CN107814353A - The method that nanometer pinpoint array is prepared on transparent flexible substrate - Google Patents

Abstract

The invention provides a method for preparing a nano-tip array on a transparent flexible substrate, realizing the preparation of a nano-tip array on a flexible substrate, which has the characteristics of large preparation area and simple process, and is characterized in that the method comprises the following steps: 1. Preparation of PS ball array template by liquid surface self-assembly; Step 2. Using oxygen plasma etching combined with ion beam irradiation to construct a nano-tip array template on the substrate; Step 3. On the surface with a nano-tip array template Spin-coat PDMS on the substrate, and then peel off to obtain a PDMS template; Step 4. Spin-coat a layer of UV-curable light agent on the transparent flexible substrate, press the PDMS template on the transparent flexible substrate, and use UV lamps to irradiate and cure, The PDMS template was peeled off to obtain a nano-tip array.

Description

Method for preparing nano-tip array on transparent flexible substrate

technical field

The invention belongs to the field of preparation of nanometer materials, and in particular relates to a method for preparing nanometer needle tip arrays on a transparent flexible substrate.

technical background

The emergence of nanotechnology has greatly promoted the progress of science and technology. With the continuous advancement of technology, its processing precision has reached the nanometer scale. Now nanofabrication technology has been widely used in the fields of machinery, optics, electronic information, energy and so on. The main processing methods are divided into physical and chemical methods, including photolithography, focused ion beam, nanoimprint technology, scanning probe processing technology, etc. Highly ordered nanotip arrays have important applications in the fields of photocatalysis, solar cells, optoelectronic devices, and SERS due to their specific optical properties. However, limited by the current technology, it is still a challenge to obtain a large-area, ultra-high-uniform nanoscale tip array. Traditional methods of fabricating large-area arrays, such as ultraviolet lithography and focused ion beam, have their limitations. Photolithography technology can realize large-area and highly uniform arrays, but it is difficult to achieve nanoscale arrays. Although the focused ion beam system can realize the array structure below 50 nanometers, it cannot realize the large-area preparation.

In order to obtain large-area, small-size nanotip arrays, some improved processing techniques have been introduced into this field. Such as atomic lithography, due to its small diffraction limit, atomic lithography can reach 0.1 nanometers, so it has extremely high resolution, but how to obtain high-intensity atomic beams is a difficult problem. Another example is nanoimprinting. Nanoimprinting can realize large-area, fast, and high-precision nanostructure preparation; but when the structure scale is reduced to the nanoscale, the cost becomes higher. These improved methods have their advantages, but there are still some problems that need to be solved urgently.

Contents of the invention

The present invention is carried out in order to solve the above problems, and the purpose is to provide a method for preparing a nano-tip array on a transparent flexible substrate, which can realize the preparation of a nano-tip array on a flexible substrate, and has the advantages of large preparation area and simple process specialty.

In order to achieve the above object, the present invention adopts the following scheme:

The invention provides a method for preparing a nano needle tip array on a transparent flexible substrate, which is characterized in that it comprises the following steps: Step 1. Prepare a PS ball array template through liquid surface self-assembly; Step 2. Utilize oxygen plasma etching to combine Ion beam irradiation constructs a nano-tip array template on the substrate; Step 3. Spin-coat PDMS on the substrate with a nano-tip array template on the surface, and then peel off to obtain a PDMS template; Step 4. Spin on a transparent flexible substrate Apply a layer of UV-curable light agent, press the PDMS template on the transparent flexible substrate, use UV lamps to irradiate and cure, and then peel off the PDMS template to obtain a nano-needle tip array.

Further, the method for preparing a nano-tip array on a transparent flexible substrate provided by the present invention may also have the following characteristics: In step 2, the ion beam used is a nitrogen ion beam, the irradiation energy is 20keV, and the irradiation dose is greater than or equal to 3×10 ¹⁶ ions/cm ² and less than 1×10 ¹⁷ ions/cm ² .

Further, the method for preparing a nano-needle tip array on a transparent flexible substrate provided by the present invention may also have the following features: in step 3, put the substrate spin-coated with PDMS into an oven and heat it to 50-70°C, and Keep it warm for 1 to 2 hours, and then perform the stripping operation.

Further, the method for preparing a nano-tip array on a transparent flexible substrate provided by the present invention may also have the following characteristics: in step 3, a curing agent is mixed in PDMS, where PDMS is SYLGARD 184 glue, divided into A, B Glue, B glue is the cured glue, and the mass ratio of A and B glue is 10:1. Before spin coating, mix the two evenly and centrifuge to eliminate air bubbles.

Further, the method for preparing a nano-needle tip array on a transparent flexible substrate provided by the present invention may also have the following features: In step 4, the transparent flexible substrate is a PET film substrate.

Further, the method for preparing nano-needle tip arrays on a transparent flexible substrate provided by the present invention may also have the following features: In step 4, the UV curing light agent is NOA61.

Further, the method for preparing a nano-needle tip array on a transparent flexible substrate provided by the present invention may also have the following characteristics: In step 4, the parameter of spin-coating the UV curing light agent is 3000-5000 rpm, 30-60 seconds .

Further, the method for preparing nano-needle tip arrays on a transparent flexible substrate provided by the present invention may also have the following features: In step 4, the curing time by ultraviolet radiation is 30 minutes.

Function and Effect of Invention

The method for preparing a nano-tip array on a transparent flexible substrate provided by the present invention has high stability, good repeatability, simple process, low cost, and can effectively print and prepare a wafer-level needle-tip array. The size of the nano-tip is 50 nanometers Around, the area can reach the 4-inch wafer level.

Description of drawings

Fig. 1 is the SEM picture of the template process of preparing the nano-tip array template in the first embodiment of the present invention, wherein, (a) is the SEM picture of the PS sphere array, (b) is the SEM picture after the plasma treatment is carried out to the PS sphere, (c ) is a SEM image after further ion beam irradiation treatment, and (d) is a cross-sectional view of (c);

Fig. 2 is the image of the nano-needle tip array prepared on PET by reverse imprinting method in Example 1 of the present invention, wherein, (a) is a macroscopic photo; (b) is a SEM image;

Figure 3 is an AFM image of the nano-tip array prepared in Example 1 of the present invention, wherein (a) is an AFM three-dimensional topography, (b) is an AFM two-dimensional topography, and (c) is a cross-sectional height curve ;

Figure 4(a) is the SEM image of the process of preparing the nano-tip array in Example 2 of the present invention, wherein (a) is the SEM image of the PS ball after plasma treatment and ion beam irradiation treatment, (b) is the nanometer SEM image of tip array;

Figure 5 is an AFM diagram of the nano-tip array prepared in Example 2 of the present invention, wherein (a) is a three-dimensional AFM topography diagram, (b) is a two-dimensional AFM topography diagram, and (c) is a cross-sectional height curve ;

Fig. 6 is the SEM image of the process of preparing the nano-tip array in the third embodiment of the present invention, wherein (a) is the SEM image of the PS ball after plasma treatment and ion beam irradiation treatment, (b) is the nano-tip array SEM image.

Detailed ways

The specific implementation of the method for preparing a nano-needle tip array on a transparent flexible substrate according to the present invention will be described in detail below with reference to the accompanying drawings.

<Example 1>

In the first embodiment, the method for preparing a nano-tip array on a flexible substrate (PET) is mainly divided into two processes.

The first process is to prepare a nano-tip array template on a silicon substrate by ion beam irradiation combined with a PS ball mask. The specific operations are as follows:

As shown in Figure 1(a), a large-area uniform and densely packed PS ball array is prepared on a silicon substrate by liquid surface assembly; the substrate needs to be treated with clean water in advance, generally soaked in SDS. Then, the silicon substrate covered with the PS array was subjected to oxygen plasma treatment with a power of 30W and a time of 1h to obtain the structure shown in Figure 1(b). After the treatment, the diameter of the PS sphere was less than 500nm, which was beneficial to shorten the ion beam in the next step. The time of irradiation. Further, shortening the irradiation time of the ion beam can also reduce the damage of the ion beam to the substrate. Because large doses of ion beam irradiation will cause cavities on the surface of the substrate, which will affect our subsequent experimental process.

After the oxygen plasma treatment of the PS ball array, the sample was placed in an ion implanter for ion irradiation treatment. The implantation energy was 20keV, and the dose was 5×10 ¹⁶ ions/cm ² . The SEM image of the treated sample is shown in Figure 1 As shown in (c), Figure 1(d) is its corresponding cross-sectional SEM image. The size of the nano-needle tip obtained under this irradiation parameter is about 50 nanometers, and the height is about 200 nanometers.

The second process is to use the reverse imprinting method to reversely imprint the nano needle tip on the PET substrate, the specific operation is as follows:

First, coat the nano-tip template with PDMS at a speed of 4000 rpm for 30 seconds; PDMS needs to be mixed with a curing agent and stirred evenly (mass ratio PDMS: curing agent = 10:1), and centrifuged until there are no bubbles in the solution .

Then, put the sample into an oven and bake at a temperature of 70°C for 1 hour. This process is to accelerate the curing of PDMS to form a reverse imprinting template. After the PDSM is completely cured, the PDMS is peeled off. Nanohole arrays will be formed on the peeled PDMS membrane, which can be used as a mold template for preparing nanoneedle tips.

Next, spin-coat a layer of NOA61 UV-curable adhesive on PET by spin-coating method. PET needs to be cleaned before spin coating, and ultrasonically cleaned with acetone, ethanol, and deionized water respectively. After spin-coating the UV-curable adhesive, the peeled PDMS template was pressed on the PET for 30 minutes of ultraviolet light irradiation, and then the PDMS template was peeled off, as shown in Figure 2, which is the nano-needle tip array prepared on the PET by reverse imprinting. SEM images show that this method can realize the preparation of ultra-large-area nano-tips. As shown in FIG. 3 , it can be known that the height of the nano-needle tip is about 50 nanometers through measurement.

<Example 2>

In this embodiment two, the preparation process is the same as in embodiment one, only the specific experimental parameters are different:

First, a large-area uniform and densely packed array of PS spheres is prepared on a silicon substrate using liquid surface assembly; then, the silicon substrate covered with the PS array is treated with oxygen plasma at a power of 30W for 1h, so that the diameter of the PS spheres after treatment is less than 500nm.

After oxygen plasma treatment was performed on the PS ball array, the sample was put into an ion implanter to perform ion irradiation treatment, the implantation energy was 20keV, and the dose was 3×10 ¹⁶ ions/cm ² .

Subsequently, the nano-tip template is coated with PDMS at a speed of 4000 rpm for 30 seconds; PDMS needs to be mixed with a curing agent and stirred evenly (PDMS:curing agent=10:1), and centrifuged until there are no bubbles in the solution.

Then, put the sample into an oven and bake at a temperature of 70° C. for 1 hour. After the PDSM is completely cured, the PDMS is peeled off. Nanohole arrays will be formed on the peeled PDMS membrane, which can be used as a mold template for preparing nanoneedle tips.

Next, spin-coat a layer of NOA61 UV-curable adhesive on PET by spin-coating method. PET needs to be cleaned before spin coating, and ultrasonically cleaned with acetone, ethanol, and deionized water respectively. After spin-coating the UV-curable glue, the peeled PDMS template was pressed on the PET for UV irradiation for 30 minutes, and then the PDMS template was peeled off. It can be found that when the size of the template increases, the size of the array obtained by reverse imprinting also increases correspondingly. As shown in Figure 5, the tip diameter reaches about 240nm and the height is 180nm.

<Example Three>

In this embodiment three, the preparation process is the same as in embodiment one, only the specific experimental parameters are different:

First, a large-area evenly packed array of PS spheres is prepared on a silicon substrate using liquid surface assembly; then, the silicon substrate covered with the PS array is subjected to oxygen plasma treatment with a power of 30W and a time of 1h, so that the diameter of the PS spheres after treatment is less than 500nm.

After oxygen plasma treatment was performed on the PS ball array, the sample was put into an ion implanter to perform ion irradiation treatment, the implantation energy was 20keV, and the dose was 1×10 ¹⁷ ions/cm ² .

Subsequently, the nano-tip template is coated with PDMS at a speed of 4000 rpm for 30 seconds; PDMS needs to be mixed with a curing agent and stirred evenly (PDMS:curing agent=10:1), and centrifuged until there are no bubbles in the solution.

Then, put the sample into an oven and bake at a temperature of 70° C. for 1 hour. After the PDSM is completely cured, the PDMS is peeled off.

Next, spin-coat a layer of NOA61 UV-curable adhesive on PET by spin-coating method. After spin-coating the UV-curable glue, the peeled PDMS template was pressed on the PET for UV irradiation for 30 minutes, and then the PDMS template was peeled off.

As shown in Figure 6, almost all the PS spheres were etched away, and the nano-tip array could not be obtained, indicating that the irradiation dose was too large, which was not conducive to the preparation of the nano-tip array.

The above embodiments are merely illustrations for the technical solution of the present invention. The method for preparing a nano-needle tip array on a transparent flexible substrate in the present invention is not limited to the content described in the above embodiments, but is subject to the scope defined in the claims. Any modifications, supplements or equivalent replacements made by those skilled in the art of the present invention on the basis of the embodiments are within the protection scope of the claims of the present invention.

Claims (8)

1. A kind of 1. method that nanometer pinpoint array is prepared on transparent flexible substrate, it is characterised in that comprise the following steps：

   Step 1. prepares PS ball array templates by liquid level self assembly；

   Step 2. constructs nanometer pinpoint array template using the irradiation of oxygen plasma etch coupled ion beam on substrate；

   Step 3. spin coating PDMS on substrate of the surface with nanometer pinpoint array template, then peel off and obtain PDMS templates；

   Step 4. one layer of ultra-violet curing photo etching of spin coating on transparent flexible substrate, PDMS templates are pressed on transparent flexible substrate, After being solidified using uv light irradiation, take PDMS templates off, obtain nanometer pinpoint array.
2. 2. the method according to claim 1 that nanometer pinpoint array is prepared on transparent flexible substrate, it is characterised in that：

   Wherein, in step 2, the ion beam used is nitrogen ion beam, irradiation energy 20keV, irradiation dose be more than or equal to 3 × 10¹⁶ions/cm², and less than 1 × 10¹⁷ions/cm²。
3. 3. the method according to claim 1 that nanometer pinpoint array is prepared on transparent flexible substrate, it is characterised in that：

   Wherein, in step 3, the substrate that spin coating has PDMS is put into baking oven and is heated to 50~70 DEG C, and it is small to be incubated 1~2 When, strip operation is then carried out again.
4. 4. the method according to claim 1 that nanometer pinpoint array is prepared on transparent flexible substrate, it is characterised in that：

   Wherein, in step 3, be mixed with curing agent in PDMS, both be mixed evenly before spin coating, and centrifuged with Eliminate bubble.
5. 5. the method according to claim 1 that nanometer pinpoint array is prepared on transparent flexible substrate, it is characterised in that：

   Wherein, in step 4, transparent flexible substrate is PET film substrate.
6. 6. the method according to claim 1 that nanometer pinpoint array is prepared on transparent flexible substrate, it is characterised in that：

   Wherein, in step 4, ultra-violet curing photo etching is NOA61.
7. 7. the method according to claim 1 that nanometer pinpoint array is prepared on transparent flexible substrate, it is characterised in that：

   Wherein, in step 4, the parameter of spin coating ultra-violet curing photo etching is 3000~5000 revs/min, 30~60 seconds.
8. 8. the method according to claim 1 that nanometer pinpoint array is prepared on transparent flexible substrate, it is characterised in that：

   Wherein, in step 4, ultraviolet irradiation hardening time is 30 minutes.