• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.407-410
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• 2002

Thermal oxidations of 3C-SiC thin-films grown on Si(100) by APCVD(atmospheric pressure chemical vapor deposition) were carried out. The oxidations of 3C-SiC were performed at $1100^{\circ}C$ for 1~6 hr in wet and dry $O_2$ ambient, respectively. Ellipsometry was used to determine the thickness and index of refraction of oxide films. The oxide thickness vs. the oxidation time follows the general relationship used for the thermal oxidation of Si. The surface roughness was analyzed by using AFM(atomic force microscopy). The surface roughness of oxidized 3C-SiC was rougher than before oxidation. The thermal oxide was found to be $SiO_2$ by XPS(X-ray photoelectron spectroscopy) analysis. Auger analysis showed them to be homogeneous with near stoichiometric composition.

• Journal of information and communication convergence engineering
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• v.9 no.2
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• pp.217-219
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• 2011

As silicon devices shrink and their density increases, the low dielectric constant materials instead of $SiO_2$ film is required. SiOC film as low-k films was deposited by the capacitively coupled plasma chemical vapor deposition and then annealed at $300{\sim}500^{\circ}C$ to find out the properties of the dependence on the temperature and polarity. This study researched the dielectric constant using by the structure of the metal/SiOC film/p-Si, chemical shift, thickness, refractive index and hardness. The trend of reflective index was inverse proportioned the thickness, but the dielectric constant was proportioned it. The dielectric constant decreased with decreasing the thickness and the increment of the refractive index.

• Journal of Ceramic Processing Research
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• v.23 no.4
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• pp.535-540
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• 2022

Atmospheric pressure plasma (APP) systems operate at atmospheric pressure and low temperatures, eliminating the need forvacuum systems such as vacuum chambers and pumps. In this paper, we studied that silicon dioxide thin films were formedat room temperature (25 oC) and 400 oC by APP processes on silicon wafers. A mixture of hexamethyldisilazane, oxygen,helium, and argon was supplied to the plasma apparatus to form the SiO2 layer. It was observed that a heat insulating layerhaving a thickness of about 22 nm at 25 oC and about 75 nm at 400 oC was formed. Although the surface was clean in samplestreated at 400 oC, small grains were observed in samples processed at room temperature. However, no void or defect in allsamples is observed inside the thin film from the surface. The physical property of the SiO2 thin film carried out by measuringrefractive index and density. The experimental refractive index of silicon dioxide grown by applying heat can be fitted to theSellmeier equation. Also, the film density of the sample at 400 oC using a XRR was observed to be 2.25 g/cm3, similar to thatof the glass, but that of the sample treated at room temp. was very low at 1.68 g/cm3. We also investigated the voltagedependentcurrent change in the oxide material. The SiO2 layer coated at room temperature showed a breakdown electricalfield of 2.5 MV/cm, while oxides deposited at 400 oC showed a characteristic of 9.9 MV/cm.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.247-250
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• 2001

We studied optical properties of SiON thin-film in the applications of optical waveguide. SiON thin-film was grown in 300$^{\circ}C$ by PECVD(plasma enhanced chemical vapor deposition) system. The change of SiON thin-film composition and refractive Index was studied as a function of varying NH$_3$ gas flow rate. As NH$_3$ gas flow rate was increased, Quantity of N and refractive index were increased at the same time. By the results, we could form the SiON thin-film to use of a waveguide with refractive index of 1.6. We analyzed the conditions of the thin-film with FTIR(fourier transform infrared) and OES(optical emission spectroscopy). N-H bonding(3390cm$\^$-1/) can be removed by thermal annealing. And we could observe the SiH bonding state and quantity by OES analysis in SiH$_4$

• Journal of the Korean Vacuum Society
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• v.18 no.1
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• pp.24-29
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• 2009

The SiOC film as inter layer insulator was researched the reason of the decreasing the dielectric constant by the ionic polarization and electronic polarization, respectively. The dielectric constant was measured using the conventional C-V measurement system, and the reflective index owing to the electronic polarization. Two kinds of dielectric constants were compared and then induced the origin of low-k materials. The chemical properties of the SiOC film were analyzed by the FTIR spectra, and the carbon content was obtained by the deconvoluted data of FTIR spectra. The variation of the carbon content tended to similar to the trend of reflective index, but was in inverse proportion to the dielectric constant. The effect of the electronic polarization did not affect the decreasing the dielectric constant, however the ionic polarization decreased effectively the dielectric constant of the SiOC film.

• Journal of the Korean Ceramic Society
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• v.27 no.5
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• pp.583-588
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• 1990

Glass films in the binary system B2O3-SiO2 and Al2O3-SiO2 were prepared on soda-lime-silica slide glass by the dip-coating technique from TEOS and boric acid or aluminum nitrate. Thickness of the films varying with viscosity and withdrawal speed were measured and effect of composition and firing temperature on the properties such as transmittance and refractive index were investigated. nM2O3.(100-n)SiO2(M=B or Al) films containing up to 20mol% B2O3 and 40mol% Al2O3 were transparent. Maximum transmittance at visible range were obtained for the sample containing 15mol% Ba2O3 and 32.5mol% Al2O3 and heat-treated at 50$0^{\circ}C$, respectively. Refractive index of the film containing 15mol% B2O3 was mininum in the B2O3-SiO2 binary system and minimal refractive index was appeared at the film containing 32.5mol% Al2O3. In IP spectra, addition of B2O3 were increased absorption peak intensity of B-O and Si-O-B bond and addition of Al2O3 were decreased absorption peak intensity of Si-O bond, respectively.

• Journal of the Korean Vacuum Society
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• v.18 no.6
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• pp.453-458
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• 2009

SiOC film was deposited by the chemical vapor deposition using BTMSM and oxygen mixed precursor. The characteristic of SiOC film varied with increasing of the gas flow rate ratios. The dielectric constant was obtained by C-V measurement using the structure of metal/SiOC film/Si. The space effect due to the steric hindrance between alkyl group at terminal bond of Si-$CH_3$ made the pores, and increased the thickness. However, the SiOC film due to the lowering of the polarization decreased the thickness and then decreased the dielectric constant. After annealing process, the dielectric constant decreased because of the evaporation of the OH or $H_2O$ sites. The thickness was related to the lowering of the dielectric constant by the reduction of the polarization and the thickness decreased with the decrease of the dielectric constant. The refractive index was in inverse proportion to thickness. The trends of the thickness and refractive index did not change after annealing.

• Journal of dental hygiene science
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• v.13 no.1
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• pp.91-96
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• 2013

The purpose of this study was to examine the possibility of the existence of high-risk groups of dental caries and influential factors for the high-risk groups, as there was a possibility that certain people might especially be at risk of suffering from dental caries when decayed, missing, and filled teeth index were analyzed, which were the typical indicators of dental caries. The data of the 4th National Health & Nutrition Survey for 2007, 2008 and 2009 were analyzed. Significant caries index (SiC index) were calculated, which were one of the representative devices to indicate high-risk groups of dental caries, and the SiC index and related factors were analyzed by using $x^2$ (chi-square) test. Besides, logistic regression analysis was utilized to find out influential factors, and a statistical package STATA 11.0 was employed. As a result of analyzing what factors would be linked to high-risk groups of dental caries, it's found that women were more likely to belong to high-risk groups than men (p<0.01). How the related factors affected the high-risk groups was analyzed, and it's found that those who didn't find themselves to be in good oral health were more likely to be classified into a high-risk group, and that those who brushed their teeth three times a more a day on a regular basis were more likely to belong to a high-risk group than the others who didn't (p<0.01). Thus, SiC index were calculated in this study to confirm the existence of dental caries high-risk groups, and what factors impacted on the high-risk groups was ascertained. It's required to implement efficient national policies to step up the promotion of national oral health based on the findings of the study.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.10
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• pp.447-450
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• 2003

This paper presents a process optimization of antireflection (AR) coating on crystalline Si solar cells. Theoretical and experimental investigations were performed on a double-layer AR (DLAR) coating of MgF$_2$/CeO$_2$. We investigated CeO$_2$ films as an AR layer because they have a proper refractive index of 2.46 and demonstrate the same lattice constant as Si substrate. RF sputter grown CeO$_2$ film showed strong dependence on a deposition temperature. The CeO$_2$ deposited at 40$0^{\circ}C$ exhibited a strong (111) preferred orientation and the lowest surface roughness of 6.87 $\AA$. Refractive index of MgF$_2$ film was measured as 1.386 for the most of growth temperature. An optimized DLAR coating showed a reflectance as low as 2.04% in the wavelengths ranged from 0.4${\mu}{\textrm}{m}$ to 1.1${\mu}{\textrm}{m}$. We achieved the efficiencies of solar cells greater than 15% with 3.12% improvement with DLAR coatings. Further details on MgF$_2$, CeO$_2$ films, and cell fabrication parameters are presented in this paper.

• Journal of the Korean Vacuum Society
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• v.6 no.S1
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• pp.75-79
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• 1997

Optical and mechanical characteristics of $TiO-2, ZrO_2 \;and\; SiO_xN_y$ thin films prepared by ion assisted deposition (IAD) were investigated. IAD films were bombarded by Ar or nitrogen ion beam from a Kaufman ion source while they were grown in as e-beam evaporator. The result shows that the Ae IAD increases the refractive index and packing density of $TiO_2 films close to those of the bulk. For $ZrO_2$ films the Ar IAD increases the average refractive index decreases the negative inhomogeneity of refractive index and reverses to the positive inhomogeneity. The optical properties result from improved packing density and denser outer layer next to air The Ar-ion bombardment also induces the changes in microstructure of $ZrO_2$ films such as the preferred (111) orientation of cubic phase increase in compressive stress and reduction of surface roughness. Inhomogeneous refractive index SiOxNy films were also prepared by nitrogen IAD and variable refractive index of $SiO_xN_y$ film was applied to fabricate a rugate filter.