CN100382980C - Biological Template Nanoimprinting Method - Google Patents

Abstract

The main process of the bio-template nano-imprinting method of the present invention is as follows: firstly, a layer of imprinting glue is coated on the surface of the silicon chip and dried, and the side of the biological template with the nanostructure is placed on the surface of the imprinting glue downwards, and a cover is placed on it. Another silicon wafer, and then put it into the nanoimprinting equipment for imprinting under heating and pressure conditions. After the mold is released, a negative structure corresponding to the biological template is obtained on the surface of the imprinting rubber, thereby realizing the replication of the nanostructure on the biological surface Its imitation of special functions. The present invention directly uses the biological surface nanostructure existing in nature as the nanoimprint template, which avoids the complicated process of conventional template preparation, and the biological surface structure forms a natural anti-adhesion layer during the growth process, which can further simplify the process and reduce the cost. The biological template used in the present invention can be embossed multiple times, reused, and can realize the preparation of large-area nanostructures.

Description

Biological Template Nanoimprinting Method

technical field

The invention relates to an improved nano-imprint technology, which belongs to the technical field of nano-structure preparation.

technical background

Nanoimprint technology is a nanostructure preparation technology that emerged in the mid-1990s, which is completely different from the concept of traditional lithography technology. This technology presses out patterns of thickness contrast on the resist thin layer carried by the substrate by means of compression molding, and then uses anisotropic etching to transfer the pattern to the substrate, which has high resolution, large area, high efficiency and low cost. Significant advantages (Science, 272 (1996) 85). The shape and resolution of the replicated graphics depend on the template. Therefore, the selection of template material and its preparation process are the key to the realization of the entire technology. At present, the materials of nanoimprint templates are mainly semiconductor materials such as silicon and silicon dioxide. The preparation process generally adopts electron beam or ion beam exposure technology, which needs to go through processes such as exposure, development, reactive ion etching, metal deposition and stripping. Moreover, anti-adhesive treatment needs to be carried out on the template before imprinting, so as to avoid defects in bonding between the template and the imprinting adhesive (PMMA).

There are many biological surface nanostructures with special functions in nature. These surface nanostructures have special biological functions after a long evolution of biological populations in nature, and are closely related to their survival (PeteVukusic and J. Roy Sambles, Nature 424(2003) 852-855). For example, the regular hexagonal array nanostructures (also known as photonic crystals, as shown in Figure 1) on the compound eyes and wing surfaces of certain insects have strong anti-reflection effects in the ultraviolet and visible light bands, and butterfly wing scales The regular nanostructures can produce diffraction, interference and scattering in the visible light band, resulting in structural color. These above-mentioned biological surface structures with special functions or their similar structures not only have sufficient strength and stability to be directly used as nanoimprint templates, but also form a natural anti-adhesion layer during the growth process.

Contents of the invention

The purpose of the present invention is to provide a nano-imprint method, which directly uses the biological surface nano-structure existing in nature as a nano-imprint template to prepare the nano-structure, and realizes the replication of the biological surface nano-structure and the imitation of special functions.

The main process of the biological template nanoimprinting method of the present invention is as follows (as shown in Figure 2):

(1) Apply a layer of embossing glue on the surface of a silicon wafer and dry it;

(2) Place the side of the biological template with the nanostructure downward on the surface of the imprinting glue, and cover another silicon wafer on the surface of the biological template;

(3) Putting it into a nano-imprinting device for imprinting under heating and pressure conditions;

(4) After the mold is withdrawn, a negative structure corresponding to the nanostructure of the biological template is obtained on the surface of the imprinting glue, and the entire imprinting process is completed.

The imprinting glue used in the bio-template nanoimprinting method of the present invention is usually a thermoplastic organic polymer such as polymethylmethacrylate (PMMA), which is spin-coated on a silicon wafer and then baked and dried at 160-180°C for 30-60 minutes; Biological templates include insect compound eyes and photonic crystals on the surface of wings and other similar biological surface structures. The embossing temperature is 150-220° C., the pressure is 40-55 bar, and the embossing time is 2-5 minutes.

The present invention directly uses biological surface structures with special functions existing in nature as nanoimprint templates to prepare nanostructures, avoids the complicated process of conventional template preparation, and realizes the replication of biological surface nanostructures and the imitation of special functions; at the same time, the biological surface The structure forms a layer of natural anti-adhesive layer during the growth process, and using it as a template can further simplify the process, reduce costs, and improve the competitiveness of nanoimprint technology; and the biological template used in the present invention can be imprinted multiple times, repeated Use; this technology can also realize the preparation of large-area nanostructures.

Description of drawings

Figure 1 is an electron micrograph of the nanostructure on the surface of a cicada wing.

Fig. 2 is a process flow diagram of the bio-template nanoimprinting method.

Fig. 3 is an electron micrograph of the negative nanostructure obtained on the surface of the imprinting glue after imprinting the biological template.

In the picture:

1-Silicon wafer 2-Imprint glue 3-Biological template

Detailed ways

Example 1

(1) Adult cicada wings were ultrasonically cleaned in acetone for 5 minutes, then ultrasonically cleaned in ultrapure water for 2 minutes, and placed in air to dry naturally.

(2) Spin-coat the embossing adhesive PMMA on the surface of the silicon wafer after cleaning, and bake and dry at 170°C for 30 minutes;

(3) Place the cleaned and dried cicada wings on the surface of the imprinting plastic PMMA, and cover a silicon wafer of the same size on the surface of the biological template, and then put the sample into the nanoimprinting equipment for imprinting at 190°C and 40bar After 3 minutes, the biological template was separated from the imprinting glue, and a negative structure corresponding to the biological template was obtained on the surface of the imprinting glue, as shown in FIG. 3 .

Example 2

(1) Adult cicada wings were ultrasonically cleaned in acetone for 5 minutes, then ultrasonically cleaned in ultrapure water for 2 minutes, and placed in air to dry naturally.

(2) Spin-coat the embossing adhesive PMMA on the surface of the silicon wafer after cleaning, and bake and dry at 160°C for 55 minutes;

(3) Place the cleaned and dried cicada wings on the surface of the imprinting rubber, and cover a silicon wafer of the same size on the surface of the biological template, and then put the sample into the nanoimprinting equipment and imprint at 150°C and 55bar for 5min After the biological template is separated from the imprinting glue, a negative structure corresponding to the biological template is obtained on the surface of the imprinting glue.

Example 3

(1) Adult cicada wings were ultrasonically cleaned in acetone for 5 minutes, then ultrasonically cleaned in ultrapure water for 2 minutes, and placed in air to dry naturally.

(2) Spin-coat the embossing adhesive PMMA on the surface of the silicon wafer after cleaning, and bake and dry at 180°C for 30 minutes;

(3) Place the cleaned and dried cicada wings on the surface of the imprinting glue, and cover a silicon wafer of the same size on the surface of the biological template, then put the sample into the nanoimprinting equipment and imprint for 2 minutes at 170°C and 45bar After the biological template is separated from the imprinting glue, a negative structure corresponding to the biological template is obtained on the surface of the imprinting glue.

Claims (6)

1. A nanoimprint method, comprising the steps of: (1) Apply a layer of embossing glue on the surface of a silicon wafer and dry it; (2) Using the biological surface nanostructure that exists in nature as a template, place the side of the template with the nanostructure downward on the surface of the imprinting rubber, and cover another silicon chip on the surface of the template; (3) Putting it into a nano-imprinting device for imprinting under heating and pressure conditions; (4) After the mold is released, a negative structure corresponding to the nanostructure of the biological surface is obtained on the surface of the imprinting rubber. 2. The method according to claim 1, wherein the embossing glue is a thermoplastic organic polymer. 3. The method of claim 2, wherein the thermoplastic organic polymer is polymethyl methacrylate. 4. The method according to claim 3, characterized in that: said step (1) is to spin-coat polymethyl methacrylate on the surface of the silicon wafer and then bake and dry at 160-180° C. for 30-60 minutes. 5. The method according to claim 1, characterized in that: the biological surface nanostructures are photonic crystals on the surface of compound eyes or wings of insects. 6. The method according to claim 1, characterized in that the embossing temperature is 150-220° C., the pressure is 40-55 bar, and the embossing time is 2-5 minutes.

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