NANOSTRUCTURE FORMATION DEVICE USING MICROWAVES

Abstract

The present invention relates to a nanostructure formation device using microwaves and, more specifically, to a novel structure of a nanostructure formation device using microwaves, the device being capable of introducing a solution process factor to a conventional nanostructure formation device using microwaves, so as to stably manufacture a nanostructure by using a microwave while consistently maintaining the concentration of a formation solution and the process conditions for it when the nanostructure is formed through a solution process.

Description

BACKGROUND OF THE INVENTION

Field of the Invention

[0001] The present invention relates to a nanostructure formation device using microwaves and, more specifically, to a novel structure of a nanostructure formation device using microwaves, the device being capable of introducing a solution process factor to a conventional nanostructure formation device using microwaves, so as to stably manufacture a nanostructure by using a microwave while consistently maintaining the concentration of a formation solution and the process conditions for it when the nanostructure is formed through a solution process.

Related Art

[0002] Ongoing research is currently being conducted to make semiconductor devices, optical devices, and memory devices by using nanomaterials' unique electrical, optical, and magnetic properties. To construct a device using nanomaterials, it is essential to employ a technology for growing nanomaterials where they are needed.

[0003] Conventionally, a nanostructure of such a device was made using a top-down method, in which a semiconductor thin film is grown and then etched to leave a structure where it is needed. However, etching the semiconductor thin film with this method cannot avoid physical and chemical damage to the deposited material caused by the process. This critical problem with the conventional process serves as a hindrance to making active optical devices such as lasers.

[0004] As alternatives to this approach, bottom-up methods such as solution reaction and electrochemical deposition reaction are being used to form nanostructures on a substrate. Methods for forming nano thin-films and nanostructures from the bottom up to form thin films of nanomaterials on a wafer include frame hydrolysis deposition (FHD), chemical vapor deposition (CVD), modified chemical vapor deposition (MCVD), physical vapor deposition (PVD), sputtering, e-beam evaporation deposition, spin coating, and plasma surface treatment using microwaves.

[0005] Methods for forming nanostructures include atomic layer deposition (ALD), which involves synthesis in a vacuum atmosphere, and metal organic chemical vapor deposition (MOCVD). These methods allow for uniform and stable growth of nanoparticles. However, the vapor deposition methods require expensive systems and complex process steps, and the ALD and MOCVD processes have stability problems because metal organic sources, which are toxic and pyrophoric, are mainly used as precursors.

[0006] Besides, hydrothermal synthesis, which involves synthesis in a solution, electrochemical deposition, chemical bath deposition (CBD), etc. may be used. These methods are advantageous in that the process is simple and costs low compared to the aforementioned vacuum process, allows for easy large-area deposition, and is relatively free from environmental pollution and safety issues.

[0007] In addition, plasma surface treatment using microwaves is increasingly used thanks to its short processing time, the ease of installation, its low installation cost, and its efficiency and economic advantages.

[0008] FIG. 1 shows a conventional process of forming a nanostructure using microwaves. In the conventional process of forming a nanostructure using microwaves, the surface 5 of a processing object is processed by a microwave generator 7 and an electrically conductive target 3. The microwave generator 7 includes a chamber 1. A magnetron, which generates microwaves 2, is mounted at one side of the chamber 1, and a table 6 for the target 3 and the processing object 4 to sit on is mounted in the chamber 1. Microwaves 2 are distributed within the chamber 1 and emitted to the target 3 by the operation of a stirrer 18. The target 3 may be composed of metal, carbon, etc., for example.

[0009] However, deposition methods involving such a solution process have difficulties in producing uniform materials due to changes in concentration and reaction conditions caused by the evaporation of a reaction solution during a reaction process.

[0010] Accordingly, there is a need to develop a novel processing device that allows for the development of organic and inorganic materials based on a solution process that shows high reproducibility while keeping the concentration of the reaction solution constant and that is simple and costs low, in order to make up for the problems occurring in the conventional solution process.

SUMMARY OF THE INVENTION

[0011] The present invention has been made in an effort to provide a nanostructure formation device using microwaves that enables supply of a solution in real time by introducing a solution process factor to a conventional nanostructure formation device using microwaves and allows for the manufacture of stable materials by minimizing changes in concentration of the solution caused by the evaporation of the solution during the process.

[0012] The present invention provides a nanostructure formation device using microwaves, the device including: a chamber; a microwave generator mounted within the chamber; and a reaction container part contained in the chamber including a reaction solution and a substrate.

[0013] FIG. 2 shows a nanostructure formation device using microwaves according to an exemplary embodiment of the present invention. As shown in FIG. 2, the nanostructure formation device using microwaves according to an exemplary embodiment of the present invention includes: a chamber 10; a microwave generator 20 mounted within the chamber; and a reaction container part including a reaction container 30 for containing a reaction solution and the substrate 40.

[0014] In the nanostructure formation device using microwaves according to the present invention, the microwave generator 20 includes a magnetron that generates microwaves, and the microwaves generated by the operation of the magnetron form a microwave field within the chamber. In the nanostructure formation device using microwaves according to the present invention, microwaves 20 for heating the substrate 40 immersed in a solution preferably have a frequency of 2.45 GHz and an intensity of 2 kW or less.

[0015] The nanostructure formation device using microwaves according to the present invention may further include a reaction solution circulator for circulating a reaction solution from a reaction solution reservoir outside the chamber to a reaction container inside the chamber. In the nanostructure formation device using microwaves according to the present invention, the reaction solution circulator may further include an actuating pump.

[0016] FIG. 3 shows a nanostructure formation device using microwaves according to another exemplary embodiment of the present invention. As shown in FIG. 3, the nanostructure formation device using microwaves according to an exemplary embodiment of the present invention further includes a reaction solution circulator including a reaction solution inlet 53 and a reaction solution outlet 52', that is connected into the chamber to circulate a reaction solution from a reaction solution 60' reservoir outside the chamber to the reaction container inside the chamber, and a metering pump 51.

[0017] The reaction solution circulator 50 is mounted outside the chamber, and performs a circulation function to keep the concentration of the reaction solution in the reaction container constant. Also, the metering pump 51 enables the formation of nanostructures on a large-area substrate by supplying a large quantity of reaction solution into the chamber.

[0018] In the nanostructure formation device using microwaves according to the present invention, the reaction solution circulator 50 includes a reaction solution inlet pipe and a reaction solution outlet pipe that are connected to the outside of the chamber.

[0019] In the nanostructure formation device using microwaves according to the present invention, the reaction solution inlet pipe and the reaction solution outlet pipe are formed of an outer metal pipe and an inner Teflon pipe. The reaction solution inlet pipe and the reaction solution outlet pipe may prevent a reaction from proceeding before the reaction solution reaches the substrate by inserting the Teflon pipe into the outer metal pipe to allow the outer metal pipe to stop microwaves emitted from inside from reaching the inner Teflon pipe.

[0020] In the nanostructure formation device using microwaves according to the present invention, the reaction container part 300 includes an upper reaction container 310, a substrate 40, and a lower reaction container 320 that are sequentially stacked in a disassemblable or assemblable state, wherein the portion where the bottom of the upper reaction container 310 adjoins the substrate 40 includes an elastic body 330. In the nanostructure formation device using microwaves according to the present invention, the upper reaction container 310 includes: a vertical portion 312 having a vertical height to contain a reaction solution; and a tapered sloping portion 311 formed above the vertical portion 312.

[0021] The nanostructure formation device using microwaves according to the present invention may include a plurality of reaction containers for containing the reaction solution.

[0022] FIGS. 4 and 5 show a nanostructure formation device using microwaves according to another exemplary embodiment of the present invention. As shown in FIGS. 4 and 5, the nanostructure formation device using microwaves according to an exemplary embodiment of the present invention further includes a plurality of reaction containers 30 and 31 within the chamber, for containing the reaction solution. Preferably, the nanostructure formation device using microwaves may further include an inner reaction solution circulator 70 for circulating a reaction solution between each reaction container.

[0023] The nanostructure formation device using microwaves according to the present invention further includes an inner reaction solution circulator 70 for circulating a reaction solution between the plurality of reaction containers.

[0024] In the nanostructure formation device using microwaves according to the present invention, the reaction container part 300 may further include a heating means for heating the substrate 40 included therein. In the nanostructure formation device using microwaves according to the present invention, the heating means is not specifically limited.

[0025] The nanostructure formation device using microwaves according to the present invention may further include a rotating plate for rotating the reaction container part 300.

[0026] FIG. 6 shows a nanostructure formation device using microwaves according to another exemplary embodiment of the present invention. As shown in FIG. 6, the nanostructure formation device using microwaves according to an exemplary embodiment of the present invention further includes a stirrer 18, and the microwaves 20 may be distributed within the chamber 10 by the operation of the stirrer 18.

[0027] The nanostructure formation device using microwaves according to the present invention allows for the manufacture of stable materials by consistently maintaining the concentration of a reaction solution and the process conditions for it when thin-film formation, surface treatment, and nanostructure manufacture, and chemical bath deposition are performed by using microwaves.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] FIG. 1 is a schematic view of the inside of a chamber of a conventional nanostructure formation device using microwaves.

[0029] FIGS. 2 through 6 are schematic views of the inside of a chamber of a nanostructure formation device using microwaves according to the present invention.

[0030] FIG. 7 is a schematic view of the front part of the nanostructure formation device using microwaves according to the present invention.

[0031] FIG. 8 is a schematic view of a solution inlet pipe and solution outlet pipe of the nanostructure formation device using microwaves according to the present invention.

[0032] (a) of FIG. 9 is a schematic view showing a cross-section of a reaction container part of the nanostructure formation device using microwaves according to the present invention, and (b) of FIG. 9 shows the real appearance of the reaction container part. (b-1) is top plan exploded view and bottom exploded view of the reaction container part, and (b-2) is a top plan view, perspective view, and bottom perspective view of the reaction container part.

[0033] FIGS. 10 to 11 are SEM analysis images of ZnO nanorods synthesized by using the nanostructure formation device using microwaves according to the present invention and ZnO nanorods synthesized by traditional synthesis methods.

[0034] (a) of FIG. 10 is an SEM analysis image of ZnO nanorods synthesized by using the nanostructure formation device using microwaves according to the present invention, and (b) and (c) are SEM analysis images of ZnO nanorods synthesized by a traditional hydrothermal synthesis method, and (a) of FIG. 11 is an SEM analysis image of ZnO nanorods synthesized by a traditional atomic layer deposition method, (b) is an SEM analysis image of ZnO nanorods synthesized by a traditional hydrothermal synthesis method, (c) is an SEM analysis image of ZnO nanorods synthesized by a traditional chemical bath deposition method, and (d) is an SEM analysis image of ZnO nanorods synthesized by a modified chemical bath deposition method.

[0035] FIG. 12 is SEM analysis images of a Fe.sub.2O.sub.3 nano thin film formed by using the nanostructure formation device using microwaves according to the present invention and a Fe.sub.2O.sub.3 nano thin film synthesized by a traditional hydrothermal synthesis method.

[0036] (a) of FIG. 12 is an SEM analysis image of a Fe.sub.2O.sub.3 nano thin film formed by using the nanostructure formation device using microwaves according to the present invention, and (b) is an SEM analysis image of a Fe.sub.2O.sub.3 nano thin film synthesized by a traditional hydrothermal synthesis method.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0037] Hereinafter, an exemplary embodiment of the present invention will be described in more details. However, the present invention is not limited by the following embodiment.

<Exemplary Embodiment> Manufacture of Nanostructure Formation Device Using Microwaves

[0038] FIGS. 7 through 9 show a nanostructure formation device using microwaves that is manufactured according to an exemplary embodiment of the present invention.

[0039] As shown in FIG. 7, the nanostructure formation device using microwaves that is manufactured according to an exemplary embodiment of the present invention includes a chamber 100, and a microwave feeder 110 and a temperature controller 120 that are formed outside the chamber.

[0040] Moreover, as shown in FIG. 8, the nanostructure formation device using microwaves that is manufactured according to an exemplary embodiment of the present invention includes a reaction solution inlet pipe 52' and a reaction solution outlet pipe 53 that are connected to the outside of the chamber.

[0041] FIG. 9 shows a reaction container part 300 used in the nanostructure formation device using microwaves that is manufactured according to an exemplary embodiment of the present invention. As shown in FIG. 9, the reaction container part 300 according to an exemplary embodiment of the present invention includes an upper reaction container 310, a substrate 40, and a lower reaction container 320 that are sequentially stacked in a disassemblable or assemblable state, wherein the portion where the bottom of the upper reaction container 310 adjoins the substrate 40 includes an elastic body 330, and, when the upper reaction container 310, the substrate 40, and the lower reaction container 320 are assembled after being stacked, the elastic body 330 serves as a gasket so that a reaction solution is contained in a vertical portion 312 of the upper reaction container.

[0042] <Test Examples> Formation of Nanostructure Using Nanostructure Formation Device Using Microwaves

Test Example 1: Efficiency (Growth Rate) Analysis of ZnO Nanorod Synthesis Process Using Microwaves

[0043] ZnO nanorods were synthesized by using the nanostructure formation device using microwaves manufactured according to an exemplary embodiment, and ZnO nanorods were synthesized by traditional hydrothermal synthesis methods. The growth rate for each synthesis process was analyzed and the results were tabulated in Table 1 below.

TABLE-US-00001 TABLE 1 Process efficiency of traditional Test Example 1 hydrothermal synthesis methods Process method Microwave-chemical Hydrothermal Hydrothermal bath deposition synthesis synthesis Process 15 mins 12 hours 20 hours time Nanorod App. 453 nm App. 1,500 nm App. 1,000 nm length Nanorod App. 64 nm App. 150 nm App. 40 to 80 nm diameter Growth 1,812 nm/hour 125 nm/hour 50 nm/hour rate

[0044] As shown in Table 1, the ZnO nanorod synthesis process using the nanostructure formation device using microwaves manufactured according to an exemplary embodiment of the present invention showed a large increase in growth rate (nanorods synthesized per hour), in comparison with the ZnO nanorod synthesis processes using traditional hydrothermal synthesis methods, and it can be seen that, in comparison with the traditional hydrothermal synthesis methods, the process time was greatly reduced but the process efficiency was definitely increased.

[0045] The SEM analysis images of the ZnO nanorods synthesized by the aforementioned synthesis processes are depicted in FIG. 10.

Test Example 2: ZnO Nanorods (Full Width at Half Maximum Analysis)

[0046] The full width at half maximum of ZnO nanorods synthesized by using the nanostructure formation device using microwaves manufactured according to an exemplary embodiment, and the full width at half maximum of ZnO nanorods synthesized by traditional synthesis methods such as atomic layer deposition (ALD), hydrothermal synthesis, chemical bath deposition (CBD), and modified chemical bath deposition (M-CBD) was analyzed and the results were tabulated in Table 2 below.

TABLE-US-00002 TABLE 2 Test Example 2 Traditional synthesis methods Process method Microwave-chemical Atomic layer Chemical solution Modified chemical bath deposition deposition Hydrothermal deposition bath deposition (MC-CBD) (ALD) synthesis (CBD) (M-CBD) Full width at 0.15~0.18 0.3~0.4 0.16~0.32 0.35~0.44 0.18~0.21 half maximum

[0047] As shown in Table 2, the ZnO nanorods synthesized by using the nanostructure formation device using microwaves manufactured according to an exemplary embodiment of the present invention showed a decrease in XRD full width at half maximum, in comparison with the ZnO nanorods synthesized by the traditional synthesis methods.

[0048] The decrease in full width at half maximum means that the particles have high crystalline quality. Accordingly, it can be seen that the ZnO nanorods synthesized by using the nanostructure formation device using microwaves manufactured according to an exemplary embodiment of the present invention have excellent crystalline quality.

[0049] The SEM analysis images of the ZnO nanorods synthesized by the aforementioned synthesis processes are depicted in FIG. 11.

Test Example 3: Efficiency (Growth Rate) Analysis of Fe.sub.2O.sub.3 Nano Thin Film Synthesis Process Using Microwaves

[0050] A Fe.sub.2O.sub.3 nano thin film was synthesized by using the nanostructure formation device using microwaves manufactured according to an exemplary embodiment, and a Fe.sub.2O.sub.3 nano thin film was synthesized by traditional hydrothermal synthesis methods. The growth rate for each synthesis process was analyzed and the results were tabulated in Table 3 below.

TABLE-US-00003 TABLE 3 Process efficiency of traditional hydrothermal Test Example 3 synthesis methods Process method Microwave-chemical Hydrothermal Hydrothermal Hydrothermal bath deposition synthesis synthesis synthesis Process time 10 mins 4 to 24 hours 2 hours 12 hours Thin film thickness 40 nm 120 nm 100 nm 10 nm Growth rate 2,400 nm/hour 29.9 nm/hour 50.04 nm/hour 0.83 nm/hour

[0051] As shown in Table 1, the Fe.sub.2O.sub.3 nano thin film synthesis process using the nanostructure formation device using microwaves manufactured according to an exemplary embodiment of the present invention showed a large increase in growth rate (nanorods synthesized per hour), in comparison with the Fe.sub.2O.sub.3 nano thin film synthesis processes using traditional hydrothermal synthesis methods, and it can be seen that, in comparison with the traditional hydrothermal synthesis methods, the process time was greatly reduced but the process efficiency was definitely increased.

[0052] The SEM analysis images of the Fe.sub.2O.sub.3 nano thin films synthesized by the aforementioned synthesis processes are depicted in FIG. 12.

[0053] The nanostructure formation device using microwaves according to the present invention allows for the manufacture of stable materials by consistently maintaining the concentration of a reaction solution and the process conditions for it when thin-film formation, surface treatment, and nanostructure manufacture, and chemical bath deposition are performed by using microwaves.

Claims

1. A nanostructure formation device using microwaves, the device comprising: a chamber; a microwave generator mounted within the chamber; and a reaction container part contained in the chamber comprising a reaction solution and a substrate.

2. The nanostructure formation device of claim 1, further comprising a reaction solution circulator for circulating a reaction solution from a reaction solution reservoir outside the chamber to a reaction container inside the chamber.

3. The nanostructure formation device of claim 2, wherein the reaction solution circulator comprises a reaction solution inlet and a reaction solution outlet.

4. The nanostructure formation device of claim 3, wherein the reaction solution circulator further comprises an actuating pump.

5. The nanostructure formation device of claim 3, wherein the reaction solution circulator comprises a reaction solution inlet pipe and a reaction solution outlet pipe that are connected to the outside of the chamber.

6. The nanostructure formation device of claim 5, wherein the reaction solution inlet pipe and the reaction solution outlet pipe are fainted of double pipes consisting of an outer metal pipe and an inner Teflon pipe.

7. The nanostructure formation device of claim 1, wherein the reaction container part comprises an upper reaction container, a substrate, and a lower reaction container that are sequentially stacked in a disassemblable or assemblable state, wherein the portion where the bottom of the upper reaction container adjoins the substrate comprises an elastic body.

8. The nanostructure formation device of claim 7, wherein the upper reaction container comprises: a vertical portion having a vertical height to contain a reaction solution; and a tapered sloping portion formed above the vertical portion.

9. The nanostructure formation device of claim 1, comprising a plurality of reaction container parts within the chamber.

10. The nanostructure formation device of claim 9, further comprising an inner reaction solution circulator for circulating a reaction solution between the plurality of reaction container parts.

11. The nanostructure formation device of claim 1, comprising a microwave feeder and a temperature controller that are formed outside the chamber.