• Journal of the Korean Crystal Growth and Crystal Technology
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• v.17 no.2
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• pp.47-51
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• 2007

F-doped SiOC : H thin films with low refractive index were deposited on Si wafer and glass substrate by plasma enhanced chemical vapor deposition (PECVD) as a function of rf powers, substrate temperatures, gas rates and their composition flow ratios ($SiH_4,\;CF_4$ and $N_2O$). The refractive index of the F-doped SiOC : H film continuously decreased with increasing deposition temperature and rf power. As $N_2O$ gas flow rate decreased, the refractive index of the deposited films decreased down to 1.3778, reaching a minimum value at rf power of 180W and $100^{\circ}C$ without $N_2O$ gas. The fluorine content of F-doped SiOC : H film increased from 1.9 at% to 2.4 at% as the rf power was increased from 60 W to 180 W, which results in the decrease of refractive index.

• Journal of Veterinary Science
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• v.23 no.2
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• pp.24.1-24.10
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• 2022

Background: Small interfering RNA technology has been considered a prospective alternative antiviral treatment using gene silencing against influenza viruses with high mutations rates. On the other hand, there are no reports on its effectiveness against the highly pathogenic avian influenza H5N1 virus isolated from Indonesia. Objectives: The main objective of this study was to improve the siRNA design based on the nucleoprotein gene (siRNA-NP) for the Indonesian H5N1 virus. Methods: The effectiveness of these siRNA-NPs (NP672, NP1433, and NP1469) was analyzed in vitro in Marbin-Darby canine kidney cells. Results: The siRNA-NP672 caused the largest decrease in viral production and gene expression at 24, 48, and 72 h post-infection compared to the other siRNA-NPs. Moreover, three serial passages of the H5N1 virus in the presence of siRNA-NP672 did not induce any mutations within the nucleoprotein gene. Conclusions: These findings suggest that siRNA-NP672 can provide better protection against the Indonesian strain of the H5N1 virus.

• Solar Energy
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• v.6 no.1
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• pp.12-23
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• 1986

The PECVD $SiN_x:H$ films were made from the $SiH_4-N_2$ gas mixtures under such deposition conditions as 0.01 to 1.0 of $SiH_4/N_2$ volume ratio, 0.1 to $0.8W/cm^2$ of RF power, and 100 to $400^{\circ}C$ of substrate temperature. The deposition rate, refractive index, hydrogen concentration, N/Si composition, optical gap and electric conductivity were measured, and the thermal stability and the optimum deposition conditions were investigated for the application of these films to the solar cell materials.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.178-181
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• 2005

Quaternary Ti-Si-C-N coatings were deposited on WC-Co substrates by a hybrid coating system of arc ion plating (AIP) and sputtering techniques using Ti and Si targets, in an $Ar/N_2/CH_4$ gaseous mixture. The crystallinity, bending status, and microstructure of the Ti-Si-C-N coatings were measured by X-ray diffractometer (XRD) and X-ray photoelectron spectroscope (XPS), The micro-hardness of Ti(C,N) and Ti-Si-N coatings were about 30 and 40 GPa, respectively. As the Si was incorporated into Ti(C,N) coatings, the Ti-Si-C-N coatings having Si content of $8.9\;at.\%$ showed the maximum hardness value of about 55 GPa. In this work, the microstructure and mechanical properties of Ti-Si-C-N coatings were systematically investigated.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.11
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• pp.1686-1690
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• 1989

Using the anisotropic etching characteristics of N2H4-H2O solutions, Si diaphragm was fabricated for the integrated sensors. The optimal composition and temperature of the etching solution in (100) Si etching process was established to be 50mol% N2H4 in H2O at 105\ulcorner\ulcorner for both higher etch rate (=2.6\ulcorner/min) and better surface quality of etched (100) planes. Based on the above optimal etching condition, the electrochemical etch-stop technique was employed to form n-type Si diaphragm having a thickness of 20\ulcorner and the thickness of diapragm could exactly be controlled to 20\ulcorner\ulcorner.

• Journal of the Korean Ceramic Society
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• v.39 no.8
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• pp.783-788
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• 2002

In this study, nano-sized Si-C-N precursor powders were synthesized by Chemical Vapor Condensation Method(CVC) using TMS(Tetramethylsilane: Si($CH_3)_4$), $NH_3$ and $H_2$ gases under the various reaction conditions of the reaction temperature, TMS/$NH_3$ ratio and TMS/$H_2$ ratio. XRD and FESEM were used to analysis the crystalline phase and the average particle size of the synthesized powders. It was found that the obtained powders under the considering conditions were all spherical amorphous powder with the particle size of 87∼130 nm. The particle size was decreased as the reaction temperature increased and TMS/$NH_3$ and TMS/$H_2$ ratio decreased. As the results of EA analysis, it was found that the synthesized powders had been formed the powders composed of Si, N, C and H. Through FT-IR results, it was found that the synthesized powders were Si-C-N precursor powders with Si-C, Si-N and C-N bonds.

• Proceedings of the IEEK Conference
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• 2002.06b
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• pp.245-248
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• 2002

In this paper, the influence of Si surface damage on the NiSi formation has been characterized. The silicon surface is damaged using ion beam type spotter. Then, the effect of H2 anneal and TiN capping layer on the damaged has also been analyzed. The sheet resistance of NiSi formed on damaged Si increased rapidly as the damaging time increases while thermal stability of damaged NiSi was stabler than the undamaged one. In the case when H\ulcorner anneal and TiN capping layer were applied together, the characteristics of NiSi shows a little improvement of the sheet resistance.

• Journal of the Korean Applied Science and Technology
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• v.16 no.1
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• pp.33-40
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• 1999

We used Cu as a representative of metals to be directly adsorbed on the bare Si surface and studied its removal DHF, DHF-$H_2O_2$ and BHF solution. It has been found that Cu ion in DHF adheres on every Si wafer surface that we used in our study (n, p, n+, p+) especially on the n+-Si surface. The DHF-$H_2O_2$ solution is found to be effective in removing metals featuring high electronegativity such as Cu from the p-Si and n-Si wafers. Even when the DHF-$H_2O_2$ solution has Cu ions at the concentration of 1ppm, the solution is found effective in cleaning the wafer. In the case the n+-Si and p+-Si wafers, however, their surfaces get contaminated with Cu When Cu ion of 10ppb remains in the DHF-$H_2O_2$ solution. When BHF is used, Cu in BHF is more likely to contaminate the n+-Si wafer. It is also revealed that the surfactant added to BHF improve wettability onto p-Si, n-Si and p+-Si wafer surface. This effect of the surfactant, however, is not observed on the n+-Si wafer and is increased when it is immersed in the DHF-$H_2O_2$ solution for 10min. The rate of the metallic contamination on the n+-Si wafer is found to be much higher than on the other Si wafers. In order to suppress the metallic contamination on every type of Si surface below 1010atoms/cm2, the metallic concentration in ultra pure water and high-purity DHF which is employed at the final stage of the cleaning process must be lowered below the part per trillion level. The DHF-$H_2O_2$ solution, however, degrades surface roughness on the substrate with the n+ and p+ surfaces. In order to remove metallic impurities on these surfaces, there is no choice at present but to use the $NH_4OH-H_2O_2-H_2O$ and $HCl-H_2O_2-H_2O$ cleaning.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.04b
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• pp.45-46
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• 2009

We have fabricated advanced metal-oxide-semiconductor (MOS) capacitors with thin (${\approx}10\;nm$) Inductive-Coupled Plasma (ICP) CVD $Si_xN_y$ dielectric layers and investigated electrical properties of nitrided $SiO_2$/4H-SiC interface after oxidizing the $Si_xN_y$ in dry oxidation and/or $N_2$ annealing. An improvement of electrical properties have been revealed in capacitance-voltage (C-V) and current density-electrical field (J-E) measurements if compared with non-annealed oxidized-SiN. The improvements of SiC MOS capacitors formed by oxidized-SiN have been explained in this paper.

• Journal of the Korean Ceramic Society
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• v.23 no.1
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• pp.67-73
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• 1986

SiC and $SiC-Si_3N_4$ powder were synthesized via the carbiding and carbiding-nitriding reaction of Jecheon quartz respectively using graphite as a reducing agent. $\beta$-SiC+($\alpha$+$\beta$)-$Si_3N_4$ composite was obtained by the carbiding-nitriding reaction of Jecheon quartz-graphite mixture at 1, 35$0^{\circ}C$ in $H_2$ atmosphere. $\beta$-SiC+($\alpha$+$\beta$)-$Si_3N_4$ composite was obtained by the carbidint-nitriding reaction of Jecheon quartz-graphite mixture at 1, 35$0^{\circ}C$ in $N_2-H_2$ atmosphere. The ratio of $\beta$-SiC+($\alpha$+$\beta$)-$Si_3N_4$ content in a produced composite could be controlled by adjusting the reaction time and gaseous mixture.