• Journal of Industrial and Engineering Chemistry
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• v.68
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• pp.42-47
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• 2018

This work reports a facile and effective antibacterial coating for oxide substrates. As a coating material, a random copolymer, abbreviated as poly(TMSMA-r-PEGMA), was synthesized by radical polymerization of 3-(trimethoxysilyl)propyl methacrylate (TMSMA) and poly(ethylene glycol) methyl ether methacrylate (PEGMA). Polymeric self-assembled monolayers of poly(TMSMA-r-PEGMA) were formed on various inorganic oxide substrates, including silicon oxide, titanium dioxide, aluminum oxide, and glass, via the simple dip-coating process. The polymer-coated substrates were characterized by ellipsometry, contact angle measurements, and X-ray photoelectron spectroscopy. The bacterial adhesion on the polymer-coated substrates was completely suppressed compared to that on the uncoated substrates.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.186.1-186.1
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• 2014

Graphene, which is a 2-dimensional carbon material, has been attracting much interest due to its unique properties and potential applications. So far, many interesting experimental and theoretical works have been done concerning the electronic properties of graphene on various substrates. Especially, there are many experimental reports about doping in graphene which is caused by interaction between graphene and its supporting substrates. Here, we report the study of charge transfer between graphene and oxide substrates using density functional theory (DFT) calculations. In this study, we have investigated the charge transfer related with graphene considering various oxide substrates such as SiO2(0001) and MgO(111). Details in charge transfer between graphene and oxides are analyzed in terms of charge density difference, band structure and work function.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.3
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• pp.146-150
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• 2014

As a method of simple patterning of transparent conductive oxide (TCO) films deposited on flexible substrates, laser direct etching was carried out on TCO films sputtered on polycarbonate (PC) substrates. As a result of different binding energies in TCO films, indium tin oxide (ITO) and indium gallium zinc oxide (IGZO) were more easily etched than zinc oxide with different $Nd:YVO_4$ laser beam conditions.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.405-406
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• 2008

The amorphous indium zinc oxide (IZO) thin films were deposited on polyethersulfone (PES) and glass substrates by facing targets sputtering. IZO thin films deposited as functions of gas flow ratio on PES and glass substrates, respectively. The electrical, optical and structural properties of IZO thin films were evaluated by a Hall Effect Measurement, an X-Ray Diffractormeter, UV/VIS spectrometer in visible range and a scanning electron microscopy, respectively. As-deposited IZO thin films exhibited resistivity of $5.4\times10^{-4}$ and $4.5\times10^{-4}$ [$\Omega$-cm] on PES and glass substrates, respectively. The optical transmittance showed over 85% in the visible region on PES and glass substrates.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.309-309
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• 2011

There have been large research activities on the high quality oxide films for the realization oxide based electronics. However, the interface interdiffusion prohibits achieving high quality oxide films, when the oxide films are grown on non-oxide substrates. In the case of Si substrates, there exist lattice mismatch and interface interdiffusion when oxide films deposited on direct Si surface. In this presentation, we report the interface characteristics of yttria-stabilized zirconia films grown on silicon substrates. From x-ray reflectivity analysis we found that the film thickness and interface roughness decreased as the growth temperature increased, indicating that the growth mechanism varies and the chemical reaction is limited to the interface as the growth condition varies. Furthermore, the packing density of the film increased as the growth temperature increased and the film thickness decreased. X-ray photoelectron spectroscopy analysis of very thin films revealed that the amount of chemical shift increased as the growth temperature increased. Intriguingly, the direction of the chemical shift of Zr was opposite to that of Si due to the second nearest neighbor interaction.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.319-323
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• 1988

For finding the effects of As on $TiSi_2$ formation, sputter deposited Ti film on Si substrates implanted with various doses of As have been rapid thermal annealed in Ar atmosphere at temperatures of 600-900$^{\circ}C$ for 20 sec. The sheet resistance of Ti-Silicides was examined with 4-point probe, the thickness with ${\alpha}$-step, and the As dopant behavior in Si substrates with ASR. The thickness of Ti-Silicides decreased with increasing As doping, but Ti-Silicides sheet resistance increased with increasing it. However, the critical concentration effect reported by Park et al. was not observed. We observed that the thickness of native oxide increase with increasing As doping. Thus, we concluded that native oxide act as a "barrier" for the Si diffusion.

• Journal of the Korean Vacuum Society
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• v.13 no.4
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• pp.145-149
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• 2004

We have grown piezoelectric oxide films by RF magnetron sputtering using miscut substrates. Films were Brown on(001) $SrTiO_3$ substrates with miscut angles from 0 to 8 degrees toward the (100) direction. Films on high miscut substrates (>$4^{\circ}$) showed almost the pure perovskite phase in x-ray diffraction and were nearly stoichiometric. In contrast, films on exact (001) $SrTiO_3$ contained a high volume fraction of pyrochlore phases. A film on an $8^{\circ}$ miscut substrate exhibits a polarization hysteresis loop with a remnent polarization of 20$\mu$C/$\textrm{cm}^2$ at room temperature.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.8
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• pp.846-851
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• 2004

Transparent conducting indium tin oxide (TC-ITO) thin films on polymeric substrates have been deposited by a dc reactive magnetron sputtering without heat treatments. The polymeric substrates are acryl (AC), poly carbornate (PC), and polyethlene terephthalate (PET) as well as soda lime glass is also used to compare with the polymeric substrates. Sputtering parameters are an important factor for high quality of TC-ITO thin films prepared on polymeric substrates. Furthermore, the material, electrical and optical properties of as-deposited ITO films are dominated by the ratio of oxygen partial pressure. As the experimental results, the surface roughness of ITO films becomes rough as the oxygen partial pressure increases. The electrical resistivity of as-deposited ITO films decreases initially, and then increases with the increase of oxygen partial pressure. The optical transmittance at visible wavelength for all polymeric substrates is above 82 %.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.534-536
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• 2009

We have fabricated solution-processed zinc-tin oxide thin film transistors (TFTs) and simple circuits on glass substrates. We report a solutionprocessed zinc-tin oxide TFTs on silicon wafer with mobility greater than 9 $cm^2/V{\cdot}s$ (W/L = 100/5 ${\mu}m$) and threshold voltage variation of less than 1 V after bias-stressing. Also, we fabricated solution-processed zinc-tin oxide circuits including inverters and 7-stage ring oscillators fabricated on glass substrates using the developed zinc-tin oxide TFTs.

• Korean Journal of Materials Research
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• v.9 no.5
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• pp.491-495
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• 1999

In this study, we focus on Ca contaminant which affects on the roughness Si substrate after thermal process. The initial Si substrates were contaminated intentionally by using a standard Ca solution. The contamination levels of Ca impurity were measured by TXRF and the chemical composition of that was analyzed by AES. Then we gre the thermal oxide to investigate the effect of Ca contaminants. The microroughness of the Si surface, the thermal oxide surface, and the surface after removing the thermal oxide were measured to examine the electrical characteristics. The initial substrates that were contaminated with the standard solution of Ca exhibited the contamination levels of 10\ulcorner~10\ulcorneratoms/$\textrm{cm}^2$ which was measured by TXRF. The Ca contaminants were detected by AES and exhibited the peaks of Ca, SI, C and O.After intentional contamination, the surface microroughness of this initial substrate was increased from $1.5\AA$ to 4$\AA$ as contamination levels became higher. The microroughness of the thermal oxide surfaces of both contaminated and bare Si substrates exhibits similar values. But the microroughness of the contaminated$ Si/SiO_2$ interface was increased as contamination increased. The thermal oxide of contaminated substrate exhibited the small minority carrier diffusion length, low breakdown voltage, and slightly high leakage current.