KR102522250B1 - Preparation method of substrate - Google Patents

Abstract

This application relates to a method for manufacturing a substrate. In the present application, it is possible to provide a method for manufacturing a substrate on which contact/via holes are formed without variation in the diameter or shape of the hole while miniaturization capable of responding to the high degree of integration demand is possible.

Description

Manufacturing method of substrate {PREPARATION METHOD OF SUBSTRATE}

This application relates to a method for manufacturing a substrate.

A block copolymer is a copolymer in which polymer blocks having different chemical structures are connected through covalent bonds. Such a block copolymer may form a periodically arranged structure such as a sphere, a cylinder, or a lamella by phase separation. The shape and size of the domains of the structure formed by the self-assembly of the block copolymer can be controlled in a wide range, for example, by the type of monomers forming each block or the relative ratio between the blocks.

Due to these characteristics, the application of block copolymers to fabrication of various next-generation nanodevices such as nanowires, quantum dots or metal dots, or lithography methods capable of forming high-density patterns on a predetermined substrate has been studied. .

One example of the above review is application to fabrication of contact/via holes necessary for the formation of large-scale integrated circuits (LSI) and the like. That is, since more miniaturization is required for large-scale integrated circuits (LSI), a technique for processing delicate structures is required, and block copolymers can be applied to this demand. However, it is not an easy task to reduce the deviation of the hole diameter or shape while finely manufacturing the contact/via hole pattern.

This application provides a method for manufacturing a substrate. This application may be, for example, a method of manufacturing a substrate on which contact/via holes are formed. One object of the present application is to provide a method for manufacturing a substrate having contact/via holes without variation in diameter or shape of the hole while being miniaturized to meet the high level of integration requirements.

In this specification, the term alkyl group may refer to an alkyl group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms, unless otherwise specified. The alkyl group may be a straight-chain, branched or cyclic alkyl group, and may be optionally substituted with one or more substituents.

In this specification, the term alkoxy group may refer to an alkoxy group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms, unless otherwise specified. The alkoxy group may be a straight-chain, branched or cyclic alkoxy group, and may be optionally substituted with one or more substituents.

In this specification, the term alkenyl group or alkynyl group means an alkenyl group or alkynyl group having 2 to 20 carbon atoms, 2 to 16 carbon atoms, 2 to 12 carbon atoms, 2 to 8 carbon atoms, or 2 to 4 carbon atoms, unless otherwise specified. can do. The alkenyl group or alkynyl group may be straight-chain, branched or cyclic, and may be optionally substituted with one or more substituents.

In this specification, the term alkylene group may mean an alkylene group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms, unless otherwise specified. The alkylene group may be a straight-chain, branched or cyclic alkylene group, and may be optionally substituted with one or more substituents.

In this specification, the term alkenylene group or alkynylene group, unless otherwise specified, is an alkenylene group or alkynylene having 2 to 20 carbon atoms, 2 to 16 carbon atoms, 2 to 12 carbon atoms, 2 to 8 carbon atoms, or 2 to 4 carbon atoms. can mean ki. The alkenylene group or alkynylene group may be straight-chain, branched or cyclic, and may be optionally substituted with one or more substituents.

In this specification, the term aryl group or arylene group, unless otherwise specified, has a benzene ring structure, two or more benzene rings are connected while sharing one or two carbon atoms, or connected by any linker It may mean a monovalent or divalent residue derived from a compound having a structure or a derivative thereof. Unless otherwise specified, the aryl group or arylene group may be, for example, an aryl group having 6 to 30 carbon atoms, 6 to 25 carbon atoms, 6 to 21 carbon atoms, 6 to 18 carbon atoms, or 6 to 13 carbon atoms.

In this application, the term aromatic structure may mean the above aryl group or arylene group.

In this specification, the term alicyclic ring structure refers to a cyclic hydrocarbon structure other than an aromatic ring structure unless otherwise specified. Unless otherwise specified, the alicyclic ring structure may be, for example, an alicyclic ring structure having 3 to 30 carbon atoms, 3 to 25 carbon atoms, 3 to 21 carbon atoms, 3 to 18 carbon atoms, or 3 to 13 carbon atoms. .

In this application, the term single bond may mean a case in which no separate atom exists at the corresponding site. For example, in the structure represented by A-B-C, when B is a single bond, no separate atom exists at the site represented by B, and A and C are directly connected to form a structure represented by A-C.

In the present application, substituents that may be optionally substituted on an alkyl group, an alkenyl group, an alkynyl group, an alkylene group, an alkenylene group, an alkynylene group, an alkoxy group, an aryl group, an arylene group, a chain or an aromatic structure, etc. include a hydroxyl group, a halogen atom , carboxyl group, glycidyl group, acryloyl group, methacryloyl group, acryloyl group oxy, methacryloyl group oxy group, thiol group, alkyl group, alkenyl group, alkynyl group, alkylene group, alkenylene group, alkynylene group , An alkoxy group or an aryl group may be exemplified, but is not limited thereto.

This application relates to a method for manufacturing a substrate. In one example, the manufacturing method may be a manufacturing method of forming a contact/via hole in the substrate. The method may be performed, for example, by a lithography method using a directed self assembly material as a template. In the above, the induced self-assembly material may be, for example, a block copolymer.

The method of the present application may include forming a layer of an inducing self-assembly material on a substrate having a template formed thereon, and inducing self-assembly.

In the above, the template may be a guide pattern in which the guide hole is formed, and the block copolymer, which is the induction self-assembly material, may form a self-assembled structure inside the guide hole.

The type of substrate applied to the method of the present application is not particularly limited. As the substrate, for example, various types of substrates requiring formation of contact/via holes may be used. Examples of substrates of this kind include semiconductor substrates such as silicon substrates, silicon germanium substrates, GaAs substrates, and silicon oxide substrates. As the substrate, for example, a substrate applied to formation of fin field effect transistors (finFETs) or other electronic devices such as diodes, transistors, or capacitors may be used. In addition, other materials such as ceramics may also be used as the substrate depending on the purpose, and the type of substrate applicable in the present application is not limited thereto.

A guide pattern in which at least one guide hole is formed is formed on the surface of the substrate applied to the method of the present application. For example, the guide holes may be spaced apart from each other at regular intervals and arranged in a guide pattern. The number of the guide holes is not particularly limited and may be adjusted according to use. The guide hole may play a role of guiding a self-assembled structure of the block copolymer formed when a film including an induced self-assembly material such as a block copolymer is formed.

1 and 2 are schematic diagrams of the substrate on which the guide pattern is formed as described above, FIG. 1 is a case in which the substrate is viewed from the side, and FIG. 2 is a view in which the substrate is viewed from the upper side (the side where the guide hole is formed) am.

As shown in FIG. 1 , a guide pattern 200 is formed above the substrate 100 , and a guide hole 2001 is formed in the guide pattern 200 . As shown in FIG. 2 , the guide hole 2001 may have a cylindrical shape having a circular cross-section. In the above, the cross section may refer to a surface viewed from the front of the guide pattern 200 or a surface viewed by cutting the guide pattern 200 parallel to the surface of the substrate 100 .

The shape of the guide hole may be adjusted in consideration of the desired efficiency of pattern formation.

In one example, the cross section of the guide hole may have a diameter (D in FIGS. 1 and 2) within a range of approximately 30 nm to 100 nm. In another example, the diameter (D) is about 35 nm or more, 95 nm or less, 90 nm or less, 85 nm or less, 80 nm or less, 75 nm or less, 70 nm or less, 65 nm or less, 60 nm or less, 55 nm or less , may be on the order of 50 nm or less or 45 nm or less.

In addition, in one example, the height of the guide hole (H in FIG. 1) may be within a range of approximately 50 nm to 200 nm. In another example, the height H is approximately 55 nm or more, 60 nm or more, 65 nm or more, 70 nm or more, or 75 nm or more, or 190 nm or less, 180 nm or less, 170 nm or less, 160 nm or less, or 150 nm or less. , 140 nm or less, 130 nm or less, 120 nm or less, 110 nm or less, 100 nm or less, or 90 nm or less.

In addition, the ratio (H/D) of the height (H) to the diameter (D) of the face of the guide hole may be in the range of about 1.5 to about 5. In another example, the ratio (H/D) may be approximately 4.5 or less, 4 or less, 3.5 or less, 3 or less, or 2.5 or less.

The guide holes may be arranged so that the distance L is within a range of about 80 to 500 nm. In the above, the interval is the distance from the center of the guide hole 2001 to the center of another adjacent guide hole 2001, and is indicated by L in FIG. 2 .

The guide hole of the above type is combined with the block copolymer of the present application to be described later so that a finer contact/via hole pattern can be formed with a uniform diameter and shape.

The guide pattern as described above, for example, SiO ₂ , ACL (Amorphous carbon layer), SOG (Pin-on-glass), SOC (Spin-on-carbon), silicon nitride (silicon nitride), hard mask (Hard mask), antireflective coating, organic polarizing layer (OPL), or the like.

A method of forming the guide pattern as described above on the substrate is not particularly limited, and a known method may be applied. For example, the pattern may be formed by etching the substrate in a suitable manner or by depositing a suitable material on the substrate.

For example, the guide pattern may include sequentially forming a layer of a guide pattern material, an antireflection layer, and a resist layer on a substrate; patterning the resist layer; and etching the guide pattern material layer using the patterned resist layer as a mask.

In the above, the type of guide pattern material is not particularly limited. For example, the layer of the material is etched by an etching process using a patterned resist layer as a mask, and in this process, a material capable of being etched appropriately may be used. For example, SiO ₂ , ACL (Amorphous carbon layer), SOG (Pin-on-glass), SOC (Spin-on-carbon), or silicon nitride may be applied as the material. A layer of such a material may be coated by a method such as spin coating or formed by a deposition method such as chemical vapor deposition (CVD). When the layer of the material is formed, its thickness is not particularly limited, and may be formed to an appropriate thickness in consideration of the desired height H of the guide hole.

An antireflection layer may be formed on top of the guide pattern material layer. The antireflection layer may be formed of SiARC using, for example, a silicon material (Si), and other known materials may be applied. The antireflection layer can be formed by a known coating or vapor deposition method.

A resist layer may be formed on the antireflection layer. The resist layer may be formed using a known material, for example, a material that can be patterned by a known lithographic process. Such a resist layer may be patterned by a known lithography method, and the patterned resist layer may be applied as a mask in a subsequent mesa formation process. Patterning of the resist layer may be performed so that the size of the guide hole can be adjusted to a desired level in a subsequent etching process.

Following the patterning of the resist layer, an etching process may be performed in which the patterned resist layer is applied as an etch mask. In this etching process, reflection of areas other than areas protected by the mask The barrier layer and the layer of guide pattern material may be etched away. Such etching may be performed by a known etching method, and may be performed by, for example, a reactive ion etching (RIE) method. By this etching, the mesa structure described above is formed, whereby a trench may be formed. The etching may be performed until all of the guide pattern material in a region not protected by the etch mask is removed, or a portion of the material may remain. Accordingly, the guide hole may be formed by the side wall and the lower surface of the substrate made of the guide pattern material, or both the side wall and the lower part made of the guide pattern material.

In the above, the content has been described based on the fact that one layer of the guide pattern material and the antireflection layer are formed on the surface of the substrate and lithography is performed, but if necessary, the layer of the guide pattern material and the antireflection layer are formed in two layers, respectively. Abnormalities may form alternately.

The method of the present application may include forming a self-assembled structure of the block copolymer inside the guide hole formed in the above manner. The self-assembling structure of the block copolymer formed in the guide hole may be, for example, a sphere, a cylinder, or a lamellar structure, and in one example may be a lamellar structure or a cylinder structure. It is not limited.

For example, when a block copolymer comprising first and second blocks is used as the block copolymer, the first or second blocks or other segments within the segments of other blocks covalently bonded thereto have a lamellar shape or It may form a regular structure such as a cylinder shape.

When the phase-separated structure formed by the block copolymer is a lamellar structure, the ratio (D/P) of the pitch (P) of the lamellar structure and the diameter (D) of the cross section of the guide hole may be in the range of 1 to 1.5. . In another example, the ratio (D/P) may be approximately 1.45 or less, 1.4 or less, 1.35 or less, or 1.3 or less, or 1.05 or more, 1.1 or more, 1.15 or more, 1.2 or more, or 1.25 or more.

When the phase separation structure formed by the block copolymer is a lamellar structure, the ratio (H/P) between the pitch (P) of the lamellar structure and the height (H) of the guide hole may be in the range of 1.5 to 5. In another example, the ratio (H/P) may be approximately 4.5 or less, 4 or less, 3.5 or less, 3 or less, or 2 or more.

In addition, when the phase separation structure formed by the block copolymer is a cylinder structure, the ratio (D/P) of the pitch (P) of the cylinder structure and the diameter (D) of the cross section of the guide hole may be in the range of 0.7 to 1.3. . In another example, the ratio (D/P) may be about 1.25 or less, 1.2 or less, 0.75 or more, 0.8 or more, 0.85 or more, 0.9 or more, 0.95 or more, about 1 or more, 1.05 or more, 1.1 or more, or 1.15 or more.

When the phase separation structure formed by the block copolymer is a cylinder structure, the ratio (H/P) of the pitch (P) of the cylinder structure and the height (H) of the guide hole may be in the range of 1.5 to 5. In another example, the ratio (H/P) may be about 4.5 or less, 4 or less, 3.5 or less, 3 or less, 2.5 or less, or 2 or more.

Through the above adjustment, it is possible to form a self-assembly pattern more suitable for forming a contact/via hole.

Meanwhile, the pitch of the lamellar structure or the cylindrical structure may be in the range of about 10 nm to 60 nm in one example, and may be about 20 nm or more or 25 nm or more, or 50 nm or less or 40 nm or less in another example. .

In the above, a so-called neutral layer or surface treatment may not be present on the surface of the guide hole where the block copolymer is self-assembled, that is, on the sidewall and bottom of the guide hole where the block copolymer contacts. That is, the sidewall and the bottom of the guide hole that the block copolymer contacts may be the material of the guide pattern itself or the surface of the substrate that has not been subjected to neutral treatment, wherein the neutral treatment is a neutral brush layer or chemical It can be interpreted as meaning including a known process for achieving homeotropic alignment such as preliminary patterning. Also, in the present application, that a certain layer or film is formed in contact with a certain surface may mean a case where no other layer exists between the layer or film and the surface.

The present inventors do not form a neutral layer on the guide pattern including the guide hole controlled as described above, and when a self-assembled structure is formed using a block copolymer described later, a finer contact / via hole (contact / via hole) It was confirmed that the hole pattern could be formed uniformly and accurately.

The block copolymer applicable to the above process is not particularly limited, but is a block copolymer showing a self-assembling structure more suitable for forming a contact/via hole on the above-mentioned guide pattern, exemplified below. block copolymers may be used.

In the present application, a block copolymer including a first block to be described later and a second block to be described later that is different from the first block may be applied. Each block of the block copolymer may be formed of only one type of monomer or two or more types of monomers. The block copolymer may be a diblock copolymer including only one first block and one second block. The block copolymer further includes one of each of the first and second blocks, further includes any one or both of the first and second blocks, or blocks other than the first and second blocks. It may be a block copolymer of more than triblock including additionally.

The block copolymer of the present application may include a first block including repeating units represented by Formula 1 below and a second block including repeating units represented by Formula 2 below.

[Formula 1]

In Formula 1, R is hydrogen or an alkyl group having 1 to 4 carbon atoms, X is an oxygen atom, a sulfur atom, -S(=O) ₂ -, a carbonyl group, -C(=O)-O- or -OC(=O )-, P is an arylene group having 6 to 18 carbon atoms, Q is a single bond, an oxygen atom, a sulfur atom, -S(=O) ₂ -, a carbonyl group, -C(=O)-O- or -OC (=O)-, and Z is a hydrocarbon chain of 8 to 20 carbon atoms:

[Formula 2]

In Formula 2, X ₂ is a single bond, an oxygen atom or a sulfur atom, and W is an aryl group having 6 to 18 carbon atoms and containing 3 or more halogen atoms.

In Formula 1, X may be an oxygen atom, a carbonyl group, -C(=O)-O- or -OC(=O)-, or -C(=O)-O- in another example, but is not limited thereto no.

In Formula 1, P may be an arylene group having 6 to 18 carbon atoms, an arylene group having 6 to 12 carbon atoms, or a phenylene group.

In Formula 1, Q may be connected to the para position when P is a phenylene group.

Q in Formula 1, in one example, may be a single bond, an oxygen atom, a sulfur atom, -S(=O) ₂ -, a carbonyl group, -C(=O)-O- or -OC(=O)- , For example, it may be a single bond, an oxygen atom, a carbonyl group, -C(=O)-O- or -OC(=O)-, but is not limited thereto.

Z in Formula 1 is a hydrocarbon chain having 8 to 20 carbon atoms. In another example, the number of carbon atoms in the hydrocarbon chain may be 9 or more, 10 or more, 11 or more, or 12 or more, or 19 or less, 18 or less, 17 or less, 16 or less, 15 or less, 14 or less, 13 or less, or 12 or less. The hydrocarbon chain may be a straight chain hydrocarbon chain, and may be, for example, a straight chain alkyl group, an alkenyl group or an alkynyl group. The number of carbon atoms in the straight-chain alkyl group, alkenyl group or alkynyl group is 8 or more, 9 or more, 10 or more, 11 or more, or 12 or more, or 20 or less, 19 or less, 18 or less, 17 or less, 16 or less, 15 or less, 14 or less, It may be 13 or less or 12 or less.

In one example, the hydrocarbon chain is a chain including a straight chain structure, and at this time, the number of carbon atoms forming the straight chain structure may be within the range of 8 to 20. The chain may be straight or branched, but the number of carbon atoms calculated only by the number of carbon atoms forming the longest straight chain may be within the range of 8 to 20. In the case of a branched chain, the number of carbon atoms forming the straight chain structure can be calculated as the number of carbon atoms forming the longest chain. For example, when the chain is an n-pentyl group, the number of carbon atoms forming the linear structure is 5, and when the chain is a 2-methylpentyl group, the number of carbon atoms forming the linear structure is 5.

The hydrocarbon chain including the straight-chain structure may be a straight-chain or branched-chain alkyl, alkenyl, or alkynyl group, wherein the number of carbon atoms forming the straight-chain structure is 8 or more, 9 or more, 10 or more, 11 or more, or 12 or more, 20 or less, 19 or less, 18 or less, 17 or less, 16 or less, 15 or less, 14 or less, 13 or less, or 12 or less.

In one example, one or more of the carbon atoms of the alkyl group, alkenyl group, or alkynyl group, which is the hydrocarbon chain, may be optionally replaced with a hetero atom for a carbon atom such as an oxygen atom, and at least one of the alkyl group, alkenyl group, or alkynyl group A hydrogen atom may be optionally substituted by another substituent.

In the block copolymer of the present application, the first block may consist of only repeating units comprising the units of Chemical Formula 1, or may include other repeating units in addition to the repeating units. In one example, the first block includes about 80 mol% or more, 82 mol% or more, 84 mol% or more, 86 mol% or more, 88 mol% or more, or 90 mol% or more of repeating units of the unit of Formula 1, or , About 100 mol% or less, 98 mol% or less, 96 mol% or less, 94 mol% or less, 92 mol% or less, or 90 mol% or less.

Types of other units that may be additionally included in the first block are not particularly limited as long as they do not adversely affect the desired self-assembly structure. The unit may be, for example, a vinylpyrrolidone unit, a lactic acid unit, a vinylpyridine unit, a styrene unit such as styrene or trimethylsilylstyrene, or an ethylene oxide unit. An alkylene oxide unit, a butadiene unit, an isoprene unit, or an olefin unit such as ethylene, or a repeating unit composed of such a unit may be exemplified.

The second block having the repeating unit represented by Formula 2 exhibits an excellent interaction with the first block to exhibit a self-assembled structure more suitable for forming a contact/via hole in the guide hole. can

In Formula 2, X ₂ may be a single bond in one example.

In Formula 2, the aryl group may be, for example, an aryl group having 6 to 18 carbon atoms or 6 to 12 carbon atoms, or a phenyl group.

As the halogen atom included in Formula 2, a fluorine atom or a chlorine atom may be exemplified, and a fluorine atom may be appropriately exemplified, but is not limited thereto. The halogen atom may be substituted with the aryl group.

In one example, W in Formula 2 has 6 to 18 carbon atoms or 6 to 12 carbon atoms substituted with 1 or more, 2 or more, 3 or more, 4 or more or 5 or more halogen atoms (fluorine atoms or chlorine atoms, etc.) It may be an aryl group or a phenyl group. The upper limit of the number of halogen atoms substituted in the above is not particularly limited, and for example, 10 or less, 9 or less, 8 or less, 7 or less, or 6 or less halogen atoms may be present.

The unit of Formula 2 may be represented by Formula 3 below in another example.

[Formula 3]

In Formula 3, X ₂ is a single bond, an oxygen atom or a sulfur atom, R ₁ to R ₅ are each independently hydrogen, an alkyl group, a haloalkyl group or a halogen atom, and the number of halogen atoms included in R ₁ to R ₅ is There may be three or more.

In Formula 3, X ₂ may be a single bond in another example.

In Formula 3, R ₁ to R ₅ are each independently hydrogen, an alkyl group, a haloalkyl group, or a halogen atom, but R ₁ to R ₅ are 1 or more, 2 or more, 3 or more, 4 or more, or 5 or more halogen atoms. , for example, a fluorine atom or a chlorine atom. The number of halogen atoms included in R ₁ to R ₅ may be 10 or less, 9 or less, 8 or less, 7 or less, or 6 or less. The halogen atoms may be included in a haloalkyl group, and one or more, two or more, three or more, four or more, or five of R ₁ to R ₅ may be halogen atoms. In this case, the halogen atom may be a fluorine atom or a chlorine atom.

In the block copolymer, the second block may consist only of repeating units comprising units represented by Chemical Formula 2 or 3, or may include other repeating units in addition to the repeating units. In one example, the second block contains about 80 mol% or more, 82 mol% or more, 84 mol% or more, 86 mol% or more, 88 mol% or more, or 90 mol% or more of repeating units of Formula 2 or 3. or about 100 mol% or less, 98 mol% or less, 96 mol% or less, 94 mol% or less, 92 mol% or less, or 90 mol% or less.

Types of other units that may be additionally included in the second block are not particularly limited as long as the desired self-assembly characteristics are not adversely affected. The unit may be, for example, a vinylpyrrolidone unit, a lactic acid unit, a vinylpyridine unit, a styrene unit such as styrene or trimethylsilylstyrene, or an ethylene oxide unit. An alkylene oxide unit, a butadiene unit, an isoprene unit, or an olefin unit such as ethylene, or a repeating unit composed of such a unit may be exemplified.

In one example, the second block may further include an alkyl styrene unit or a styrene unit together with a repeating unit of Formula 2 or 3. Through these additional units, a phase separation pattern more suitable for forming a contact/via hole within the guide hole can be implemented.

In the alkyl styrene unit, an alkyl group may be included in a para position, and thus the alkyl styrene unit may be a para-alkyl styrene unit.

The alkyl group included in the alkyl styrene unit may be a linear or branched alkyl group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms.

The alkyl styrene unit may be a unit in which R ₆ to R ₁₀ are hydrogen or an alkyl group and at least one of R ₆ to R ₁₀ is an alkyl group in Formula 4 below. In one example, the para-alkyl styrene unit is represented by the following formula In 4, R ₈ may be an alkyl group, and R ₆ , R ₇ , R ₉ and R ₁₀ may be a hydrogen atom.

The alkyl group of the alkyl styrene unit may be a linear or branched alkyl group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms. Such an alkyl group may be an alkyl group of any one of R ₆ to R ₁₀ or an alkyl group of R ₈ .

Meanwhile, the styrene unit is a unit in which R ₆ to R ₁₀ are all hydrogen in the following Chemical Formula 4.

[Formula 4]

The present inventors have confirmed that the alkyl styrene unit or styrene unit, together with the repeating unit comprising the unit of Chemical Formula 2 or 3 in the second block, allows the second block to properly interact with the first block.

If the second block further includes a unit of Formula 3, it may include a repeating unit of Formula 2 or 3 within the range of 60 mol% to 97 mol%. In another example, the ratio may be about 65 mol% or more or 70 mol% or more, or may be 95 mol% or less, 93 mol% or less, 91 mol% or less, or 90 mol% or less.

When the second block includes the alkyl styrene unit or the styrene unit, it may be included within a range of 3 mol% to 40 mol%. In other examples, the ratio is about 5 mol% or more, about 7 mol% or more, about 9 mol% or more, or about 10 mol% or more, or about 38 mol% or less, about 36 mol% or less, about 34 mol% or less, about It may be 32 mol% or less or about 30 mol% or less.

In the block copolymer, when the volume of the first block and the second block is set to 1, the volume fraction of the first block is in the range of 0.3 to 0.8, and the volume fraction of the second block is in the range of 0.2 to 0.7 can

Typically, one factor that determines the type of phase separation pattern implemented by the block copolymer is the volume fraction of each block of the block copolymer.

In one example, when a lamellar pattern described later is to be formed with the block copolymer, the volume fraction of the first block is about 0.35 or more, about 0.4 or more, or about 0.45 or more, or about 0.75 or less, about 0.7 or less, It may be about 0.65 or less, about 0.6 or less, about 0.55 or less, or about 0.5 or less. In addition, the volume fraction of the second block may be about 0.25 or more, 0.3 or more, 0.35 or more, 0.4 or more, 0.45 or more, or about 0.5 or more, or about 0.65 or less, about 0.6 or less, or about 0.55 or less in another example. The lamellar structure realized by the above volume fraction is more suitable for realizing the desired contact/via hole pattern in the guide hole described above.

In one example, when a cylinder pattern described later is to be formed with the block copolymer, the volume fraction of the first block is, in another example, about 0.35 or more, about 0.4 or more, about 0.45 or more, or about 0.5 or more, or about 0.75 or less, It may be about 0.7 or less, about 0.65 or less, or about 0.6 or less. In another example, the volume fraction of the second block may be about 0.25 or more, 0.3 or more, 0.35 or more, or 0.4 or more, or about 0.65 or less, about 0.6 or less, about 0.55 or less, or about 0.5 or less. The cylinder structure realized by the above volume fraction is more suitable for implementing a desired contact/via hole pattern in the guide hole described above.

The volume fraction of each block can be obtained based on the density of each block and the molecular weight measured by gel permeation chromatography (GPC).

The number average molecular weight (Mn) of the block copolymer may be, for example, in the range of 10,000 to 100,000. The term number average molecular weight in this specification is a value in terms of standard polystyrene measured using GPC (Gel Permeation Chromatograph), and the term molecular weight in this specification means number average molecular weight unless otherwise specified. In addition, unless otherwise specified, the unit of number average molecular weight is g/mol.

When the block copolymer is configured to implement the aforementioned lamellar structure, the molecular weight of the block copolymer may be about 40,000 or less within the above range. In this case, the molecular weight may be approximately 25,000 or more, 30,000 or more, or 35,000 or more in another example. Through this range of molecular weight, it may be more efficient to realize a desired contact/via hole in the guide hole under the volume fraction realizing the aforementioned lamellar structure.

Meanwhile, when the block copolymer is configured to implement the above-described cylindrical structure, the molecular weight of the block copolymer may be greater than 40,000 within the above range. In this case, the molecular weight may be approximately 90,000 or less, 80,000 or less, 70,000 or less, 60,000 or less, 50,000 or less, or 45,000 or less in another example. Through this range of molecular weight, it may be more efficient to implement a desired via hole in a guide hole under a volume fraction that implements the aforementioned cylindrical structure.

A specific method for preparing the block copolymer as described above applied to the present application is not particularly limited, and, for example, a known method for preparing a block copolymer using a monomer capable of forming each block is applied. Block copolymers can be prepared.

For example, the block copolymer may be prepared by a Living Radical Polymerization (LRP) method. For example, anionic polymerization in which an organic rare earth metal complex is used as a polymerization initiator or an organic alkali metal compound is used as a polymerization initiator in the presence of an inorganic acid salt such as an alkali metal or alkaline earth metal salt, or an organic alkali metal compound is polymerized. Anionic polymerization method synthesized in the presence of an organoaluminum compound using an initiator, an atom transfer radical polymerization method (ATRP) using an atom transfer radical polymerizer as a polymerization control agent, and an atom transfer radical polymerization method using an atom transfer radical polymerizer as a polymerization control agent but electrons ARGET (Activators Regenerated by Electron Transfer) atom transfer radical polymerization (ATRP), ICAR (Initiators for continuous activator regeneration) atom transfer radical polymerization (ATRP), inorganic reducing agent reversible addition- A polymerization method by reversible addition-cleavage chain transfer (RAFT) using a cleavage chain transfer agent or a method using an organic tellurium compound as an initiator may be used, and an appropriate method may be selected and applied from among these methods.

For example, the block copolymer may be prepared by a method comprising polymerizing a reactant including monomers capable of forming the block by a living radical polymerization method in the presence of a radical initiator and a living radical polymerization reagent. .

In the preparation of the block copolymer, the method of forming other blocks included in the copolymer together with the block formed using the monomer is not particularly limited, and an appropriate monomer is selected in consideration of the type of the desired block, and the other blocks are formed. blocks can be formed.

The manufacturing process of the block copolymer may further include, for example, a process of precipitating the polymerization product produced through the above process in a non-solvent.

The type of radical initiator is not particularly limited and may be appropriately selected in consideration of polymerization efficiency. For example, AIBN (azobisisobutyronitrile) or 2,2'-azobis-2,4-dimethylvaleronitrile (2,2' Azo compounds such as -azobis-(2,4-dimethylvaleronitrile)) or peroxides such as benzoyl peroxide (BPO) or di-t-butyl peroxide (DTBP) may be used.

The living radical polymerization process is, for example, methylene chloride, 1,2-dichloroethane, chlorobenzene, dichlorobenzene, benzene, toluene, acetone, chloroform, tetrahydrofuran, dioxane, monoglyme, diglyme, dimethylform amide, dimethylsulfoxide or dimethylacetamide and the like.

As the non-solvent, for example, alcohols such as methanol, ethanol, normal propanol or isopropanol, glycols such as ethylene glycol, ethers such as n-hexane, cyclohexane, n-heptane or petroleum ether may be used, It is not limited thereto.

In the present application, a method of forming a self-assembled structure in a guide hole using the block copolymer as described above is not particularly limited.

For example, the structure may be formed by forming the block copolymer or a coating solution diluted in an appropriate solvent on the guide pattern by applying, and if necessary, annealing the layer.

The annealing treatment may be, for example, thermal annealing or solvent annealing.

The annealing treatment may be performed, for example, based on the phase transition temperature or glass transition temperature of the block copolymer, and may be performed, for example, at a temperature equal to or higher than the glass transition temperature or phase transition temperature. The time for performing this heat treatment is not particularly limited, and may be performed within a range of about 1 minute to 72 hours, for example, but may be changed as necessary. In addition, the heat treatment temperature may be, for example, 100° C. to 250° C., but may be changed in consideration of the block copolymer used.

In another example, the formed layer may be solvent aged in a non-polar solvent and/or a polar solvent at room temperature for about 1 minute to 72 hours.

The manufacturing method of the substrate of the present application may further include a step of selectively removing any one block from the self-assembled block copolymer formed in the guide hole as described above. For example, if the block copolymer includes the first block and the second block described above, the method may include a process of selectively removing the first or second block from the block copolymer. Through this process, only blocks that are not removed may exist inside the guide hole. The method of manufacturing the substrate may also include etching the substrate after selectively removing any one or more blocks of the block copolymer as described above.

In the above method, the method of selectively removing any one block of the block copolymer is not particularly limited, and, for example, a method of removing a relatively soft block by irradiating a polymer film with appropriate electromagnetic waves, such as ultraviolet rays, etc. can be used In this case, the UV irradiation condition is determined according to the type of block of the block copolymer, and for example, it may be performed by irradiating UV light having a wavelength of about 254 nm for 1 minute to 60 minutes.

In addition, a step of further removing segments decomposed by ultraviolet rays by treating the polymer film with an acid or the like may be performed following irradiation with ultraviolet rays.

In addition, the step of etching the substrate using the selectively block-removed polymer film as a mask is not particularly limited, and may be performed, for example, through a reactive ion etching step using CF ₄ /Ar ions, etc. Subsequently, a step of removing the polymer film from the substrate by oxygen plasma treatment or the like may also be performed.

This application relates to a method for manufacturing a substrate. In the present application, it is possible to provide a method for manufacturing a substrate on which contact/via holes are formed without variation in the diameter or shape of the hole while miniaturization capable of responding to the high degree of integration demand is possible.

1 and 2 are exemplary diagrams for explaining the shape of a guide pattern.
3 and 4 are views showing a self-assembling structure of a block copolymer formed in a guide hole in an embodiment.

Hereinafter, the present application will be described in more detail through examples and comparative examples according to the present application, but the scope of the present application is not limited by the examples presented below.

1. NMR measurement

NMR analysis was performed at room temperature using an NMR spectrometer including a Varian Unity Inova (500 MHz) spectrometer with a triple resonance 5 mm probe. The analyte was diluted to a concentration of about 10 mg/ml in a solvent for NMR measurement (CDCl ₃ ), and the chemical shift was expressed in ppm.

<Applicable Abbreviations>

br = wide signal, s = singlet, d = doublet, dd = double doublet, t = triplet, dt = double triplet, q = quartet, p = quintet, m = multiplet.

2. Gel Permeation Chromatograph (GPC)

Number average molecular weight (Mn) and molecular weight distribution were measured using GPC (Gel permeation chromatography). A polymer to be measured was put in a 5 mL vial, and diluted in tetrahydro furan (THF) to a concentration of about 1 mg/mL. Subsequently, the standard sample for calibration and the sample to be analyzed were filtered through a syringe filter (pore size: 0.45 μm) and then measured. The analysis program used ChemStation from Agilent technologies. The elution time of the sample was compared with the calibration curve to obtain the weight average molecular weight (Mw) and number average molecular weight (Mn), respectively, and the molecular weight distribution (PDI) was calculated using the ratio (Mw/Mn). ) was calculated. The measurement conditions of GPC are as follows.

<GPC measurement conditions>

Device: 1200 series by Agilent technologies

Column: Use 2 PLgel mixed B from Polymer laboratories

Solvent: THF

Column temperature: 35 ℃

Sample concentration: 1mg/mL, 200L injection

Standard samples: Polystyrene (Mp: 3900000, 723000, 316500, 52200, 31400, 7200, 3940, 485)

Preparation Example 1. Synthesis of monomer (A)

A compound of Formula A (DPM-C12) was synthesized in the following manner. Hydroquinone (10.0 g, 94.2 mmol) and 1-bromododecane (23.5 g, 94.2 mmol) were put in a 250 mL flask, dissolved in 100 mL of acetonitrile, and the excess Potassium carbonate was added and reacted at 75° C. for about 48 hours under nitrogen conditions. After the reaction, the remaining potassium carbonate was removed by filtering, and acetonitrile used in the reaction was also removed. Here, a mixed solvent of DCM (dichloromethane) and water was added to work up, and the separated organic layer was collected and dehydrated by passing through MgSO ₄ . Subsequently, the target product (4-dodecyloxyphenol) (9.8 g, 35.2 mmol) was obtained as a white solid in a yield of about 37% by column chromatography using dichloromethane (DCM).

<NMR analysis result>

¹ H-NMR (CDCl ₃ ): δ6.77 (dd, 4H); δd4.45 (s, 1H); [delta]d3.89(t, 2H); δd1.75 (p, 2H); δd1.43 (p, 2H); δd1.33-1.26 (m, 16H); δd 0.88 (t, 3H).

4-Dodecyloxyphenol (9.8 g, 35.2 mmol), methacrylic acid (6.0 g, 69.7 mmol), dicyclohexylcarbodiimide (DCC) (10.8 g, 52.3 mmol) and p-dimethylaminopyridine (DMAP) (1.7 g) synthesized in a flask. , 13.9 mmol) was added, and 120 mL of methylene chloride was added, followed by reaction at room temperature under nitrogen for 24 hours. After completion of the reaction, the salt (urea salt) generated during the reaction was removed with a filter, and the remaining methylene chloride was also removed. In column chromatography, impurities were removed using hexane and dichloromethane (DCM) as mobile phases, and the obtained product was recrystallized from a mixed solvent of methanol and water (1:1 mixture) to obtain the target product (7.7 g, 22.2 mmol) as a white solid. It was obtained in a yield of 63%.

<NMR analysis result>

¹ H-NMR (CDCl ₃ ): δ 7.02 (dd, 2H); [delta]d6.89 (dd, 2H); [delta]d6.32 (dt, 1H); [delta]d5.73 (dt, 1H); [delta]d3.94(t, 2H); [delta]d2.05 (dd, 3H); δd1.76 (p, 2H); δd1.43 (p, 2H); 1.34-1.27 (m, 16H); δd 0.88 (t, 3H).

[Formula A]

In Formula A, R is a straight-chain alkyl group having 12 carbon atoms.

Preparation Example 2. Synthesis of Block Copolymer (A1)

2.0 g of the monomer (A) of Preparation Example 1, 31.9 mg of cyanoisoprotyldithiobenzoate as a RAFT (Reversible Addition-Fragmentation chain transfer) reagent, 11.8 mg of AIBN (Azobisisobutyronitrile) as a radical initiator, and 4.69 mL of benzene were added to 10 mL. After putting it in a Schlenk flask and stirring at room temperature for 30 minutes under a nitrogen atmosphere, RAFT (Reversible Addition-Fragmentation chain transfer) polymerization reaction was performed at 70 ° C. for 4 hours. After polymerization, the reaction solution was precipitated in methanol as an extraction solvent, filtered under reduced pressure and dried to prepare a pink macroinitiator. The yield of the large initiator was about 90.9% by weight, and the number average molecular weight (Mn) and molecular weight distribution (Mw/Mn) were 14,200 and 1.22, respectively.

0.3 g of the macroinitiator, 2.7174 g of pentafluorostyrene monomer, and 1.306 mL of benzene were put in a 10 mL Schlenk flask and stirred for 30 minutes at room temperature under a nitrogen atmosphere, followed by RAFT (Reversible Addition-Fragmentation chain transfer) at 115 ° C. for 4 hours A polymerization reaction was performed. After polymerization, the reaction solution was precipitated in 250 mL of methanol as an extraction solvent, and then filtered and dried under reduced pressure to prepare a light pink block copolymer. The yield of the block copolymer was about 18% by weight, and the number average molecular weight (Mn) and molecular weight distribution (Mw/Mn) were 39,400 and 1.18, respectively. The block copolymer is the first block (volume fraction of the first block: 0.47) derived from the monomer (A) of Preparation Example 1 and the second block derived from the pentafluorostyrene monomer (volume fraction of the second block: 0.53). Contains 2 blocks. The prepared block copolymer is a block copolymer capable of forming a lamellar pattern, and the pitch at the time of formation of the lamellar pattern is about 31 nm. The pitch can be confirmed by the Fast Fourier Transform method for the block copolymer forming the lamellar pattern.

Preparation Example 3. Synthesis of Block Copolymer (A2)

5.0 g of the monomer (A) of Preparation Example 1, 106.5 mg of RAFT (Reversible Addition-Fragmentation chain transfer) reagent cyanoisoprotyldithiobenzoate, 39.5 mg of AIBN (Azobisisobutyronitrile) as a radical initiator, and 12.0 mL of benzene were added to 25 mL. After putting it in a Schlenk flask and stirring at room temperature for 30 minutes under a nitrogen atmosphere, RAFT (Reversible Addition-Fragmentation chain transfer) polymerization reaction was performed at 70 ° C. for 4 hours. After polymerization, the reaction solution was precipitated in methanol as an extraction solvent, filtered under reduced pressure and dried to prepare a pink macroinitiator. The yield of the macro initiator was about 82.0% by weight, and the number average molecular weight (Mn) and molecular weight distribution (Mw/Mn) were 18,700 and 1.23, respectively. 0.35 g of the macroinitiator, 2.811 g of pentafluorostyrene monomer, and 3.176 mL of benzene were put in a 10 mL Schlenk flask, stirred for 30 minutes at room temperature under a nitrogen atmosphere, and then RAFT (Reversible Addition-Fragmentation Chain Transfer) at 70 ° C. for 12 hours A polymerization reaction was performed. After polymerization, the reaction solution was precipitated in 250 mL of methanol as an extraction solvent, and then filtered and dried under reduced pressure to prepare a light pink block copolymer. The yield of the block copolymer was about 22% by weight, and the number average molecular weight (Mn) and molecular weight distribution (Mw/Mn) were 42,300 and 1.24, respectively. The block copolymer is composed of a first block derived from the monomer (A) of Preparation Example 1 (volume fraction of the first block: 0.55) and a second block derived from the pentafluorostyrene monomer (volume fraction of the second block: 0.45). The prepared block copolymer is a block copolymer capable of forming a cylinder pattern, and the pitch at the time of formation of the cylinder pattern is about 34 nm. The pitch can be confirmed by the Fast Fourier Transform method for the block copolymer forming the cylinder pattern.

Example 1.

A guide pattern with guide holes was formed on a silicon wafer substrate (low-resistance silicon wafer substrate) in the following manner. A SiO ₂ layer was formed to a thickness of about 80 nm on the silicon wafer substrate by a known deposition method. Subsequently, an ER (Electron-beam Resist, Positive-tone Resist, PMMA (poly(methylmethacrylate)) series, trade name: 950 PMMA series, manufacturer: Microchem) material was coated on the layer of SiO ₂ to a thickness of about 100 nm. After exposing the layer of the ER material by electron-beam lithography, the exposed layer of the ER material is used as a mask to etch the lower layer of SiO ₂ by a reactive ion etching (RIE) method to obtain the SiO A _two- layered guide pattern was produced.

The guide pattern has a circular cross section with a diameter of about 40 nm and a cylindrical guide hole having a height of about 80 nm, which is arranged at an interval of 120 nm or 240 nm from each other.

Thereafter, the block copolymer (A1) prepared in Preparation Example 2 was introduced into the formed guide hole by spin coating, and thermal annealing was performed to form a self-assembled structure. Specifically, a coating solution prepared by diluting the block copolymer in fluorobenzene at a concentration of about 0.3% by weight was spin-coated to a thickness of about 16 nm on the guide pattern of the substrate, dried at room temperature for about 1 hour, and then again about A self-assembled structure was formed in the guide hole by thermal aging at 200° C. for 15 minutes. In the above, the thickness of the coating solution is the thickness measured based on the surface of the substrate (the surface of the guide pattern), and in this way, the block copolymer can permeate into the guide hole by capillary force or the like. 3 is a photograph of the result, and through this, it can be confirmed that a self-assembly structure capable of forming a contact/via hole is formed.

Example 2.

A guide pattern with guide holes was formed on a silicon wafer substrate (low-resistance silicon wafer substrate) in the same manner as in Example 1. The guide pattern has a circular cross section with a diameter of about 40 nm and a cylindrical guide hole having a height of about 80 nm, which is arranged at an interval of 120 nm or 240 nm from each other. Thereafter, the block copolymer (A2) prepared in Preparation Example 3 was introduced into the formed guide hole by spin coating and subjected to thermal annealing to form a self-assembled structure. Specifically, a coating solution prepared by diluting the block copolymer in fluorobenzene at a concentration of about 0.4% by weight was spin-coated to a thickness of about 19 nm on the guide pattern of the substrate, dried at room temperature for about 1 hour, and then again about A self-assembled structure was formed in the guide hole by thermal aging at 200° C. for 15 minutes. In the above, the thickness of the coating solution is the thickness measured based on the surface of the substrate (the surface of the guide pattern), and in this way, the block copolymer can permeate into the guide hole by capillary force or the like. 4 is a photograph of the result, and through this, it can be confirmed that a self-assembly structure capable of forming a contact/via hole is formed.

Claims (12)

Forming a self-assembled structure of a block copolymer inside the guide hole of a substrate on which a guide pattern having a guide hole is formed,
The block copolymer is a block copolymer having a first block including a unit of Formula 1 and a second block including a unit of Formula 2 below. Manufacturing method of a substrate having contact/via holes:
[Formula 1]

In Formula 1, R is hydrogen or an alkyl group having 1 to 4 carbon atoms, X is an oxygen atom, a sulfur atom, -S(=O) ₂ -, a carbonyl group, -C(=O)-O- or -OC(=O )-, P is an arylene group having 6 to 18 carbon atoms, Q is a single bond, an oxygen atom, a sulfur atom, -S(=O) ₂ -, a carbonyl group, -C(=O)-O- or -OC (=O)-, and Z is a hydrocarbon chain of 8 to 20 carbon atoms:
[Formula 2]

In Formula 2, X ₂ is a single bond, an oxygen atom or a sulfur atom, and W is an aryl group having 6 to 18 carbon atoms and containing 3 or more halogen atoms. The method of claim 1 , wherein the cross section of the guide hole has a circular shape with a diameter in the range of 30 nm to 100 nm. The method of claim 2, wherein the ratio (H/D) of the height (H) of the guide hole and the diameter (D) of the cross section is in the range of 1.5 to 5. The method of claim 1 , wherein the neutral layer is not formed on the bottom and side walls of the guide hole where the block copolymer contacts. The method of claim 1, wherein the self-assembled structure of the block copolymer is a lamellar structure. The method of claim 5, wherein the ratio (D/P) of the pitch (P) of the lamellar structure and the diameter (D) of the cross section of the guide hole is in the range of 1 to 1.5. 6. The method of claim 5, wherein the ratio (H/P) of the pitch (P) of the lamellar structure and the height (H) of the guide hole is in the range of 1.5 to 5. The method of claim 1, wherein the self-assembled structure of the block copolymer is a cylindrical structure. The method of claim 8, wherein the ratio (D/P) of the pitch (P) of the cylindrical structure and the diameter (D) of the cross section of the guide hole is within a range of 0.7 to 1.3. 9. The method of claim 8, wherein the ratio (H/P) of the pitch (P) of the cylindrical structure and the height (H) of the guide hole is in the range of 1.5 to 5. The method of claim 1 , further comprising selectively removing any one block from among the first and second blocks of the block copolymer implementing the self-assembled structure. 12. The method of claim 11, further comprising: selectively removing any one of the first and second blocks and etching the substrate using the remaining block copolymer pattern as a mask.

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