KR20110112501A - Block copolymer for nanostructure with high aspect ratio and manufacturing method thereof - Google Patents

Abstract

Provided are methods of making nanostructures having high aspect ratios, thereby making nanostructures and applications thereof.
Nanostructure manufacturing method according to the present invention comprises the steps of applying a block copolymer comprising a silicon-containing polymer block on the first layer laminated on the substrate; Annealing the applied block copolymer to self-assemble; And oxygen reactive ion etching the self-assembled silicon-containing block copolymer. Nanostructure manufacturing method according to the present invention is to apply a silicon-containing block copolymer easily synthesized using a monomer containing silicon to the upper layer of the bilayer without the additional process of adding a silicon compound, in the present invention Since the block copolymer can be used immediately, the process is short and simple, and the microstructure of tens of nanoscales can be realized by using the self-assembly of the silicon-containing block copolymer. In addition, a block having high etching resistance enables pattern transfer to the lower organic polymer layer. In addition, the fine nanostructure having a high aspect ratio formed through this can be applied as a template for forming a variety of other nanostructures, and also has the advantage that can be used in a variety of lower layers, substrates, etc. for all applications requiring nanostructures Can be applied.

Description

Block copolymer for producing nanostructures having high aspect ratio and method for manufacturing the same {Block copolymer for nanostructure with high aspect ratio and manufacturing method

The present invention relates to a block copolymer capable of producing nanostructures in the form of spheres, cylinders, and lamellas, and a method of manufacturing the same. More particularly, the present invention relates to a bilayer system. The present invention relates to a block copolymer for preparing nanostructures and a method of manufacturing the nanostructures capable of controlling the orientation and allowing the prepared nanostructures to have high aspect ratios.

Nanostructures are in the limelight as new material structures that can be used in magnetic storage media, optoelectronic devices, organic semiconductors, etc. Nanostructure manufacturing technology One of several technologies is a technique for manufacturing nanostructures using template of nanostructure shape. to be. The nanostructure template technology is very important to how effectively, in order to make the nano-sized template in an aligned state. One of the technologies for manufacturing nano-moulds, anodizing aluminum oxide (AAO) template manufacturing technology is widely used. This has the advantage of producing aligned cylinders with high aspect ratios having a diameter in the range of 25 to 300 nm with different anodization conditions. However, such anodization technology has a problem that a multi-step process is required in anodization, an electrochemical reaction, and there is a problem that extreme conditions must be used for removing a mold. In addition, the problem of not being able to make molds on multiple substrates has the disadvantage that they cannot be easily applied to many applications requiring multiple electrode substrates.

As a method to solve the problem of the mold manufacturing technology using the anodization process there is a technique using a block copolymer in a thin film state. The thin film block copolymer can reproduce several structures in the form of spheres, cylinders, or lamellas on the order of tens of nanometers by self-assembly. These block copolymer properties are attracting attention as next generation lithography technology because it is very easy to form structures such as fine dots or lines of several tens of nanometers, which are difficult to realize in semiconductor manufacturing methods using photolithography, which is currently used in the industry. However, in application to molds, despite the advantages of being able to form structures below 25nm and varying in shape, which are difficult to achieve in aluminum oxide, traditional block copolymer assembly methods have low aspect ratios with film thicknesses of less than 50nm. There is a limitation to the mold because of the disadvantage.

In an effort to solve this problem and to form a mold having a high aspect ratio, it is possible to heat a polystyrene-block-polymethacrylate (PS-b-PMMA) polymer by applying an electric field while simultaneously heating it above the glass transition temperature. A technique for producing a nanowire mold having an aspect ratio has been published ( Science , 2000 , 290 , 2126). However, since the technique requires an external electric field, the process is complicated, and it is difficult to produce a uniform mold. there is a problem. Another technique involves the addition of a single PMMA polymer to an asymmetric PS-b-PMMA polymer ( Advanced Materials, 2004, 16, 533) is a problem in the process that must be added to separate substances, and a separate multi-step process for the interfacial energy control between the substrate and the block copolymer is desired in a self-assembly process for a long time, that uneconomical there is a problem.

A new technology for this is H.C. Kim et al. Used a double layer lithography system to add a silicon-containing inorganic material to the block copolymer to achieve a high aspect ratio structure. (US Patent No. 2009/0107950, hereinafter Prior Art 1) However, the prior art 1 has a problem that a separate process of adding an inorganic material to the block copolymer is required, and furthermore, the behavior of the inorganic material in the organic copolymer. There is a problem that this is difficult to predict.

As another method of introducing an inorganic material into a block copolymer, U.S. Patent 5,318,877 (hereinafter referred to as Prior Art 2) uses a composition obtained by adding a silicone using a double bond of a diene block in a polystyrene-diene block copolymer as an image layer, This produced a hard etching mask subjected to an oxygen plasma treatment. However, the prior art 2 is an attempt to improve the low numerical stability caused by the low glass transition temperature of the silicon-containing copolymers used in the existing double layer, which is the magnetic of the block copolymer itself as described below It is different from the method of inducing assembly to form tens of nanoscale nanostructures, and the result also shows a big difference. In addition, prior arts related to a method for manufacturing a block copolymer containing silicon have been proposed. However, this is a study on a simple synthesis method, and a block copolymer and a method for manufacturing the same have a high aspect ratio nanostructure. It has not been published. Accordingly, the present invention set forth below provides a silicone-containing block copolymer that is readily synthesized using monomers comprising silicone without the addition of silicone compounds. The block copolymer provided in the present invention is used in the upper layer of the bilayer lithography process, is a form containing silicon directly, and the pattern transfer to the lower organic polymer layer is possible by the block having high etching resistance. In addition, fine nanostructures having a high aspect ratio can be produced by the block copolymer according to the present invention.

Accordingly, the problem to be solved by the present invention is to provide a novel block copolymer, which can be used as a top layer of the bilayer lithography without the separate inorganic material addition process, can be self-assembled.

Another problem to be solved by the present invention is to provide a method for producing a new block copolymer, which can be used as a top layer of bilayer lithography without a separate inorganic material addition process, can be self-assembled.

In order to solve the above problems, the present invention is a block copolymer for producing a nanostructure, the block copolymer is a first polymer block made of a monomer containing silicon; And

It provides a block copolymer for producing a nanostructure, characterized in that consisting of; a second polymer block made of another monomer containing no silicon.

In one embodiment of the present invention, the first polymer block is synthesized by polymerization between monomers containing silicon, the first polymer block contains a silicon moiety bonded to a monomer, and the silicon moiety is the block It can be combined into the side chain of. The block copolymer can be used as the top layer material of a bilayer lithography process.

In order to solve the above problems, the present invention is a method for producing a block copolymer for producing a nanostructure, the method comprises the steps of: first polymerizing a monomer containing no silicon to synthesize a first polymer block; And second polymerizing a monomer containing silicon from the first polymer block to produce a second polymer block bonded to the first polymer block, the second polymer block comprising the monomer containing silicon. The polymerization and the second polymerization may be in the same polymerization mode. The first polymerization and the second polymerization may be anionic polymerization or radical polymerization.

Another embodiment of the present invention is a method for producing a block copolymer for manufacturing a nanostructure,

The method comprises the steps of: first polymerizing a monomer containing silicon to synthesize a first polymer block; And second polymerizing a monomer containing no silicon from the first polymer block to produce a second polymer block bonded to the first polymer block and composed of the monomer containing no silicon. It provides a method for producing a block copolymer for producing a nanostructure.

The first polymerization and the second polymerization may be the same polymerization scheme, and the first polymerization and the second polymerization may be anionic polymerization or radical polymerization.

The present invention provides a block copolymer for producing a nanostructure prepared in the above-described manner, in order to solve the another problem, the block copolymer may be a block copolymer of the formula (1) .

(1)

(One)

The silicon-containing block copolymer according to the present invention is economical because it can be easily synthesized using monomers containing silicon without the addition of silicone compounds to the block copolymer. Furthermore, when the silicon-containing block copolymer according to the present invention is used for the upper layer of the double layer, even without a separate silicon addition process, it is possible to implement a microstructure of several tens of nano-size using the self-assembly phenomenon of the silicon-containing block copolymer. . In addition, a pattern having high etching resistance enables pattern transfer to the lower organic polymer layer, and the high aspect ratio fine nanostructures formed therefrom can be applied as a template for forming various other nanostructures, and also a lower layer. The advantage of using a variety of substrates, such as nanostructures can be applied to all applications that require.

1 is a view for explaining a block copolymer according to an embodiment of the present invention.
Figure 2 is a step of the nanostructure manufacturing method according to the invention.
3 is a schematic diagram of a method of manufacturing a double-layer lithography nanopore array according to an embodiment of the present invention.
4 is a view showing a method for synthesizing a PS-b-PSSi block copolymer according to an embodiment of the present invention.
5 is an atomic force microscope (AFM) image of a block copolymer thin film obtained in one embodiment of the present invention.
6A and 6B are scanning electron microscope (SEM) frontal images and cross-sectional images tilted at 45 analyzing the etching results over time in the bilayer structure.
7 is an SEM image of a cylindrical nanopore array fabricated on a large area substrate in accordance with one embodiment of the present invention.
8 is an SEM image of a nanopore array fabricated on various substrates in accordance with one embodiment of the present invention.
9 is an AFM image of a gold nano dot array prepared in one embodiment of the present invention.
10 is a graph comparing the etching rates of the PSSi matrix and the organic polymer layer SU-8, which is a commonly used lower first layer.
11 is an atomic force microscope (AFM) image of the obtained block copolymer thin film.
FIG. 12 is an SEM image of a nanopore array prepared when the solvent volume ratio is 4, ie, the ratio of heptane is larger.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the drawings. The following embodiments are provided as examples to ensure that the spirit of the present invention to those skilled in the art will fully convey. Therefore, the present invention is not limited to the embodiments described below, but may be embodied in other forms. In the drawings, the width, length, thickness, etc. of the components may be exaggerated for convenience.

Like numbers refer to like elements throughout. In addition, in PS-b-PSSi displayed throughout this specification, b means a block copolymer, and PS, PSSi, etc. are understood as abbreviations indicating block polymers of the copolymer used. In addition, the silicon moiety may be any material including silicon, but in one embodiment of the present invention, the silicon moiety was a silane group substituted with an alkyl group having 1 to 5 carbon atoms, but the present invention is not limited thereto. . In addition, nanostructures as used throughout this specification includes any and all structures having nanometer size, including nanopores, nanowires, nanodots, nanospheres, and the like.

The present invention provides a block copolymer polymerized together with other monomers after covalently introducing a silicone moiety into the unit monomers of the block copolymer, in order to solve the problems of the prior art described above. In this case, the prepared block copolymer can be used directly in the upper layer of the double layer lithography process without adding an inorganic material such as a separate silicone to the block copolymer. That is, in the block copolymer according to the present invention, after the silicon is covalently bonded to the unit monomers in advance, the polymer is prepared by polymerizing the second polymer block, and the second polymer block and the first polymer block and the second polymer are not contained again. The polymer blocks are combined to provide new block copolymers for the manufacture of high aspect ratio bare structures.

1 is a view for explaining a block copolymer according to an embodiment of the present invention.

Referring to FIG. 1, a block copolymer according to an embodiment of the present invention discloses a first polymer block made of a first monomer (M (Si)) containing silicon (Si). Herein, the silicon-containing form may be a covalent bond between the first monomer and the silicon moiety, but may also contain silicon as a member of the first monomer.

The block copolymer according to the invention also comprises a second polymer block covalently bonded to the first polymer block (M) and consisting of monomers (N) which do not contain silicone. The "silicone containing block copolymer" according to the present invention is different from the polymer block (first polymer block) prepared by polymerizing the monomers after the silicone moiety is bonded to the monomer itself in the form of a covalent bond. And any block copolymer having a structure in which another polymer block (second polymer block) prepared by polymerizing another monomer containing no silicon is bonded.

In one embodiment of the present invention, the silicon-containing block copolymer comprises a second polymer block polymerized with a styrene monomer and a first polymer block covalently bonded to the second polymer block, wherein the silicon moiety is covalently contained. A block copolymer having a structure is provided. As an example, the present inventors use the polystyrene-block-poly (4- ( tert -butyldimethylsilyl) oxystyrene) (PS-b-PSSi) block copolymer of the following formula 1 as the silicone-containing block copolymer, Nanostructures were prepared through bilayer lithography of organic polymer-block copolymers.

The PS-b-PSSi block copolymer of the formula (1) is a structure in which the silicon-containing moiety corresponding to the formula (2) is bonded to the side chain of the block, more specifically, a structure substituted with a styrene monomer phenyl group of polystyrene. However, the scope of the present invention is not limited thereto, and any compound containing silicon may be the silicon containing moiety.

That is, the block copolymer for preparing nanostructures according to the present invention may be prepared by co-bonding the silicon moiety to the monomer in advance and then preparing the silicon moiety-containing block copolymer by one continuous polymerization reaction. Furthermore, in the present invention, the styrene monomers used in the block unit of the block copolymer can be easily polymerized, and in particular, two blocks can be continuously produced by the same chain reaction. Can be effectively overcome.

The present invention provides a method for preparing a block copolymer for preparing a nanostructure, comprising: synthesizing a first polymer block by first polymerizing a monomer not containing silicon; And second polymerizing a monomer containing silicon from the first polymer block to produce a second polymer block bonded to the first polymer block, the second polymer block comprising the monomer containing silicon. It provides a block copolymer manufacturing method for producing a nanostructure. That is, the first polymer block and the second polymer are successively synthesized and polymerized in the same manner as the first polymer block containing no silicon, and through the second polymerization in which the polymerization is initiated from the terminal unit of the first polymer block. To prepare a block copolymer in the form in which the polymer blocks are bonded. In an embodiment of the present invention, the first polymerization and the second polymerization were anionic polymerizations, but the scope of the present invention is not limited thereto, and a method such as radical polymerization is also possible.

Unlike the above configuration, after the first polymer block is made of a monomer not containing silicon, the monomer containing silicon may be continuously polymerized from the first polymer block. Referring to FIG. 4, first, a styrene monomer not containing the silicon moiety of Formula 2 is polymerized to synthesize a polystyrene block, and the polystyrene block and the styrene monomer containing the silicon moiety are continuously anionized. By polymerization, a PS-b-PSSi block copolymer was prepared. In this case, the silicon-containing block copolymer can be economically produced through the polymerization process in the same manner in a continuous manner without a separate silicon addition process.

In one embodiment of the present invention, the styrene monomers are polymerized by an anion polymerization method, in addition to radical polymerization is also possible. That is, in one embodiment of the present invention, each block polymer may be prepared by one continuous anionic polymerization reaction without using an additive including a functional group that may be used in a side reaction such as a chain termination reaction, and each block is covalently bonded. The block copolymer can be polymerized, and a block copolymer of polystyrene- (silicon moiety-introduced polystyrene) can be prepared by introducing a silicone-containing moiety into any one of the styrene monomer blocks in advance.

The present invention effectively transfers the nanostructure array to the substrate through a so-called bilayer lithography technique using the silicon-containing block copolymer thin film prepared according to the present invention as an upper layer and an organic polymer layer as a lower layer, as described above. One embodiment is an organic block of a copolymer which is applied on an organic polymer layer applied on a substrate and then removed in subsequent oxygen reactive ion etching through an annealing process (solvent annealing). It is self-assembled into a cylinder (cylinder) or layered (lamellae) or sphere (sphere) shape. That is, in the block copolymer self-assembled on the organic polymer layer by an annealing process, the organic block (second polymer block) containing no silicon is removed by the oxygen plasma process and at the same time the upper layer of the silicon containing block (first polymer block). Is converted to a silicon oxide hard etch mask.

In particular, the present invention provides a nanostructure array by applying the block copolymer containing silicon to an organic polymer layer laminated on a substrate and then self-assembling without addition of additional materials. Only the coating and annealing process of the block copolymer has an effect of transferring the nanopattern to the silicon substrate.

Figure 2 is a step diagram of a nanostructure manufacturing method according to the present invention, Figure 3 is a schematic diagram of a nanopore array manufacturing method of a double layer lithography method according to an embodiment of the present invention.

Referring to Figure 2, the nanopore array manufacturing method according to the present invention comprises the steps of laminating a first layer on the substrate; Applying a block copolymer comprising a silicon-containing polymer block on the first layer; Annealing the silicon-containing block copolymer to self-assemble; And oxygen reactive ion etching the self-assembled silicon-containing block copolymer. Referring to FIG. 3, the silicon-containing block copolymer was a PS-b-PSSi block copolymer.

The polymer block containing silicon is then subjected to O2 reactive ion etching (O _2). RIE) process, which is converted to silicon oxide, and at the same time, the organic block in which silicon is not introduced and the first exposed organic polymer first layer are etched away. In particular, in one embodiment of the present invention, the first layer is preferably a material having a higher etching rate than a copolymer containing a silicon moiety, and in one embodiment of the present invention, the lower first layer is a crosslinked organic polymer. It was a layer. The pattern of the cross-linked first layer can be etched vertically down without collapse, and can be stacked and used on a universal substrate depending on the solution conditions. In an embodiment of the present invention, the negative photoresist SU-8 was used as the organic polymer of the first layer, but polyimide or other organic polymers may also be used as the first layer, and the scope of the present invention is limited to the following examples. It doesn't work.

Hereinafter, a method for manufacturing nanostructures according to the present invention will be described in more detail with reference to Examples and Experimental Examples.

Example  One

Block copolymer  Produce

The polymerization process for the block copolymer of Chemical Formula 1 will be described below with reference to FIG. 4.

Example  1-1

tert - Butyldimethylsilyl chloride ( tert - Butyldimehtylsilyl chloride ) synthesis

tert-butyldimethylsilyl chloride containing the N- dimethylformamide (N-dimethylformamide) was added 150ml of a 3-neck flask tert-upon-butyldimethylsiloxy benzalkonium the formaldehyde (4- tert -butyldimethylsiloxybenzaldehyde, 10 g, 82 mmol) mixed I was. Imidazole (0.6 g, 8.2 mmol) was added, triethylamine (14 ml, 100 mmol) was added again, and the mixed solution was stirred for 10 hours. 1M HCl was added to the solution and extracted three times with hexane. The combined hexane extracts were washed with water and dried over anhydrous MgSO ₄ . The solvent was removed and the resulting stock was distilled off under reduced pressure and purified (14.1 g, 73% yield).

¹ H NMR (300 MHz, CDCl ₃ , d): 9.89 (s, 1H, CHO), 7.78 (d, 2H, ArH), 6.96 (d, 2H, ArH), 0.99 (s, 9H, SiC (CH ₃₎ ) ₃ ), 0.25 (s, 6H, Si (CH ₃ ) ₂ )

Example  1-2

4- (tert - butyldimethylsilyl) oxy-styrene (SSi) monomer synthesis

Methyltriphenylphosphonium bromide (21.8 g, 84 mmol) was incorporated into a 500 ml three-necked flask containing 300 ml of tetrahydrofuran and the mixture was cooled to 0 ° C. Potassium tert - butoxide was added (potassium tert -butoxide, 9.42 g, 84 mmol) and stirred the reaction mixture for 1 hour. 4-tert-butyldimethylsilyloxybenzaldehyde (4- tert- butyldimethylsilyloxybenzaldehyde, 10 g, 42 mmol) was added to the reaction mixture. After 3 hours, the mixture was concentrated and left in hexane for 2 hours, then the organic layer was filtered and concentrated. The stock was then purified by flash chromatography with hexanes. (8.4 g, yield 86%)

¹ H NMR (300 MHz, CDCl ₃ , d): 7.30 (d, 2H, ArH), 6.81 (d, 2H, ArH), 6.78 (dd, 1H, Ar-CH =), 5.64 (d, 1H, Ar -C = CH ₂ ), 5.12 (d, 1H, Ar-C = CH ₂ ), 0.99 (s, 9H, SiC (CH ₃ ) ₃ ), 0.21 (s, 6H, Si (CH ₃ ) ₂ )

Example  1-3

PS -b- PSSi Block copolymer  synthesis

40 ml of tetrahydrofuran were transferred to a flame-dried round bottom flask. The glass reactor was then cooled to -78 ° C using an acetone / dry ice cooling bath. Sec -butyllithium as an initiator was injected into the syringe until yellow disappeared, and a previously prepared amount (50 μl) of sec -butyllithium was further added. After several minutes, 0.8 ml of styrene was added to the reactor. The color changed from yellow to red. After 30 minutes, a small amount was extracted to perform gel permeation chromatography analysis of polystyrene (PS), and then 1.6 ml of the silicon containing monomer SSi was transferred to the polymerization flask. After 60 minutes the degassed methanol was added at -78 ° C to give a colorless mixture. The resulting colorless mixture was concentrated using a rotary evaporator, dissolved in tetrahydrofuran and precipitated in methanol. The precipitated polymer (ca. 2.4 g) was evaporated overnight in vacuo. The number average molecular weight (M _n ) of the finally obtained block copolymer was 75,000 g mol-1 level, and the polydispersity index (PDI) was 1.14 level. (M _n : 23,100 g / mol of PS block, M _n : 51,900 g / mol of PSSi block).

¹³ C NMR (400 MHz, inverse gated decoupling mode, CDCl ₃ , ppm): 153.1, 145.5, 139.3, 138.1, 127.9, 125.5, 119.4, 39-45, 25.7, 18.1

Example  2

Nanopores  Array manufacturing

SU-8 organopolymer layers incorporated at 10% by weight in cyclopentanone were spincoated at 2000 rpm for 60 seconds on silicon substrates, gold, platinum, copper and indium tin oxide (ITO) substrates, respectively. The spincoated SU-8 layer was baked at 95 ° C. for 1 minute and exposed to a UV light source for 100 seconds without a mask. The UV light source was an Oriel 1000-W DUV illuminator (model 82531) consisting of a high pressure Hg (Xe) lamp. The board | substrate irradiated with UV was baked at 95 degreeC for 3 minutes, and Su-8 organic polymer layer was fully bridge | crosslinked. The metal was coated by electron beam evaporation on a bare silicon substrate. Thereafter, the PS-b-PSSi block copolymer of Example 1 incorporated in xylene at 1.5 wt% was coated on the SU-8 organic polymer layer and then spin-coated at 3000 rpm. After annealing for 4 hours with a solvent vapor (volume ratio 4) mixed with heptane and toluene to prepare a self-assembled PS-b-PSSi thin film. While heptane is a selective solvent for PSSi blocks, toluene is non-selective for both blocks, and in certain directions (vertical to surface) by an annealing process in solvent conditions where the proportion of heptane is greater than toluene. A self-assembled structure of silicon-containing block copolymer of cylindrical structure oriented with was prepared. Subsequently, upon oxygen-reactive ion etching treatment of the self-assembled cylinder structure, the silicon moiety is converted into silicon oxide, which is converted into a hard etching mask having high etching resistance and high degree of alignment in the oxygen plasma, thereby high etching resistance Nano-sized line or hole pattern having a can be transferred to the substrate. Therefore, in the present embodiment, the prepared bilayer sample was etched by an oxygen reactive ion etching process to prepare a nanopore array.

5 is an atomic force microscope (AFM) image of the obtained block copolymer thin film.

Referring to FIG. 5, the diameter of the obtained cylinder structure nanopores was 30 nm, and the average center-to-center distance was about 50 nm.

6A and 6B are scanning electron microscope (SEM) frontal images and cross-sectional images tilted at 45 analyzing the etching results over time in the bilayer structure.

Referring to FIG. 6A, for the first 10 seconds, the nanoregions of the cylinder structure do not appear clearly because the polystyrene forming the cylinder shape was not completely removed and the silicon moiety was not converted to silicon oxide. Twenty seconds later, well-aligned cylinder nanopores were observed in large areas, but a slightly increased hole diameter was also observed due to the mass loss that occurs when PSSi is converted to SiO ₂ . Judging.

Referring to FIG. 6B, it can be seen that the SiO ₂ layer acts as a hard mask, making nano holes of high aspect ratio. It can be seen that during the initial 10 seconds only the PS-b-PSSi top layer was etched. This is the same as the result of FIG. 6A. After 10 seconds, the depth of the lower layer (SU-8 organic polymer layer) increases, and the etching contrast according to the difference in etching resistance between PSSi and SU-8 can be seen through this experimental example.

Up to 30 seconds, the overall thickness of the bilayer thin film does not decrease, and the pattern is directly transferred to the underlying layer with gentle sidewalls under certain optimized etching conditions. In practice, hard etching conditions generally result in a reduction in overall thickness and collapse of the pattern, but the bilayer thin films of the present invention do not have this problem in the hard etching process. The etching process was further performed for 2 seconds to remove all the underlying layers. As a result, cylindrical nanopores having a high degree of alignment and packing at high density were produced in a large area with a high aspect ratio, and there was no residual layer below (see FIG. 7).

The pore size was very uniform at 33 nm and the distance between centers was 50 nm. In addition, the pore shape is a structure having a smooth sidewall, and showed no roughness in the state of vertically penetrating the SiO ₂ hard mask.

Example  3

variety On a substrate Nanopores  Array manufacturing

The nanopore array manufacturing process according to the present invention was applied to various types and substrates having nanostructure arrays and used as electrodes. In this case, the SU-8 organic polymer layer was applied to the gold, platinum, copper, and ITO substrates by spin coating, and the lamination, annealing, and oxygen reactive ion etching processes of the block copolymer were performed as in Example 2.

8 is an SEM image of nanopore arrays fabricated on various substrates in this example.

Referring to FIG. 8, it can be seen that a high aspect ratio nanopore array is manufactured at a high density regardless of the type of substrate. Therefore, nanostructure arrays are manufactured according to the present invention not only on silicon substrates but also on substrates of various materials such as conductive electrode substrates including metals. When using the manufactured nanostructure arrays as templates, electronic devices of various applications may be used. I can make it.

Example  4

Nano dot  Produce

Traditional block copolymer molds have a problem of being difficult to stack because of the thin thickness of less than 50 nm. However, nanopore arrays made in accordance with the present invention have a high aspect ratio and are useful for preparing nanostructures of various materials as templates.

In order to prove this experimentally, plasmon metal nanostructures were prepared using the nanopore array of Example 2 prepared on a bare silicon substrate in this Experimental Example.

A 20 nm thick array of gold nanodots was fabricated by depositing gold on the double layer nanopore thin film pattern of Example 1 prepared on a bare silicon wafer by an electron beam evaporation process. Then, in order to remove the nanopore array template, the sample was immersed in N-methylpyrrolidone at 100 ℃ for 5 hours, sonicated while heating to 50 ℃ for 3 hours to perform a lift-off process. Next, an O ₂ / CF ₄ -reactive ion etch process was performed to remove the organic / inorganic portion. This mold removal process is comparable to the prior art where strong acid and base solutions are used to remove anodized aluminum molds. That is, the present invention, in which the mold removal process is performed under relatively less severe conditions, is superior in operation safety and more economical than the prior art.

9 is an AFM image of the gold nano dot array prepared in this example.

Referring to FIG. 9, it can be seen that dense gold nanodots were prepared on a substrate with a uniform distribution. The diameter was 30 nm level and the distance between centers was 50 nm level.

As described above, the nanostructure itself manufactured according to the present invention can be used as a template. That is, another second nanostructure made of the second material may be manufactured by stacking a second material such as a metal or a polymer on the nanostructure mold and removing the mold. In this case, the second nanostructure may be formed in various forms such as nanotubes, nanowires, as well as the above-described nanopoints, and all of them belong to the scope of the present invention.

Experimental Example  One

Etch Resistance Measurement

In order to measure the etch resistance between the PSSi matrix and SU-8, PSSi homopolymer (homo PSSi) was prepared by the free radical polymerization method and 1.5 wt% of the polymer was spincoated at 3000 rpm for 30 seconds on a silicon substrate. .

On the other hand, SU-8 mixed at 10 wt% in cyclopentanone for 60 seconds at 2000rpm on another silicon substrate was spin-coated. The spin-coated SU-8 organic polymer layer was baked at 95 ° C. for 1 minute and exposed to a UV light source for 100 seconds without a mask. The UV light source was an Oriel 1000-W DUV illuminator (model 82531) consisting of a high pressure Hg (Xe) lamp. The board | substrate irradiated with UV was baked at 95 degreeC for 3 minutes, and the SU-8 organic polymer layer which is a photoresist was fully bridge | crosslinked. The obtained organic polymer layer was 150 nm thick. These films were anisotropically etched using a vacuum ion reactive ion etching (RIE) system, model VSRIE-6000T, using an anisotropic oxygen plasma. The etching conditions were 6mTorr pressure, 30sccm flow rate, 300W RF power. The thin film thickness after each etching time was measured by ellipsometry.

In order to analyze the etch resistance of the block copolymer according to the present invention, the etching rate of the PSSi matrix and the organic polymer layer (SU-8), which is a commonly used lower first layer, was compared and shown in FIG. 10.

Referring to FIG. 10, the etching rate of the PSSi film was initially 0.86 nm / sec, but dropped to 0.4 after 20 seconds. That is, in the present invention, it can be seen that the silicon moiety is changed to silicon oxide by an oxygen reactive ion etching process, and the changed silicon oxide has excellent etching resistance. The cross-linked SU-8 exhibits a high etch rate of 4.7 nm / sec, so that the block copolymer coated on the lower first layer according to the present invention can be moisturized by one oxygen reactive ion etch without any unnecessary process. Since the tee portion is converted to a hard etching mask and the etching of the organic portion proceeds, it is possible to economically manufacture a nanopattern mask having an excellent aspect ratio.

Experimental Example  2

Cylinder  Orientation Control of Structures

Another effect of the present invention is that the orientation of the polystyrene (PS) cylinders forming the nanopore array can be controlled depending on the solvent selection in the annealing process. That is, it is possible to control the orientation of the self-assembled cylinder structure by simply selecting a solvent used in the annealing process without additional processes such as deformation of the substrate within a short time.

According to one embodiment of the present invention, the thin film of the cylinder pattern formed in parallel to the substrate surface or the thin film of the cylinder pattern formed perpendicular to the substrate surface may be selectively produced according to the solvent of the annealing process. In one embodiment of the present invention, the PS-b-PSSi block copolymer solution incorporated into xylene at 1.5% by weight was spin coated on a silicon substrate at 3,000 rpm for 60 seconds. The obtained 40 nm thick block copolymer film was annealed at room temperature for 4 hours in all non-selective toluene gas for the polymer block.

11 is an atomic force microscope (AFM) image of the obtained block copolymer thin film.

Referring to FIG. 11, it can be seen that the polystyrene (PS) cylinders aligned parallel to the surface of the silicon substrate were included in the PSSi matrix, and the center-center distance was 45 nm.

According to the present invention, the orientation of the PS cylinder structure can be freely controlled according to the selection of the solvent, and the block copolymer thin film aligned in parallel with the substrate is obtained by using toluene which is a non-selective solvent for the PS and the PSSi block. Can be.

Alternatively, different orientations are used when using so-called selective solvents such as heptane, which have good solvent properties for the PSSi block but poor solvent properties for the PS block. The present inventors analyzed the orientation characteristics of the PS cylinder structure while _varying the solvent volume ratio (V _hep / V _tol ) of heptane and toluene to confirm such characteristics.

FIG. 12 is an SEM image of a nanopore array prepared when the solvent volume ratio is 4, ie, the ratio of heptane is larger.

Referring to FIG. 12, it can be seen that as the ratio of heptane, which is a selective solvent for silicon-containing blocks, increases, nanopore arrays perpendicular to the substrate surface are produced uniformly and densely. As such, the orientation direction of the cylinder can be simply selected parallel or perpendicular to the substrate surface depending on the solvent selection in the annealing process.

Claims (13)

As a block copolymer for manufacturing nanostructures,
The block copolymer may include a first polymer block made of a monomer containing silicon; And
A second polymer block made of another monomer that does not contain silicone; Block copolymer for producing a nanostructure, characterized in that consisting of. The method of claim 1,
The first polymer block is a block copolymer for producing nanostructures, characterized in that synthesized by polymerization of monomers containing silicon. The method of claim 1,
The first polymer block contains a silicon moiety bonded to a monomer, wherein the silicon moiety is bonded to the side chain of the block. 4. The block copolymer of claim 1, wherein the block copolymer is used as a top layer material in a bilayer lithography process. In the manufacturing method of the block copolymer for producing nanostructures,
The method comprises:
First polymerizing a monomer not containing silicon to synthesize a first polymer block; And
And polymerizing a monomer containing silicon from the first polymer block to produce a second polymer block bonded to the first polymer block, the second polymer block comprising the monomer containing silicon. Method for producing block copolymer for structure production. 6. The method of claim 5,
The first polymerization method and the second polymerization method of producing a block copolymer for nanostructures, characterized in that the same polymerization method. The method of claim 6,
The first polymerization and the second polymerization is a method for producing a block copolymer for nanostructures, characterized in that anionic polymerization or radical polymerization. A block copolymer for preparing nanostructures prepared by the method according to any one of claims 5 to 7. In the manufacturing method of the block copolymer for producing nanostructures,
The method comprises:
First polymerizing a monomer containing silicon to synthesize a first polymer block; And
And polymerizing a monomer not containing silicon from the first polymer block to produce a second polymer block bonded to the first polymer block and comprising a monomer not containing silicon. Method for producing a block copolymer for producing a nanostructure. The method of claim 9,
The first polymerization method and the second polymerization method of producing a block copolymer for nanostructures, characterized in that the same polymerization method. The method of claim 9,
The first polymerization and the second polymerization is a method for producing a block copolymer for nanostructures, characterized in that anionic polymerization or radical polymerization. Block copolymer for producing a nanostructure produced by the method according to any one of claims 9 to 11. As a block copolymer for manufacturing nanostructures,
The block copolymer is a block copolymer for producing a nanostructure, characterized in that the block copolymer of the formula (1).

(One)

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