• Journal of the Semiconductor & Display Technology
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• v.18 no.2
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• pp.98-102
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• 2019

Direct plasma-enhanced atomic layer deposition (PEALD) are widely used for $SiO_2$ and SiON thin film process in current semiconductor industry. However, this exhibits poor step coverage for three-dimensional device structure due directionality of plasma species as well as plasma damage on the substrate. In this study, to overcome this issue, low temperature (< $300^{\circ}C$) $SiO_2$ and SiON thin film processes were studied using inductively coupled plasma (ICP) type remote PEALD with various reactant gases such as $O_2$, $H_2O$, $N_2$ and $NH_3$. It was confirmed that the interfacial properties such as fixed charge density and charge trapping behavior of thin films were considerably improved by hydrogen species in $H_2O$ and $NH_3$ plasma compared to the films grown with $O_2$ and $N_2$ plasma. Furthermore, the leakage current density of the thin films was suppressed for same reason.

• Korean Journal of Materials Research
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• v.10 no.11
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• pp.732-737
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• 2000

Plasma enhanced chemical vapor deposition of $TiO_{2$\pm}{\delta}$ has been carried out using TEMAT [tetrakis(ethylmethylamido) titanium] and $H_2$. Increasing the power from 300 W to 500 W produced the high density plasma, leading to the formation of TiO$_2$films with an increased ratio of Ti to O and a negligible amount of C and N. Applying the bias of 30W to the substrate in creased the growth rate of the film with a slightly increased content of Ti in the film. In addition, $H_2O$ was from either the residual gas in the gase pressure or $H_2(/He)$ gas and actively participated in the formation of $TiO_2$ films. Consequently, Ti ions created in the plasma could be a main contributor to $TiO_2$ formation with a slight amount of $H_2O(~10^{-4}Toor)$ in the ambient, which provided the dissociation of TEMAT.

• Korean Chemical Engineering Research
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• v.45 no.5
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• pp.455-459
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• 2007

Plasma catalytic methane conversion was carried out in the presence of sol-gel derived $Pt/TiO_2$ catalysts within a dielectric-barrier discharge (DBD) reactor. Plasma-assisted reduction (PAR) was applied to reduce the prepared $Pt/TiO_2$ catalysts in DBD reactor, and prepared catalysts were successively reduced by PAR within 20 min irrespective of the Pt loading and the calcination temperature. The highest methane conversion was 40% when 3 wt% $Pt/TiO_2$ and 5 wt% $Pt/TiO_2$ catalysts were used after calcination at $600^{\circ}C$. The selectivities of light alkanes ($C_2H_6$, $C_3H_8$, $C_4H_{10}$) were highly increased when $Pt/TiO_2$ catalysts were used in DBD reactor.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.491-491
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• 2013

A novel plasma system has been developed for 3-dimensional modification of the carbon nano-powders. Improvement of dispersion of these nano materials are studied by plasma discharge, not using chemical modification. The plasma process is considered to great advantages over wet chemical process due to environmental, economic viewpoint, and uniformity over the treated volume. The uniform dispersion is a critical factor for these material's nano composite applications. Using this plasma system, graphene, carbon black, and CNT was treated and functionalized. Several key discharge conditions such as Ar/H2/O2 or Ar/H2/NH3 gas ratio, treatment time, power, feeder's vibration frequency are investigated. Hydrophobic of graphene has turned some more into hydrophilic by reaction test with water, electrophoresis, surface contact angle test, and turbidity analysis. The oxygen content ratio in the plasma treated CNT has increased about 3.7 times than the untreatedone. In the case of graphene and carbon black, the oxygen- and nitrogen- content has been enhanced average 10%. O-H (N-H) peak, C-O (C-N) peak, and C=O (C=N) peak data have been detected by FTIR measurement and intensified compared to before-plasma treatment due to O2 or NH3 content.

• Journal of the Korean Vacuum Society
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• v.15 no.3
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• pp.259-265
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• 2006

We measured sputtering yield of RF $O_2-plasma$ treated MgO protective layer for AC-PDP(plasma display panel) using a Focused ion Beam System(FIB). A 10 kV acceleration voltage was applied. The sputtering yield of the untreated sample and the treated sample were 0.33 atoms/ion and 0.20 atoms/ion, respectively. The influence of the plasma-treatment of MgO thin film was characterized by XPS and AFM analysis. We observed that the binding energy of the O 1s spectra, the FWHM of O 1s spectra and the RMS(root-mean-square) of surface roughness decreased to 2.36 eV, 0.6167 eV and 0.32 nm, respectively.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.2
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• pp.93-97
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• 2010

We have studied the effect of the chemical composition of the ZnO nanorod surface on the optical characteristics. The surface was treated with H- and O-plasma at different surface temperatures. The chemical composition of the surface of the ZnO nanorod, being investigated by Auger Electron Spectroscopy(AES), was related to the Photoluminescence(PL) data reported in our previous results. The AES showed the opposite results for the $H_2$ and $O_2$ plasma treatments. The ratio of Zn to O on the surface of the ZnO nanorod increased in the case of $H_2$ plasma, while the composition rate of O increased after $O_2$ plasma treatment. The AES results seems to be correlated to the shift in PL peaks. The increase in the composition rate of Zn on the surface of ZnO nanorod is considered to cause the blue shift of the UV peak. On the contrary, the relative increase of O is considered to cause the red shift in PL peaks.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2003.05a
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• pp.54-54
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• 2003

MgO layer는 POP 패빌 내 유전증을 이온의 스퍼터링으로부터 보호하여 주며, 또한 높은 이차 전자 밤출 계수의 특성을 가지고 있어 구동 및 유지 전압을 낮춰 주는 역할을 한다. 그러나. MgO layer는 $H_20,{\;}CO_2,{\;}N_2,{\;}0_2$ 그리고 $H_2$와 같은 불순물 들을 쉽게 를착하는 단점이 있어, PDP의 특성 및 수명 단축에 영향을 줄 수 있다. 따라서, 본 연구에서는 atmospheric pressure plasma cleaning 과 low pressure i inductively coupled plasma (ICP) cleaning 처리에 의하여, 보호층으로 사용이 되는 MgO layer의 outgassing 특성을 조사하고자 한다. plasma cleaning에 의한 MgO layer 표면의 roughness와 불순물의 변화를 알아보기 위 하여 atomic force microscopy(AFM)과 x-ray p photoelectron spectroscopy(XPS)를 이용하여 측정 하였다. 또한, outgassing의 특성을 분석하기 위하여 MgO layer를 $400^{\circ}C$ 까지 온도를 가하여 온도에 따른 outgassing의 특성을 quadrupole mass spectrometer(QMS)를 이용하여 알아보았다. atmospheric pressure plasma cleaning 에서는 $He/O_2/Ar/N_2$의 gas를 사용하였으며, low pressure ICP cleaning 에 서는 Ar의 gas를 사용하였다. atmospheric pressure plasma cleaning는 low pressure ICP C cleaning과 비교해 더 낮은 outgassing을 관잘 할 수 있었으나. MgO 표면의 roughness는 low pressure ICP cleaning 후 더 낮은 것을 알 수 있었다. 또한 $He/O_2/Ar/N_2$의 gas를 사용 한 atmospheric pressure plasma cleaning 과 $Ar/O_2$의 gas를 사용한 ICP cleaning에서 이 차전자방출계수(SEEC)가 약 1.5~2.5배 증가된 것을 알 수 있었다.

• Journal of Korean Society for Atmospheric Environment
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• v.14 no.4
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• pp.333-342
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• 1998

Plasma process has great possibilities to remove SOx, NOx simultaneously with high treatment efficiency and is expected to be suitable for small or middle plants. It was accomplished to evaluate SO2, NOx control possibility and achieve basic data to control pollutants by use of Surface Discharge Induced Plasma Chemical Process (SPCP) in this study. O3 generation characteristics by discharge of a plate was proportional to O2 concentration and power consumption and inversely proportional to temperature and humidity, In case of dry air, NOx was highly generated by N2 and O2 in air during the plasma discharge process but it was decreased considerably as H2O was added. SO2 removal efficiency was very high, and removal rate was 170,350 mEA at 30,50 watt respectively in flue gas which is usually contain HIO. NOx removal efficiency was about 57% at 40 watt power consumption with 7.5% humidity. It is estimated that H2O has an important role in reaction mechanism with pollutants according to plasma discharge.

• Korean Journal of Materials Research
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• v.3 no.6
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• pp.565-574
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• 1993

The Ar/Ar- $H_{2}$ plasma method Lvas applied to reduce and refine high purity Nb metal. Inaddition, the reaction between molten Nb metal and hydrogen were also analyzed in the Ar-(20%)$H_{2}$plasma. The metallic Nb of 99.5wt% was obtained at the ratio of $C/Nb_{2}O_{5}$=5.00 in the Ar plasma reductionand the $O_2$ loss from the thermal decomposition of niobium oxides did not take place. In the Ar-(20%)Hi plasma the metallic Nb of 99.8wt% was produced at the ratio of $C/Nb_{2}O_{5}$=4.80. It was observedthat a major reaction of the deoxidation was the reaction with H, Hi, and a deoxidation by the evaporationof $NbO_x$ did not occur but a mass loss of Nb did by a "splash" effect. The deoxidation reaction rateobeyed the 1st order reaction kinetics and the reaction rate constant(k') of deoxidation was $7.8 \times 10_{-7}$(m/sec).The solubility of hydrogen in Nb metal was 60ppm and it was larger than the solubility of molecularstate hydrogen by 40ppm in the Ar-(20%)$H_{2}$ plasma method. A saturation was within 60sec anda hydrogen content was reduced below lOppm by a Ar plasma re-treatment.by a Ar plasma re-treatment.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.906-909
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• 2006

The secondary electron emission coefficient $({\gamma})$ of the cathode is an important factor for improving the discharge characteristics of AC-PDPs because of its close relationship to discharge voltage. In AC-PDPs, MgO is most widely used as a surface protective layer. In this experimental, we have investigated the electronic structure of the energy band structure of the MgO layer responsible for the high ${\gamma}$. The MgO layers have been deposited by electron beam evaporation method, where the $O_2$ partial pressures have been varied as 0, $5.2{\times}10^{-5}$ torr, $1.0{\times}10^{-4}$ torr, and $4.1{\times}10^{-4}$ torr, in this experiment. It is noted that work function that is energy gap between surface and first defect level of MgO layer has the lowest value for the highest O2 partial pressure of $4.1^{\ast}10^{-4}$ Torr.