KR20110046055A - Apparatus and method for plasma ion implantation of argentum element to improve anti-microbial property - Google Patents

Abstract

PURPOSE: A device and method for silver element plasma ion injection capable of the improvement of anti-microbial property are provided to generate high density silver plasma by applying very high electricity at the moment when the pulse is applied. CONSTITUTION: A device for silver element plasma ion injection comprises a vacuum chamber(110), a magnetron deposition(120), a sample mount(130), a first power source feeding member and a second power source feeding member. The vacuum chamber keeps the inside under vacuum condition. The magnetron deposition performs thin film deposition. The sample mount is installed in the location facing the deposition within the vacuum chamber and mount a simple. The first power source feeding member applies the pulse direct current electricity in the deposition. The second power source feeding member accelerates the plasma ions of the elemental silver towards sample.

Description

Silver element plasma ion implantation apparatus and method for improving the antimicrobial property of the material surface {APPARATUS AND METHOD FOR PLASMA ION IMPLANTATION OF ARGENTUM ELEMENT TO IMPROVE ANTI-MICROBIAL PROPERTY}

The present invention relates to a silver element plasma ion implantation method and apparatus for improving the antimicrobial properties of the material surface.

From ancient times, silver has been widely known for its antibacterial ability. Silver ions can bind to the cell membranes of bacteria and destroy the cells, thereby killing the bacteria. Therefore, various application fields using the antibacterial effect of silver have been developed, and in particular, the field for improving the antibacterial characteristics of medical devices or household goods has been in the spotlight.

As an example, a fiber using the antibacterial property of silver is disclosed in Korean Patent No. 0876111. In this document, fibers coated with silver nanoparticles are prepared by adsorbing and drying a solution containing silver particles of small size. As another example, a plastic material using the antibacterial property of silver is disclosed in Korean Patent No. 0767148. In this document, a plastic resin containing silver particles is prepared by mixing a solution containing silver particles into a resin solution. As another example, a metal material using antibacterial properties of silver is disclosed in Korean Patent No. 0699224. In this document, metal materials are produced by coating silver on their surfaces.

However, the above examples overlook the problem that silver particles are weak in mechanical wear and have low adhesion to materials. Due to the properties of these silver particles, the silver particles adsorbed or coated on fibers, plastics, and metals are lost in a short time so that the original antimicrobial properties cannot be retained for a long time. In addition, despite the fact that the antimicrobial properties are required on the surface of the plastic material, there is a problem that a large amount of silver particles should be mixed in the resin solution.

Another method using the antimicrobial properties of silver is disclosed in US Pat. No. 5520664. The prior art is to accelerate the implantation of silver ions with high energy (tens of tens to hundreds of KeV) onto the surface of the material. According to the prior art, it is possible to inject silver ions up to thousands of microns or less of the surface of the material and form a gentle composition change layer. Therefore, the prior art can maintain the antimicrobial properties continuously without the loss of silver particles as in the above-described example.

The conventional ion implantation technology has many advantages, but the ion implantation technology is very limited to be used in other material fields except the semiconductor field. The conventional ion implantation apparatus is a device developed for doping impurities into a semiconductor wafer, which is a planar sample. The ion implantation apparatus extracts ions from an ion source and accelerates them to enter a sample in the form of an ion beam. You have to shake it. This method of implanting ions in the form of ion beams is a three-way rotation of the sample for implanting ions into three-dimensional objects such as molds, tools, and mechanical component parts due to the principle of line-of-sight implantation. And the necessity of masking to prevent sputtering due to oblique incident ions. It also has the disadvantage that the equipment is very expensive compared to other surface modification equipment.

Meanwhile, another method using silver cathode arc (MEVVA) for silver ion implantation is "Surface Modification of Medical Metals by Ion Implantation of Silver and Copper" (Wan YZ, Raman S, He F, Huang Y., Vacuum 2007). 81 (9): 1114-1118. However, when the pulsed cathode arc plasma is used, macro particles of a large size are generated due to the arc, and are deposited on the surface of the ion implantation sample. In order to prevent this, there is a problem in that a filter using a magnetic field must be used.

The present invention is to solve the above problems, an object of the present invention to provide an apparatus and method for effectively injecting silver ions to the surface of the sample to improve the antimicrobial properties of the material.

According to this invention, a silver element plasma ion implantation apparatus is provided. The silver element plasma ion implantation apparatus includes a vacuum chamber for keeping the interior in a vacuum state, a magnetron deposition source for thin film deposition, a sample mounting table installed at a position opposite to the deposition source in the vacuum chamber, and a sample source mounted on the deposition source. A first power supply means for plasmalizing the silver element sputtered from the deposition source by applying pulsed direct current power, and a high contact voltage pulse synchronized with the pulsed DC power for the magnetron deposition source to the sample mounting table, thereby bringing plasma ions of the silver element toward the sample; It may include a second power supply means for accelerating the ion implantation on the surface of the sample.

According to the present invention, a silver element plasma ion implantation method is provided. The silver element plasma ion implantation method includes the steps of placing a sample on a sample mounting table in a vacuum chamber, maintaining the interior of the vacuum chamber in a vacuum state, supplying a gas to be plasmaized in the vacuum chamber, and depositing a thin film for deposition. Generating pulsed plasma ions of the silver element by applying pulsed DC power to the magnetron deposition source, and accelerating the plasma ions of the silver element to the sample by applying a high voltage pulse synchronized with the pulsed DC power for the magnetron deposition source to the sample mounting table. Ion implantation on the surface of the.

In one embodiment, the pulsed direct current power applied to the magnetron deposition source may have a density of 10 W / cm ² ~ 10 kw / cm ² . In addition, the pulsed DC power may have a frequency of 1 Hz to 10 kHz and a pulse width of 10 usec to 1 msec.

In one embodiment, the high voltage pulse applied to the sample mount has a frequency of 1 Hz to 10 kHz, a pulse width of 1 usec to 200 usec, and -1 kv to -100 kV, synchronized to a pulsed DC power for the magnetron deposition source. It can have a negative high voltage pulse.

In one embodiment, the vacuum chamber may have a gas pressure therein of 0.5 mTorr to 5 mTorr.

In one embodiment, the gas supply unit for supplying a gas to be plasma to the vacuum chamber,

The gas supply unit may further include a gas control unit for adjusting the pressure of the gas supplied by the gas supply unit.

In one embodiment, further means for generating an inductively coupled plasma in the vacuum chamber can increase the ionization rate of the silver element and lower the operating pressure of the deposition source. Means for generating an inductively coupled plasma in a vacuum chamber includes an RF antenna mounted in the vacuum chamber to radiate RF power to generate an inductively coupled plasma, an RF power supply unit for applying RF power to the RF antenna, an RF power supply unit and an RF antenna, The RF matching unit may include an RF matching unit.

According to the silver element plasma ion implantation apparatus and method according to an embodiment of the present invention, plasma ions of the silver element may be injected into the sample by applying pulsed DC power to the magnetron deposition source. Since the magnetron deposition source operates in the pulsed mode, it is possible to apply very high power at the moment the pulse is applied while maintaining a low average power so that there is no problem in cooling the magnetron deposition source. Therefore, a high density silver plasma can be generated and the ionization rate of silver element is raised. The ions of the silver element generated in this way are accelerated toward the sample by the synchronized negative high voltage pulse applied to the sample so that the silver ions are effectively injected into the surface of the sample.

Hereinafter, a silver element plasma ion implantation apparatus and method according to an embodiment of the present invention will be described in detail.

1 is a view showing the configuration of a silver element plasma ion implantation apparatus according to an embodiment of the present invention.

Referring to FIG. 1, a silver element plasma ion implantation apparatus 100 according to an embodiment of the present invention includes a vacuum chamber 110 having a vacuum inside thereof, a magnetron deposition source 120 for thin film deposition, The silver element is sputtered from the deposition source by applying a pulse direct current power 141 to the deposition source 130 and the sample mounting table 130 on which the sample 131 is mounted at a position opposite to the deposition source in the vacuum chamber 110. First power supply means for generating plasma ions and a high voltage pulse 151 synchronized to the pulse DC power 141 to the sample mounting table 130 to accelerate the plasma ions of the silver element toward the sample 131. And a second power supply means. The first power supply means includes a pulsed DC power supply 140. The pulsed DC power 141 may apply a high power at the moment a pulse is applied while maintaining a low average power. In one embodiment, the pulsed DC power 141 has a density of 10 W / cm ² to 10 kw / cm ² , a frequency of 1 Hz to 10 kHz, and a pulse width of 10 usec to 1 msec. Can have

In one embodiment, the second power supply means includes a high voltage pulse power supply 150. The high voltage pulse 151 is synchronized to the pulse DC power 141 so that the plasma ions of the silver element can be accelerated toward the sample 131 to be ion implanted. In one embodiment, the high voltage pulse 151 synchronized to the pulse DC power 141 applied to the magnetron deposition source 120 has a frequency of 1 Hz to 10 kHz, which is the same frequency as the pulse DC power 141, It can have a pulse width of 1 usec to 200 usec and a negative high voltage pulse of -1 kv to -100 kV.

Preferably, the gas pressure inside the vacuum chamber 110 is 0.5 mTorr to 5 mTorr. To this end, the silver element plasma ion implantation apparatus 100 according to the present invention, the gas supply unit 161 for supplying the gas to be plasmaized to the vacuum chamber 110 and the gas supplied by the gas supply unit 161 A gas control unit 162 for adjusting the pressure (or flow rate) is further provided.

In addition, the silver element plasma ion implantation apparatus 100 according to the present invention further includes a means for generating an inductively coupled plasma in the vacuum chamber 110 to increase the ionization rate of the silver element and to increase the magnetron deposition source 120. The operating pressure can be lower than that of a typical magnetron deposition source. In one embodiment, the means 170 for generating the inductively coupled plasma is mounted in the vacuum chamber 110 to the RF antenna 171 and the RF antenna 171 to radiate RF power to generate the inductively coupled plasma. An RF power supply unit 173 for applying RF power and an RF matching unit 172 for RF impedance matching between the RF power supply unit 173 and the RF antenna 171 may be included.

The principle of the silver element plasma ion implantation apparatus 100 according to the present invention is as follows.

The vacuum chamber 110 maintains a predetermined degree of vacuum by the vacuum pump 111 and the vacuum valve 112, and is grounded through the ground portion 113.

First, after the sample 131 is mounted on the sample mounting table 130 located in the vacuum chamber 110, the vacuum degree inside the vacuum chamber 110 is exhausted to the high vacuum region by using the vacuum pump 111. Thereafter, the gas supply unit 161 introduces a gas for generating a plasma into the vacuum chamber 110 through the gas control unit 162 to adjust the pressure therein. The gas is controlled by the gas control unit 162 and the supply amount of gas is introduced into the vacuum chamber 110 through the gas valve 163. In one embodiment, the gas includes argon, neon, and the like. In one embodiment, the pressure inside the vacuum chamber 110 is adjusted to 0.5 mTorr to 5 mTorr. The reason for this is that plasma is difficult to be generated at a pressure of 0.5 mTorr or lower while the gas pressure inside the vacuum chamber 110 is higher than 5 mTorr. This is because the energy loss of silver ions accelerated by frequent collisions is very severe.

As described above, when the gas is introduced and the pressure inside the vacuum chamber 110 is stabilized, the pulsed DC power source 141 uses the pulsed DC power supply unit 140 to the magnetron deposition source 120 mounted on the vacuum chamber 110. By applying a high voltage pulse 151 to the conductive sample mounting unit 130 by using the high voltage pulse power supply unit 150 to operate the magnetron deposition source 120. Perform the process.

The pulsed DC power 141 applied to the magnetron deposition source 120 and the negative high voltage pulse 151 applied to the conductive sample holder 130 are synchronized to operate at the same frequency. This means that the silver element sputtered from the magnetron deposition source 120 is ionized by the high density plasma at the moment when the magnetron deposition source 130 is pulsed on by the pulsed DC power 141. This is because the negative ions applied to the conductive sample mounting plate 130 are accelerated to the sample 131 by the negative high voltage pulse 151 and ions are injected into the surface of the sample 131. Therefore, synchronization must be achieved.

In the above, the pulsed direct current power 141 applied to the magnetron deposition source 120 is not necessarily limited thereto, but has a density of 10 W / cm ² to 10 kw / cm ² . The reason is that it is difficult to generate high density silver plasma with high ionization rate from the magnetron deposition source 120 with a low pulse DC power of 10 W / cm ² or less, whereas it is practical to use a value of 10 kw / cm ² or more. This is because there are many difficulties in manufacturing the DC power supply unit 140. In one embodiment, the pulsed DC power 141 is not necessarily limited thereto, but has a frequency of 1 Hz to 10 kHz and a pulse width of 10 usec to 1 msec. The reason is that the low plasma frequency of 1 Hz or less takes too much time for the plasma implantation process, thus reducing the economic value of the present technology, while fabricating a pulsed DC power supply unit 140 that operates at a high frequency of 10 kHz or higher. Because there are many difficulties. In addition, since the generation of high density silver plasma is not sufficient at a short pulse width of 10 usec or less, the ionization rate of the generated silver element is low, whereas at a long pulse width of 1 msec or more, an arc in the magnetron deposition source 120 is caused by high pulse power. Is likely to occur and the process is unstable.

In addition, the high voltage pulse 151 applied to the sample mounting table 130 is not necessarily limited thereto, but the frequency of 1 Hz to 10 kHz, which is the same frequency as that of the pulse DC power 141 applied to the magnetron deposition source 120. The frequency must be synchronized and used. The pulse width is 1 usec-200 usec, and the negative high voltage pulse is -1 kv--100 kV. The reason is that silver plasma ion implantation is not effectively performed at short pulse widths of 1 usec or less, and plasma sheaths due to negative high voltage applied to the conductive sample holder 130 at long pulse widths of 200 usec or more ( The sheath may expand too much and the plasma may be turned off while touching the wall of the vacuum chamber 110. As the time for which the high voltage is applied to the sample holder 130 becomes long, an arc may occur in the sample holder 130. This is because there is a high possibility. In addition, at a low voltage of -1 kV or less, the depth at which silver ions are injected into the surface of the sample 131 is too shallow, and fabrication of the high voltage pulse power supply 150 of -100 kV or more is practically difficult.

The characteristics of the silver element plasma ion implantation apparatus according to the present invention are as follows.

The magnetron deposition source 120, which is commonly used as a deposition source for thin film deposition, is equipped with a silver sputtering target, and its operation is performed in a pulse mode using the pulsed DC power 141, and is synchronized with the negative high voltage. By applying the pulse 151 to the sample 131, silver ions generated from the magnetron deposition source 120 may be accelerated to effectively inject silver ions onto the surface of the sample 131. When the magnetron deposition source 120 is operated in a pulse mode instead of continuous operation, very high pulse power can be applied at the moment pulse is applied while maintaining a low average power so that cooling of the magnetron deposition source 120 is not a problem. Therefore, a high density of silver plasma can be generated on the surface of the sputtering target, which increases the ionization rate of the silver element emitted from the sputtering target surface. The silver ions generated in this manner are accelerated toward the sample 131 by the synchronized negative high voltage pulse applied to the sample 131, and silver ions can be effectively injected into the surface of the sample 131. have. In addition, when RF power is applied by mounting an RF antenna between the silver magnetron deposition source 120 and the sample 131, the ionization rate of the emitted silver element may be further increased by generating an inductively coupled plasma. By enabling the operation at a pressure lower than the general operating pressure of the magnetron deposition source, it is possible to minimize the collision with the gas particles during silver plasma ion implantation to perform the plasma ion implantation of the silver element more effectively.

The silver element plasma ion implantation method according to the present invention includes the steps of placing the sample 131 on the sample mounting table 130 in the vacuum chamber 110, maintaining the interior of the vacuum chamber 110 in a vacuum state, and vacuum Supplying a gas to be plasmaized in the tank 110, applying a DC pulse power 141 to the magnetron deposition source 120 for thin film deposition, generating plasma ions of the silver element, and the sample holder 130 Applying a high voltage pulse 151 synchronized to the pulse DC power 141 to accelerate the plasma ions of the silver element toward the sample 131. In one embodiment, the silver element plasma ion implantation method may further comprise generating an inductively coupled plasma in the vacuum chamber (110).

The silver elemental plasma ion implantation experiment of the apparatus according to the present invention was carried out as follows.

A pure silver target of 75 mm in diameter and 6 mm in thickness was used as the magnetron deposition source 120, and stainless steel was used as the ion implantation sample 131. After attaching the stainless steel sample 131 to the conductive sample mounting unit 130, the vacuum chamber 110 was evacuated to a vacuum of 5 x 10 ^-6 Torr, and then argon gas was introduced to reduce the argon pressure inside the vacuum chamber. Kept at 2 mTorr. In addition, an argon plasma was generated by applying RF power of 13.56 MHz and 200 Watt to the RF antenna for plasma generation, and the magnetron deposition source 120 was operated by applying a pulsed DC power 141 to the magnetron deposition source 120. . The applied pulsed DC voltage was -1.0 kV and the pulsed DC current was 15 A, and a pulse power of about 300 W / cm ² was used. In addition, the frequency of the pulse DC electric power 141 was 100 Hz, and the pulse width was 200 usec. Therefore, the average power was 300 W so that there was no problem in cooling the magnetron deposition source 120.

In addition, the magnetron deposition source 120 was operated by the method described above, and a negative ion high voltage pulse 151 was applied to the stainless steel sample 131 to perform a plasma ion implantation process of silver element for 30 minutes. . The negative high voltage pulse 151 had a pulse width of -60 kV and 40 usec, and was synchronized to the same frequency of 100 Hz as the pulsed DC power 141. In addition, after the pulsed DC power 141 of 200 usec pulse width is applied to the magnetron deposition source 120, a negative high voltage pulse 151 of 40 usec pulse width is applied to the sample 131 after about 130 usec. To be authorized. Therefore, silver plasma ion implantation is performed in a state where silver plasma ion density is sufficiently high.

In the stainless steel sample implanted with plasma ions of the silver element by the above apparatus and method, an antimicrobial test against E. Coli, which is a gram negative bacillus, was performed as follows.

Incubate the specimens on slope medium from conserved strains at (35 ± 1) ° C for 16-20 hours, and incubate the cultured strains (Nutrient Broth) (1/500 NB) diluted 500-fold. ^{5 to} 2.5 × 10 ⁵ ) cells / mL were suspended and used as the inoculum bacterial solution. Prepare a flat section of the plasma-implanted and non-implanted control specimens (50 ± 2) mm in square size, and clean all sides of the specimen with ethanol (95%) or ultraviolet light. Used for the test. 0.4 mL of the prepared inoculum solution was inoculated on the test surface of each test piece placed in a Petri dish, and the inoculation solution was spread evenly on each test piece by covering the film on the inoculum solution. Thereafter, the stopper of the Petri dish was closed and incubated for 24 hours at (35 ± 1) ° C. and a relative humidity of 90% or more. After incubation, each specimen is aseptically transferred to a sample bag, 10 ml of SCDPL medium is added, and the bacterial solution of each specimen is collected using an extractor. The recovered bacterial solution was cultured for 40 to 48 hours at (35 ± 1) ° C. using PCA medium, and then the medium was observed.

Figure 2 is a photograph showing the culture results of E. coli according to the silver ion implantation.

As shown in FIG. 2, a large amount of Escherichia coli was grown in the medium (a) cultured from the non-ion-injected stainless steel test specimen, while no coliform was grown in the medium (b) cultured from the silver plasma ion-implanted test specimen. It can be seen that the antimicrobial properties of the stainless steel test specimens injected with silver plasma ion were very excellent.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. It will be clear to those who have knowledge of.

1 is a view showing the configuration of a silver element plasma ion implantation apparatus according to an embodiment of the present invention.

Figure 2 is a photograph showing the culture results of E. coli according to the silver ion implantation.

<Description of the symbols for the main parts of the drawings>

110: vacuum chamber

111: vacuum pump

112: vacuum valve

113: ground

120: deposition source

130: sample stand

140: pulse DC power supply

150: high voltage pulse power supply

161: gas supply unit

162: gas control unit

171: RF antenna

172: RF matching unit

173: RF power supply

Claims (13)

A vacuum chamber for keeping the interior in a vacuum state, Magnetron deposition source for thin film deposition, A sample mounting table installed at a position opposite to the deposition source in the vacuum chamber to mount a sample thereon; First power supply means for applying a pulsed direct current power to the deposition source to plasma the silver element sputtered from the deposition source; Second power supply means for accelerating plasma silver ions of the silver element toward the sample by applying a high voltage pulse synchronized to the pulse DC power to the sample mounting table; Silver element plasma ion implantation apparatus comprising a. The method of claim 1, The pulsed DC power applied to the magnetron deposition source has a density of 10 W / cm ² ~ 10 kw / cm ² A silver element plasma ion implantation device. The method of claim 1, The pulse DC power applied to the magnetron deposition source, With a frequency of 1 Hz to 10 kHz, With a pulse width of 10 usec to 1 msec Silver element plasma ion implantation device. The method of claim 1, The high voltage pulse applied to the sample mounting table, A frequency of 1 Hz to 10 kHz synchronized with the pulsed DC power applied to the magnetron deposition source, Pulse width of 1 usec to 200 usec, With negative high voltage pulses from -1 kv to -100 kV Silver element plasma ion implantation device. The method of claim 1, The vacuum chamber has an internal gas pressure of 0.5 mTorr to 5 mTorr Silver element plasma ion implantation device. The method of claim 5, A gas supply unit for supplying a gas to be plasmaized to the vacuum chamber; Further comprising a gas control unit disposed between the gas supply and the vacuum chamber Silver element plasma ion implantation device. The method according to any one of claims 1 to 6, Means for generating an inductively coupled plasma in the vacuum chamber to increase the ionization rate of the silver element and to lower the operating pressure of the deposition source. Silver element plasma ion implantation device. The method of claim 7, wherein Means for generating the inductively coupled plasma, An RF antenna mounted in the vacuum chamber to radiate RF power to generate the inductively coupled plasma; An RF power supply unit applying RF power to the RF antenna; RF matching unit for RF impedance matching between the RF power supply and the RF antenna Silver element plasma ion implantation device. Placing the sample on the sample holder in the vacuum chamber; Maintaining the interior of the vacuum chamber in a vacuum state; Supplying a gas to be plasmaized into the vacuum chamber; Generating plasma ions of elemental silver by applying pulsed direct current power to the magnetron deposition source; Applying a high voltage pulse synchronized with the pulse DC power to the sample mounting stage to accelerate plasma ions of the silver element toward the sample to implant ions into the sample surface; Silver element plasma ion implantation method comprising a. 10. The method of claim 9, The pulsed DC power applied to the magnetron is, With a density of 10 W / cm ² to 10 kw / cm ² , With a frequency of 1 Hz to 10 kHz, With a pulse width of 10 usec to 1 msec Silver elemental plasma ion implantation method. 10. The method of claim 9, The high voltage pulse applied to the sample mounting table A frequency of 1 Hz to 10 kHz synchronized with the pulsed DC power applied to the magnetron deposition source, Pulse width of 1 usec to 200 usec, With negative high voltage pulses from -1 kv to -100 kV Silver elemental plasma ion implantation method. 10. The method of claim 9, The vacuum chamber has an internal gas pressure of 0.5 mTorr to 5 mTorr Silver elemental plasma ion implantation method. The method according to any one of claims 9 to 12, Generating an inductively coupled plasma in the vacuum chamber; Silver elemental plasma ion implantation method.

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