KR102327635B1 - A method for preparing nano pore filter and the nano pore filter prepared thereby - Google Patents

Abstract

The present invention relates to a method for manufacturing a nanopore filter capable of controlling both the nanopore density and size by performing an etching process in a way that combines a physical and chemical etching process with a two-dimensional material such as graphene, and a nanopore filter manufactured therefrom will be.

Description

Nanopore filter manufacturing method and nanopore filter prepared therefrom {A method for preparing nano pore filter and the nano pore filter prepared thereby}

The present invention relates to a method for manufacturing a nanopore filter capable of controlling both the nanopore density and size by performing an etching process in a way that combines a physical and chemical etching process with a two-dimensional material such as graphene, and a nanopore filter manufactured therefrom will be.

Recently, nanofilm materials with nanopores are being actively studied because of their high application potential in various fields such as DNA sequencing, water desalination, protein analysis, gas separation, and filtration.

In the application technology of nano-film materials having such nano-pores, it can be said that the nano-pore size and density control technology are key. Although the physical etching method using plasma or the like can control the density of nanopores, it is difficult to uniformly control the size of the nanopores, so there is a problem in that nanopores of various sizes are formed. Chemical etching methods such as thermal oxidation, etching solution, and atomic layer etching (ALE) can control the size of nanopores, but there is a limitation in that it is difficult to control the density. In addition, physical etching methods using Focused Ion Beam (FIB) or Transmission Electron Microscopy (TEM) can control the size and density of nanopores, but they are very expensive and have low productivity. Therefore, there is a demand for a nanopore formation technology that has characteristics of low process price and high productivity and can simultaneously control density and size according to the purpose.

As a representative example,

Diagnosis and prevention of diseases are becoming very important technologies as interest in health gradually increases, but it is difficult to analyze small protein aggregates at the nanometer level, which are biomarkers of some diseases. In particular, as in the case of Alzheimer's disease, in order to develop research and diagnosis and prevention technologies for diseases using the phenomenon that the size of protein aggregates increases to the nanometer level as the disease progresses, target substances are classified according to the nanometer size. It is very important to have the skills to

In addition, in relation to the present invention, Korean Patent Registration No. 10-1061551 (registration date of August 26, 2011) discloses a technology for 'a low-density protein separation device for plasma, a method for manufacturing a low-density protein separation device for plasma, and a method for separating low-density protein' has been disclosed.

In the case of the above registered patent, it includes a technique for forming nanopores in a SiN film using FIB. The etching using the FIB has a problem that the price is very high and the productivity is low. In addition, it is difficult to form nanometer-level nanopores on a SiN film using other highly productive processes such as plasma etching, and it is even more difficult to simultaneously control the nanopore density and size.

Republic of Korea Patent Registration 10-1061551 (Registration Date 2011.08.26)

An object of the present invention is to provide a method for manufacturing a nano-pore filter capable of manufacturing by controlling the density and size of nano-pores according to various application purposes, and a nano-pore filter manufactured therefrom.

In order to achieve the above object,

The present invention relates to a process of forming a crystal defect including nanopores and functional groups of a target density by subjecting a two-dimensional material to a physical etching process,

Provided is a method for manufacturing a nanopore filter comprising the step of forming nanopores of a target size by additionally etching the formed crystal defects with sub-nanometer precision using a chemical etching process.

In addition, it provides a nanopore filter manufacturing method in which the nanopore filter manufacturing method presented above is a basic core process, and another process is added before or after the basic core process.

in other words,

The process of forming an opening in the substrate;

The process of transferring the two-dimensional material to a large area so as to cover the opening of the substrate as a whole;

The two-dimensional material is subjected to a physical etching process to achieve a target density of nano A process of forming a crystal defect including a nanopore and a functional group, and

A method for manufacturing a nanopore filter comprising the step of further etching the formed crystal defects with sub-nanometer precision to form nanopores of a target size using a chemical etching process;

The process of forming a crystal defect including nanopores and functional groups of a target density by subjecting the two-dimensional material to a physical etching process;

The process of forming nanopores of a target size by further etching the formed crystal defects with sub-nanometer precision using a chemical etching process;

A nanopore filter manufacturing method comprising the process of changing the hydrophilicity of the surface of the two-dimensional material through surface treatment to prevent deterioration of filter performance caused by the object to be filtered adsorbed to the surface of the two-dimensional material;

The process of forming an opening in the substrate;

The process of transferring the two-dimensional material to a large area so as to cover the opening of the substrate as a whole;

A process of forming a crystal defect including nanopores and functional groups of a target density by subjecting the two-dimensional material to a physical etching process;

The process of forming nanopores of a target size by further etching the formed crystal defects with sub-nanometer precision using a chemical etching process;

Provided is a method for manufacturing a nanopore filter comprising a process of changing the hydrophilicity of the surface of the two-dimensional material through surface treatment in order to prevent deterioration of filter performance caused by adsorption of an object to be filtered on the surface of the two-dimensional material.

And it provides a nano-pore filter manufactured according to the nano-pore filter manufacturing method of the four embodiments presented above.

The nano-pore filter manufacturing method and nano-pore filter according to the present invention have the following effects.

first. Through the nanopore filter manufacturing method made through the combination of the physical etching process and the chemical etching process presented in the present invention, it is possible to precisely control both the size and density of the nanopores at a low price and high productivity.

second. A plurality of filters having uniformly sized nanopores are manufactured, but the nanopore size of each filter is varied from sub-nanometers to several tens of nanometers, so that the filtering target material such as protein aggregates can be classified according to the size.

1 is a manufacturing process diagram of a nano-pore filter according to Example 1 of the present invention.
2 illustrates a state (a) in which crystal defects of nanopores are formed and a state (b) in which crystal defects of functional groups are formed by performing a physical etching process on a two-dimensional material according to the present invention; schematic drawing.
Figure 3 is a nano-pore filter manufacturing process diagram according to Example 2 of the present invention.
Figure 4 is a side cross-sectional view of the substrate used in the nano-pore filter manufacturing process according to Example 2 of the present invention.
Figure 5 is a nano-pore filter manufacturing process diagram according to Example 3 of the present invention.
Figure 6 is a nano-pore filter manufacturing process diagram according to Example 4 of the present invention.

Hereinafter, detailed technical contents according to the method for manufacturing a nano-pore filter of the present invention presented in four embodiments will be described with the drawings.

[Example 1]

1 shows a first embodiment of a method for manufacturing a nano-pore filter according to the present invention,

In the nanopore filter manufacturing method of Example 1, a physical etching process is performed on the two-dimensional material 10 to form a crystal defect including nanopores and functional groups of a target density. process and

and further etching the formed crystal defects with sub-nanometer precision using a chemical etching process to form nanopores 101 having a target size.

The two-dimensional material 10 is graphene; graphene oxide; reduced graphene oxide; h-BN; phosphorene; MoS ₂ , MoSe ₂ , MoTe ₂ , WS ₂ , WSe ₂ or WTe ₂ containing transition metal chalcogen compounds; transition metal oxides; transition metal carbides/nitrides; silicene; germanene; arsenene; antimonene; Any one or two or more materials selected from a material having a planar crystal structure and a thickness at the level of a single atomic layer or multiple layers, including borophene, are used.

A physical etching process for forming a crystal defect in the two-dimensional material 10 may include plasma _{of Ar, O 2} , H ₂ or N _{2 ;} UV/ozone; Focused Ion Beam; Transmission Electron Microscopy; Scanning Probe Microscope tip; It is an etching process using any one or two or more selected from among.

By surface-treating the two-dimensional material 10 by the physical etching process, a crystal defect with high chemical reactivity is formed. In this case, the defect is present in nanometer-level pores or an ideal two-dimensional material. It means including the vacancy of an atom, a functional group, and the like.

As a specific example of the physical etching process, when graphene is _{treated with 20 W of O 2} plasma for 1.5 seconds, nanopores having an average size of 0.5 to 1 nm are formed at a density of ^{1 pore/100 nm 2 .} During the plasma treatment, by controlling the power and time, nanopores or crystal defects having a desired density are formed.

2 is a view exemplarily illustrating a crystal defect formed by performing a physical etching process on a two-dimensional material according to the present invention. An example of a state (a) in which crystal defects of nanopores are formed and a state in which crystal defects of functional groups are formed (b) are shown.

As shown in FIG. 2 , a crystal defect refers to a phenomenon in which the hexagonal structure of carbon is broken. Etching occurs in the portion of the crystal defect formed in this way, and a pore is formed.

The 2D material has very low chemical reactivity in a basal plane portion except for defects formed by such a physical etching process.

Accordingly, it is possible to form nanopores 101 of a target size by further etching the crystal defects with sub-nanometer precision through a chemical etching process that selectively reacts with the defects formed through the physical etching process.

That is, by increasing the precision so that the pore size increase rate by the chemical etching process is 0.5 to 0.8 nm per minute, it is possible to effectively form the desired target size of the nanopores 101 .

The chemical etching process may include thermal oxidation; electrochemical reaction; wet etching with KMnO ₄ /H ₂ SO ₄ or Zn/HCl; or atomic layer etching; It is an etching process using any one or two or more selected from among.

As a specific example of the chemical etching process, the nanopore size of graphene was reduced from 0.5 to 0.8 nm/ using a thermal oxidation process under the conditions of _{800° C., 25 mTorr O 2} , 1 Torr 10% NH _{3 in Ar.} The nanopore size can be expanded at an increasing rate of min.

At this time, the nanopores of the desired size are formed by controlling the combination of temperature, gas, partial pressure, and processing time.

As such, the technical feature of the method for manufacturing a nanopore filter according to the present invention is to determine the density of the nanopore by a physical process and to determine the nanopore size through a chemical process, after the physical etching process By undergoing a chemical etching process, nanopores of controlled density and size can be formed.

These technical features are equally applied to the method of manufacturing a nano-pore filter of another embodiment to be described later.

[Example 2]

3 shows a second embodiment of a method for manufacturing a nano-pore filter according to the present invention,

The process of forming the opening 110 in the substrate 100, and

The process of transferring the two-dimensional material 10 to a large area so as to cover the opening 110 of the substrate as a whole;

The process of forming a crystal defect including nanopores and functional groups of a target density by subjecting the two-dimensional material 10 to a physical etching process;

and further etching the formed crystal defects with sub-nanometer precision using a chemical etching process to form nanopores 110 of a target size.

In the nanopore filter manufacturing method according to the second embodiment, in the nanopore filter manufacturing method of the first embodiment, the process of forming the opening 110 in the substrate 100, and the opening 110 of the substrate as a whole is covered There is a difference in the process of transferring the two-dimensional material 10 to a large area to cover. The rest of the process is the same.

As shown in FIG. 4 , the substrate 100 is integrally formed by laminating a SiN film on an upper portion of the Si base substrate.

Looking at the process of forming the opening 110 in the substrate 100 in more detail, before forming the opening 110 in the base substrate of a highly doped p-type Si wafer (525um) , toluene, acetone, and isopropyl alcohol (IPA) sequentially to wash.

Then, a portion to form an opening on the SiN film is patterned using photolithography and dry etching. Thereafter, the opening 110 is formed by wet etching the Si base substrate under the SiN film using potassium hydroxide (KOH). In this case, the size and shape of the opening 110 can be adjusted to suit the field to be utilized.

The process of transferring the two-dimensional material 10 to a large area so as to cover the opening 110 of the substrate as a whole may vary depending on the type of the two-dimensional material 10, but a specific example is given as follows.

1. Prepare graphene grown by chemical vapor deposition (CVD) on copper foil.

2. After spin coating the PMMA solution on the graphene, bake through heat treatment.

3. Graphene grown on the back side of the copper foil is _{removed by O 2} plasma treatment (150W, 60s).

4. Put PMMA/graphene/copper foil in Na ₂ S ₂ O ₈ /H ₂ O (18g/200ml) solution and etch the copper foil for 12h. After the etching is completed, it is transferred and floated in DI water to remove ions around the graphene.

5. PMMA/graphene floating on water is transferred to be positioned on the opening 110 of the substrate 10 .

6. After drying water at room temperature for more than 8 hours, put it in acetone to remove PMMA.

7. The graphene transferred onto the substrate is washed in the order of acetone, IPA, DI water, and IPA, and then dried with _{N 2 gas.}

In this way, after the process of transferring the two-dimensional material 10 to a large area so as to cover the opening 110 of the substrate as a whole, the nanopore filter is formed through the same process as that described in Example 1 above. manufacture

[Example 3]

5 shows a third embodiment of a method for manufacturing a nano-pore filter according to the present invention,

The process of forming a crystal defect including nanopores and functional groups of a target density by subjecting the two-dimensional material 10 to a physical etching process;

The process of forming nanopores 101 of a target size by further etching the formed crystal defects with sub-nanometer precision using a chemical etching process;

and changing the hydrophilicity of the surface of the two-dimensional material through surface treatment to prevent deterioration of filter performance caused by the object to be filtered adsorbed to the surface of the two-dimensional material.

In the nano-pore filter manufacturing method according to Example 3, in the nano-pore filter manufacturing method of Example 1, an object to be filtered is adsorbed on the surface of the two-dimensional material 10 to prevent deterioration of filter performance. There is a difference in the process of changing the hydrophilicity of the surface of the two-dimensional material 10 through the surface treatment. The rest of the process is the same.

According to the nanopore filter manufacturing method according to the third embodiment, after the physical and chemical etching process, the object to be filtered is adsorbed to the surface of the two-dimensional material 10 to prevent the filtering performance from being deteriorated. A surface treatment process of the two-dimensional material 10 is performed.

That is, by surface-treating the two-dimensional material 10 on which the nano-pores 101 are formed, the surface of the two-dimensional material 10 is hydrophilic.

At this time, the surface treatment is an etching process using any one or two or more selected from processes for changing the hydrophilicity of the surface, including _{ozone, UV/ozone, O 2 plasma, or SAM (Self Assembled Monolayer).} done through

Looking at the surface treatment as an example, the graphene film on which the nano-pores 101 are formed is put into an ozone treatment device, and ozone and oxygen are flowed in a ratio of 1:9. At this time, the partial pressure of the gas is 30 Torr, and when ozone treatment is performed at 80 ° C. for 10 minutes, a hydrophilic surface can be formed without etching graphene.

Through such a surface treatment, it is possible to block the generation of noise by combining the target material with the surface of the two-dimensional material 10 without the protein aggregate passing through the nanopores.

[Example 4]

6 shows a fourth embodiment of a method for manufacturing a nano-pore filter according to the present invention,

The process of forming the opening 110 in the substrate 100, and

The process of transferring the two-dimensional material to a large area so as to cover the opening 110 of the substrate 100 as a whole;

The process of forming a crystal defect including nanopores and functional groups of a target density by subjecting the two-dimensional material 10 to a physical etching process;

The process of forming nanopores 101 of a target size by further etching the formed crystal defects with sub-nanometer precision using a chemical etching process;

and changing the hydrophilicity of the surface of the two-dimensional material 10 through surface treatment to prevent deterioration of filter performance caused by the object to be filtered adsorbed to the surface of the two-dimensional material 10 .

The nanopore filter manufacturing method according to Example 4 includes all of the processes added in Examples 2 and 3 to the basic core process of Example 1.

At this time, since the added process is the same as that described in Examples 2 and 3, additional descriptions will be omitted.

By using the nanopore filter manufacturing method made through the combination of the physical etching process and the chemical etching process presented in the present invention, both the size and density of the nanopores can be precisely controlled with low thickness and high productivity. Through the nanopore filter manufacturing method presented in the present invention, several filters having a uniform size of nanopores are manufactured, but the nanopore size of each filter is varied from sub-nanometers to tens of nanometers to filter target substances such as protein aggregates. can be classified according to size. Using these filters, it is possible to analyze the size distribution of biomarkers that increase in size according to the stage of disease, such as Alzheimer's disease, and the analysis results can be used for research on diseases and development of diagnostic technology, so industrial applicability is very high. high.

10: two-dimensional material
101: nano pores
100: substrate
110: opening

Claims (9)

The process of forming a crystal defect including nanopores and functional groups of a target density by subjecting the two-dimensional material to a physical etching process;
and further etching the formed crystal defects with sub-nanometer precision using a chemical etching process to form nanopores of a target size.
The process of forming an opening in the substrate;
The process of transferring the two-dimensional material to a large area so as to cover the opening of the substrate as a whole;
A process of forming a crystal defect including nanopores and functional groups of a target density by subjecting the two-dimensional material to a physical etching process;
and further etching the formed crystal defects with sub-nanometer precision using a chemical etching process to form nanopores of a target size.
The process of forming a crystal defect including nanopores and functional groups of a target density by subjecting the two-dimensional material to a physical etching process;
The process of forming nanopores of a target size by further etching the formed crystal defects with sub-nanometer precision using a chemical etching process;
A method of manufacturing a nanopore filter comprising the step of changing the hydrophilicity of the surface of the two-dimensional material through surface treatment to prevent deterioration of filter performance caused by adsorption of an object to be filtered on the surface of the two-dimensional material.
The process of forming an opening in the substrate;
The process of transferring the two-dimensional material to a large area so as to cover the opening of the substrate as a whole;
A process of forming a crystal defect including nanopores and functional groups of a target density by subjecting the two-dimensional material to a physical etching process;
The process of forming nanopores of a target size by further etching the formed crystal defects with sub-nanometer precision using a chemical etching process;
A method of manufacturing a nanopore filter comprising the step of changing the hydrophilicity of the surface of the two-dimensional material through surface treatment to prevent deterioration of filter performance caused by adsorption of an object to be filtered on the surface of the two-dimensional material.
5. The method according to any one of claims 1 to 4,
Two-dimensional materials include graphene; graphene oxide; reduced graphene oxide; h-BN; phosphorene; MoS ₂ , MoSe ₂ , MoTe ₂ , WS ₂ , WSe ₂ or WTe ₂ containing transition metal chalcogen compounds; transition metal oxides; transition metal carbides/nitrides; silicene; germanene; arsenene; antimonene; borophene; has a planar crystal structure and has a thickness of a single atomic layer level or a multi-layered material, comprising any one or two or more selected from a nanopore filter manufacturing method.
5. The method according to any one of claims 1 to 4,
The physical etching process may include plasma _{of Ar, O 2} , H ₂ or N _{2 ;} UV/ozone; Focused Ion Beam; Transmission Electron Microscopy; Scanning Probe Microscope tip; Nanopore filter manufacturing method, characterized in that the etching process using any one or two or more selected from among.
5. The method according to any one of claims 1 to 4,
Chemical etching processes include thermal oxidation; electrochemical reaction; wet etching with KMnO ₄ /H ₂ SO ₄ or Zn/HCl; or atomic layer etching; Nanopore filter manufacturing method, characterized in that the etching process using any one or two or more selected from among.
5. The method according to claim 3 or 4,
Surface treatment is an etching process using any one or two or more selected from processes for changing the hydrophilicity of the surface, including ozone, UV/ozone, O _{2 plasma, or SAM (Self Assembled Monolayer).} Nanopore filter manufacturing method characterized in that.
Nanopore filter, characterized in that manufactured by the method of any one of claims 1 to 4 selected.

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