• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.165-165
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• 2013

Nickel oxide was deposited on mesoporous silica by atomic layer deposition (ALD) consisting of sequential exposures to Ni(cp)2 and $H_2O$. NiO/silica samples were characterized by inductively coupled plasma-mass spectroscopy (ICP-MS), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), etc. The flow-type reactor was used to measure activity of NiO/silica catalyst for catalytic combustion of toluene. The activity of NiO/silica catalyst was evaluated in terms of toluene removal efficiency and selectivity to $CO_2$ and compared with those of bare nickel oxide nanoparticles. In order to investigate influence of reaction temperature on combustion aspect, the catalytic combustion experiments were carried out at various temperatures. We show that both bare and supported NiO can be efficient catalysts for total oxidation of toluene at a temperature as low as $250^{\circ}C$.

• Korean Journal of Materials Research
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• v.15 no.3
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• pp.149-154
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• 2005

Teflon like fluorocarbon thin films have been deposited on silicon and oxide molds as an antistiction layer for the hot embossing process by an inductively coupled plasma (ICP) chemical vapor deposition (CVD) method. The process was performed at $C_4F_8$ gas flow rate of 2 sccm and 30 W of plasma power as a function of substrate temperature. The thickness of film was measured by a spectroscopic ellipsometry. These films were left in a vacuum oven of 100, 200 and $300^{\circ}C$ for a week. The change of film thickness, contact angle and adhesion and friction force was measured before and after the thermal test. No degradation of film was observed when films were treated at $100^{\circ}C$. The heat treatment of films at 200 and $300^{\circ}C$ caused the reduction of contact angles and film thickness in both silicon and oxide samples. Higher adhesion and friction forces of films were also measured on films treated at higher temperatures than $100^{\circ}C$. No differences on film properties were found when films were deposited on either silicon or oxide. A 100 nm silicon template with 1 to $500\;{\mu}m$ patterns was used for the hot embossing process on $4.5\;{\mu}m$ thick PMMA spun coated silicon wafers. The antistiction layer of 10 nm was deposited on the silicon mold. No stiction or damages were found on PMMA surfaces even after 30 times of hot embossing at $200^{\circ}C$ and 10 kN.

• Journal of the Korean Vacuum Society
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• v.15 no.4
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• pp.427-433
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• 2006

We have fabricated nanodot arrays by using phase separated (PS- b- PMMA) diblock copolymer film and anodic aluminum oxide (AAO) membrane as templates with hexagonal arrays of cylindrical microdomains perpendicular to the substrate. Pulsed laser deposition technique was used to deposit various kinds of materials including Ag, Ni, ZnO, Si:Er, and Co/Pt onto Si substrates. The size and separation of nanodots correspond to those of the templates used, The density of nanodots was estimated to be $6{\times}10^{11}/cm^2$ and $1{\times}10^{10}/cm^2$ when the diblock copolymer and AAO were used, respectively. In particular, the optical properties of ZnO and Si: Er nanodot arrays were investigated and the strong photoluminescence at 380 nm and $1.54{\mu}m$ was observed from ZnO and Si:Er nanodot arrays, respectively.

• Journal of the Microelectronics and Packaging Society
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• v.11 no.2 s.31
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• pp.29-35
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• 2004

Hafnium-oxide gate dielectric films deposited by a metal organic chemical vapor deposition technique on a $N_2-plasma$ treated SiNx and a hydrogen-terminated Si substrate have been investigated. In the case of $HfO_2$ film deposited on a hydrogen-terminated Si substrate, suppressed crystallization with effective carbon impurity reduction was obtained at $450^{\circ}C$. X-ray photoelectron spectroscopy indicated that the interface layer was Hf-silicate rather than phase separated Hf-silicide and silicon oxide structure. Capacitance-voltage measurements show equivalent oxide thickness of about 2.6nm for a 5.0 nm $HfO_2/Si$ single layer capacitor and of about 2.7 nm for a 5.7 nm $HfO_2/SiNx/Si$ stack capacitor. TEM shows that the interface of the stack capacitor is stable up to $900^{\circ}C$ for 30 sec.

• Journal of the Korean Ceramic Society
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• v.47 no.1
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• pp.75-81
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• 2010

The feasibility of using the thin film technology in utilizing lanthanum strontium manganite (LSM) for a solid oxide fuel cell (SOFC) cathode in a low-temperature regime is investigated in this study. Thin film LSM cathodes were fabricated using pulsed laser deposition (PLD) on anode-supported SOFCs with yttria-stabilized zirconia (YSZ) electrolytes. Although cells with a 1 ${\mu}m$-thick LSM cathode showed poor low-temperature cell performance compared to that of a cell with a bulk-processed cathode due to the lack of a triple-phase boundary length, the cell with 200 nm-thick gadolinia-doped ceria (GDC) inserted between the LSM and YSZ showed enhanced performance and more stable operation characteristics in a comparison of a cell without a GDC layer. We postulate that the GDC layer likely improved the cathode adhesion, therefore contributing to the improvement of the cell performance instead of serving as an interfacial reaction buffer.

• Journal of the Korean institute of surface engineering
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• v.38 no.5
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• pp.188-192
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• 2005

Indium zinc oxide (IZO) thin films were deposited on glass substrate by dc magnetron sputtering. The effects of oxygen flow rate and deposition temperature on electrical and optical properties of the films were investigated. With addition of small amount of oxygen gas, the characteristic properties of amorphous IZO films were improved and the specific resistivity was about $4.8{\times}10^{-4}\Omega{\cdot}cm$. Change of structural properties according to the deposition temperature was observed with XRD, SEM, and AFM. Films deposited above $300^{\circ}C$ were found to be polycrystalline. Surface roughness of the films was increased due to the formation of grains on the surface. Electrical conductivity became deteriorated for polycrystalline IZO films. Consequently, high quality IZO films could be prepared by do sputtering with $O_{2}/Ar{\simeq}0.03$ and deposition temperature in range of $150\~200^{\circ}C$; a specific resistivity of $3.4{\times}10^{-4}{\Omega}{\cdot}cm$, an optical transmission over $90\%$ at wavelength of 550 nm, and a rms value of surface roughness about $3{\AA}$.

• Korean Journal of Materials Research
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• v.27 no.7
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• pp.392-397
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• 2017

Fluorine-doped tin oxide (FTO) coated NiCrAl alloy foam is fabricated using ultrasonic spray pyrolysis deposition (USPD). To confirm the influence of the FTO layer on the NiCrAl alloy foam, we investigated the structural, chemical, and morphological properties and chemical resistance by using USPD to adjust the FTO coating time (12, 18, and 24 min). As a result, when an FTO layer was coated for 24 min on NiCrAl alloy foam, it was found to have an enhanced chemical resistance compared to those of the other samples. This improvement in the chemical resistance of using USPD NiAlCr alloy foam can be the result of the existence of an FTO layer, which can act as a protection layer between the NiAlCr alloy foam and the electrolyte and also the result of the increased thickness of the FTO layer, which enhances the diffusion length of the metal ion.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.1
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• pp.74-80
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• 2023

Gallium oxide (Ga₂O₃) thin films were grown on c-, a-, m-, r-plane sapphire substrates using a mist chemical vapor deposition system. Various growth temperature range of 400~600℃ was applied for Ga₂O₃ thin film deposition. Then, several structural properties were characterized such as film thickness, crystal phase, lattice orientation, surface roughness, and optical bandgap. Under the certain growth temperature of 500℃, all grown Ga₂O₃ featured rhombohedral crystal structures and well-aligned preferred orientation to sapphire substrate. The films grown on c-and r-plane sapphire substrates, showed low surface roughness and large optical bandgap compared to those on a-and m-plane substrates. Therefore, various sapphire orientation can be potentially applicable for future Ga₂O₃-based electronics applications.

• Proceedings of the Korean Ceranic Society Conference
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• 2004.10a
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• pp.83.2-83.2
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• 2004

• Proceedings of the Korean Vacuum Society Conference
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• 2003.08a
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• pp.178-178
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• 2003