KR101022538B1 - Plasma generator and Plasma Spectroscopy including the same - Google Patents

Abstract

A plasma generator that can improve the reliability of component analysis is disclosed. The plasma generating device is located on a lower plate, a lower plate having a first fluid reservoir in the upper surface, a second fluid reservoir spaced apart from the first fluid reservoir, and a fluid channel located between the fluid reservoirs, and connected to the first fluid reservoir. A first electrode and a first electrode disposed on the lower surface of the upper plate and the lower plate having a first through hole and a second through hole connected to the second fluid reservoir, respectively corresponding to the first fluid reservoir and the second fluid reservoir; It includes two electrodes.

Description

Plasma generator and plasma spectrometer having same {Plasma generator and Plasma Spectroscopy including the same}

The present invention relates to a plasma generating apparatus, and more particularly, to a plasma generating apparatus using a fluid and a plasma spectroscopic analysis apparatus having the same.

Recently, as water pollution is accelerated, devices for analyzing components such as metals included in water pollution have been developed. The component analyzer is based on atomic emission spectroscopy, which generates plasma and analyzes light emitted from the plasma.

Sufficient plasma must be emitted for the component analysis of the metal. However, there has been a difficulty in generating a large amount of plasma in the past.

In addition, conventionally, since a metal electrode for applying a voltage to the liquid electrode is manufactured to be inserted into the liquid electrode, the metal electrode is corroded by the electrochemical reaction between the liquid electrode and the metal electrode and the life of the apparatus is reduced. In addition, since the metal electrode is inserted in the liquid electrode, the reliability of the component analysis is deteriorated due to the plasma inflow of the metal component.

An object of the present invention for solving the above problems is to provide a plasma generating device that can improve the reliability of the component analysis.

Another object of the present invention for solving the above problems is to provide a plasma spectroscopic analysis device that can improve the reliability of the component analysis.

The present invention for achieving the above object of the present invention is a bottom plate having a first fluid reservoir in the upper surface, a second fluid reservoir spaced apart from the first fluid reservoir, and a fluid channel located between the fluid reservoirs, Located on the lower plate and having a first through-hole connected to the first fluid storage chamber, and a second through-hole connected to the second fluid storage chamber and located on the lower surface of the lower plate, the first fluid storage chamber And a first electrode and a second electrode positioned to correspond to the second fluid storage chamber, respectively.

The fluid channel may have a bottleneck area that is narrower in width than the other in part thereof.

The bottleneck area of the fluid channel may be formed by protrusions protruding from the side walls and the bottom of the fluid channel.

The upper or lower plate may be a transparent substrate.

The top plate includes a third through hole connected to the first fluid storage chamber and spaced apart from the first through hole, and a fourth through hole connected to the second fluid storage chamber and spaced apart from the second through hole. The first fluid injection tube may be connected to the through hole or the third through hole, and the second fluid injection tube may be connected to the second through hole or the fourth through hole.

According to another aspect of the present invention, there is provided a bottom plate having a first fluid reservoir, a second fluid reservoir spaced apart from the first fluid reservoir, and a fluid channel located between the fluid reservoirs. And an upper plate disposed on the lower plate and having a first through hole connected to the first fluid storage chamber and a second through hole connected to the second fluid storage chamber, and positioned on a lower surface of the lower plate, wherein the first fluid A plasma generator including a first electrode and a second electrode positioned correspondingly to the storage chamber and the second fluid storage chamber, and an alternating current generator electrically connected to the first electrode and the second electrode, and the plasma generator; Provided is a plasma spectrometer including a spectrometer for detecting the emitted light.

The fluid channel may have a bottleneck area that is narrower in width than the other in part thereof.

The bottleneck area of the fluid channel may be formed by protrusions protruding from the side walls and the bottom of the fluid channel.

The structure of the plasma generator has a simple structure because it does not need an additional device for forming or adjusting the spacing of the electrodes for the ignition of the fluid, and impurities other than the used fluid may not be introduced during the plasma generation. In the analysis, the source of signal noise may be reduced.

In addition, by placing the electrodes on the lower surface of the lower plate, the electrochemical reaction between the electrode and the fluid does not occur, the life of the electrode is long, as well as the plasma inflow of metal components can be blocked to enhance the reliability of the component analysis.

1 shows a bottom plate of a plasma generating apparatus according to an embodiment of the present invention.
2A through 2G are cross-sectional views taken along the cutting line I-I 'of FIG.
3 shows a plan view of 2d.
Figure 4 shows a top plate of the plasma generating apparatus according to an embodiment of the present invention.
5A through 5F are cross-sectional views taken along the cutting line I-I 'of FIG.
6 is an exploded perspective view showing a plasma generating apparatus according to an embodiment of the present invention.
7A to 7C are schematic diagrams showing the principle of plasma generation according to an embodiment of the present invention.
8 is a conceptual diagram illustrating a plasma maintenance principle according to an embodiment of the present invention.
9A to 9D are images showing plasma generated by using a plasma generator according to an embodiment of the present invention.
10 shows a plasma spectrometer according to an embodiment of the present invention.
11 is a graph showing the results of spectroscopic analysis using the plasma generator according to an embodiment of the present invention.
12 is a graph showing the results of spectroscopic analysis using a standard liquid electrode.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments disclosed herein are provided so that the disclosure can be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the thicknesses of layers and regions are exaggerated for clarity. Like numbers refer to like elements throughout.

1 shows a bottom plate of a plasma generating apparatus according to an embodiment of the present invention.

Referring to FIG. 1, the lower plate 110 of the plasma generating apparatus includes a first fluid storage chamber 112, a second fluid storage chamber 114, a fluid channel 116, a first electrode 118, and a second electrode 119. It may include. The first fluid storage chamber 112 is formed in the upper surface of the lower plate 110, and the second fluid storage chamber 114 is spaced apart from the first fluid storage chamber 112 in the upper surface of the lower plate 110. Can be formed.

The fluid channel 116 may be located between the fluid reservoirs 112 and 114. The fluid channel 116 may have a bottleneck region that is narrower in width than another portion in a portion thereof, and the bottleneck region may be formed by a protrusion 212 protruding from the side wall and the bottom of the fluid channel 116. Can be.

The first electrode 118 and the second electrode 119 are formed on the lower surface of the lower plate 110, and may be positioned to correspond to the first fluid storage chamber 112 and the second fluid storage chamber 114, respectively. .

When the electrodes 118 and 119 are formed on the lower surface of the lower plate 110 as described above, since the electrodes 118 and 119 do not come into contact with the fluid, the electrochemical reaction with the fluid does not occur and the lifespan of the electrodes 118 and 119 may be long. In addition, since the plasma of the metal component flowing from the electrode can be blocked, the reliability of the component analysis can be improved.

2A through 2G are cross-sectional views taken along the cutting line II ′ of FIG. 1 according to the process steps, and FIG.

Referring to FIG. 2A, a bottom plate 110 is provided. The lower plate 110 may be a glass substrate or a ceramic substrate.

Referring to FIG. 2B, a hard mask layer 230 is formed on the lower plate 110. The hard mask layer 230 may be formed using sputtering. The hard mask layer 230 may be a metal layer.

Referring to FIG. 2C, a photoresist pattern 240 is formed on the first substrate 110 on which the hard mask layer 230 is formed. The photoresist pattern 240 may include a storage compartment defining pattern 241 and a bottleneck forming pattern 242.

3 and 2D, a hard mask pattern 232 is formed by etching the hard mask layer using the photoresist pattern 240 as a mask. The hard mask layer 230 may be performed using a wet etching method or a dry etching method.

Referring to FIG. 2E, the lower plate 110 is etched using the hard mask patterns 232 as a mask. The lower plate 110 may be etched using an isotropic etching method, specifically, a wet etching method. As a result, the first fluid reservoir 112, the second fluid reservoir 114, and the fluid channel 116 positioned therebetween may be formed in the lower plate 110.

In this case, when the photoresist pattern 240 includes the bottleneck forming pattern 242, a protrusion 212 forming a bottleneck region may be formed in the fluid channel 116. Specifically, in the process of etching the lower plate 110 using the hard mask patterns 232 as a mask, the undercuts formed on both lower sides of the bottleneck forming pattern 242 meet each other to form the fluid channel 116. Underneath, protrusions 212 that are not etched substrate materials may be formed. To this end, the width of the bottleneck forming pattern 242 needs to be properly adjusted.

The etching solution may be a hydrofluoric acid solution or a hydrofluoric acid mixed solution.

Referring to FIG. 2F, the remaining photoresist 240 and the hard mask pattern 232 are removed.

Referring to FIG. 2G, the first electrode 118 and the second electrode 119 are formed on the lower surface of the lower plate 110 formed through the processes of FIGS. 2A to 2F. The electrodes 118 and 119 may be patterned through a lift off method.

Figure 4 shows a top plate of the plasma generating apparatus according to an embodiment of the present invention.

Referring to FIG. 4, the upper plate 120 of the plasma generator may include a first through hole 122 and a second through hole 124.

The first through hole 122 and the second through hole 124 may be connected to the first fluid storage chamber 112 and the second fluid storage chamber 114 of the lower plate 110, respectively.

The through holes 122 and 124 may be an inlet for injecting a fluid into the fluid reservoirs 112 and 114 and a discharge port through which steam escapes.

In addition, the top plate 120 is connected to the first fluid storage chamber 112 and spaced apart from the first through hole 122 and the second through hole 126 and the second fluid storage chamber 114, and the second A fourth through hole 128 spaced apart from the through hole 124 may be further provided.

As described above, the first through hole 122 and the second through hole 124 may further include a third through hole 126 and a fourth through hole 128 to separate and use the fluid inlet and the vapor discharge port. have.

In addition, a first fluid injection tube may be connected to the first through hole 122 or the third through hole 126, and a second fluid injection into the second through hole 124 or the fourth through hole 128 may be performed. The tube can be connected. The fluid injection tubes may easily inject fluids into the fluid reservoirs 112 and 114.

5A through 5F are cross-sectional views taken along the cutting line I-I 'of FIG.

Referring to FIG. 5A, a top plate 120 is provided. The upper plate 120 may be a glass substrate or a ceramic substrate.

Referring to FIG. 5B, a hard mask layer 230 is formed on the second substrate 120. The hard mask layer 230 may be formed using sputtering. The hard mask layer 230 may be a metal layer.

4 and 5C, the photoresist pattern 240 is formed on the first substrate 110 on which the hard mask layer 230 is formed. The photoresist pattern 240 may include photoresist patterns 243 and 244 for forming the first through hole 122 and the second through hole 124.

Referring to FIG. 5D, the hard mask layer 230 is etched using the photoresist pattern 240 as a mask to form a hard mask pattern 232. The hard mask layer 230 may be etched by using a wet etching method or a dry etching method.

Referring to FIG. 5E, the second substrate 120 is etched using the hard mask patterns 232 formed by etching the hard mask layer 230 as a mask. The second substrate 120 may be etched using an isotropic etching method, specifically, a wet etching method. As a result, the first through hole 122 and the second through hole 124 may be formed in the second substrate 120. The etching solution may be a hydrofluoric acid solution or a hydrofluoric acid mixed solution.

If the third through hole 126 and the fourth through hole 128 are to be formed on the second substrate 120 in addition to the first through hole 122 and the second through hole 124, the first through hole 122 and the second through hole 124 may be formed. The third through hole 126 spaced apart from the first through hole 122 and the second through hole 124 by using the same method as the manufacturing method of the through hole 122 and the second through hole 124. The fourth through hole 128 may be further formed.

Referring to FIG. 5F, the remaining photoresist 240 and the hard mask pattern 232 are removed.

6 is an exploded perspective view showing a plasma generating apparatus according to an embodiment of the present invention.

Referring to FIG. 6, the upper plate 120 and the lower plate 110 may be formed by being joined to each other up and down. In the upper plate 120 and the lower plate 110, the first through hole 122 and the second through hole 124 of the upper plate 120 correspond to the first fluid storage chamber 112 and the second fluid storage chamber 114, respectively. Can be bonded so as to.

Bonding of the plates 110 and 120 may be performed by immersing water between the plates 110 and 120 and maintaining the temperature at about 650 ° C. for 1 hour. As described above, the water between the plates 110 and 120 may separate molecules at high temperatures, and hydrogen bonding may occur, and thus the plates 210 and 220 may be bonded to each other.

7A to 7C are schematic diagrams showing the principle of plasma generation according to an embodiment of the present invention. The fluid may be a gas or a liquid, but the embodiment describes a case in which the fluid is a liquid, that is, a liquid filled in the fluid reservoirs and the fluid channel.

Referring to FIG. 7A, an AC voltage is electrically applied to the electrodes 118 and 119 of the plasma generator. The AC voltage may be used in the frequency range of about 1kHz to 1MHz.

The alternating current applied to the electrodes 118 and 119 of FIG. 6 causes an alternating current to be induced in the liquid L inside the fluid reservoirs 112 and 114 of FIG. 6 and inside the fluid channel 116. The width of the narrow shape, that is, the current density is relatively high due to the protrusions 212, the bubble 250 is generated by Joule heating.

Referring to FIG. 7B, the bubble 250 vaporizes liquid due to an alternating voltage applied continuously, and the bubble grows 260.

Referring to FIG. 7C, the bubble 260 grown inside the fluid channel 116 grows until it comes into contact with the side wall of the fluid channel 116 to separate the liquid L. FIG. Since the separated liquid L is continuously applied with an alternating voltage, a potential difference between the liquids is generated and discharged.

8 is a conceptual diagram illustrating a plasma maintenance principle according to an embodiment of the present invention.

Referring to FIG. 8, the steam generated at the same time as the plasma is generated in the fluid channel is generated by the first through hole (122 in FIG. 6) or the third through hole (126 in FIG. 6) and the second through due to temperature and pressure difference. It is drawn out through the sphere 124 (FIG. 6) or the fourth through hole (128 in FIG. 6), and fluid flows along the surface of the fluid reservoirs (112, 114 in FIG. 6) by capillary action. Flock to

The fluid introduced into the fluid channel 116 and the discharged vapor are in equilibrium, and this may be maintained while the fluid remains in the fluid reservoirs 112 and 114 of FIG. 6.

9A to 9D are images showing plasma generated by using a plasma generator according to an embodiment of the present invention.

As a liquid electrode for generating the plasma, a 1% NaCl solution was used. 9A to 9C photograph the plasma generation state at 30 msec intervals, and FIG. 9D photographs the plasma state after 1 sec. The plasma generation state was photographed using a CCD camera.

Referring to FIG. 9A, an image of a fluid channel 116 measured in an initial state before plasma is generated.

Referring to FIG. 9B, as a result of measuring the state after about 30 msec has elapsed, it can be seen that the plasma is generated and ignited.

Referring to FIG. 9C, as a result of measuring the state after about 60 msec has elapsed, it can be seen that the plasma is expanded and formed on the surfaces of both upper and lower ends of the fluid channel 116.

Referring to FIG. 9D, it can be seen that the plasma is stabilized in the fluid channel 116 as a result of measuring the state after about 1 sec has elapsed.

10 shows a plasma spectrometer according to an embodiment of the present invention. The plasma generator described below may be the same as the plasma generator described above.

Referring to FIG. 10, the apparatus for plasma spectroscopy includes a lower plate 110 having a first fluid reservoir 112, the first fluid reservoir 112, a second fluid reservoir 114, and a fluid channel 116. A plasma generating device and an alternating current generating device 130 including a top plate 120 having a first through hole 122 and a second through hole 124, and a first electrode 118 and a second electrode 119; It may include a spectrometer 140. In addition, the plasma spectrometer may further include a controller 150 and a CCD camera 160.

The alternator 130 is electrically connected to the first electrode 118 and the second electrode 119, and applies a voltage to the fluid stored in the fluid reservoirs 112 and 114 from the electrodes 118 and 119. It may be provided to.

The spectrometer 140 may be provided to detect light generated from the plasma generator.

The control device 150 may be a computer, and may output an image stored in the CCD camera 160 on the screen, or control the spectrometer 140 and the CCD camera 160.

Experimental Example : Pb Spectroscopic analysis

11 is a graph showing the results of spectroscopic analysis using the plasma generator according to an embodiment of the present invention.

Fluid is 0.1M HNO ₃ A solution was used, and a solution containing 100 ppm of Pb was mixed and injected into the respective fluid reservoirs through the first fluid injection tube and the second fluid injection tube, and then the AC generator was turned on to apply an AC voltage. It was. In this case, an AC voltage having a frequency of 50 kHz was used.

Referring to FIG. 11, as a result of using a liquid electrode containing 100 ppm of Pb, it can be seen that peaks are detected at wavelengths of 368 nm and 405 nm corresponding to Pb.

In addition, each of OH and H detected at 306 nm and 486 and 656 nm is determined to be detected from HNO ₃ solution, and Na detected at 589 nm is determined to be a material included in the transparent substrate used in the upper or lower plate.

Comparative example Spectroscopic Analysis of Standard Liquid Electrodes

In this comparative example, spectroscopic analysis was performed using the same method as the experimental example except for the following. In this comparative example, 0.1 M HNO ₃ was used as the fluid.

12 is a graph showing the results of spectroscopic analysis using a standard liquid electrode.

Referring to FIG. 12, when 0.1 M HNO ₃ is used, OH and H present in the liquid electrode were detected in the same wavelength band as HNO ₃ and the like, and no peak was detected in the same wavelength band as Pb.

Plasma generators of the above structure are simple because no additional device is needed to vaporize the fluid or to form or control the spacing of the electrodes for initial ignition.

In addition, since the signal noise may be reduced because no additional gas other than the fluid is used in the process of generating the plasma, the materials corresponding to the respective wavelength bands may be equally measured during the reanalysis, as shown in the above experimental and comparative examples. Can be.

Hereinafter, Table 1 shows a metal capable of spectroscopic analysis using a plasma generating apparatus according to an embodiment of the present invention. It is apparent that the metal capable of spectroscopic analysis is not limited to the following metals, and may include metals described below.

element Wavelength (nm) element Wavelength (nm) Al 308.215 Mg 279.079 Sb 206.833 Mn 257.610 As 193.696 Mo 202.030 Ba 455.403 Ni 231.604 Be 313.042 K 766.491 B 249.773 Se 196.026 CD 226.502 Si 288.158 Ca 317.933 Ag 328.068 Cr 267.716 Na 588.995 Co 228.616 Sr 407.771 Cu 324.754 Tl 190.864 Fe 259.940 V 292.402 Li 670.784 Zn 213.856

Referring to Table 1, in addition to Pb presented in the experimental example of the present invention, Al, Sb. By analyzing liquid electrodes containing As, Ba, Be, B, or Cd, spectroscopic analysis of the elements can be derived by comparing the wavelengths of the elements as described above.

Such a plasma generating apparatus can be manufactured in a small size because of its simple structure, and can be used for microscopic and portable spectroscopic analyzers for component detection. That is, by using the plasma generating apparatus according to the present invention, it is possible to quantitatively analyze harmful heavy metals contained in soil, food, river water, drinking water, wastewater, and the like.

The present invention has been described above with reference to the above embodiments, but the present invention is not limited thereto. Those skilled in the art will appreciate that modifications and variations can be made without departing from the spirit and scope of the present invention and that such modifications and variations also fall within the present invention.

110: top plate 120: bottom plate
112: first fluid reservoir 114: second fluid reservoir
116: flow channel 118: the first electrode
119: second electrode 122: first through hole
124: second through hole

Claims (8)

A lower plate having a first fluid reservoir in the upper surface, a second fluid reservoir spaced apart from the first fluid reservoir, and a fluid channel located between the fluid reservoirs;
An upper plate positioned on the lower plate and having a first through hole connected to the first fluid storage chamber and a second through hole connected to the second fluid storage chamber; And
Located on the lower surface of the lower plate, the plasma generating device comprising a first electrode and a second electrode corresponding to the first fluid storage chamber and the second fluid storage chamber, respectively. The method of claim 1,
Wherein said fluid channel has a bottleneck region that is narrower in width than another in its portion. The method of claim 2,
And the bottleneck region is formed by protrusions protruding from sidewalls and bottoms of the fluid channel. The method of claim 1,
The upper plate or the lower plate is a plasma generating apparatus. The method of claim 1,
The top plate includes a third through hole connected to the first fluid storage chamber and spaced apart from the first through hole, and a fourth through hole connected to the second fluid storage chamber and spaced apart from the second through hole,
And a first fluid injection tube connected to the first through hole or a third through hole, and a second fluid injection tube connected to the second through hole or the fourth through hole. A lower plate having a first fluid reservoir in the upper surface, a second fluid reservoir spaced apart from the first fluid reservoir, and a fluid channel located between the fluid reservoirs; An upper plate positioned on the lower plate and having a first through hole connected to the first fluid storage chamber and a second through hole connected to the second fluid storage chamber; And a first electrode and a second electrode positioned on a lower surface of the lower plate, the first electrode and the second electrode corresponding to the first fluid storage chamber and the second fluid storage chamber, respectively.
An alternating current generating device electrically connected to the first electrode and the second electrode; And
And a spectrometer for detecting light generated from the plasma generator. The method according to claim 6,
And the fluid channel has a bottleneck region that is narrower than the other portion in a portion thereof. The method of claim 7, wherein
The bottleneck region is formed by a projection protruding from the side wall and the bottom of the fluid channel.

Images