• Journal of the Korean institute of surface engineering
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• v.34 no.1
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• pp.10-16
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• 2001

Recently plasma etching research has been focused on the metal surfaces in the nuclear industry. In this study, surface etching reaction of metallic Co and Mo, principal contaminants in the spent nuclear components, in CF$_4$/O$_2$, gas plasma has been experimentally investigated to look into the applicability and the effectiveness of the technique for the surface decontamination. Experimental variables are $CF_4$/$O_2$ ratio and substrate temperature between 29$0^{\circ}C$ and 38$0^{\circ}C$. Experimental results Show that the optimum gas composition is 80%CF$_4$-20%$O_2$ and the metallic Co and Mo are etched out well enough in the temperatures range. Cobalt starts to be etched above $350^{\circ}C$ and the etching rate increases with increasing substrate temperature. Maximum rate achieved at 38$0^{\circ}C$ under 220 W r.f. plasma power is 0.06 $\mu\textrm{m}$/min. On the other hand, the metallic Mo is etched easily even at low temperature and the reaction rate drastically increases as the substrate temperature goes up. Highest rate obtained under the same conditions is $1.9\mu\textrm{m}$/min. OES (Optical Emission Spectroscopy) analysis reveals that the intensities of F atom and CO molecule reach maximum at the optimum gas composition, which demonstrates that the principal reaction mechanism is fluorination and/or carbonyl reaction. It is confirmed, therefore, that dry processing technique using reactive plasma is quite feasible and applicable for the decontamination of surface-contaminated parts or equipments.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.5
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• pp.388-392
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• 2002

In this work, the etching of $CeO_2$ thin films has been performed in an inductively coupled $Ar/CF_4/Cl_2$ plasma. The highest etch rate of the $CeO_2$ thin film ws 250 ${\AA}/min$ and the selectivity of CeO$_2$to SBT was 0.4 at a 10% additive $Cl_2$ into Ar/($Ar+CF_4$)gas mixing ratio of 0.8. From result of X-ray photoelectron spectroscopy (XPS) analysis, there are Ce-Cl and Ce-F bonding by chemical reaction between Cl, F and Ce. During the etching of $CeO_2$ thin films in $Ar/CF_4/Cl_2$ plama, Ce-Cl and Ce-F bond is formed, and these prodcuts can be removed by the physical bombardment of Ar ions. The 10% additive $Cl_2$ into the Ar/($Ar+CF_4$)gas mixing ratio of 0.8 could enhance the reaction between Cl, F and Ce.

• Journal of the Korean Ceramic Society
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• v.42 no.4
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• pp.232-236
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• 2005

The etching characteristics of a $LiNbO_{3}$ optical waveguide structure have been investigated using neutral loop discharge plasma with the mixture of $C_{3}F_{8}$ and Ar and the bias power parameters. The etching rate and profile angle of optical waveguide with etching parameters were evaluated by scanning electron microscopy. Also, the etching RMS roughness was evaluated by atomic force microscopy. From the results of optimum etching conditions are the $C_{3}F_{8}$ gas flow ratio of 0.2 and the bias power of 300 W.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.168-168
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• 2008

Dimension of a transistor has rapidly shrunk to increase the speed of device and to reduce the power consumption. However, it is accompanied with several problems like direct tunneling through the gate dioxide layer and low conductivity characteristic of poly-Si gate in nano-region. To cover these faults, study of new materials is urgently needed. Recently, high dielectric materials like $Al_2O_3$, $ZrO_2$, and $HfO_2$ are being studied for equivalent oxide thickness (EOT). However, poly-Si gate is not compatible with high-k materials for gate-insulator. Poly Si gate with high-k material has some problems such as gate depletion and dopant penetration problems. Therefore, new gate structure or materials that are compatible with high-k materials are also needed. TiN for metal/high-k gate stack is conductive enough to allow a good electrical connection and compatible with high-k materials. According to this trend, the study on dry etching of TiN for metal/high-k gate stack is needed. In this study, the investigations of the TiN etching characteristics were carried out using the inductively coupled $BCl_3$-based plasma system and adding $Cl_2$ gas. Dry etching of the TiN was studied by varying the etching parameters including $BCl_3$/Ar gas mixing ratio, RF power, DC-bias voltage to substrate, and $Cl_2$ gas addition. The plasmas were characterized by optical emission spectroscopy analysis. Scanning electron microscopy was used to investigate the etching profile.

• Transactions on Electrical and Electronic Materials
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• v.16 no.6
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• pp.346-350
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• 2015

In this study, we carried out an investigation of the etch characteristics of TiO₂ thin films and the selectivity of TiO₂ to SiO₂ in adaptive coupled C1₂/Ar plasma. The maximum etch rate of the TiO₂ thin film was 136±5 nm/min at a gas mixing ratio of C1₂/Ar (75%:25%). The X-ray photoelectron spectroscopy (XPS) analysis showed the efficient destruction of oxide bonds by the ion bombardment as well as the accumulation of low volatile reaction products on the etched surface.

• Textile Coloration and Finishing
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• v.4 no.1
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• pp.1-9
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• 1992

In order to study on the surface modification of the poly(ethylene Terephthalate)(PET) fabrics, low temperature plasma$(O_2)$ has been irradiated on the PET fabrics in various conditions. Experiments were carried out at pressure ranging from 0.5 tort to 3 tort. The properties of PET fabrics treated with low temperature plasma($(O_2)$, such as bathochromic, wettability, antistatic property were measured. Etching ratio was increased as the pressure and the output of discharge increased. When its were put on the cathode, the most efficient effect of etching according to the position of sample between anode and cathode was obtained. The bathochromic effect has more or less improved as pressure was getting higth in case of dyed fabrics treated with only low temperature plasma$(O_2)$ . And when it was treated with the low refractive index resin, the bathochromic of dyed fabrics treated with low temperature plasma$(O_2)$ was better than that of the dyed fabrics untreated.

• Transactions on Electrical and Electronic Materials
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• v.4 no.3
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• pp.1-4
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• 2003

The etching of Au thin films has been performed in an inductively coupled $CF_4 / Cl_2 / Ar$ plasma. The etch properties including etch rate and selectivity were examined as $CF_4$ content adds from o to $30\%$ to $Cl_2/Ar$ plasma. The $Cl_2/(Cl_2 + Ar)$ gas mixing ratio was fixed at $20\%$. Other parameters were fixed at an rf power of 700 W, a dc bias voltage of -150 V, a chamber pressure of 15 mTorr, and a substrate temperature of $30^{\circ}C$. The highest etch rate of the Au thin film was 370 nm/min at a $10\%$ additive $CF_4$ into $Cl_2/Ar$ gas mixture. The surface reaction of the etched Au thin films was investigated using x-ray photoelectron spectroscopy (XPS) analysis. The XPS analysis shows that the intensities of Ail peaks are changed, indicating that there is a chemical reaction between Cl and Au. Au-Cl is hard to remove on the surface because of its high melting point. However, etching products can be sputtered by Ar ion bombardment.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.6
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• pp.451-455
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• 1999

The highest etch rate of Pt film was obtained at 10% $Cl_2$/90% Ar gas mixing ratio in our previous investigation. However, the problems such as the etch residues(fence) remained on the pattern sidewall, low selectivity to oxide as mask and low etch slope were presented. In this paper, the etching by additive $O_2$ gas to 10% $Cl_2$/90% Ar gas base was examined. As a result, the fence-free pattern and higher etch slope as about 60$^{\circ}$was observed and the selectivity to oxide increased to 2.4 without decreasing of the etch rate $1500{\AA}$/min. XPS surface analysis proved that a only little $O_2$ gas removes the Pt-CI compounds as residues on the etched surface.

• Transactions on Electrical and Electronic Materials
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• v.11 no.4
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• pp.166-169
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• 2010

In this study, we changed the etch parameters (gas mixing ratio, radio frequency [RF] power, direct current [DC]-bias voltage, and process pressure) and then monitored the effect on the $HfAlO_3$ thin film etch rate and the selectivity with $SiO_2$. A maximum etch rate of 108.7 nm/min was obtained in $Cl_2$ (3 sccm)/$BCl_3$ (4 sccm)/Ar (16 sccm) plasma. The etch selectivity of $HfAlO_3$ to $SiO_2$ reached 1.11. As the RF power and the DC-bias voltage increased, the etch rate of the $HfAlO_3$ thin film increased. As the process pressure increased, the etch rate of the $HfAlO_3$ thin films increased. The chemical state of the etched surfaces was investigated with X-ray photoelectron spectroscopy. According to the results, the etching of $HfAlO_3$ thin film follows the ion-assisted chemical etching.

• Transactions on Electrical and Electronic Materials
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• v.15 no.1
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• pp.49-54
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• 2014

In this study, we carried out an investigation of the etch characteristics of silicon (Si) film, and the selectivity of Si to $SiO_2$ in $SF_6/O_2$ plasma. The etch rate of the Si film was decreased on adding $O_2$ gas, and the selectivity of Si to $SiO_2$ was increased, on adding $O_2$ gas to the $SF_6$ plasma. The optical condition of the Si film with this work was 1,350 nm/min, at a gas mixing ratio of $SF_6/O_2$ (=130:30 sccm). At the same time, the etch rate was measured as functions of the various etching parameters. The X-ray photoelectron spectroscopy analysis showed the efficient destruction of oxide bonds by ion bombardment, as well as the accumulation of high volatile reaction products on the etched surface. Field emission auger electron spectroscopy analysis was used to examine the efficiency of the ion-stimulated desorption of the reaction products.