KR100558967B1 - Fabrication Method of Patterned Relief Arrays Useful to Microelectronics and Optical Devices - Google Patents

Abstract

According to an aspect of the present invention, there is provided a method of forming an embossed array pattern, the method comprising: forming a negative pattern by stacking and curing a soft first polymer on an upper surface of an embossed patterned master; Separating a first polymer layer having a negative pattern from the master and filling predetermined first particles in the pattern; Stacking a second adhesive polymer on a top surface of the first polymer layer having a pattern formed thereon and attaching an embossed pattern composed of the first particles to the surface of the second polymer layer; And separating the second polymer layer from the first polymer layer and filling the second particles into grooves formed in the second polymer layer.

In addition, the method according to the second aspect of the present invention, the step of laminating a soft polymer on the upper surface of the embossed patterned master and hardened to form a negative pattern; Separating the polymer layer having the negative pattern from the master and filling predetermined first particles in the pattern; Attaching a predetermined substrate to a surface on which a negative pattern of the polymer layer is formed; Etching the polymer layer to form an embossed pattern formed of the first particles on the substrate; And filling a second particle in the groove formed on the substrate.

Description

Fabrication Method of Patterned Relief Arrays Useful to Microelectronics and Optical Devices             

1 is an explanatory diagram of a manufacturing process of an embossed pattern according to the present invention

2 is an SEM image of a polydimethylsiloxane template replicated on a master in accordance with the present invention.

3A and 3B are SEM images of spherical particles of different sizes inserted using dip coating into a mold used in the present invention.

Figure 4a, b is a preferred embodiment according to the present invention, the SEM image of the embossed array having a pyramidal shape obtained by coating the polyurethane on the spherical particle array through UV curing and peeled from the first polymer layer

Figures 5a, b, c is a preferred embodiment according to the present invention, SEM image obtained by filling another spherical particles on an embossed patterned surface with particles of different sizes

6A and 6B illustrate a preferred embodiment according to the present invention, in which SEM images of a new porous particle pattern using oxygen plasma etching and a particle array having three different particle sizes are illustrated.

The present invention relates to a method for obtaining a regular relief pattern useful in the production of microelectronic and optical devices, and more particularly to the production of microelectronic and optical devices consisting of two or more different particles in a simple process using soft lithography. It is about how to obtain a useful regular relief pattern.

To store more information in a smaller area, micro or nanometerization of the pattern is required. Existing processes for the fabrication of sub-micron patterns have mainly been done using photolithography. However, since photolithography is performed by diffraction or interference of light, there is a limitation in the line width that can be realized, and thus, a method of forming a pattern using electron beam lithography or X-ray lithography is required to manufacture more fine patterns. But. While the above methods can realize precise line width and high resolution than photolithography, they have a long process time and high cost. In order to overcome such drawbacks, techniques using soft lithography have been actively studied.

Soft lithography is a method of forming a pattern using a soft material such as polydimethyl siloxane (PDMS) as a mask, and it is easy to manufacture a pattern even at the laboratory level, not in a clean room requiring extreme cleanness. However, it has the advantage that it is possible to form a repeating pattern even on a spherical surface.

In order to apply such a pattern to a device, a technique of depositing and etching required materials using a mask on the pattern is required. When manufacturing devices such as transistors and diodes, the process of depositing and etching materials using various masks in a multi-step process is very complicated.

In addition, techniques such as chemical vapor deposition, sputtering, and dip coating are used to coat particles or materials on thin films. In this case, wet etching or plasma using chemicals may be used to pattern patterns of various sizes and shapes. There is a need for a dry etching method using corona.

Finely patterned particle arrays can be used in applications requiring high integration and miniaturization of pixels in order to increase the resolution of display (optical) devices, and can be widely applied to photonic crystal devices using regular arrays of particles. have.

For this reason, in recent years, as part of a method for obtaining a regular pattern of particles, various methods using chemical specificities of microchannels and surfaces have been performed. (A) Aizenberg, J .; Braun, PV; Wiltzius, P. Phys. Rev. Lett . 2000, 84 , 2997. (b) Tien, J .; Terfort, A .; Whitesides, GM Langmuir , 1997 , 13 , 5349. (c) Aizenberg, J .; Black, AJ; Whitesides, GM Nature , 1999, 398 , 495 (d) Zheng, H .; Rubner, MF; Hammond, PT Langmuir , 2002, 18 , 4505. (e) Chen, KM; Jiang, X .; Kimberling, LC; Hammond, PT Langmuir , 2000, 16 , 7825. (f) Lee, I .; Zheng, H .; Rubner, MF; Hammond, PT Adv. , 2002, 14, 572. (g ) Hua, F .; Shi, J .; Lvov, Y .; Cui, T. Nano Lett 2002, 2, 1219. (h) Doshi, DA;. Hesing, NK; Lu (M); Fan, H .; Lu, Y .; S.-Potter, K .; Potter Jr., BG; Hurd, AJ; Brinker, CJ Science , 2000, 290 , 107. (i) Zheng, H. Lee, I .; Rubner, MF; Hammond, PT Adv. Mater , 2002, 14 , 569. (j) Gu, Z.-Z .; Fujishima, A .; Sato, O. Angew.Chem.Int.Ed. 2002, 41 , 2067. However, these conventional methods of particle arraying are all limited to arrays consisting of single particles, or are cumbersome requiring special surface treatment with chemicals. In addition, the results of regular arrangements composed of two or more kinds of particles are still very limited.

The present invention has been made to solve the problems of the prior art as described above, the purpose is to obtain a regular relief pattern useful in the production of microelectronic and optical elements composed of two or more different particles in a simple process In providing a method.

In addition, another object of the present invention is to provide a method of forming an embossed pattern that can be selected and arranged in advance the particles of the desired properties, free to choose the particles that can be used, and to impart different functions depending on the shape of the pattern. have.

The present invention according to the first aspect for achieving the above object,

Stacking and curing the soft first polymer on the upper surface of the embossed patterned master to form a negative pattern;

Separating a first polymer layer having a negative pattern from the master and filling predetermined first particles in the pattern;

Stacking a second adhesive polymer on a top surface of the first polymer layer having a pattern formed thereon, and attaching an embossed pattern composed of the first particles to a surface of the second polymer layer; And

Separating the second polymer layer from the first polymer layer and filling the second particles in the groove formed in the second polymer layer provides a method of forming a relief pattern.

In addition, the present invention according to the second aspect for achieving the above object,

Stacking and curing the soft polymer on the upper surface of the embossed patterned master to form an intaglio pattern;

Separating a polymer layer having a negative pattern from the master and filling predetermined first particles in the pattern;

Attaching a predetermined substrate to a surface on which a negative pattern of the polymer layer is formed;

Etching the polymer layer to form an embossed pattern formed of the first particles on the substrate; And

It provides a method of forming a relief array pattern comprising the step of filling a second particle in the groove formed on the substrate.

Hereinafter, the content of the present invention will be described in more detail.

Patterned masters can be fabricated from a variety of materials, including quartz, common glass, various metal plates, and polymeric flexible materials, as well as silicon wafers that have previously been used in photolithography processes. The polymer flexible material does not require any special limitation as long as it is a material having soft and flexible properties, and examples thereof include polydimethylsiloxane, urethane, polyimide, polystyrene, polymethacrylate, and the like.

Patterning the material to be the master is conventional electron beam [for example, '(a) Moreau, WM; S emicoductor Lithography: Principles and Materials , Plenum, New York, 1988. (b) Brabley, D .; Martin, B .; Prewell, PD Adv. Mater. Opt. Electron. 1994, 55. (c) Handbook of Microlithography, Micromachining, and Microfabrication, Vol. 1 (Ed .: P. Rai-Choudhury) , SPIE Optical Engineering Press, Bellingham, Wa, 1997. et al.] Or photolithography (eg, '(a) Okazaki, SJ Vac. Sci. Technol. B. 1991, 9, 2829. (b) Jeong, HJ; Markle, DA; Owen, G .; Pease, F .; Greville, A .; von Bunau, R. Solid State Technol. 1994, 37, 39 'method can be carried out by the process. The pattern formed from the above technique is not particularly limited and may be provided in a desired shape according to the needs of those skilled in the art.

The first polymer is laminated and cured on the upper surface of the embossed patterned master to form a first polymer layer having a negative pattern on the laminated surface opposite the embossed pattern. The material that can be such a first polymer layer is not particularly limited as long as it is easy to cure, flexible, and easy to handle. For example, polydimethylsiloxane, polyurethane, epoxy, polystyrene, polyimide, And at least one polymer selected from the group of polymethyl methacrylate and polyvinyl chloride.

The intaglio pattern is a method generally known in the art and is a replica molding method (for example, 'Xia, Y .; Kim, E .; Zhao, X.-M .; Rogers, JA; Pretiss, M .; Whitesides, GM'). Science 1996, 273, 347 '), imprinting methods (eg,' (a) Chou, SY; Krauss, PR; Renstrom, PJ Appl. Phys. Lett. , 1995, 67, 3114, Science 1996, 272, 85. (b) Gale, MT in Micro-Optics; Elements, Systems and Applications (Ed .: HP Herzig), Taylor and Francis, London, 1997, 153. ' Method, such as the method described in "Kumar, A; Whitesides, GM Appl. Phys. Lett., 1993, 63, 2002." For example, the method described in 'Kim, E .; Xia, Y .; Whitesides, GM Nature 1995, 376, 581'), a transition molding method (eg 'Zhao, X.-M .; Xia, Y. Whitesides, GM Adv. Mater. 1996, 8, 837 ').

The predetermined particles (hereinafter referred to as 'first particles') filled in the intaglio pattern formed on the surface of the first polymer layer do not require special limitation, but preferably those having the same kind of uniform particle size. Examples of the polymer include single particles or two or more mixed particles selected from the group of polymer beads, phosphors, magnetic materials, metal materials, and ceramics. The polymer bead is a bead-shaped polymer having a uniform size, and more specific examples thereof include polystyrene and polymethyl methacrylate. Phosphors collectively refer to materials that absorb the energy of an electron beam and emit light, and emit different colors in red, blue, and green depending on the doped material. The magnetic material is a generic name for a material that magnetizes under a magnetic field. More specifically, for example, Co alloys (Co, CoCrPt, CoCrTa, CoPt, CoPd), FePt, FeO ₃ , FePd, SmCo _5, MnAl, FeNdB including CrTi, CrMn , CrMo, Ti, Pd, Au, Ni, Cr). The metal material generally refers to a material having a property of having electrical conductivity, and specific examples of the metal to be used include Fe, Ni, Co, Au, Ag, Cu, and the like. Specific examples of ceramics include SiO ₂ , Al ₂ O ₃ , Ce ₂ O ₃ , TiO _2, and the like.

The size or shape of the particles that can be used as the first particles does not require any particular limitation as long as the particles can be filled in the pattern. Preferably the particles are particles at the micro level or hundreds of nanometers.

The filling process of the first particles into the intaglio pattern is not particularly limited, and the particles are dispersed in a solution phase to provide deep coating (eg, 'Gu, Z. -Z .; Fujishima, A .; Sato, O. Chem. Mater. 2002, 14, 760, Yang, SM; Miguez, H .; Ozin, GA Adv. Funct. Mater. 2002, 12. '). In addition, it can be carried out according to the method of chemical vapor deposition or electroplating. Chemical vapor deposition is a method of depositing a desired material on a thin film by decomposition of a reaction gas under a gaseous atmosphere . For example, 'Choy, KL Prog. Polym. Sci., 2003, 48 (2) 57. 'may be used. In addition, the electroplating method is a method in which particles are flowed through a metal ion-containing solution to coat a thin metal thin film on a desired substrate. Examples of such methods include 'Riley, D. J; Current opinion in colloid & interface sci. 2002, 7 (3-4), 186. '

According to the first aspect of the present invention, there is provided a method of forming an embossed array pattern, wherein a second polymer layer is laminated on a surface on which a pattern of the first polymer layer is formed to form a second polymer layer. It includes a process of transferring to the surface of the polymer layer as it is. To this end, preferably, the material constituting the second polymer layer is a sticky material, and does not require any particular limitation. For example, polydimethylsiloxane, polyurethane, epoxy, polystyrene, polyimide, polyvinyl At least one polymer selected from the group of chlorides.

The above process may be performed by installing a predetermined substrate on the intaglio pattern and filling a predetermined polymer capable of becoming the second polymer layer into pores of the intaglio pattern by using a capillary phenomenon. This is illustrative and one skilled in the art may refer to the description of the present invention to form the second polymer layer through another method.

In the method of forming an embossed array pattern of the present invention according to the second aspect, a predetermined substrate is attached to a surface on which a negative pattern of the polymer layer is formed, and the polymer layer is etched to form the first substrate on the substrate. It includes a process of forming an embossed pattern composed of particles.

The substrate usable above is not particularly limited, and for example, any of a silicon wafer and a glass substrate can be used. As a method for attaching the substrate to the polymer layer, a method of curing using a polyurethane precursor sensitive to ultraviolet rays may be used.

Etching of the polymer layer may be performed by a method such as reactive ion etching or decomposition by high temperature heat treatment. In the case of selectively etching only the polymer layer according to the same method, an embossed pattern composed of only the first particles is obtained on the substrate.

The second polymer layer or the surface groove of the substrate having the relief pattern formed according to the present invention on the first side and the second side is filled with second particles which are the same as or different from the first particles.

The material capable of being the second particle is not particularly limited, but is preferably homogeneous and uniformly sized particles, for example, in the group of polymer beads, phosphors, magnetic materials, metal materials, ceramics Single particle or 2 or more mixed particle selected can be mentioned. The polymer bead is a bead-shaped polymer having a uniform size, and more specifically, for example, polystyrene or polymethyl methacrylate. Phosphor is a generic name for a material that absorbs the energy of an electron beam and emits light. The color of light emitted in red, blue, and green varies depending on the doped material.

The magnetic material is a generic name for a material having a property of magnetizing under a magnetic field, and more specifically, for example, Co alloy (Co, CoCrPt, CoCrTa, CoPt, CoPd), FePt, FeO ₃ , FePd, SmCo _5, MnAl, FeNdB CrTi, CrMn, CrMo, Ti, Pd, Au, Ni, Cr). The metal material is generally referred to as a material having electrical conductivity, and more specific examples thereof include Fe, Ni, Co, Au, and Ag. Specific examples of ceramics include SiO ₂ , Al ₂ O ₃ , Ce ₂ O ₃ , TiO _2, and the like.

The size or shape of the particles that can be used as the second particles does not require any particular limitation as long as the particles can be filled in the grooves. Preferably the particles are particles at the micro level or hundreds of nanometers.

The filling process of the second particles may be performed according to any one method selected from the methods of dip coating, chemical vapor deposition, and electroplating as in the case of the first particles.

The pattern of the relief array manufactured by the above process may be provided as a template for reducing the size of the pixel of the display element or by manufacturing another microcomposite pattern by regularly arranging at least two different particles.

Hereinafter, the content of the present invention will be described in more detail through specific preparation examples.

Figure 1 shows the manufacturing process of the embossed pattern presented as a preferred embodiment according to the present invention. A is a cross-sectional view of an embossed patterned master, which can be fabricated by an electron beam or photolithography process. Step A → B is a manufacturing process of the first polymer layer having an intaglio pattern opposite to the embossed pattern of the master replicated using the master of A as a template. The first polymer layer comprises at least one component selected from a precursor of a flexible polymer material, for example, liquid polydimethylsiloxane, polyurethane, epoxy, polystyrene, polyimide precursor, etc., on the surface of the patterned master. After pouring, the temperature can be increased to cure these precursors. In this case, the cured first polymer layer has an intaglio pattern having a shape opposite to that of the master of the relief pattern, which is a mold as in B.

Step B → C is filled into the first pattern, for example, a single particle selected from the group of polymer beads, phosphors, magnetic materials, metal materials, ceramics or two or more mixed particles in the intaglio pattern formed in the first polymer layer. It shows the process of becoming. In this case, any one method selected from the method of dip coating, chemical vapor deposition, electroplating may be used as a method for filling the first particles. In particular, in the case of dip coating, for example, the dip coating depends on the surface tension around the particles and the solvent, the rate of rise of the substrate to be coated, or the rate of evaporation of the solvent around the particles, so that these variables are dependent on these variables. It is important to optimize. At this time, when the charges of the first particles and the first polymer layer of the template are the same, the particles are not allowed to remain on the surface of the mold due to the pushing force, and enter into the intaglio pattern by the capillary force.

Step C → D consists of at least one component selected from a second polymer layer, for example polydimethylsiloxane, polyurethane, epoxy, polystyrene, polyimide, etc., having the same relief pattern as the master of A The process of manufacturing the structure. The structure of the embossed pattern of D forms a sticky second polymer layer on the pattern of the first polymer layer, and separates the second polymer layer from the first polymer layer by the first particles. It can be obtained by the process of transition to the polymer layer. This process is described in more detail as follows. After drying the structure of C, a predetermined substrate is placed on the patterned surface, and a liquid polymer precursor is injected between the substrate and the first polymer layer using a capillary principle, followed by heat or light. Irradiating to cure the polymer precursor can be obtained a second polymer layer. In this case, the second polymer layer has sufficient adhesiveness, so that when the second polymer layer is separated from the first polymer layer, the first particles filled in the intaglio pattern of the first polymer layer are transferred to the second polymer layer. Through this process, the first particles form the same relief pattern found on the master of A on the surface of the second polymer layer.

In addition to the above method, the structure of D may be obtained by attaching structure C to a predetermined substrate through a surface on which a pattern is formed and removing the first polymer layer by etching.

Step D → E is a process of inserting a second particle, which is the same as or different from the first particle, into the groove formed between the arrays of the first particles by the same procedure as in the filling of the first particles. Through the entire process from A to E, a pattern having two arrays having different properties and sizes can be formed, and through the repetition of the above process, the pattern can be expanded into a variety of patterns.

The method of the present invention as shown in FIG. 1 has the following advantages over methods of selectively arranging embossed particles after making an existing pattern.

First, the photo, electron beam or X-ray lithography method has been conventionally used as a method for elaborating patterns, but requires a long process time and high cost to perform the process for mass production purposes. However, the method of the present invention using the soft lithography method, if only the master is prepared, it is possible to produce a pattern in large quantities in a repetitive manner in a short time.

Second, in order to arrange particles, a high level of technology using a mask or an atomic force is required. However, in the case of using a grooved master, this study can easily perform regular alignment of particles due to the depletion effect.

Third, existing processes can only use certain materials that are fixed to a specific framework. However, in the case of the present invention, there is an advantage not limited to the material of the material.

Hereinafter, the content of the present invention will be described in more detail with reference to Examples. However, these examples are only presented to understand the content of the present invention, and the scope of the present invention should not be construed as being limited to these embodiments.

<Example>

In a typical laboratory environment, rather than in a clean room where no dust or suspended solids are present, it is advisable to keep the surface of the master used immediately before the experiment. In particular, in the case of the silicon wafer used in the present embodiment, when the organic matter on the surface is removed using toluene, ethanol and distilled water, a cleaner copying mold can be obtained.

Fabrication of Integrated Embossed Patterns

In this embodiment, in order to produce an embossed pattern, a master made of a silicon wafer having a V-shape was used. First, polydimethylsiloxane was poured onto the master as a soft polymer material and cured at 80 ° C. for 1 hour. 2 shows an SEM image of a fully cured polydimethylsiloxane template poured and detached from the master. The first particles were then filled into the fully cured mold using dip coating. The first particles used at this time are spherical silica particles corresponding to 300 nm and 1 micron, and have a uniform shape. The rise time during dip coating was fixed at 200 nm / sec.

3A and 3B show the surface morphology of the first particles arranged in a V-groove template at 300 nm and 1 micron, respectively. In order to obtain an embossed pattern, a glass substrate was placed on a mold filled with particles, and a polyurethane precursor was poured as a sticky material using a capillary principle. The polyurethane precursor was cured by irradiating 20 minutes of light of 410 nm. The fully cured polyurethane was removed from the polydimethylsiloxane template by applying physical force. At this time, the form in which the first particles were arranged remained embossed. 4A and 4B show embossed patterns at 300 nm and 1 micron, respectively.

Embossed patterns having two modes can be manufactured by injecting particles having a different size from the previous process into the V grooves seen in the completed relief pattern. In this case, a pattern prepared by injecting the 300 nm particle embossed pattern by using a deep coating method again in the case of 1 micron, and in the case of 1 micron by using the deep coating method is shown in Figures 5a and 5b. 5C is an embossed pattern having the size of 600 nm and 1 micron of particles used in the same manner as in the above procedure.

6 is a patterned porous particle array in which an embossed pattern made of 300 nm and 600 nm particles is mixed with 1 micron of polystyrene and 50 nm of silica particles to perform a dip coating and remove polystyrene particles through oxygen plasma etching. Is showing. As shown in the 6a (300nm) and 6b (600nm) images, the pattern of the removed polystyrene particles is different, which is due to the fact that the line width is smaller than b. As such, since the arrangement of the embossed particles required for the secondary array is changed by adjusting the line width, it can be seen that the production of various different patterns is possible using this.

According to the present invention, it is possible to obtain a regular relief pattern useful for fabricating microelectronic and optical devices composed of two or more different particles using a simple process using soft lithography. In addition, particles of desired properties can be selected and arranged in advance, so that the selection of the particles that can be used is free, and it is possible to give different functions depending on the shape of the pattern.

Claims (12)

Stacking and curing the soft first polymer on the upper surface of the embossed patterned master to form a negative pattern; Separating a first polymer layer having a negative pattern from the master and filling predetermined first particles in the pattern; Stacking a second adhesive polymer on an upper surface of the first polymer layer having a pattern, and attaching an embossed pattern composed of the predetermined particles to the surface of the second polymer layer; And Separating the second polymer layer from the first polymer layer and filling the second particles into grooves formed in the second polymer layer. The method of claim 1, wherein the intaglio pattern is formed by one method selected from among microcontact printing, capillary molding, and transition molding. The method of claim 1, wherein the first polymer comprises at least one polymer selected from the group consisting of polydimethylsiloxane, polyurethane, epoxy, polystyrene, polyimide, and polyvinyl chloride. The method according to claim 1, wherein the first particles and the second particles are single particles or two or more mixed particles selected from the group consisting of polymer beads, phosphors, magnetic materials, metal materials, and ceramics, respectively. The method of claim 1, wherein the filling of the first particles and the second particles is performed according to any one method selected from the methods of dip coating, chemical vapor deposition, and electroplating. The method of claim 1, wherein the forming of the second polymer layer comprises forming a predetermined substrate on the intaglio pattern and filling a predetermined polymer into the pores of the intaglio pattern using a capillary phenomenon. The method of claim 1, wherein the second polymer comprises at least one polymer selected from the group consisting of polydimethylsiloxane, polyurethane, epoxy, polystyrene, and polyimide. Stacking and curing the soft polymer on the upper surface of the embossed patterned master to form an intaglio pattern; Separating a polymer layer having a negative pattern from the master and filling predetermined first particles in the pattern; Attaching a predetermined substrate to a surface on which a negative pattern of the polymer layer is formed; Etching the polymer layer to form an embossed pattern formed of the first particles on the substrate; And Forming a relief pattern comprising the step of filling the second particles in the groove formed on the substrate The method of claim 8, wherein the intaglio pattern is formed by one method selected from among microcontact printing, capillary molding, and transition molding methods. The method of claim 8, wherein the soft polymer comprises at least one polymer selected from the group of polydimethylsiloxane, polyurethane, epoxy, polystyrene, polyimide. The method of claim 8, wherein the first particles and the second particles are single particles or two or more mixed particles selected from the group consisting of polymer beads, phosphors, magnetic materials, and metal materials, respectively. The method of claim 8, wherein the filling of the first and second particles is performed according to any one method selected from the methods of dip coating, spin coating, chemical vapor deposition, and electroplating.

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