CN103227102B - A kind of graphical nano-particles self assemble manufacture method - Google Patents

Abstract

The invention relates to a patterned nanoparticle self-assembly manufacturing method, the steps of which include: using a single-sided polished single-crystal silicon substrate, and depositing a layer of parylene film on the surface of the silicon substrate by chemical vapor deposition; Through the traditional photolithography method, the required photoresist mask pattern is made on the surface of the silicon substrate; the exposed parylene film is etched by the oxygen plasma etching method; the silicon substrate is processed by a diamond scribing machine. Scribing; use acetone to remove the photoresist on the surface of the silicon substrate; soak the silicon substrate after removing the photoresist in a mixture of concentrated sulfuric acid and hydrogen peroxide, take it out and clean it with deionized water; take a certain amount to prepare Drop the suspension of nanoparticles into a container containing ethanol, mix the two liquids evenly and slowly pour them into a petri dish filled with deionized water; completely soak the obtained silicon substrate in the petri dish After the liquid was taken out, it was placed in another petri dish, and placed horizontally in a dry box, and after natural evaporation at room temperature, a silicon substrate with patterned nanoparticle self-assembly was obtained.

Description

A patterned nanoparticle self-assembly manufacturing method

technical field

The invention relates to a method for manufacturing patterned nanoparticle self-assembly, in particular to a method for preparing a hydrophilic-hydrophobic silicon substrate to assist nanoparticle self-assembly by utilizing the self-assembly phenomenon induced by nanoparticle evaporation.

Background technique

Self-assembly (self-assembly) refers to the process in which structural units such as molecules and nanoparticles spontaneously associate into thermodynamically stable, structurally determined, and special-performance aggregates through non-covalent bonds under equilibrium conditions. The biggest feature of self-assembly is that once the self-assembly process starts, it will automatically proceed to a certain expected end point, and the structural units such as molecules will be automatically arranged into an orderly pattern, and no external force is required even to form a complex functional system. Self-assembly can form monolayers, membranes, vesicles, micelles, microtubules, small rods and more complex organic-metallic, organic-inorganic, biological-abiotic complexes, etc., and its diversity exceeds that prepared by other methods s material. There are many methods for self-assembly and arrangement of nanoparticles, and the main methods are: dip coating, spin coating, electrophoretic deposition, and evaporative self-assembly.

During evaporative self-assembly, soak the properly treated substrate in the nanoparticle suspension (or drop the suspension on the surface of the substrate), control the temperature, humidity, gas flow rate, etc. of the surrounding environment, and make the suspension Evaporate at a certain speed. When the thickness of the liquid surface is close to or smaller than the diameter of the nanoparticles, the nanoparticles will gradually precipitate out, and factors such as surface tension and van der Waals force them to be fixed on the substrate surface and arranged closely, so that regular and ordered nanoparticles with special structures can be obtained on the substrate. array. Compared with other self-assembly and arrangement methods, the evaporative self-assembly method has significant advantages in operability and regularity of arrangement results. However, since the substrate used is a single-crystal silicon wafer with single-sided polishing and no other structures on the surface, the prepared nano-particle close-packed structure is distributed on the entire substrate surface without specific patterns. Therefore, this self-assembly method is less controllable, difficult to pattern, and has limited applicability.

Contents of the invention

In view of the above problems, the object of the present invention is to improve the controllability of the nanoparticle self-assembly process and realize patterned arrangement, and propose a hydrophilic and hydrophobic silicon substrate-assisted nanoparticle self-assembly manufacturing method.

In order to achieve the above object, the present invention adopts the following technical solutions: a patterned nanoparticle self-assembly manufacturing method, which includes the following steps: 1) using a 4-inch single-sided polished single-crystal silicon substrate, through the chemical vapor deposition method on the silicon Deposit a layer of parylene film on the surface of the substrate; 2) Make the required photoresist mask pattern on the surface of the silicon substrate by traditional photolithography; 3) Use the oxygen plasma etching method to etch Bare parylene film; 4) Scribing the silicon substrate with a diamond dicing machine; 5) Using acetone to remove the photoresist on the surface of the silicon substrate; 6) Putting the silicon substrate at a temperature of 120°C Soak in the mixture of concentrated sulfuric acid and hydrogen peroxide for 10 minutes, take it out and wash it with deionized water for 5 to 10 times; 7) Take 10 to 15uL of the prepared nanoparticle suspension and drop it into a container containing 1mL of ethanol , mix the two liquids evenly and slowly pour them into a petri dish filled with deionized water; 8) After the silicon substrate obtained in step 6) is completely immersed in the liquid in the petri dish, take it out and place it in another petri dish placed in a drying box horizontally, and evaporated naturally at room temperature to obtain a silicon substrate with patterned nanoparticles.

In the step 2), the thickness of the photoresist mask is 1.0 μm˜2.0 μm.

In the step 3), the thickness of the parylene film is 50nm-150nm.

In the step 6), the mass fraction of hydrogen peroxide is 40%, and the volume ratio of concentrated sulfuric acid and hydrogen peroxide is 4:1.

The nanoparticle suspension in step 7) is polystyrene nanoparticle suspension.

The nanoparticle suspension in the step 7) is a silica nanoparticle suspension.

In the step 8), nitrogen gas is passed into the drying box to accelerate evaporation.

Due to the adoption of the above technical scheme, the present invention has the following advantages: 1. The present invention uses the difference in hydrophilicity and hydrophobicity of the silicon substrate surface to position the self-assembly of nanoparticles in a limited area, which solves the problem of poor controllability and difficulty in patterning of self-assembly of nanoparticles. Compared with other self-assembly methods, the present invention has obvious advantages in operability, controllability and regularity of arrangement results, especially in the preparation of patterned regular dense Its role in arranging nanoparticle arrays is irreplaceable. 2. Both the oxygen plasma dry degumming technology and the conventional photolithography technology used in the present invention are derived from the microelectronics manufacturing technology, so batch and parallel processing can be realized conveniently. 3. The present invention adopts the evaporation self-assembly method, and the operation is simple. The present invention can be widely used in the fields of optoelectronics, biopharmaceuticals, chemical industry, etc., and has an unpredictable promotion effect on some fields.

Description of drawings

Fig. 1 is the schematic diagram of growing parylene film on the substrate of the present invention

Fig. 2 is that the present invention defines photoresist mask pattern by traditional photolithography; Fig. 2 a is the schematic diagram of the present invention coated with photoresist mask; Fig. 2 b is the schematic diagram after photolithography photoresist mask by traditional photolithography

Fig. 3 is the schematic diagram of the present invention after etching parylene film with oxygen plasma

Fig. 4 is a schematic diagram of a patterned substrate with hydrophilic difference obtained after acetone degumming of the present invention

Fig. 5 is a schematic diagram of evaporation self-assembly on the basis of a patterned substrate in the present invention

Figure 6 is a schematic diagram of the self-assembly of patterned nanoparticles finally realized by the present invention

Figure 7 is a schematic top view of Figure 6

Fig. 8 is an electron microscope rendering of the result of self-assembly arrangement of patterned nanoparticles obtained by the method of the present invention; Fig. 8a is an electron microscope rendering of the result of self-assembly arrangement of nanoparticles of the present invention; Fig. 8b is a partially enlarged view of Fig. 8a picture

detailed description

The present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.

1) As shown in Figure 1, prepare a 4-inch single-sided polished single-crystal silicon substrate 1, and deposit a layer of parylene (Parylene) on the surface of the silicon substrate 1 by chemical vapor deposition (Chemical Vapor Deposition-CVD) method Film 2.

2) As shown in Fig. 2, by traditional photolithography method, a photoresist 3 mask is spin-coated on the surface of silicon substrate 1 (as shown in Fig. The production sequence of development is to form the required photoresist 3 mask pattern on the surface of the silicon substrate 1 (as shown in Figure 2b);

Wherein, the mask thickness of the photoresist 3 is 1.0 μm˜2.0 μm.

3) As shown in FIG. 3 , the exposed parylene film 2 is etched by an oxygen plasma etching method.

Wherein, when the oxygen plasma stripping machine adopted in the present invention etches the photoresist 3 mask and the parylene film 2, the etching speed is basically equal, about 3nm/s; and the photoresist 3 mask thickness Much larger than the parylene film 2, so when the exposed parylene film 2 is completely removed, the photoresist 3 mask still exists on the surface of the silicon substrate 1 with the parylene film 2.

Wherein, the thickness of the parylene film 2 is 50nm-150nm.

4) Using a diamond dicing machine to scribe the silicon substrate 1 with a step distance of 1cm×1cm;

5) As shown in Figure 4, remove the photoresist 3 mask on the surface of the silicon substrate 1 from the silicon substrate 1 obtained in step 3) with the photoresist 3 mask and the parylene film 2 using acetone , to obtain a silicon substrate 1 with a patterned surface with a difference in hydrophilicity and hydrophobicity.

Wherein, the surface of the exposed silicon substrate 1 is activated by oxygen plasma and is very hydrophilic, while the surface of the parylene film 2 protected by the photoresist 3 is relatively hydrophobic.

6) Routine cleaning, soaking the silicon substrate 1 in a mixture of concentrated sulfuric acid and hydrogen peroxide at 120°C for 10 minutes, taking it out and cleaning it with deionized water for 5 to 10 times;

Among them, the mass fraction of hydrogen peroxide in the mixed liquid is 40%, and the volume ratio of concentrated sulfuric acid and hydrogen peroxide is 4:1.

7) Configure the nanoparticle suspension 4, use a pipette with a volume range of 20uL to 200uL, take 10 to 15uL of the prepared nanoparticle suspension 4, drop it into a container containing 1mL of ethanol, and mix the two liquids Mix well and pour slowly into a Petri dish already filled with deionized water.

Wherein, due to the presence of ethanol in the petri dish, the nanoparticle suspension 4 will be rapidly dispersed in deionized water, so that the nanoparticles 5 can be evenly arranged on the surface of the silicon substrate 1 after evaporation;

Wherein, the nanoparticle suspension 4 is obtained by diluting the original solution of the nanoparticle with deionized water, and the original solution of the nanoparticle is a commercially available product; the amount of deionized water in the nanoparticle suspension 4 is based on the original solution of the nanoparticle and The concentration of the suspension that needs to be prepared is calculated. In order to achieve a single-layer dense arrangement of nanoparticles, the concentration of the prepared nanoparticle suspension is generally about 1×10 ¹² to 8×10 per milliliter of suspension. ¹² nanoparticles; the concentration here is only for reference, and repeated trials are required in actual operation to find the optimal concentration range. Nanoparticle suspension 4 is suitable for silica nanoparticle suspension and polystyrene nanoparticle suspension; the nanoparticle suspension covers a variety of nanoparticle diameters, ranging from 250nm to 940nm.

8) Soak the silicon substrate 1 cleaned in step 6) in the nanoparticle suspension 4 prepared in step 7) at room temperature, and wait until the silicon substrate 1 is completely soaked in the nanoparticle suspension 4. can be taken out. As shown in Figure 5, due to the difference in hydrophilicity and hydrophobicity, the nanoparticle suspension 4 will be confined to the hydrophilic region on the surface of the silicon substrate 1, while the surface of the relatively hydrophobic parylene film 2 has no nanoparticle suspension. Liquid 4 is attached; place the treated silicon substrate 1 horizontally in another petri dish, put the petri dish horizontally into a drying oven, and evaporate naturally at room temperature, and the evaporation can be completed within 24 hours.

Wherein, the drying box can prevent pollutants in the air from contaminating the petri dish; in addition, the nanoparticle suspension 4 can also be accelerated to evaporate by nitrogen.

As shown in Figure 6 and Figure 7, after the nanoparticle suspension 4 is completely evaporated, the silicon substrate 1 is taken out; under the action of factors such as surface tension and van der Waals force, the nanoparticles 5 are fixed in an orderly manner on the surface with hydrophilic properties. on the surface of the silicon substrate 1 (as shown in FIG. 8 ).

The present invention solves the problem of positioning and arrangement of self-assembly of nanoparticles 5 within a limited area, that is, obtains a certain structure at a specific position, proposes and realizes a manufacturing method for self-assembly of nanoparticles 5 assisted by hydrophilic and hydrophobic silicon substrate 1, and is very good The problem of poor controllability and difficult patterning of nanoparticle self-assembly is solved, and the application range of self-assembly is improved.

Above-mentioned each embodiment is only for illustrating the present invention, wherein the structure of each component, connection mode etc. all can be changed to some extent, every equivalent conversion and improvement carried out on the basis of the technical solution of the present invention, all should not be excluded from the present invention. outside the scope of protection of the invention.

Claims (8)

1. a graphical nano-particles self assemble manufacture method, it comprises the following steps:

1) adopt 4 inches of single-sided polishing monocrystalline substrate, deposit out one layer of parylene film by chemical gas-phase deposition method in surface of silicon;

2) by conventional photolithographic method, required photoresist mask graph is made in surface of silicon;

3) adopt oxygen plasma etch method, etch exposed parylene film;

4) adopt diamond dicing saw that silicon substrate is carried out scribing;

5) acetone is adopted to remove the photoresist in surface of silicon;

6) by silicon substrate the concentrated sulphuric acid that temperature is 120 DEG C, hydrogen peroxide mixed liquor in soak 10 minutes, after taking-up with deionized water clean 5～10 times;

7) the nano-particle suspension prepared of 10～15uL is taken, it is added dropwise in the container equipped with 1mL ethanol, uniformly and being poured slowly in the culture dish having been loaded with deionized water by two kinds of liquid mixing, the concentration of nano-particle suspension is containing 1 × 10 in every milliliter of suspension¹²～8 × 10¹²Individual nano-particle;

8) by step 6) silicon substrate that obtains be fully immersed in culture dish liquid after, take out and be placed in another culture dish, and level puts into a drying baker, at ambient temperature after natural evaporation, namely obtains the silicon substrate with graphical nano-particle.

2. a kind of graphical nano-particles self assemble manufacture method as claimed in claim 1, it is characterised in that: described step 2) in, photoresist mask thickness is 1.0 μm～2.0 μm.

3. a kind of graphical nano-particles self assemble manufacture method as claimed in claim 1, it is characterised in that: described step 3) in, parylene film thickness is 50nm～150nm.

4. a kind of graphical nano-particles self assemble manufacture method as claimed in claim 2, it is characterised in that: described step 3) in, parylene film thickness is 50nm～150nm.

5. a kind of graphical nano-particles self assemble manufacture method as claimed in claim 1 or 2 or 3 or 4, it is characterised in that: described step 6) in, the mass fraction of hydrogen peroxide is 40%, and the volume ratio of concentrated sulphuric acid and hydrogen peroxide is 4:1.

6. a kind of graphical nano-particles self assemble manufacture method as claimed in claim 1 or 2 or 3 or 4, it is characterised in that: described step 7) in nano-particle suspension be polystyrene nanoparticles suspension.

7. a kind of graphical nano-particles self assemble manufacture method as claimed in claim 1 or 2 or 3 or 4, it is characterised in that: described step 7) in nano-particle suspension be nano SiO 2 particle suspension.

8. a kind of graphical nano-particles self assemble manufacture method as claimed in claim 1 or 2 or 3 or 4, it is characterised in that: described step 8) in, in drying baker, pass into nitrogen accelerate evaporation.