• Journal of the Korean institute of surface engineering
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• v.54 no.6
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• pp.365-370
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• 2021

In this research, we proceeded with research on plasma resistance of the cleaning process of APS(Atmospheric Plasma Spray)-Y₂O₃ coated parts used for semiconductor and display plasma process equipment. CF₄, O₂, and Ar mixed gas were used for the plasma environment, and respective alconox, surfactant, and piranha solution was used for the cleaning process. After APS-Y₂O₃ was exposed to CF₄ plasma, the surface changed from Y₂O₃ to YF₃ and a large amount of carbon was deposited. For this reason, the plasma corrosion resistance was lowered and contamination particles were generated. We performed a cleaning process to remove the defect-inducing surface YF₃ layer and carbon layer. Among three cleaning solutions, the piranha cleaning process had the highest detergency and the alconox cleaning process had the lowest detergency. Such results could be confirmed through the etching amount, morphology, composition, and accumulated contamination particle analysis results. Piranha cleaning process showed the highest detergency, but due to the very large thickness reduction, the base metal was exposed and a large number of contaminated particles were generated. In contrast, the surfactant cleaning process exhibit excellent properties in terms of surface detergency, etching amount, and accumulated contamination particle analysis.

• Journal of the Korean Society of Visualization
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• v.19 no.3
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• pp.123-129
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• 2021

Many plants and animals in nature have superhydrophobic surfaces. This superhydrophobic surface has various properties such as self-cleaning, moisture collection, and anti-icing. In this study, the superhydrophobic properties of PTFE surface were treated by plasma etching. There were four important factors that changed the surface properties. Micro-sized protrusions were formed by plasma etching. The most influential parameter was RF Power. The contact angle of the pristine PTFE surface was about 113.8°. The maximum contact angle of the surface after plasma treatment with optimized parameters was about 168.1°. In this case, the sliding angle was quite small about 1°. These properties made it possible to remove droplets easily from the surface. To verify the self-cleaning effect of the surface, graphite was used to contaminate the surface and remove it with water droplets. Graphite particles were easily removed from the optimized surface compared to the pristine surface. As a result, a surface having water repellency and self-cleaning effects could be produced with optimized plasma etching parameters.

• 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 the Semiconductor & Display Technology
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• v.19 no.2
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• pp.45-50
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• 2020

We investigated the Si_1-xGe_x surface properties when dry cleaning the films using NF₃ / H₂O remote plasma. After the dry cleaning process, it was found that about 80-250 nm wide bumps were formed on the SiGe surface regardless of Ge concentration in the rage of x = 0.1 ~ 0.3. In addition, effects of the dry cleaning processing parameters such as pressure, substrate temperature, and H₂O flow rates were examined. It was found that the surface bump is significantly dependent on the flow rate of H₂O. Based on these observations, we would like to provide additional guidelines for implementing the dry cleaning process to SiGe materials.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.2
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• pp.111-117
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• 2008

We have studied surface roughness, contamination of impurity, bonding with some gas element, reflectance and zeta potential on masks to be generated or changed during photolithography/dry or wet etching process. Mask surface roughness was not changed after photolithography/dry etching process. But surface roughness was changed on some area under MoSi film of Cr/MoSi/Qz. There was not detected any impurity on mask surface after plasma dry etching process. Reflectance of mask was increased after variable plasma etching treatment, especially when mask was treated with plasma including $O_2$ gas. Blank mask was positively charged when the mask was treated with Cr plasma etching gas($Cl_2:250$ sccm/He:20 $sccm/O_2:29$ seem, source power:100 W/bias power:20 W, 300 sec). But this positive charge was changed to negative charge when the mask was treated with $CF_4$ gas for MoSi plasma etching, resulting better wet cleaning. There was appeared with negative charge on MoSi/Qz mask treated with Cr plasma etching process condition, and this mask was measured with more negative after SC-1 wet cleaning process, resulting better wet cleaning. This mask was charged with positive after treatment with $O_2$ plasma again, resulting bad wet cleaning condition.

• Journal of the Semiconductor & Display Technology
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• v.21 no.3
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• pp.74-79
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• 2022

In this study, the plasma corrosion resistance and the change in the number of contamination particles generated using the plasma etching process and cleaning process of coating parts for semiconductor plasma etching equipment were investigated. As the coating method, atmospheric plasma spray (APS) was used, and the powder materials were Y₂O₃ and Y₃Al₅O₁₂ (YAG). There was a clear difference in the densities of the coatings due to the difference in solubility due to the melting point of the powdered material. As a plasma environment, a mixed gas of CF₄, O₂, and Ar was used, and the etching process was performed at 200 W for 60 min. After the plasma etching process, a fluorinated film was formed on the surface, and it was confirmed that the plasma resistance was lowered and contaminant particles were generated. We performed a surface cleaning process using piranha solution(H₂SO₄(3):H₂O₂(1)) to remove the defect-causing surface fluorinated film. APS-Y₂O₃ and APS-YAG coatings commonly increased the number of defects (pores, cracks) on the coating surface by plasma etching and cleaning processes. As a result, it was confirmed that the generation of contamination particles increased and the breakdown voltage decreased. In particular, in the case of APS-YAG under the same cleaning process conditions, some of the fluorinated film remained and surface defects increased, which accelerated the increase in the number of contamination particles after cleaning. These results suggest that contaminating particles and the breakdown voltage that causes defects in semiconductor devices can be controlled through the optimization of the APS coating process and cleaning process.

• Transactions on Electrical and Electronic Materials
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• v.9 no.2
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• pp.79-83
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• 2008

The dampness by treating the surface with polyethylene terephthalate (PET) film was measured to grasp the plasma parameters and was observed the surface condition with an atomic force microscope (AFM) to find the causes of the dampness. Also, the vibrational and rotational temperatures in the plasma were calculated after identifying the radicals within the plasma by analyzing the emission spectral with an emission spectrum. The hydrophilic properties were enhanced, by treating the surface of the PET film with non-equilibrium atmospheric discharge plasma. When the rotational temperature was 0.22 to 0.31 eV within the plasma, surface modification control could be easily carried out to surface treatment of PET film on non-equilibrium atmospheric pressure plasma.

• Journal of the Korean Vacuum Society
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• v.10 no.2
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• pp.267-274
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• 2001

Removal of Cr, Ni and Cu impurities on Si surfaces using remote plasma-excited hydrogen was investigated. Si surfaces were contaminated intentionally by acetone with low purity. To determine the optimum process condition, remote plasma-excited hydrogen cleaning was conducted for various rf-powers and plasma exposure times. After remote plasma-excited hydrogen cleaning, Si surfaces were analyzed by Total X-ray Reflection Fluorescence(TXRF), Surface Photovoltage(SPV) and Atomic Forece Microscope(AFM). The concentrations of Cr, Ni and Cu impurities were reduced and the minority carrier lifetime increased after remote plasma-excited hydrogen. Also RMS roughness decreased by more than 30% after remote plasma-excited hydrogen cleaning. AFM analysis results also show that remote plasma-excited hydrogen cleaning causes no damage to the Si surface. TXRF analysis results show that remote plasma-excited hydrogen cleaning is effective in eliminating metallic impurities from Si surface only if it is performed under an optimum process conditions. The removal mechanism of the Cr, Ni and Cu impurities using remote plasma-excited hydrogen treatments is proposed to be the lift-off during removal of underlying chemical oxides.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.326-328
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• 1995

SiC buffer layers were grown on Si(100) substrates by ultra-high-vacuum electron cryclotron resonance plasma (UHV ECR plasma) from $CH_4/H_2$ mixture at 700$^{\circ}C$. The electron densities and temperature were measured by single probe. The axial plasma potentials measured by emissive probe had the double layer structure at positive substrate bias. Piranha cleaning was carried out as ex-situ wet cleaning. Clean and smooth silicon surface were prepared by in-situ hydrogen plasma cleaning at 540$^{\circ}C$. A short exposure to hydrogen plasma transforms the Si surface from 1$\times$1 to 2$\times$1 reconstruction. It was monitored by reflection high energy electron diffraction (RHEED). The defect densities were analysed by the dilute Schimmel etching. The results showed that the substrate bias is important factor in hydrogen plasma cleaning. The low base pressure ($5\times10^{-10}$ torr) restrains the $SiO_2$ growth on silicon surface. The grown layers showed different characteristics at various substrate bias. RHEED and K-ray Photoelectron spectroscopy study showed that grown layer was SiC.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2006.04a
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• pp.85-85
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• 2006