrate deforming step are multi-inclined structures having a small gap between them and different inclination angles depending on their positions. 8. The method of claim 7,
Wherein the flexible substrate is a flexible substrate and is in close contact with a curved substrate support during the substrate pulling step to maintain a curved shape. 9. The method of claim 8,
Wherein the stretchable substrate forms a convex or concave single curved surface. 9. The method of claim 8,
Wherein the flexible substrate forms multiple curved surfaces composed of a combination of a plurality of curved surfaces having at least one of a curvature radius and a curvature direction different from each other. 8. The method of claim 7,
Wherein the X-ray mask is made of a flexible mask and is disposed in close contact with the photosensitive layer, or is made of a hard mask and positioned at a distance from the photosensitive layer. 8. The method of claim 7,
Wherein the flexible substrate is flatly deformed in the substrate deformation step. 8. The method of claim 7,
Wherein the flexible substrate is deformed into a curved surface at least one of a curvature radius and a curvature direction at the photosensitive layer forming step.

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