CN111438859A - A patterned nano-array template and its preparation method and application - Google Patents

Abstract

The present application belongs to the technical field of nano-array materials, and in particular relates to a patterned nano-array template and a preparation method and application thereof. The application provides a patterned nano-array template, including a micro-via template layer and a nano-hole template layer; the micro-via template layer has a diameter of 5-30 μm; The micrometer through holes are arranged in a pattern; the diameter of the nanoholes of the nanohole template layer is 10-300 nm; the micrometer through hole template layer is detachably fixed on the nanohole surface of the nanohole template layer. The patterned nano-array template of the present application can prepare array structures with specific patterns and different sizes, which effectively solves the technical defect that the existing nano-hole array template method can only prepare nano-pillar arrays with no pattern and a single size.

Description

A patterned nano-array template and its preparation method and application

technical field

The present application belongs to the technical field of nano-array materials, and in particular relates to a patterned nano-array template and a preparation method and application thereof.

Background technique

In recent years, nanoarray structured materials have been widely used in biosensing, optical components, heterogeneous catalysis and other fields due to their nanoscale effects and special optoelectronic properties. The nanopillar array generally refers to an array structure formed by periodic arrangement of cylinders with a diameter in the nanoscale range and a relatively high aspect ratio on a substrate. By rationally designing parameters such as the composition, structure and position distribution of the nanopillar array, the optimal adjustment of its performance can be achieved. The nanostructures have special optical and electrical properties, and have been widely used in sensing, detection, catalysis and other fields. The patterning of nanopillar arrays is an important way to control the properties and functions of nanopillar arrays, which is of great significance for the development of new micro-nano devices.

Commonly used methods for fabricating patterned nanopillar arrays include electron beam lithography, laser interference lithography, and nanoimprinting. However, the above-mentioned methods require expensive equipment, complicated operations and high production costs. In recent years, technicians have developed highly ordered nanohole array templates to prepare nanopillar arrays. The method has the advantages of strong flexibility, simple operation and low cost.

However, since the existing nanohole array template has only a single-structure nanohole array, the existing template method is generally used to prepare a patternless nanopillar array, and the nanopillar array prepared by the existing template method can only To achieve a nanoscale array, pattern structures other than nanoscale cannot be fabricated, thus limiting the application prospect of the existing nanopore array template method.

SUMMARY OF THE INVENTION

In view of this, the present application provides a patterned nano-array template and a preparation method and application thereof. The template of the present application can prepare an array structure with specific patterns and different sizes, effectively solving the problem that the existing nano-hole array template method is limited. The technical drawbacks of being able to fabricate unpatterned, single-sized nanopillar arrays.

A first aspect of the present application provides a patterned nano-array template, including a micro-via template layer and a nano-hole template layer;

The pore diameter of the micron through-holes in the micron through-hole template layer is 5-30 μm;

The micron vias of the micron via template layer are arranged in a pattern;

The pore size of the nanopores of the nanopore template layer is 10-300 nm;

The micro-hole template layer is detachably fixed on the nano-hole surface of the nano-hole template layer.

Preferably, the preparation method of the micro-via template layer comprises the following steps:

Step 1, spin-coating photoresist on the substrate and baking to obtain a first mold;

Step 2, place a photolithography mask on the photoresist surface of the first mold, and then perform ultraviolet exposure treatment, and then remove the photoresist in the unexposed area of the first mold and bake it to prepare the first mold. get the second mold;

Step 3, using plasma treatment and gelatin solution treatment on the photoresist surface of the second mold in turn to cover the surface of the photoresist mold with a thin layer of gelatin to prepare a third mold;

Step 4, coating the photoresist surface of the third mold with a polydimethylsiloxane prepolymer mixture to prepare a fourth mold;

Step 5, bonding the gel layer of the composite gel sheet on the polydimethylsiloxane prepolymer mixture layer of the fourth mold, wherein the composite gel sheet includes a substrate layer and a The gel layer to which the substrate layer is attached;

Step 6. After the polydimethylsiloxane prepolymer mixture layer of the fourth mold is cured, remove the composite gel plate and the substrate and the photoresist of the fourth mold to obtain a micron pass through. Hole template layer.

In the present application, the gel layer of the composite gel plate can be tightly crimped on the polydimethylsiloxane prepolymer mixture layer of the fourth mold in a conventional manner.

In some embodiments, the present application may place a magnet under the substrate of the fourth mold and a magnet above the substrate layer, facing each other up and down, to clamp the entire device, so that the gel layer of the composite gel plate can be tightly is crimped onto the polydimethylsiloxane prepolymer mixture layer of the fourth mold.

In some embodiments, the photoresist of the present application may be a negative photoresist or a positive photoresist, such as a negative photoresist such as SU-8, or a positive photoresist such as AZ.

In some embodiments, the substrate of the present application may be a silicon wafer or glass.

In some embodiments, the baking process of step 1 may be pre-baking on a hot plate at 95° C. for 10 minutes.

In some embodiments, the ultraviolet exposure treatment in step 2 may be ultraviolet light treatment for 10s, 18.9mW·cm ² ultraviolet light.

In some embodiments, in step 2, the photoresist in the unexposed area of the first mold is removed and baked, wherein the baking may be baking in an oven at 120° C. for 30 minutes, so that the photoresist mask 3 The SU-8 photoresist 5 exposed to the protected ultraviolet light is fully bonded to the silicon wafer 1 .

In some embodiments, after the UV exposure process of step 2, before removing the photoresist in the unexposed areas of the first mold. It also includes baking the product. The baking treatment can be heated at 65°C for 1 minute and then heated at 95°C for 12 minutes.

In some embodiments, the plasma treatment in step 3 can be 1-3 min, the plasma is conventionally used plasma, and the plasma treatment is used to generate hydroxyl groups on the surface of the photoresist mold.

In some embodiments, the gelatin solution treatment in step 3 may be immersion in a 60° C. gelatin solution with a mass volume percentage of 5% for 3 hours.

In some embodiments, the polydimethylsiloxane prepolymer mixture of step 4 is an existing conventionally used prepolymer mixture, such as a polydimethylsiloxane prepolymer matrix and its crosslinking agent.

In some embodiments, the substrate layer in step 5 may be glass or silicon wafer.

In some embodiments, the gel layer in step 5 may be a hydrogel such as agarose gel or polyacrylamide gel.

Specifically, the micro-via template layer is a PDMS film formed after the polydimethylsiloxane prepolymer mixture layer is cured.

Preferably, after removing the composite gel plate in step 6 of the preparation method of the micron through-hole template layer, the method further includes:

A polydimethylsiloxane frame is bonded on the cured polydimethylsiloxane prepolymer mixture layer of the fourth mold, and the polydimethylsiloxane frame is used for grasping by the user, and the In the subsequent preparation of the patterned nano-pillar array, the nano-array liquid material can be accommodated in the frame.

Preferably, the micro-via template layer is fixed on the nano-hole surface of the nano-hole template layer by physical or chemical means.

Preferably, the micro-via template layer is fixed on the nano-hole surface of the nano-hole template layer by an adhesive or a photocurable glue.

In some embodiments, the adhesive may be AB glue or other fast-curing adhesives; the light-curing adhesive may be a photo-crosslinked polymer prepolymer mixture, such as NOA series light-curing adhesive, light-curing polydimethyl Siloxane etc.

A second aspect of the present application provides a method for preparing a patterned nanoarray template, comprising the following steps:

Step 1, spin-coating photoresist on the substrate and baking to obtain a first mold photoresist substrate;

Step 2, place a photolithography mask on the photoresist surface of the first mold photoresist substrate, then perform ultraviolet exposure treatment, and then wash the first mold photoresist substrate with the developer solution and baking the photoresist in the unexposed area to obtain a second patterned photoresist mold;

Step 3, using plasma treatment and gelatin solution treatment on the photoresist surface of the second mold patterned photoresist mold in sequence to prepare the patterned photoresist mold after the third mold treatment;

Step 4, coating the photoresist surface of the patterned photoresist mold after the third mold treatment with the polydimethylsiloxane prepolymer mixture to prepare the fourth mold;

Step 5. Laminate the gel of the composite gel sheet on the polydimethylsiloxane prepolymer mixture layer of the fourth mold, wherein the composite gel sheet includes a substrate layer and a The gel layer to which the substrate layer is attached;

Step 6. After the polydimethylsiloxane prepolymer mixture layer of the fourth mold is cured, remove the composite gel plate and the substrate and photoresist of the fourth mold to obtain a hole template layer;

Step 7: Fix the micro-via template layer on the nano-hole surface of the nano-hole template layer by physical or chemical means.

Preferably, in step 3, the plasma treatment includes plasma treatment for 1 to 3 minutes.

Preferably, in step 3, the gelatin solution treatment includes soaking in a gelatin solution with a mass percentage of 5% at 60° C. for 3 hours.

A third aspect of the present application provides a method for preparing a patterned nanoarray from a patterned nanoarray template, comprising the following steps:

Step A, adding a nano-array liquid material on the micron through-hole template layer of the patterned nano-array template to prepare a first patterned nano-array plate;

In step B, vacuuming and high-speed centrifugation are performed on the first patterned nano-array plate, and after the nano-array liquid material is solidified, the patterned nano-array template is removed to obtain a patterned nano-array.

In some embodiments, patterned nano-pillar arrays with different patterns can be obtained by the above-mentioned nano-replication technology by replacing the micro-via template layer with different patterns on the nano-hole template layer.

Preferably, the nano-array liquid material is selected from a mixture of photocrosslinked polymer prepolymers, such as NOA series photocurable glue, photocurable polydimethylsiloxane, and the like.

Specifically, the present application can use UV-curable NOA with extremely high light transmittance as a material to obtain patterned nano-pillar arrays with good optical properties through nano-replication technology.

The purpose of this application is to address the technical defect that the nanohole array template method in the prior art can only prepare nanopillar arrays with no pattern and a single size. Therefore, the present application provides a novel patterned nano-array template, which has a double-layer structure, including a patterned micro-via template layer and a highly ordered non-patterned nano-hole template layer. Double-layer template; the patterned nano-array prepared by using the patterned nano-array template of the present application has both a micro-scale patterned structure and a nano-pillar array, and at the same time, the patterned nano-array template of the present application can be reused many times , and different patterned nano-array templates can be obtained by replacing the different patterned micro-via template layers, so as to control their surface properties. Under mild conditions, metal nanolayers are sprayed on the surface of patterned nanopillar arrays or deposited metal nanoparticles, which are expected to be used in biochemical sensing, environmental monitoring, reaction catalysis and other fields.

Description of drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the accompanying drawings that are required to be used in the description of the embodiments or the prior art.

Fig. 1 shows the preparation process of the micron via template layer provided by the present application;

Fig. 2 shows the physical diagram of the micron via template layer provided by the present application;

FIG. 3 shows a structural diagram of the patterned nanoarray template provided in the present application;

FIG. 4 shows a flow chart of preparing a patterned nanoarray from the patterned nanoarray template provided in the present application;

Fig. 5 is a physical view of the patterned nanoarray prepared in Fig. 4;

FIG. 6 is a scanning electron micrograph of the patterned nanoarray of FIG. 5 , wherein a is a patterned nanoarray containing micron-scale patterns, and b is an enlarged view of the nanopillars in a;

Figure 7 shows a scanning electron micrograph of a prior art unpatterned nanopillar array fabricated using commercially available silicon oxide-based nanoporous templates.

Detailed ways

The present application provides a patterned nano-array template and its preparation method and application, which are used to solve the technical defect that the existing nano-hole array template method can only prepare non-patterned, single-sized nano-pillar arrays in the prior art. Technical flaws.

The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

Wherein, the raw materials used in the following examples are self-made or commercially available.

Example 1

The embodiment of the present application provides a micro-via template layer, and the preparation method thereof includes the following steps:

Please refer to FIG. 1 and FIG. 2 , FIG. 1 provides the preparation process of the micro-via template layer for the application, and FIG. 2 is a physical diagram of the micro-via template layer provided by the application.

Step 1. Spin-coat a layer of 20 μm SU-8 photoresist 2 on the silicon wafer 1 and bake it for 10 minutes before laying it on a hot plate at 95° C. to obtain the first mold (ie, the photoresist substrate). );

Step 2. Place the photolithography mask 3 (the photolithography mask 3 is a photolithography mask containing a specific pattern) on the photoresist surface of the first mold, and then perform an ultraviolet exposure treatment (10s, 18.9mW·cm) in turn. ² UV light 4 exposure treatment) and baking treatment (the baking treatment is heated at 65°C for 1min and then heated at 95°C for 12min), then, the developer removes the SU-8 photoresist in the unexposed area of the first mold and carries out Baking (baking in an oven at 120° C. for 30 minutes, so that the SU-8 photoresist 5 after exposure to ultraviolet light protected by the photolithography mask 3 is fully bonded to the silicon wafer 1) to obtain a second mold (that is, a photoresist mold with a pattern); wherein, after the developer treatment, the second mold is the silicon wafer 1 and the SU-8 after exposure to ultraviolet light protected by the photolithography mask 3 placed on the silicon wafer 1 photoresist 5;

Step 3. Put the photoresist side of the second mold into a vacuum plasma cleaning machine for surface plasma treatment for about 1-3min and soak in gelatin solution (the mass fraction of gelatin solution is 5%, the treatment temperature is 60°C, and the time For 3h), the third mold (that is, the patterned photoresist mold after processing) is prepared;

Step 4. Coat the photoresist surface of the third mold with the polydimethylsiloxane prepolymer mixture 6 (the volume ratio of the matrix of the PDMS prepolymer mixture: the crosslinking agent is 10:1) to obtain the first Four molds;

Step 5. Laminate the gel of the composite gel plate on the polydimethylsiloxane prepolymer mixture layer of the fourth mold, and clamp the silicon wafer 1 and the substrate layer 7 with magnets 9, and two magnets 9 Align and clamp up and down, wherein, the composite gel plate includes a glass layer 7 and an agarose gel layer 8 attached to the glass layer, and the thickness of the agarose gel layer 8 is 3 mm;

Step 6. After the polydimethylsiloxane prepolymer mixture layer 6 of the fourth mold is cured (PDMS is cured at room temperature for about 12 hours), the magnet 9 is removed, and the glass layer 7 and the agarose gel layer 8 are removed, wherein , the polydimethylsiloxane prepolymer mixture layer 6 is cured to form a PDMS film;

Step 7. Bond a polydimethylsiloxane frame on the polydimethylsiloxane prepolymer mixture layer of the cured fourth mold (the frame can be a 1cm×1cm PDMS square frame, so that it can be connected with the PDMS film. bonding), then remove the silicon wafer 1 and the SU-8 photoresist 5 placed on the silicon wafer 1 after exposure to ultraviolet light protected by the photolithography mask 3 to obtain a micron via template layer A, micron vias The template layer A includes a PDMS square frame and a patterned PDMS film bonded thereto.

Example 2

The embodiment of the present application provides a patterned nano-array template, and the preparation method thereof includes the following steps:

Please refer to FIG. 3 , which is a structural diagram of the patterned nanoarray template provided in this application.

Step 1. Place the micro-via template layer A on a commercially purchased silicon oxide-based nano-micro-hole template B (the diameter of the nano-micro holes is about 300 nm, the depth of the nano-micro holes, and the periodic interval between adjacent nano-micro holes is about 1.5 μm. );

Step 2. Apply a thin layer of NOA on the contact edge of the micro-via template layer A and the silicon oxide-based nano-micro-porous template B, and irradiate with ultraviolet light for 30 minutes to fix the micro-via-hole template layer A on the silicon oxide-based nano-microporous template B. Patterned nanoarray templates were prepared.

Example 3

The embodiments of the present application provide a method for preparing a patterned nanoarray from a patterned nanoarray template, including the following steps:

Please refer to FIG. 4 and FIG. 5 , FIG. 4 is a flow chart of preparing a patterned nano-array from the patterned nano-array template provided in the application; FIG. 5 is a physical view of the patterned nano-array prepared in FIG. 4 .

Step 1. Drop 2 mL of UV-curable NOA71 liquid into the area of the PDMS square frame of the patterned nanoarray template prepared in Example 2;

Step 2: Repeat vacuuming and high-speed centrifugation (1500rpm, 20min) twice for the product of Step 1 to remove the residual gas in the silicon oxide-based nanoporous template B of the patterned nanoarray template prepared in Example 2;

Step 3. After standing on the water platform for a period of time, transfer to the UV lamp;

Step 4, UV exposure (wavelength 365nm, 60min) to fully cure NOA71;

Step 5. Gently lift the cured NOA71 with tweezers to obtain a patterned nano-pillar array using NOA71 as a material.

Scanning electron microscopy was performed on the patterned nano-pillar array prepared in this example, and the result is shown in FIG. 6 , which is a scanning electron micrograph of the patterned nano-array in FIG. 5 .

The embodiment of the present application also provides a nano-pillar array made by using a commercially purchased silicon oxide-based nano-micro-hole template according to the method of this embodiment (without using the micro-via template layer A), and scanning electrons is performed on the nano-pillar array. Microscopic inspection, the result is shown in FIG. 7 , FIG. 7 is a scanning electron micrograph of an unpatterned nano-pillar array prepared by using a commercially purchased silicon oxide-based nano-microporous template in the prior art.

It can be clearly seen from Figure 6 and Figure 7 that Figure 6 has a pattern on the micrometer scale, the pattern is a number 42 and a micrometer circle, and there are also nanopillars on the nanometer scale (picture b is a nanopillar structure); however, Figure 7 has only a single The nanopillar array structure cannot form a specific pattern.

Comparative Example 1

The comparative example of the present application also provides electron beam lithography, laser interference lithography, and nanoimprinting to prepare patterned nanoarrays, and the methods are as follows:

Referring to Zhang Kun, Lin Gang, Liu Gang, Tian Yangchao, and Wang Xiaoping published in the Journal of Electron Microscopy in 2006, "The Principle of Electron Beam Lithography and Its Application in Micro-nano Processing and Nano-device Fabrication", it can be seen that electron beam lithography The process is to spin-coat the electron beam photoresist on the surface of the substrate first; then use the electron beam to scan the photoresist surface according to the designed pattern; then develop the pattern after the electron beam treatment to remove the unexposed part; Then, metal is deposited on the developed pattern; finally, the photoresist of the exposed part is removed to obtain the desired nano-metal pattern. Features: High resolution (up to 3-5nm), but low yield (long preparation time), high equipment cost (need electron beam exposure machine system), not suitable for mass production.

Referring to the "Overview of the Application of Laser Interference Lithography" published by He Haidong and Yang Haifeng in Modern Manufacturing Engineering in 2012, it can be seen that the laser interference lithography process is spin-coating photoresist on the substrate, using the interference and diffraction characteristics of light, the light beam The combination of specific ways produces the desired light intensity distribution field, and the exposed photoresist is developed to produce the desired pattern. Features: low resolution (sub-micron level), high equipment cost (laser interference system), difficult to use for the preparation of small-diameter nano-pillar arrays.

Referring to the "Research on Key Technologies of High-speed and High-precision Micro-Nano Imprinting" published by Pilihua at Soochow University in 2014, it can be seen that the basic principle of nano-imprinting technology to prepare patterned nano-arrays is to use electron beam direct writing technology to prepare all kinds of micro-nano-imprinting technology. The nano-array template to be patterned is then transferred to thermoplastic photoresist, UV-sensitive liquid photoresist or polydimethylsiloxane by hot imprinting, UV curing imprinting or soft imprinting. Features: simple operation, high resolution (10nm), good repeatability, high production efficiency, low equipment cost, but when preparing patterned arrays, the corresponding patterned nanoarray templates need to be customized for different patterns (that is, electron beams need to be used. Direct writing technology customizes nanoarray templates with desired patterning), and cannot use the same nanoarray template to prepare nanoarrays with different patterns, which increases the manufacturing cost.

To sum up, compared with the existing electron beam lithography process, laser interference lithography process and nano-imprinting technology, the preparation cost of the patterned nano-pillar array prepared by the method for preparing the patterned nano-array of the present application is low. The equipment cost is low, and the pattern size of the fabricated nanopillar array can reach the micrometer level, with high repeatability and high yield.

The present application solves the technical defect that the nanohole array template method in the prior art can only prepare nanopillar arrays with no pattern and a single size. The purpose of the present application is to provide a template that can be reused many times and can prepare micron-scale patterned nano-pillar arrays.

The above are only the preferred embodiments of the present application. It should be pointed out that for those skilled in the art, without departing from the principles of the present application, several improvements and modifications can also be made. It should be regarded as the protection scope of this application.

Claims (10)

1. A patterned nano-array template is characterized by comprising a micro-through hole template layer and a nano-hole template layer;

the aperture of the micron through hole template layer is 5-30 microns;

the micron through holes of the micron through hole template layer are arranged according to patterning;

the aperture of the nano-pores of the nano-pore template layer is 10-300 nm;

the micron through hole template layer is detachably fixed on the nano hole surface of the nano hole template layer.

2. The patterned nanoarray template of claim 1, wherein the method of fabricating the microvia template layer comprises the steps of:

step 1, spin-coating photoresist on a substrate and baking to prepare a first mold;

step 2, placing a photoetching mask on the photoresist surface of the first mold, then carrying out ultraviolet exposure treatment, then removing the photoresist on the unexposed area of the first mold and baking to obtain a second mold;

step 3, sequentially treating the photoresist surface of the second mold by using plasma and gelatin solution to prepare a third mold;

step 4, coating the photoresist surface of the third mold with a polydimethylsiloxane prepolymer mixture to prepare a fourth mold;

step 5, pressing a gel layer of the composite gel plate on the polydimethylsiloxane prepolymer mixture layer of the fourth mold, wherein the composite gel plate comprises a substrate layer and a gel layer attached to the substrate layer;

and 6, after the polydimethylsiloxane prepolymer mixture layer of the fourth mold is cured, removing the composite gel plate, the substrate of the fourth mold and the photoresist to prepare the micron through hole template layer.

3. The patterned nanoarray template of claim 2, further comprising, after removing the composite gel sheet in step 6 of the method of fabricating the micro-via template layer:

and bonding a polydimethylsiloxane frame on the solidified polydimethylsiloxane prepolymer mixture layer of the fourth die.

4. The patterned nanoarray template of claim 1, wherein the microvia template layer is physically or chemically secured to a nanopore face of the nanoarray template layer.

5. The patterned nanoarray template of claim 1, wherein the micro-via template layer is secured on the nanohole surface of the nanohole template layer by an adhesive or a photo-curable adhesive.

6. A preparation method of a patterned nano array template is characterized by comprising the following steps:

step one, spin-coating photoresist on a substrate and baking to prepare a first mold;

step two, arranging a photoetching mask on the photoresist surface of the first mould, then carrying out ultraviolet exposure treatment, then washing the photoresist on the unexposed area of the first mould by using a developing solution, and baking to obtain a second mould;

step three, sequentially treating the photoresist surface of the second mold by using plasma and gelatin solution to prepare a third mold;

coating the photoresist surface of the third mold with a polydimethylsiloxane prepolymer mixture to obtain a fourth mold;

pressing a gel layer of the composite gel plate on the polydimethylsiloxane prepolymer mixture layer of the fourth die in a pressing mode, wherein the composite gel plate comprises a substrate layer and the gel layer attached to the substrate layer;

sixthly, after the polydimethylsiloxane prepolymer mixture layer of the fourth mold is cured, removing the composite gel plate, the substrate of the fourth mold and the photoresist to prepare a micron through hole template layer;

and seventhly, fixing the micro through hole template layer on the nano hole surface of the nano hole template layer in a physical or chemical mode.

7. The method according to claim 6, wherein in step three, the plasma treatment comprises plasma treatment for 1min to 3 min.

8. The preparation method according to claim 6, wherein in step three, the gelatin solution treatment comprises soaking the gelatin solution with a mass volume percentage of 5% at 60 ℃ for 3 h.

9. A method of making a patterned nanoarray according to the patterned nanoarray template of any one of claims 1 to 5, comprising the steps of:

step A, adding a nano-array liquid material on a micron through hole template layer of the patterned nano-array template to prepare a first patterned nano-array plate;

and B, carrying out vacuum pumping and high-speed centrifugal treatment on the first patterned nano array plate, and removing the patterned nano array template after the nano array liquid material is solidified to obtain the patterned nano array.

10. The method of claim 9, wherein the nano-array liquid material is selected from a photo-crosslinking polymer prepolymer mixture.

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