CN110066370B

CN110066370B - PS-b-PMA (Az) block copolymer, and preparation method and application thereof

Info

Publication number: CN110066370B
Application number: CN201910288022.5A
Authority: CN
Inventors: 陈爱华; 屈婷
Original assignee: Beihang University
Current assignee: Beihang University
Priority date: 2019-04-11
Filing date: 2019-04-11
Publication date: 2020-08-04
Anticipated expiration: 2039-04-11
Also published as: CN110066370A

Abstract

The invention provides a PS-b-PMA (Az) block copolymer and a preparation method and application thereof, wherein the PS-b-PMA (Az) block copolymer has the following structure:

Description

PS-b-PMA (Az) block copolymer, and preparation method and application thereof

Technical Field

The invention relates to the technical field of novel high polymer materials, in particular to a PS-b-PMA (Az) block copolymer, a preparation method and application thereof.

Background

Block Copolymers (BCPs) are specialized polymers made up of two or more distinct polymer segments chemically linked together. The difference of the block structures enables the BCP to be phase separated to form a periodic nano structure with rich appearance. Among them, AB diblock copolymers are the simplest. Incompatibility between the blocks of the block copolymer (expressed by Flory-Huggins parameter, χ)_AB) Causing phase separation of the copolymer system. The degree of polymerization (N, i.e., the number of repeating units) determines the effective size of the phase separation, solely from the BCP structure. And the volume content (f) of the two phases A or B in the BCP determines the final self-assembly morphology. According to the difference of the proportion (f) of the two-phase components, the structure is roughly spherical, cylindrical, layered and regular bicontinuous and double-diamond. Based on the theory, a self-assembly micro-nano processing technology of a block copolymer film from bottom to top is gradually developed and becomes a research hotspot of the current photoetching technology.

Generally, in the block copolymer film self-assembly micro-nano processing technology, two block polymers are coated on a support body in a spinning mode to form an ultrathin polymer film. According to BCP and supportSurface interactions between the bodies form parallel or vertically oriented nanostructures. Among them, polystyrene-b-polymethyl methacrylate (PS-b-PMMA) has a large difference in lithography, and is widely used in the field of lithography. Through high-temperature thermal annealing treatment for several hours at 180-200 ℃, PS-b-PMMA can form an ordered vertically oriented nano structure on a neutral polymer brush, and the industrialization requirement of the microelectronic field is greatly met. However, χ between PS-b-PMMA_ABVery small, 300K χ_ABOnly 0.06. This makes it difficult for the system to obtain pattern templates with microphase separation sizes smaller than 20 nm. Meanwhile, the interface between the two phases of PS-b-PMMA and the support body has larger energy, and a vertical columnar or layered structure is difficult to obtain in a wider film thickness range. Highly ordered vertical lamellar and columnar structure patterns can only be prepared by modifying the surface of the support (e.g., preparing a layer of suitable random polymer brush on the support before spin-coating the BCP film, chemical pre-patterning, external field modulation, etc.).

In 2002, Iyoda task group prepared a series of PEO-based liquid crystal side-chain block copolymers by Atom Transfer Radical Polymerization (ATRP). By introducing side chain liquid crystal groups, the BCP can form a small-size columnar phase separation film structure with a film thickness ranging from a few nanometers to a few micrometers and high order. Meanwhile, PEO has a certain electron-withdrawing ability, and is often used to form block copolymers with polymethacrylates containing different side chain liquid crystal structural units, such as azobenzene, diphenylethylene, benzylidene aniline, phenyl styrenone, and the like. The PEO-based side-chain liquid crystal BCP template is also widely used for preparing inorganic or metal nano materials. However, the etching difference between PEO and azo liquid crystal is not large, and the BCP is difficult to further popularize in the field of nano lithography.

Therefore, in order to meet the requirements of the photoetching field, the azo liquid crystal side chain with a large chi value is introduced into the PMMA block part to improve the chi of the BCP by virtue of excellent photoetching difference of PS and PMMA_ABThereby realizing nano-lithography patterns with a size of 20nm or less. The block polymer (PS-b-PMA (Az)) has important significance in the development and application of the BCP photoetching field.

Disclosure of Invention

The invention aims to provide a PS-b-PMA (Az) block copolymer, a preparation method and application thereof. In order to achieve the above object, one of the technical solutions of the present invention is: a PS-b-PMA (Az) block copolymer having the structure:

wherein x is 0-15; m is 10 to 800; n is 2 to 200.

The value of x is preferably 1-11, the value of m is preferably 50-200, 25-100 or 10-100, and the value of n is preferably 2-100, 5-70 or 45-70.

In a preferred embodiment, x is 0, m is 100, and n is 20; or x is 6, m is 100, n is 23; or x is 11, m is 28, n is 68; or x is 11, m is 42, n is 16; or x is 11, m is 60, n is 15; or x is 11, m is 100, n is 44; or x is 11, m is 100, n is 22; or x is 11, m is 100 and n is 18.

In another preferred embodiment, x is 11, m is 100, and n is 44 in the block copolymer.

Preferably, the PS-b-PMA (Az) block copolymer of the present invention has a PS volume content f_PSBetween 0.001 and 0.9, preferably between 0.001 and 0.7.

The second technical scheme of the invention is as follows: a preparation method of a PS-b-PMA (Az) block copolymer specifically comprises the following steps:

(1) using a micromolecular initiator, a ligand, styrene and cuprous chloride as raw materials, and obtaining a PS macromolecular initiator through atom transfer radical polymerization reaction;

(2) and (3) carrying out atom transfer radical polymerization on the PS macroinitiator, the ligand, the azobenzene monomer and cuprous chloride serving as raw materials to obtain a PS-b-PMA (Az) block copolymer.

Preferably, the small-molecule initiator is selected from one of α -ethyl bromoisobutyrate, 1-chlorophenyl ethane, α -bromophenylethane, α -methyl bromoisobutyrate, α -ethyl chloroisobutyrate and α -methyl chloroisobutyrate, preferably α -ethyl bromoisobutyrate.

Preferably, in steps (1) and (2), the same ligand is used, said ligand being selected from tris (2-dimethylaminoethyl) amine (Me)₆TREN), Pentamethyldiethylenetriamine (PMDETA) and pentamethyldipropylenetriamine, preferably PMDETA.

Preferably, in the step (2), the azobenzene monomer (containing different alkyl flexible spacers) is selected from one of {11- [4- (4-butylbenzazoxy) phenoxy ] pentadecyl methacrylate } or MA (Az) -0-14C; wherein x is as defined above for the PS-b-PMA (Az) block copolymer (e.g., 0 to 15, preferably 1 to 11, etc.).

Preferably, step (1) is carried out in a solvent selected from chlorobenzene, N-Dimethylformamide (DMF) or a mixture of both; in order to ensure the smooth progress of the reaction, the invention preferably uses a water removal solvent as the reaction solvent, i.e. anhydrous chlorobenzene, one or a mixture of anhydrous DMF (dimethyl formamide), and more preferably anhydrous chlorobenzene; when a mixture of the two is used as the reaction solvent, the ratio of the amounts of the two is not particularly limited.

According to the invention, anhydrous chlorobenzene is preferably selected as a solvent for synthesizing the PS macroinitiator, and the solvent can well dissolve the micromolecule initiator, the ligand, the styrene monomer and the like at room temperature, so that ATRP is polymerized into a homogeneous system, and the reaction is carried out more thoroughly. Meanwhile, the initiator can keep high activity in the solvent, and PS homopolymer Polydispersity (PDI) obtained by initiating monomer polymerization is small, so that ATRP in the next step can be better carried out.

Preferably, step (2) is carried out in a solvent selected from one or a mixture of two or three of tetrahydrofuran, chlorobenzene, N-Dimethylformamide (DMF). Also in order to ensure the smooth progress of the reaction, the invention preferably uses an anhydrous solvent as the reaction solvent, i.e. one or a mixture of two or three of anhydrous tetrahydrofuran, anhydrous chlorobenzene and anhydrous N, N-dimethylformamide, and more preferably anhydrous chlorobenzene; when 2 or more than 2 kinds of mixed solvents are selected, the amount of each solvent is not particularly limited.

According to the invention, anhydrous chlorobenzene is preferably selected as a solvent for synthesizing PS-b-PMA (Az), and the solvent can well dissolve a polystyrene macroinitiator, MA (Az) -0-15C monomers, PS-b-PMA (Az) polymers and the like at room temperature, so that ATRP is polymerized into a homogeneous system, and the reaction is carried out more thoroughly. Meanwhile, the initiator can keep high activity in the solvent, the BCP Polydispersity (PDI) obtained by initiating monomer polymerization is small, and the defects of a BCP self-assembly structure are fewer.

Preferably, in step (1), the small molecule initiator: ligand: cuprous chloride (CuCl): styrene (St) ═ 1: (1-3): (1-2): (10-900).

Preferably, in step (2), the macroinitiator: ligand: cuprous chloride (CuCl): azo-benzene monomer ═ 1: (1-3): (1-2): (0.1-110).

Preferably, the reaction time of steps (1) and (2) is 10-20h, and more preferably 16 h.

As a preferred preparation method of the PS-b-PMA (Az) block copolymer, the raw materials used in the step (1) are α -bromoethyl isobutyrate, PMDETA, St and CuCl, the raw materials used in the step (2) are PS macroinitiator, PMDETA, MA (Az) and CuCl, and the rest ATPR is operated as above.

More preferably, the preparation method of the invention comprises the following steps:

(1) synthesis of PS macroinitiator: adding a small-molecule initiator, a ligand, styrene (St) and a solvent into a reaction vessel, freezing the reactor by using liquid nitrogen, and adding cuprous chloride (CuCl); vacuumizing for 3-7min under the condition of freezing by liquid nitrogen, thawing under the condition of introducing nitrogen, stirring for 3-7min, repeating the vacuumizing and thawing operations for 2-5 times, and finally reacting for 6-72h at 90-120 ℃ under the vacuum state to obtain a crude product;

(2) synthesis of PS-b-PMA (Az) Block copolymer: adding a PS macroinitiator, a ligand, an azobenzene monomer (MA (Az) -0-15C) and a solvent into a reaction container, freezing the reactor by adopting liquid nitrogen, and adding cuprous chloride; vacuumizing for 3-7min under freezing condition of liquid nitrogen, thawing under nitrogen gas introduction condition, stirring for 3-7min, repeating the vacuumizing and thawing operation for 2-5 times, and reacting at 90-120 deg.C for 6-72 hr under vacuum condition to obtain crude product;

wherein the term "thawing" refers to taking the reaction vessel out of a liquid nitrogen environment.

In order to ensure the quality of the product, the preparation method further comprises a step of post-treating the reaction solution of the steps (1) and (2), and the same operation can be adopted for the post-treatment of the two-step reaction, namely: quenching the reaction by using liquid nitrogen, removing copper salt, spin-drying the reaction solution, precipitating by using ether and alcohol solvents, and washing the product;

wherein the ether solvent is petroleum ether, diethyl ether or a mixture of the petroleum ether and the diethyl ether; the product is preferably precipitated and washed with cold ether solvents.

Preferably, the copper salt is removed using a neutral alumina column. Further preferably, the reaction product is dissolved with dichloromethane before the copper salts are removed.

The invention also provides a PS-b-PMA (Az) block copolymer prepared by any one of the methods.

The PS-b-PMA (Az) block copolymer synthesized by the invention is polymerized by two-step ATRP reaction. Strict degassing treatment in the polymerization process comprises: reasonable and standard operation, multiple times of freezing and thawing operation and nitrogen gas exhaust treatment of all added solvents, thereby successfully realizing the effective synthesis of ATRP of the PS-based liquid crystal block copolymer.

The third technical scheme of the invention is as follows: a PS-b-PMA (Az) block copolymer photolithographically patterned film formed from any of the above-described PS-b-PMA (Az) block copolymers or the PS-b-PMA (Az) block copolymers prepared by any of the above-described methods.

Preferably, the PS-b-PMA (Az) block copolymer photolithographically patterned film is in a vertical pillar or vertical layer structure.

Preferably, the vertical pillar-shaped thin film pillar has a diameter of several nanometers to several tens of nanometers.

Preferably, the vertical layered film interlayer distance is several nanometers to several tens of nanometers.

The PS-b-PMA (Az) block copolymer photoetching pattern film is in a vertical column or vertical layer structure, and the diameter of the vertical column film column or the interlayer distance of the vertical layer film can be adjusted; for example, the volume content f of PS is selected_PSThe block copolymer with different m value between 0.001 and 0.9 can obtain the vertical column film with the column diameter of several nanometers to dozens of nanometers or the vertical layered film with the interlayer spacing of several nanometers to dozens of nanometers.

The fourth technical scheme of the invention is as follows: a preparation method of PS-b-PMA (Az) block copolymer photolithographic pattern film specifically comprises the following steps: spin-coating the prepared PS-b-PMA (Az) block copolymer solution on a support to form a thin film with a certain thickness, and carrying out thermal annealing and Reactive Ion Etching (RIE) on the thin film to obtain the high-performance high-density polyethylene (HDPE).

The PS-b-PMA (Az) block copolymer is any one of the PS-b-PMA (Az) block copolymers or is prepared by any one of the methods.

In order to ensure the effect of the coating, the support is cleaned before the coating, the cleaning can adopt the conventional technical means in the field, and the preferred cleaning operation of the invention is as follows: the support body is respectively placed in acetone and ethanol for ultrasonic cleaning, and then nitrogen is used for blowing and drying.

Preferably, the support is one of a silicon wafer, polyethylene terephthalate (PET), and aluminum foil.

Preferably, the PS-b-PMA (Az) block copolymer solution is prepared in a concentration of 0.5 wt% to 5 wt% using chloroform and/or toluene as a solvent.

Preferably, the spin coating is specifically: dropping the prepared solution on a support, spin-coating at a coating speed of 1000-5000rpm to form a film, controlling the film thickness to be 100-500 nm, and drying at room temperature after coating.

Preferably, the annealing conditions are: annealing at 100-; more preferably at 120-150 ℃ for 5-10 min.

Preferably, O is used₂And Ar mixed gas is used for annealing the polymer film after heat annealingEtching is carried out, wherein the volume flow of the mixed gas is 5-40/5-10 sccm, the etching power is 30-100W, and the etching time is 10-50 s; more preferably, the volume flow is 40/10sccm, the etching power is 30-50W, and the etching time is 10-30 s.

The thickness of the annealed film of the PS-b-PMA (Az) block copolymer photoetching pattern film prepared by the invention can reach 100nm-500nm, and the cross section of the annealed film can be clearly seen to be in a highly ordered PS hexagonal columnar dispersed phase structure and a PMA (Az) vertical columnar structure which is a continuous phase; and a vertical layered structure.

The fifth technical scheme of the invention is as follows: the use of any one of the above PS-b-PMA (Az) block copolymer lithographic patterned films or of any one of the above PS-b-PMA (Az) block copolymer lithographic patterned films prepared by the above method in the field of microelectronics; preferably in the preparation of inorganic nano materials.

In the block copolymer, one block is poly {11- [4- (4-butyl benzene azo) phenoxy ] alkyl methacrylate } (PMA (Az) -0-15C), and has the properties of easy phase separation and photodegradation (azo group); the other block is Polystyrene (PS) and has the characteristic of higher ion etching rate; the block copolymer has large Huggins parameter value of interaction between two blocks, contains an azo block with stable phase separation, is easy to realize the requirement that the characteristic size of the template is below 20 nanometers, and provides a potential copolymer material for block copolymer photoetching, metal nanowire preparation and integrated circuit board preparation. The BCP film template can form highly ordered vertical columnar and layered pattern morphology. After the PMA (Az) phase is etched, the material can be used for preparing semiconductors, transition metals, metal nanowires and other materials with complete and long-range order structures by combining an atomic deposition technology.

The terms "PS-b-PMA (Az)", "PS-b-PMA (Az) diblock copolymer", "PS-b-PMA (Az) liquid crystal block copolymer", "PS-b-PMA (Az) block copolymer" and "PS-b-PMA (Az) copolymer" used herein have the same meanings.

The raw materials or reagents involved in the present invention are commercially available.

On the basis of the common knowledge in the field, the above-mentioned preferred conditions can be combined with each other to obtain the preferred embodiments of the present invention.

Drawings

FIG. 1 shows the preparation of synthetic two-block copolymers of PS-b-PMA (Az) -0C and PS-b-PMA (Az) -6C¹H NMR chart with PS from top to bottom₁₀₀-b-PMA(Az)₂₃-6C and PS₁₀₀-b-PMA(Az)₂₀of-0C¹H NMR chart;

FIG. 2 is a diagram of a synthetic PS, PS-b-PMA (Az) -11C diblock copolymer¹H NMR spectrum of PS from top to bottom₂₈-b-PMA(Az)₆₈-11C，PS₁₀₀-b-PMA(Az)₄₄-11C，PS₄₂-b-PMA(Az)₁₆-11C，PS₆₀-b-PMA(Az)₁₅-11C，PS₁₀₀-b-PMA(Az)₂₂-11C，PS₁₀₀-b-PMA(Az)₁₈of-11C and PS¹H NMR spectrum;

FIG. 3 is a DSC plot of temperature drop of the synthesized PS, PS-b-PMA (Az) -11C diblock copolymer, which corresponds to PS from bottom to top₂₈，PS₄₂，PS₆₀，PS₁₀₀，PS₁₀₀-b-PMA(Az)₁₈-11C，PS₁₀₀-b-PMA(Az)₂₂-11C，PS₆₀-b-PMA(Az)₁₅-11C，PS₄₂-b-PMA(Az)₁₆-11C，PS₁₀₀-b-PMA(Az)₄₄-11C and PS₂₈-b-PMA(Az)₆₈-DSC profile of 11C;

FIG. 4 is a SEM image of the cross-section of the PS-b-PMA (Az) -0C layered BCP film prepared in example 6 after RIE;

FIG. 5 is a SEM image of the cross-section of the PS-b-PMA (Az) -6C layered BCP film prepared in example 7 after RIE;

FIG. 6 is an SEM photograph of the upper surface of a layered BCP film prepared in example 8 and having PS-b-PMA (Az) -11C structure after RIE;

FIG. 7 is a SEM image of the cross-section of the PS-b-PMA (Az) -11C layered BCP film prepared in example 8 after RIE;

FIG. 8 is an SEM photograph of the upper surface of a PS-b-PMA (Az) -11C columnar BCP film prepared in example 9 after RIE;

FIG. 9 is a SEM image of the cross-section of a PS-b-PMA (Az) -11C columnar BCP film prepared in example 9 after RIE;

FIG. 10 is an SEM image of a film after RIE under different annealing conditions prepared in example 10, wherein (a) is a top surface SEM image and (b) is a cross-sectional SEM image;

fig. 11 is an optical diagram and top surface SEM images of the BCP thin films prepared in example 11 after annealing and further RIE on different supports, wherein the optical diagram of the BCP thin film formed by the support being aluminum foil is (a) in fig. 11, and the top surface SEM images are (c) and (e) in fig. 11; the optical diagram of the BCP film formed with the support PET is (b) in fig. 11, and the SEM images of the upper surface are (d) and (f) in fig. 11.

FIG. 12 is a top surface SEM image and cross-sectional SEM image of a BCP film prepared in example 12 after different RIE conditions: pure O₂The BCP film is obtained after the gas, the volume flow rate is 50sccm, the etching power is 50W and the etching time is 30s, wherein the SEM picture of the upper surface is (a) in FIG. 12, and the SEM picture of the section is (b) in FIG. 12; RIE condition of O₂And Ar mixed gas, the volume flow rate is 40/10sccm, the etching power is 50W, and the etching time is 60s, wherein the upper surface SEM picture is (c) in FIG. 12, and the section SEM picture is (d) in FIG. 12;

FIG. 13 is SEM images of the top surface and cross-section of different PS-b-PMA (Az) -11C films obtained in example 13 after RIE in the form of columns₆₀-b-PMA(Az)₁₅SEM image of the upper surface of the film after 11C RIE is (a) in FIG. 13, and SEM image of the cross section is (b) in FIG. 13; PS (polystyrene) with high sensitivity₄₂-b-PMA(Az)₁₆SEM image of the upper surface of the film after 11C RIE is (C) in FIG. 13, and SEM image of the section is (d) in FIG. 13; PS (polystyrene) with high sensitivity₂₈-b-PMA(Az)₆₈SEM image of the upper surface of the film after-11C RIE is (e) in FIG. 13, and SEM image of the cross section is (f) in FIG. 13.

FIG. 14 shows PS prepared in example 14₁₀₀-b-PMA(Az)₁₈SEM image (a) of the upper surface and SEM image (b) of the-11C layered BCP film after RIE.

Detailed Description

The following examples are presented to illustrate the present invention, but are not intended to limit the scope of the invention, and the operations involved in the following examples are those conventional in the art unless otherwise specified.

Example 1

PS₁₀₀-b-PMA(Az)₂₀A method for preparing a-0C block copolymer, comprising the steps of:

1) synthesis of PS macroinitiator:

6ml of dewatered chlorobenzene, 110 times of α -ethyl bromoisobutyrate molar equivalent St (6.4 ml), 75.2ul of α -ethyl bromoisobutyrate and 125ul of ligand Pentamethyldiethylenetriamine (PMDETA) are sequentially added into a clean Schlenk bottle and uniformly mixed, then the Schlenk bottle is placed in liquid nitrogen for freezing, 51mg of cuprous chloride (CuCl) is added, the upper opening of the bottle is sealed by a rubber plug, wherein the feeding molar ratio is that an initiator, namely the ligand, CuCl is 1: 1.2: 1, then the bottle is vacuumized for 5 minutes in a freezing condition, unfrozen and stirred for 5 minutes in a nitrogen gas condition, the bottle is circulated for 3 times, and finally, a high vacuum cut valve of the Schlenk bottle is screwed down in a freezing and vacuumizing condition, and then the bottle is placed in an oil bath at 110 ℃ for stirring reaction for 16 hours.

When the reaction time is reached and the viscosity of the system rises, the system is quenched with liquid nitrogen, the rubber stopper is opened and the resulting product system is dissolved with dichloromethane and passed through a neutral alumina column to remove the copper salts, the filtrate is aspirated with a dropper and precipitated and washed three times in cold petroleum ether stirred at high speed to remove unreacted St monomers and oligomers. And (3) carrying out suction filtration on the settled suspension by using a sand core funnel, and precipitating and washing the solid obtained by suction filtration twice in methanol stirred at a high speed after using a small amount of dichloro solvent. Filtering the precipitated suspension with a sand core funnel, placing the solid obtained by filtering in a vacuum oven at 20 deg.C, and drying for 16h to obtain pure and dry 3.5g white powder, i.e. PS with 100 blocks₁₀₀A macroinitiator;

2)PS₁₀₀-b-PMA(Az)₂₀synthesis of 0C diblock copolymer:

6ml of dewatered chlorobenzene, weighed 0.5g of PS, were added in sequence to a clean Schlenk bottle₁₀₀Macroinitiator, 0.4g of MA (Az) -0C monomer, 12ul of ligand Pentamethyldiethylenetriamine (PMDETA), and mixing uniformly. Then, the Schlenk bottle was cooled in liquid nitrogenFreeze for 2min, evacuate for 2min, introduce nitrogen and add 4.8mg of cuprous chloride (CuCl) under nitrogen, and seal the top of the bottle with a rubber stopper. Wherein the feeding molar ratio is as follows: ligand: 1, CuCl: 1.2: 1. vacuum was then applied for 5 minutes in the frozen state, thawed and stirred for 5 minutes under nitrogen, and cycled 3 times. The high vacuum shut-off valve of the Schlenk bottle was then tightened with a vacuum applied by freezing, thawed and placed in a 110 ℃ oil bath and stirred for 16 hours.

After 16h the system was quenched with liquid nitrogen, the rubber stopper opened and the resulting product system was dissolved with dichloro and passed through a neutral alumina column to remove the copper salt, the filtrate was pipetted and precipitated and washed three times in cold petroleum ether stirred at high speed to remove unreacted monomers and oligomers. And finally, carrying out suction filtration on the settled suspension by using a sand core funnel, dissolving the solid obtained by suction filtration by using a small amount of dichloro solvent, and then precipitating and washing twice in methanol stirred at a high speed. And finally, carrying out suction filtration on the settled suspension by using a sand core funnel, and placing the solid obtained by suction filtration in a vacuum oven at 20 ℃ for drying for 16 h. Finally, a pure, dry, pale yellow powder of 0.6g, block number PS, is obtained₁₀₀-b-PMA(Az)₂₀Block copolymers of-0C, which¹The H NMR chart is shown in FIG. 1.

Example 2

PS₁₀₀-b-PMA(Az)₂₃The preparation of the-6C block copolymer differs from example 1 only in that:

in step 1), 1-chlorophenylethane (PE-Cl) is used as an initiator, and the initiator is ligand CuCl which is 1: 2: 1 (molar ratio), the dosage of each substance is respectively 0.1g of the initiator, 297 mu L71 mg of the ligand, 9.0m L of the ligand and 6m L of the reaction solvent chlorobenzene, and finally the PS with the block number of 100 is obtained₁₀₀6.1g of macroinitiator;

in the step 2), MA (Az) -6C is taken as a monomer, and tris (2-dimethylaminoethyl) amine (Me)₆TREN) as ligand, macroinitiator, monomer, ligand and CuCl (molar ratio) 1: 35: 2: 1, wherein the dosages of the substances are respectively 0.5g of initiator, 0.72g of monomer MA (Az) -6C, 14.4 mu L4.8.8 mg of ligand and 4m L2 ml of reaction solvent chlorobenzene₁₀₀-b-PMA(Az)₂₃of-6C¹The H NMR chart is shown in FIG. 1.

Example 3

PS₄₂-b-PMA(Az)₁₆The preparation of the-11C block copolymer differs from example 1 only in that:

in the step 1), α -bromophenylethane is used as an initiator, and the initiator is CuCl as a ligand, the molar ratio of the CuCl is 1: 1.5: 1, the dosage of each raw material is 0.1g of the initiator, 121 mu L53.5.5 mg of the ligand, 2.8g of the monomer St, 3ml of DMF as a solvent and 3ml of chlorobenzene, and finally, PS with the block number of 42 is obtained₄₂Macroinitiator 2.0 g.

In step 2), the monomer is MA (Az) -11C, the macroinitiator is ligand CuCl which is 1: 1.5: 1 (molar ratio), the dosage of each raw material is 0.5g of initiator, 36 mu L11.4.4 mg of ligand, 1.5g of monomer MA (Az), the solvent is 3ml of tetrahydrofuran and 3ml of chlorobenzene, and finally 0.8g of polymer PS is obtained₄₂-b-PMA(Az)₁₆of-11C¹The H NMR chart is shown in FIG. 2, and the DSC chart is shown in FIG. 3.

Example 4

PS₁₀₀-b-PMA(Az)₂₂The preparation of the-11C block copolymer differs from example 1 only in that:

in step 1), α -methyl bromoisobutyrate was used as an initiator, and the initiator was CuCl (ligand: 1: 2: 1) (molar ratio), and the amounts of the raw materials were 0.1g of the initiator, 231. mu. L55 mg of the ligand, 6.4g of St, 3ml of DMF as a solvent, and 3ml of chlorobenzene, to finally obtain 100 blocks of PS₁₀₀5g of macroinitiator;

in the step 2), pentamethyl dipropylenetriamine is taken as a ligand, and a macroinitiator: ligand: 1, CuCl: 2: 1 (molar ratio), the dosage of each raw material is respectively as follows: 0.5g of initiator, 0.020g of ligand and 4.8mg of CuCl; solvent 6ml of chlorobenzene, monomer MA (Az)0.60g, 25 molar equivalents of PS₁₀₀The amount of (c). PS (polystyrene) with high sensitivity₁₀₀-b-PMA(Az)₂₂of-11C¹The H NMR chart is shown in FIG. 2, and the DSC chart is shown in FIG. 3.

Example 5

PS₁₀₀-b-PMA(Az)₄₄Process for preparing (E) -11C block copolymersThe difference from example 1 is only that:

in step 1), initiator: ligand: 1, CuCl: 1.5: 1 (molar ratio), the dosage of each raw material is respectively as follows: initiator 0.1g, ligand 0.14g, CuCl 51mg, St 5.86g, solvent chlorobenzene 4ml, DMF2ml, finally yielded 3.2g of PS macroinitiator with a block number of 100.

In step 2), macroinitiator: ligand: 1, CuCl: 1.5: 1 (molar ratio), the dosage of each raw material is respectively as follows: initiator 0.5g, ligand 12.5mg, CuCl 4.8 mg. 1.2g of monomer MA (Az) -11C, 2ml of tetrahydrofuran, 2ml of chlorobenzene and DMF2 ml. PS (polystyrene) with high sensitivity₁₀₀-b-PMA(Az)₄₄of-11C¹The H NMR spectrum is shown in FIG. 2, and the DSC graph is shown in FIG. 3.

Example 6

This example provides for the preparation of a vertically layered PS-b-PMA (Az) diblock copolymer lithographic patterning film comprising the steps of:

(1) preparing a block copolymer solution:

0.01g of PS-b-PMA (Az) -0C, f from example 1_PS0.49-0.70, and dissolved in 0.99g chloroform and stirred at room temperature for 2h to obtain BCP/CHCl with concentration of 1-3 wt%₃And (3) solution.

(2) Treating and coating a silicon wafer:

and (3) placing a 2 cm-2 cm monocrystalline silicon wafer in acetone for ultrasonic cleaning for 30min, and then placing in ethanol for ultrasonic cleaning for 30 min. Taking out the silicon wafer, and blowing the solvent on the surface of the silicon wafer by using nitrogen for standby. 1-3 wt% BCP/CHCl was pipetted with a 1ml pipette₃Dropping the solution on a clean silicon wafer, spin-coating at 1000-.

(3) Film thermal annealing:

and (3) placing the film in a vacuum oven with the temperature of 120-200 ℃, vacuumizing, preserving the heat for 5-10min, slowly cooling to 60 ℃, and taking out a sample.

(4) Film RIE:

the film is placed in a sample chamber of RIE-100, and etching conditions are as follows: o is₂And the Ar mixed gas has the volume flow of 40/10sccm, the etching power of 50W and the etching time of 2-30 s.

Example 7

This example provides the preparation of a layered PS-b-PMA (Az) -6C diblock copolymer lithographic patterned film, which differs from example 6 only in that: PS-b-PMA (Az) -6C, f prepared in example 2 was used_PS0.49-0.70 g of diblock copolymer, and 1-3 wt% of a spin coating solution was prepared at a spin coating speed of 1000-.

Example 8

This example provides the preparation of a vertically layered PS-b-PMA (Az) -11C diblock copolymer lithographic patterned film, similar to example 6, except that: PS-b-PMA (Az) -11C, f prepared in example 4 was used_PS0.49-0.70, the solvent for preparing the spin-coating liquid is a mixed liquid of chloroform, tetrahydrofuran and toluene in any proportion, the annealing temperature is 100-140 ℃, and the annealing time is 5-10 min.

Example 9

This example provides the preparation of a patterned vertical-pillar PS-b-PMA (Az) -11C diblock copolymer lithographic film, which differs from example 6 only in that: PS-b-PMA (Az) -11C, f prepared in example 5 was used_PS0.001-0.48, preparing a solvent toluene of the spin coating liquid, wherein the annealing temperature is 100-140 ℃, and the annealing time is 5-10 min.

Example 10

This example provides the preparation of patterned vertical-post PS-b-PMA (Az) -11C diblock copolymer films under different annealing conditions, which differs from example 9 only in that: the annealing temperature is 100-140 ℃, and the annealing time is 1 min. As can be seen from fig. 8, the film obtained with too short annealing time is not sufficiently ordered.

Example 11

This example provides the preparation of a patterned vertical-pillar PS-b-PMA (Az) -11C diblock copolymer lithographic film, similar to example 9, but differing therefrom only in that: the spin coating support is any one of PET and aluminum foil.

Example 12

This example provides the preparation of a photolithographic patterned film of a cylindrical PS-b-PMA (Az) -11C diblock copolymer under different photolithographic conditionsThe preparation method is the same as that of example 9, and only differs from the RIE conditions: (1) pure O₂The volume flow of the gas is 50sccm, the etching power is 50W, and the etching time is 30 s; (2) o is₂And Ar mixed gas, the volume flow rate is 40/10sccm, the etching power is 50W, and the etching time is 60 s. As can be seen from FIG. 10, with two different RIE conditions, the difference in etching between the PMA (Az) and PS blocks is not large, and the PS pillar pattern is not well preserved.

Example 13

This example provides the preparation of patterned vertical PS-b-PMA (Az) -11C diblock copolymers with different diameters by photolithography, as in example 9, except that: using PS₆₀-b-PMA(Az)₁₅-11C，PS₄₂-b-PMA(Az)₁₆-11C，PS₂₈-b-PMA(Az)₆₈-11C，f_PS0.001-0.48 g of diblock copolymer, and prepared into a spin coating solution with a concentration of 1-3 wt%, at a spin coating speed of 1000-5000 rpm. As can be seen in fig. 11, the PS volume fractions of the three BCPs selected are: 0.001-0.48, to obtain three PS columnar photo-etching films with a column diameter D of about 12-19 nm.

Example 14

This example provides the preparation of vertically layered PS-b-PMA (Az) -11C diblock copolymer lithographic patterned films of different layer spacings, as in example 8, except that: using PS₁₀₀-b-PMA(Az)₁₈-11C，f_PS0.49-0.58 g of diblock copolymer, and a spin coating solution having a concentration of 1-3 wt% was prepared at a spin coating speed of 1000 and 5000 rpm. As can be seen from FIG. 12, the volume fraction of BCP is 0.55, and a PS layered photolithographic film with a layer spacing W of about 20-28 nm is obtained.

In order to further illustrate the effect of the invention, the annealed film is quenched in liquid nitrogen for 5 seconds, taken out and cut by a glass cutter, and a film section electron microscope sample is prepared after gold spraying and can be used for electron microscope detection, as can be seen from fig. 4,5,6,7,8,9,10,11,12,13 and 14, the film obtained after too short annealing time has insufficient degree of order, the highly ordered vertical hexagonal columnar or lamellar arranged film can be obtained under proper annealing conditions, and the vertical hexagonal columnar structure film with adjustable diameter and the vertical lamellar film with adjustable interlayer spacing can be obtained by selecting PS with different blocks.

In addition, the films on different supports prepared in example 9, in which the films on the flexible PET support were bent several times, still yielded highly ordered hexagonal columnar structures.

Although the invention has been described in detail hereinabove by way of general description, specific embodiments and experiments, it will be apparent to those skilled in the art that many modifications and improvements can be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.

Claims

1. A preparation method of PS-b-PMA (Az) block copolymer photoetching pattern film is characterized in that prepared PS-b-PMA (Az) block copolymer solution is spin-coated on a support to form a film with a certain thickness, and the film is subjected to thermal annealing and reactive ion etching to obtain the film;

the annealing conditions are as follows: annealing at 100-;

by using O₂Etching the polymer film after thermal annealing by using Ar mixed gas, wherein the volume flow of the mixed gas is 5-40/5-10 sccm, the etching power is 30-100W, and the etching time is 10-50 s;

the PS-b-PMA (Az) block copolymer has the following structure:

wherein x is 0-15, m is 10-800, and n is 2-200;

alternatively, the PS-b-PMA (Az) block copolymer is prepared by a process comprising the steps of:

2. The process according to claim 1, wherein x is 1 to 11, m is 50 to 200 or 25 to 100 or 10 to 100, and n is 2 to 100 or 5 to 70 or 45 to 70.

3. The method of claim 2, wherein x is 0, m is 100, and n is 20; or x is 6, m is 100, n is 23; or x is 11, m is 28, n is 68; or x is 11, m is 42, n is 16; or x is 11, m is 60, n is 15; or x is 11, m is 100, n is 44; or x is 11, m is 100, n is 22; or x is 11, m is 100 and n is 18.

4. The method according to claim 1, wherein the PS-b-PMA (Az) block copolymer has a PS volume content f_PSBetween 0.001 and 0.9.

5. The method according to claim 4, wherein the PS-b-PMA (Az) block copolymer has a PS volume content f_PSIs 0.001-0.7.

6. The preparation method according to claim 1, wherein the small molecule initiator is selected from one of α -ethyl bromoisobutyrate, 1-chlorophenyl ethane, α -bromophenylethane, α -methyl bromoisobutyrate, α -ethyl chloroisobutyrate, α -methyl chloroisobutyrate, and/or:

the ligand is selected from one of tri (2-dimethylaminoethyl) amine, pentamethyl diethylenetriamine and pentamethyl dipropylenetriamine; and/or:

the azobenzene monomer is selected from one of {11- [4- (4-butyl benzene azo) phenoxy ] pentadecyl methacrylate } or MA (Az) -0-14C; and/or:

the step (1) is carried out in a solvent, wherein the solvent is one or a mixture of chlorobenzene and N, N-dimethylformamide; and/or;

the step (2) is carried out in a solvent, and the solvent is one or a mixture of two or three of tetrahydrofuran, chlorobenzene and N, N-dimethylformamide.

7. The preparation method according to claim 6, wherein the small-molecule initiator is α -ethyl bromoisobutyrate, and/or:

the ligand is pentamethyldiethylenetriamine; and/or:

the step (1) is carried out in a solvent, wherein the solvent is one or a mixture of two of anhydrous chlorobenzene and anhydrous N, N-dimethylformamide; and/or:

and (2) carrying out the step (2) in a solvent, wherein the solvent is one or a mixture of two or three of anhydrous tetrahydrofuran, anhydrous chlorobenzene and anhydrous N, N-dimethylformamide.

8. The production method according to claim 7, wherein the step (1) is carried out in a solvent which is anhydrous chlorobenzene; and/or;

and (3) carrying out the step (2) in a solvent, wherein the solvent is anhydrous chlorobenzene.

9. The method according to any one of claims 1, 6,7 or 8, wherein in step (1), the small molecule initiator: ligand: cuprous chloride: styrene ═ 1: (1-3): (1-2): (10-900);

and/or, in step (2), the macroinitiator: ligand: cuprous chloride: azo-benzene monomer ═ 1: (1-3): (1-2): (0.1-110).

10. The production method according to claim 1, 6,7 or 8, further comprising a step of post-treating the reaction solution of steps (1) and (2), wherein the post-treatment is specifically: quenching the reaction by liquid nitrogen, removing copper salt, spin-drying the reaction solution, precipitating by ether and alcohol solvents, and washing the product.

11. The method according to claim 10, wherein the ethereal solvent is petroleum ether, diethyl ether or a mixture thereof.

12. The method of claim 11, wherein the copper salt is removed using a neutral alumina column.

13. The preparation method according to claim 9, further comprising a step of post-treating the reaction solution of steps (1) and (2), wherein the post-treatment is specifically: quenching the reaction by liquid nitrogen, removing copper salt, spin-drying the reaction solution, precipitating by ether and alcohol solvents, and washing the product.

14. The method according to claim 13, wherein the ethereal solvent is petroleum ether, diethyl ether or a mixture thereof.

15. The method of claim 14, wherein the copper salt is removed using a neutral alumina column.

16. The method according to claim 1, wherein the support is one of a silicon wafer, polyethylene terephthalate, and aluminum foil.

17. The method according to claim 1, wherein the PS-b-pma (az) block copolymer solution is prepared in a concentration of 0.5 wt% to 5 wt% in chloroform and/or toluene.

18. The method of claim 1, wherein the annealing is performed under the following conditions: annealing at 120-150 deg.C for 5-10 min.

19. A PS-b-pma (az) block copolymer photolithographically patterned film produced by the method of any one of claims 1 to 18, wherein the film has a vertical columnar or vertical lamellar structure.

20. A PS-b-pma (az) block copolymer photolithographically patterned film according to claim 19 in which the vertical columnar film columns have a diameter of from a few nanometers to a few tens of nanometers.

21. A PS-b-pma (az) block copolymer photolithographically patterned film according to claim 19 in which the vertical lamellar film interlayer spacing is in the range of a few nanometers to a few tens of nanometers.

22. Use of a PS-b-PMA (Az) block copolymer photolithographically patterned film according to any one of claims 1 to 18 or a PS-b-PMA (Az) block copolymer photolithographically patterned film according to any one of claims 19 to 21 in the field of microelectronics.

23. Use of a PS-b-PMA (Az) block copolymer lithographic patterned film according to any of claims 1 to 18 or a PS-b-PMA (Az) block copolymer lithographic patterned film according to any of claims 19 to 21 in the preparation of inorganic nanomaterials.