KR20190120100A - Block copolymer, method of forming the same and method of forming pattern - Google Patents

Abstract

Provided is a block copolymer. According to one embodiment of the present invention, the block copolymer comprises: a first block represented by chemical formula 1; and a second block represented by chemical formula 2. Here, COM1 and COM2 are each selected from the group consisting of polystyrene, polymethylmethacrylate, polyethyleneoxide, polyvinylpyridine, polydimethylsiloxane, polyferrocenyldimethylsilane, and polyisoprene. R 1 is hydrogen or an alkyl group having 1 to 10 carbon atoms, x is 10 to 500, a is 1 to 50, R2 is hydrogen or an alkyl group having 1 to 10 carbon atoms, y is 10 to 500, and b is 1 to 50. According to the present invention, a novel bottle-brush type block copolymer is formed so that it is possible to minimize entanglement of a polymer, caused by side chains.

Description

BLOCK COPOLYMER, METHOD OF FORMING THE SAME AND METHOD OF FORMING PATTERN}

The present invention relates to a block copolymer, a method for forming the same, and a method for forming a pattern.

The pattern formation method using the block copolymer can form a pattern having a fine line width, and since the process is simple and the cost is low, research on the pattern formation method using the block copolymer has been actively conducted. In addition, the pattern forming method using the block copolymer can form a pattern of various sizes by adjusting the molecular weight of the block copolymer, it is possible to form a pattern of various forms by adjusting the molecular weight ratio of the block copolymer.

A block copolymer is a kind of polymer material, in which two or more polymers are connected to each other by covalent bonds. In the diblock copolymer, which is the simplest structure of the block copolymer, two polymers having different inclinations are connected to each other to form one polymer. The two polymers connected to each other are easily phase separated due to different material properties, and finally the block copolymer may self-assemble to form nanostructures. The linear block copolymer can be expressed by self-assembly within a short process time for a pattern of several tens of nanometers, but it is difficult to apply the process to the process because the time of overexpression is longer for structures having a period of 100 nm or more.

The problem to be solved by the present invention is to provide a block copolymer, a method of forming and a pattern forming method of increasing the phase expression by minimizing the entanglement (entanglement) between polymers.

Block copolymer according to an embodiment of the present invention It includes a first block represented by the formula (1) and a second block represented by the formula (2).

Block copolymer forming method according to an embodiment of the present invention to form a block copolymer using an initiator or an intermediate material represented by the following formula (6).

화학식 6

Formula 6

The pattern forming method according to an embodiment of the present invention is a step of applying a block copolymer on a substrate on which a mother pattern layer is formed to form a polymer thin film, the block of any one of the first block and the second block in the polymer thin film Selectively removing and etching the mother pattern layer using the polymer thin film having any one block removed thereon as a mask.

A block copolymer according to an embodiment of the present invention is inserted into a first block represented by COM A in the following structural formula A, a second block represented by COM B in the following structural formula A and between the first block and the second block To include a random block represented by RBC in formula A below.

구조식 A

Structural Formula A

The method for forming a block copolymer according to an embodiment of the present invention synthesizes a block copolymer based on Scheme A below.

Scheme A

The pattern forming method according to an embodiment of the present invention is a step of applying a block copolymer on a substrate on which a mother pattern layer is formed to form a polymer thin film, the block of any one of the first block and the second block in the polymer thin film Selectively removing and etching the mother pattern layer using the polymer thin film having any one block removed thereon as a mask.

Thus, according to one embodiment of the present invention, by forming a new bold brush block copolymer to minimize the entanglement (entanglement) of the polymer by the side chain to increase the speed of the top expression and the main chain is unfolded. Thus, process time can be minimized.

1 and 2 are photographs showing the vertical lamellae structure phase separation of the bottle brush-type block copolymer according to an embodiment of the present invention.
3 is a schematic view showing a block copolymer according to an embodiment of the present invention.
4 is a cross-sectional view showing a state of curing after applying the block copolymer of FIG. 3 on a substrate.
5 and 6 are photographs showing the vertical lamellae structure phase separation of the block copolymer according to an embodiment of the present invention.
7 to 10 are cross-sectional views illustrating a method of forming a pattern according to an embodiment of the present invention.
FIG. 11 is a perspective view of a pattern formed by the pattern forming method described with reference to FIGS. 7 to 10, and FIG. 12 is a cross-sectional view taken along the cutting line XII-XII of FIG. 11.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosure may be made thorough and complete, and to fully convey the spirit of the present invention to those skilled in the art.

In the drawings, the thicknesses of layers and regions are exaggerated for clarity. In addition, where a layer is said to be "on" another layer or substrate, it may be formed directly on the other layer or substrate, or a third layer may be interposed therebetween. Portions denoted by like reference numerals denote like elements throughout the specification.

Block copolymer

Block copolymer according to an embodiment of the present invention includes a first block represented by the formula (1) and a second block represented by the formula (2).

Wherein COM1 and COM2 are each selected from the group comprising polystyrene, polymethylmethacrylate, polyethylene oxide, polyvinylpyridine, polydimethylsiloxane, polyferrocenyldimethylsilane and polyisoprene, and R1 is hydrogen or 1 to 10 carbon atoms It is a personal alkyl group, x is 10-500, a is 1-50, R <2> is hydrogen or an alkyl group having 1-10 carbon atoms, y is 10-500, b is 1-50.

The block copolymer according to the present embodiment is a bottle brush block copolymer having a main chain and a side chain connected to the main chain as shown by Chemical Formulas 1 and 2. Therefore, since the entanglement between the polymers is minimized by the side chains, the upper expression speed increases and the main chain is unfolded. Due to the main chain unfolding effect, even when the length of the main chain is shorter than the linear block copolymer, a long cycle can be realized, and a short process time can be realized due to the minimization of entanglement.

In the block copolymer according to the present embodiment, COM1 in Formula 1 may include a group represented by Formula 3, and COM2 in Formula 2 may include a group represented by Formula 4.

Formula 3 Formula 4

Where n is from 10 to 1000 and m is from 10 to 1000. Ph represents a phenol group and Me represents a methyl group.

The block copolymer according to the present embodiment may be represented by the following formula (5).

화학식 5

Formula 5

Where n is from 10 to 1000 and m is from 10 to 1000. Ph represents a phenol group and Me represents a methyl group.

Hereinafter, a method of forming the bottle brush type block copolymer according to the present embodiment will be described.

Method of Forming Block Copolymer

The bottle brush type block copolymer according to an embodiment of the present invention is formed using an initiator or an intermediate material represented by the following Chemical Formula 6.

화학식 6

Formula 6

Where a is 1 to 10. Since other initiators or intermediates in the present example include a functional group (GOH) such as -OTBS at the terminal of Formula 6, hydroxyl groups may be generated or induced when synthesizing the macromers described later.

Initiators or intermediates according to this embodiment can be synthesized based on Scheme 1 below.

Scheme 1

Here, TBSCl is tert-butyldimethylsilyl chloride, THF is tetrahydrofuran, OTBS is tert-butyldimethylsilyl oxy group, DEAD is diethyl azodicarboxylate, and PPh3 is triphenylphosphine.

The bottle brush type block copolymer according to the present embodiment is formed by polymerizing a first macromer represented by the following Chemical Formula 7 and a second macromer represented by the following Chemical Formula 8 by a Ring Opening Metathesis Polymerization (ROMP) method. Can be.

화학식 7

Formula 7

화학식 8,

Formula 8,

Where a is 1 to 10, n is 10 to 1000, b is 1 to 10, and m is 10 to 1000. Ph represents a phenol group and Me represents a methyl group. In the step of polymerizing the first macromer and the second macromer, a Grubbs Catalyst may be used. As the Grubbs catalyst, it is preferable to use the third generation Grubbs catalyst as follows.

The first macromer and the second macromer according to the present embodiment can be synthesized based on Reaction Scheme 2 and Reaction Scheme 3, respectively. As shown in Scheme 2 or Scheme 3, the first macromer acts as an intermediate of the compound represented by Chemical Formula 6, and the second macromer acts as an initiator as the compound represented by Chemical Formula 6. The initiator or intermediate material synthesizes the first macromer or the second macromer using anionic polymerization.

Scheme 2

Wherein THF is tetrahydrofuran, TBAF is tetrabutylammonium fluoride, DCC is dicyclohexylcarbodiimid, DPTS is pyridinium p-toluenesulfonate, n is 10-1000 and m is 10-1000.

Scheme 3

Wherein THF is tetrahydrofuran, TBAF is tetrabutylammonium fluoride, DCC is dicyclohexylcarbodiimid, DPTS is pyridinium p-toluenesulfonate, n is 10-1000 and m is 10-1000.

Unlike the present embodiment, the first mask may be synthesized based on Scheme 4 below.

Scheme 4

Where DCC is dicyclohexylcarbodiimid, DPTS is pyridinium p-toluenesulfonate, n is from 10 to 1000 and m is from 10 to 1000.

The bottle brush type block copolymer according to the present embodiment can be synthesized based on Scheme 5 below.

Scheme 5

Where x is from 10 to 500, y is from 10 to 500, and m is from 10 to 1000.

1 and 2 are photographs showing the vertical lamellae phase separation of the bottle brush type block copolymer according to an embodiment of the present invention.

Experimental Example 1

1 shows a vertical lamellar structure with random orientation.

A neutral layer is formed on the silicon substrate, and approximately 5 wt% of the bottle brush type block copolymer is mixed with the PGMEA solution and coated on the neutral layer. Then solvent annealing (solvent annealing) for about 40 minutes at 21 degrees Celsius. Then, thermal annealing is performed at 240 degrees Celsius for 60 minutes.

Referring to Figure 1, it can be seen that the phase separation of the block copolymer is well made.

Experimental Example 2

2 shows a vertical lamellar structure in the form of nanowires aligned in a guide pattern.

After forming the neutral layer in Experimental Example 1 described above, a guide pattern having a width of about 1.5 μm was formed, and a bottle brush-type block copolymer was coated between the guide patterns. The rest of the process proceeds in the same manner as in Experiment 1.

Referring to Figure 2, the phase separation of the block copolymer is made it can be seen that the linear pattern is well formed.

Hereinafter, a block copolymer according to a modified embodiment will be described.

Block copolymer

A block copolymer according to an embodiment of the present invention is inserted into a first block represented by COM A in the following structural formula A, a second block represented by COM B in the following structural formula A and between the first block and the second block To include a random block represented by RBC in formula A below.

구조식 A

Structural Formula A

Wherein COM A and COM B are each selected from the group comprising polystyrene, polymethylmethacrylate, polyethylene oxide, polyvinylpyridine, polydimethylsiloxane, polyferrocenyldimethylsilane and polyisoprene, wherein RBC is at least two units Blocks are groups that are randomly copolymerized.

In Structural Formula A, COM A is preferably a group comprising polystyrene, and COM B is a group comprising polymethylmethacrylate.

Figure 3 is a schematic diagram showing a block copolymer according to an embodiment of the present invention.

Referring to FIG. 3, the block copolymer according to the present embodiment is a linear block copolymer in which a random block RBC is inserted between the first block NB1 and the second block NB2. Random block (RBC) has the effect of straightening the intertwined chain. Specifically, the reason that phase separation occurs in the copolymer connected to the first block and the second block is due to the repulsive force between the first block and the second block. Accordingly, since the monomers forming the first block and the monomers forming the second block are randomly mixed in the random block RBC, the monomers that do not like each other in the random block RBC will be unfolded so as not to mix with each other. In addition, the first block and the second block will also be unfolded so as not to mix with the random block (RBC). Due to this, the period in the phase separation pattern of the block copolymer can be increased and fast phase separation can be realized.

4 is a cross-sectional view showing a state of curing after applying the block copolymer of FIG. 3 on a substrate.

Referring to FIG. 4, when the linear block copolymer according to the exemplary embodiment of the present invention is cured by heat treatment or the like, phase separation proceeds to form a structure having a period T of approximately 100 nm or less.

The linear block copolymer according to the present embodiment may be a block copolymer represented by the following formula (B).

화학식 B

Formula B

Herein, the molecular weight of the formula (B) is 10,000 to 1,000,000, l and n are 10 to 10,000, m is 5 to 2,000, and the unit block represented by x and the unit block represented by y in RBC are randomly copolymerized with each other.

Hereinafter, a method of forming the linear block copolymer including the random block according to the present embodiment will be described.

Method of Forming Block Copolymer

Linear block copolymers according to one embodiment of the present invention are synthesized based on Scheme A below.

Scheme A

Here, AIBN is 2,2'-Azobis (2-methylpropionitrile), and RAFT is Reversible addition-fragmentation chin transfer polymerization.

5 and 6 are photographs showing the vertical lamellae structure phase separation of the block copolymer according to an embodiment of the present invention.

Experimental Example 3

5 shows a vertical lamella structure with random orientation.

A neutral layer is formed on the silicon substrate, and a linear block copolymer having a volume fraction of random blocks of 8%, 12% and 15% is mixed with the PGMEA solution and coated on the neutral layer. Thereafter, thermal annealing is performed at 250 degrees Celsius for about 12 hours. As a result, the cycles increased by 28%, 67%, and 70%, respectively, compared to the linear block copolymer containing no random blocks.

1 shows a phase separation phenomenon in which the linear block copolymer having a volume ratio of random blocks of 8% is heat-treated, and it can be seen that phase separation of the block copolymer is well performed.

Experimental Example 4

Figure 6 shows a vertical lamellar structure in the form of nanowires aligned in a guide pattern.

After forming the neutral layer in Experimental Example 3 described above, a guide pattern having a width of about 0.8 μm was formed, and a linear block copolymer was coated between the guide patterns. The rest of the process proceeds in the same manner as in Experiment 3.

Referring to Figure 6, it can be seen that the phase separation of the block copolymer is well formed a linear pattern.

Hereinafter, a method of forming a pattern using the above-described bottle-shaped block copolymer or a linear block copolymer including a random block will be described.

How to form a pattern

7 to 10 are cross-sectional views illustrating a method of forming a pattern according to an embodiment of the present invention.

Referring to FIG. 7, a mother pattern layer 200, which is a target material to form a pattern, is formed on the substrate 110. The neutral layer 120 is formed on the mother pattern layer 200. Substrate 110 includes a glass substrate. The neutral layer 120 is a chemically neutral layer having neither hydrophilicity nor hydrophobicity, and is a self-assembled monolayer (SAM), a polymer brush, and a cross-linked random copolymer mat (MAT) or MAT. It may be formed of an organic monomolecular layer including a (cross-linked random copolymer mat).

Although not shown, the surface of the substrate 110 may be pretreated using an acidic solution such as hydrofluoric acid (HF) on the substrate 110 before the mother pattern layer 200 is formed.

Next, the guide pattern GP is formed on the neutral layer 120. The guide pattern GP may be formed through a photolithography process using a photoresist. After the photoresist layer is formed on the neutral layer 120, the photoresist layer may be developed by irradiating light from the upper portion of the mask to form a guide pattern GP formed of a photoresist material. The guide pattern GP is not limited to the photolithography process but may be formed by other methods such as a nanoimprint process.

The guide pattern GP controls the orientation of the block copolymer to be formed thereafter. The distance between the guide patterns GP may be about 1.5 μm or less. However, when the guide pattern GP is formed by a photolithography process, the guide pattern GP may be formed larger than 1.5 μm in consideration of the limitation of the resolution of the photo equipment.

Referring to FIG. 8, the polymer thin film 140 is formed by applying the above-described bottle-shaped block copolymer or a linear block copolymer including a random block between the guide patterns GP by spin coating. The polymer thin film 140 is a polymer in which two different types of monomers are covalently bonded. Two different monomers have different physical and chemical properties. Accordingly, either one of the first monomers is relatively hydrophilic in comparison to the other of the second monomers, and the second monomer is relatively hydrophobic in comparison to the first monomers.

Referring to FIG. 9, the substrate 110 including the polymer thin film 140 is heat-treated. The heat treatment process may be performed for at least about 200 degrees Celsius and at most about 300 degrees Celsius, for at least about 2 hours at N2 or vacuum conditions. UV treatment may be used instead of heat treatment. After the heat treatment, the polymer thin film 140 is phase-separated into the first block NB1 and the second block NB2.

The first block NB1 may be formed linearly, and the second block NB2 is disposed adjacent to the first block NB1 by being separated from the first block NB1. In an embodiment of the present invention, the first block NB1 may include a PS, and the second block NB2 may include a PMMA.

In the present embodiment, the period T of the unit in which the first block NB1 and the second block NB2 are repeated may be about 100 nm or less.

Referring to FIG. 10, the second block NB2 is removed. Accordingly, the guide pattern GP remains on the neutral layer 120.

The second block NB2 may be removed through wet etching. For example, after soaking the substrate 110 including the first block NB1 and the second block NB2 in a solution containing acetic acid, only the second block NB2 may be selectively removed. Can be. In contrast, the second block NB2 may be removed through dry etching. For example, after irradiating ultraviolet rays to the first block NB1 and the second block NB2, the second block NB2 may be formed due to a difference in etching selectivity through reactive ion etching (RIE). Only bays can be removed selectively.

Next, the mother pattern layer 200 may be patterned by etching the neutral layer 120 and the mother pattern layer 200 using the first block NB1 as a mask.

Subsequently, the first block NB1 and the guide pattern GP are removed. For example, the substrate 110 including the first block NB1 and the guide pattern GP is immersed in a solution containing toluene, and then ultrasonically decomposed to form the first block NB1 and the guide pattern GP. Can be removed.

FIG. 11 is a perspective view of a pattern formed by the pattern forming method described with reference to FIGS. 7 to 10. 12 is a cross-sectional view taken along the line XII-XII of FIG. 11.

11 and 12 may be a metal pattern constituting the polarizing plate. 11 and 12, the mother pattern layer 200 is patterned to form a grid pattern 210 including a first line 210a and a second line 210b formed on the substrate 110. do.

The first and second lines 210a and 210b extend in the first direction D1 of the substrate 110. The second line 210b is disposed in a second direction D2 different from the first direction D1 of the first line 210a. The first and second lines 210a and 210b may include aluminum, silver, platinum, or the like.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

110 substrate 120 neutral layer
200 Mother Pattern Layer 210 Grid Pattern
NB1 first block NB2 second block

Claims (5)

A first block represented by COM A in Structural Formula A,
A second block represented by COM B in the following structural formula A and
A block copolymer inserted between the first block and the second block and including a random block represented by RBC in formula A:

Structural Formula A
Wherein COM A and COM B are each selected from the group comprising polystyrene, polymethylmethacrylate, polyethylene oxide, polyvinylpyridine, polydimethylsiloxane, polyferrocenyldimethylsilane and polyisoprene, wherein RBC is the first Part of the block and at least two unit blocks that are part of the second block are randomly copolymerized groups). In claim 1,
In the structural formula A COM A is a group comprising a polystyrene, COM B is a block copolymer containing a polymethyl methacrylate. In claim 2,
The block copolymer is a block copolymer represented by the formula (B):

Formula B
(Wherein, the molecular weight of formula B is 10,000 to 1,000,000, l and n are 10 to 10,000, m is 5 to 2,000, and the unit block represented by x and the unit block represented by y in RBC are randomly copolymerized with each other) . Applying the block copolymer of claim 1 on a substrate having a mother pattern layer to form a polymer thin film,
Selectively removing any one of the first block and the second block from the polymer thin film; and
And etching the mother pattern layer using the polymer thin film from which any one block is removed as a mask. In claim 4,
The pattern forming method further comprising the step of ultraviolet treatment or heat treatment of the polymer thin film.

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