• Journal of Korean Society for Atmospheric Environment
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• v.26 no.6
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• pp.690-696
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• 2010

Abatement of perfluorocompounds (PFCs) used in semiconductor and display industries has received an attention due to the increasingly stricter regulation on their emission. In order to meet this circumstance, we have developed a radio frequency (RF) driven plasma reactor with multiple annular shaped electrodes, characterized by an easy installment between a processing chamber and a vacuum pump. Abatement experiment has been performed with respect to $CF_4$, a representative PFCs widely used in the plasma etching process, by varying the power, $CF_4$ and $O_2$ flow rates, $CF_4$ concentration, and pressure. The influence of these variables on the $CF_4$ abatement was analyzed and discussed in terms of the destruction & removal efficiency (DRE), measured with a Fourier transform infrared (FTIR) spectrometer. The results revealed that DRE was enhanced with the increase in the discharge power and pressure, but dropped with the $CF_4$ flow rate and concentration. The addition of small quantity of $O_2$ lead to the improvement of DRE, which, however, leveled off and then decreased with $O_2$ flow rate.

• Applied Chemistry for Engineering
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• v.25 no.4
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• pp.386-391
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• 2014

Atmospheric-pressure nonthermal corona discharge plasma was applied to the sterilization of biologically contaminated scoria powder. Escherichia coli (E. coli) culture solution was uniformly sprayed throughout the scoria powder for artificial inoculation, which was well mixed to ensure uniformity of the batch. The effect of the key parameters such as discharge power, treatment time, type of gas and electrode distance on the sterilization efficiency was examined and discussed. The experimental results revealed that the plasma treatment was very effective for the sterilization of scoria powder; 5-min treatment at 15 W could sterilize more than 99.9% of E. coli inoculated into the scoria powder. Increasing the discharge power, treatment time or applied voltage led to an improvement in the sterilization efficiency. The effect of type of gas on the sterilization efficiency was in order of oxygen, synthetic air (20% oxygen) and nitrogen from high to low. The inactivation of E. coli under the influence of corona discharge plasma can be explained by cell membrane erosion or etching resulting from UV and reactive oxidizing species (oxygen radical, OH radical, ozone, etc.), and the destruction of E. coli cell membrane by the physical action of numerous corona streamers.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.159-162
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• 2002

Ferroelectric $YMnO_{3}$ thin films were etched with $Ar/Cl_{2}$ and $CF_{4}/Cl_{2}$ inductivly coupled plasma (ICP). The maximum etch rate of $YMnO_{3}$ thin film was $300{\AA}/min$ at a $Ar/Cl_{2}$ gas mixing ratio of 2/8, a RF power of 800 W, a dc bias of 200 V, a chamber pressure of 15 mTorr, and a substrate temperature of ${30^{\circ}C}$. From the X-ray photoelectron spectroscopy (XPS) analysis ， yttrium not only etched by chemical reactions with Cl radicals, but also assisted by Ar ion bombardments in $Ar/Cl_{2}$ plasma. In $CF_{4}/Cl_{2}$ plasma, yttrium are remained on the etched surface of $YMnO_{3}$ and formed of nonvolatile YFx compounds Manganese etched effectively by chemical reactions with Cl and F radicals. From the X-ray diffraction (XRD) analysis, the (0004) diffraction peak intensity of the $YMnO_{3}$ thin film etched in $Ar/Cl_{2}$ plasma shows lower value than that in $CF_{4}/Cl_{2}$ plasma. It is indicates that the crystallinty of $YMnO_{3}$ thin film is more easily damaged by the Ar ion bombardment than the changes of stoichiometry due to nonvolatile etch by-products.

• Journal of the Semiconductor & Display Technology
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• v.4 no.2 s.11
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• pp.39-43
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• 2005

In the study, in order to deposit TaN thin film for diffusion barrier and bottom electrode we made the Plasma Assisted ALD equipment and confirmed the electrical characteristics of TaN thin films grown PAALD method. Plasma Assisted ALD equipment depositing TaN thin film using PEMAT(pentakis(ethylmethlyamino) tantalum) precursor and NH3 reaction gas is shown that TaN thin film deposited high density and amorphous phase with XRD measurement. The degree of diffusion and reaction taking place in Cu/TaN (deposited using 150W PAALD)/$SiO_{2}$/Si systems with increasing annealing temperature was estimated for MOS capacitor property and the $SiO_{2}$, (600${\AA}$)/Si system surface analysis by C-V measurement and secondary ion material spectrometer (SIMS) after Cu/TaN/$SiO_{2}$ (400 ${\AA}$) layer etching. TaN thin film deposited PAALD method diffusion barrier have a good diffusion barrier property up to 500$^{\circ}C$.

• Applied Chemistry for Engineering
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• v.22 no.1
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• pp.31-36
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• 2011

Tetrafluoromethane ($CF_4$) has been used as the plasma etching and chemical vapor deposition (CVD) gas for semiconductor manufacturing processes. However, the gas need to be removed efficiently because of their strong absorption of infrared radiation and the long atmospheric lifetime which cause global warming effects. A waterjet gliding arc plasma system in which plasma is combined with the waterjet was developed to effectively produce OH radicals, resulting in efficient destruction of $CF_4$ gas. Design factors such as electrode shape, electrode angle, gas nozzle diameter, electrode gap, and electrode length were investigated. The highest $CF_4$ destruction of 93.4% was achieved at Arc 1 electrode shape, $20^{\circ}$ electrode angle, 3 mm gas nozzle diameter, 3 mm electrode gap and 120 mm electrode length.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.4
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• pp.375-380
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• 2005

CF₄ molecular gas is used in most of semiconductor manufacture processing and SF/sub 6/ molecular gas is widely used in industrial of insulation field. but both of gases have defect in global warming. C₃F/sub 8/ gas has large attachment cross-section more than these gases, moreover GWP, life-time and price of C₃F/sub 8/ gas is lower than them, therefor it is important to calculate transport coefficients of C₃F/sub 8/ gas like electron drift velocity, ionization coefficient, attachment coefficient, effective ionization coefficient and critical E/N. The aim of this study is to get these transport coefficients for imformation of the insulation strength and efficiency of etching process. In this paper, we calculated the electron drift velocity (W) in pure C₃F/sub 8/ molecular gas over the range of E/N=0.1∼250 Td at the temperature was 300 K and gas pressure was 1 Torr by the Boltzmann equation method. The results of this paper can be important data to present characteristic of gas for plasma etching and insulation, specially critical E/N is a data to evaluate insulation strength of a gas.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.275-278
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• 2001

Ferroelectric PZT thin films were fabricated on the RuO$_2$/Pt, Pt bottom electrode with a PZT(53/47) metal alkoxide solutions. All PZT thin films showed a uniform grain structure without the presence of rosette structure. The PZT thin films were etched as a function of Cl$_2$/Ar and additive CF$_4$ into Cl$_2$(80%)/Ar(20%). The etch rates of PZT thin films were 1970 ${\AA}$/min at 30 % additive CF$_4$ into Cl$_2$(80%)/Ar(20%). The remanent polarization and leakage current density in PZT thin film on the RuO$_2$/Pt were 64.2 ${\mu}$C/cm$^2$, 1.4${\times}$10$\^$-6/ respectively.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.109-112
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• 2006

A fluorine-doped diamond-like carbon (F-DLC) stamp which has high contact angle, high UV-transmittance and sufficient hardness, was fabricated using the following direct etching method: F-DLC is deposited on a quartz substrate using DC and RF magnetron sputtering, PMMA is spin coated and patterned using e-beam lithography and finally, $O_2$ plasma etching is performed to transfer the line patterns having 100 nm line width, 100 nm line space and 70 nm line depth on F-DLC. The optimum fluorine concentration was determined after performing several pre-experiments. The stamp was applied successfully to UV-NIL without being coated with an anti-adhesion layer.

• Korean Journal of Optics and Photonics
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• v.15 no.4
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• pp.309-312
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• 2004

Two-dimensionally arrayed nanocolumn lattices were fabricated by using double-exposure laser holographic method. The hexagonal lattice was formed by rotating the sample with 60 degree while the square lattice by 90 degree before the second laser-exposure. The size and period of nanocolumns could be controlled accurately from 125 to 145 nm in diameter and 220 to 290 nm in period for square lattice by changing the incident angle of laser beam. The reactive ion etching for a typical time of 30 min using CH$_4$/H$_2$ plasma enhanced the aspect-ratio by more than 1.5 with a slight increase of the bottom width of columns.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.99-99
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• 1999

투명전도막인 Ito(Indium Tin Oxide)는 flat panel display 와 solar cell 같은 optoelectronic 이나 microelectronic device에서 널리 이용되어 지고 있다. 현재 상용화되고 있는 거의 대부분의 ITO 박막은 sputtering법에 의해 제조되고 있으나 공정상의 이유로 15$0^{\circ}C$이상의 기판온도가 요구되어진다. 그런, 실제 display device 제조공정에서는 비정질 실리콘 박막이나 유기막 위에 ITO박막을 제작할 필요성이 증대되어 지고 있고, 또한 다른 전자소자에 있어서도 상온 ITO 박막 형성 공정에 대한 필요성이 증대되고 있다. 이러한 이유로 본 실험에서는 IBAE(Ion Beam Assisted Evsporation)을 이용하여 저온 ITO박막을 유기막 위에 증착하는 공정에 대한 연구를 수행하였다. 이렇게 증착된 ITO 박막의 결정성은 비정질이었다. 또한, 모든 display device 제작에는 식각공정이 필수인데 기존에 사용되고 있는 wet etching 법은 등방성 식각특성 때문에 미세 pattern 형성에 부적합？, 따라서 비등방성 식각에 용이한 plasma etching법을 사용하여 저온 증착된 ITO 박막의 식각특성을 알아보았다. 실험에 사용된 식각장비는 자장 강화된 유도결합형 플라즈마 식각장비(MEICP)를 사용하였으며, 13.56MHz의 RF power를 사용하였다. 식각조건으로 source power는 600W~1000W, 기판 bias boltage는 -100V~-250V를 가하였으며, Ar, CH4, O2, H2, BCl3의 식각 gases, 5mTorr~30mTorr의 working pressure 변화 그리고 기판 온도에 따른 식각특성을 관찰하였다. ITO 가 증착된 기판으로는 유기물 중 투명전도성 박막에 기판으로서 사용가능성이 클 것으로 기대되어지는 PET(polyethylene-terephtalate), PC(polycarbonate), 아크릴을 사용하여 기판 변화가 식각특성에 미치는 영향에 대해서 각각 관찰하였다. 식각속도의 측정은 stylus profiler를 이용하여 측정하였으며 식각후에 표면상태는 scanning electron spectroscopy(SEM)을 이용하여 관찰하였다.