• Journal of the Korean Crystal Growth and Crystal Technology
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• v.16 no.6
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• pp.256-259
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• 2006

The amorphous $SiO_x$ nanowires were synthesized by the vapor phase epitaxy (VPE) method. $SiO_x$ nanowires were formed on silicon wafer of temperatures ranged from $800{\sim}1100^{\circ}C$ and nickel thin film was used as a catalyst for the growth of nanowires. A vapor-liquid-solid (VLS) mechanism is responsible for the catalyst-assisted amorphous $SiO_x$ nanowires synthesis in this experiment. The SEM images showed cotton-like nanostructure of free standing $SiO_x$ nanowires with the length of more than about $10{\mu}m$. The $SiO_x$ nanowires were confirmed amorphous structure by TEM analysis and EDX spectrum reveals that the nanowires consist of Si and O.

• Journal of Sensor Science and Technology
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• v.1 no.1
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• pp.5-12
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• 1992

We have fabricated a-Si:H multilayer for contact-type linear image sensor by means of RF glow discharge decomposition method. The ITO/i-a-Si:H/Al structure has relatively high dark current due to indium diffusion and carrier injection from both electrodes, resulting in low photocurrent to dark current. To suppress the dark current and to enhance interface electric field between ITO and i-a-Si:H film we have fabricated ITO/insulator/i-a-S:H/p-a-S:H/Al multilayer film with blocking structure. The photocurrent of ITO/$SiO_{2}(300{\AA})$/i-a-Si:H/p-a-Si:H($1500{\AA}$)/Al multilayer sensor with 5V bias voltage became saturated at about 20nA under $20{\mu}W/cm^{2}$ light intensity, while the dark current was less than 0.1nA. To increase the light generation efficiency we have adopted ITO/$SiO_{x}N_{y}(300{\AA})$/i-a-Si:H/p-a-Si:H($1500{\AA}$)/Al structure, showing photocurrent of 30nA and dark current of 0.08nA with 5V bias voltage. Also the spectral photosensitivity of the multilayer was enhanced for short wavelength visible region of 560nm, compared with that of the a-Si:H monolayer of 630nm. And its photoresponse time was about 0.3msec with the film homogeneity of 5% deviation.

• Korean Chemical Engineering Research
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• v.52 no.4
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• pp.443-450
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• 2014

Selective catalytic reduction of nitrogen monoxide by hydrogen ($H_2$-SCR of NO) over platinum catalysts impregnated on zirconia-incorporated silica ($ZrO_2-SiO_2$) and manganese oxide ($MnO_x$) was investigated. $Pt-MnO_x$ catalyst showed low conversions and low yields of $N_2O$ and $NO_2$ at $100{\sim}350^{\circ}C$. On the other hand, NO conversions over $Pt/ZrO_2-SiO_2$ were very high, but $N_2O$ was predominantly produced at $100-150^{\circ}C$ and the yield of $NO_2$ increased with temperature at $200-300^{\circ}C$, resulting in poor $N_2$ yields. $Pt-MnO_x/ZrO_2-SiO_2$ exhibited a small enhancement in $N_2$ yield at $100-150^{\circ}C$ due to the synergy of $MnO_x$ and $ZrO_2-SiO_2$. The surface composition and oxidation state of the catalyst components and the acidity of the catalysts were examined. IR spectra of the adsorption of NO and their subsequent reactions with hydrogen on these catalysts were also recorded. The variations of conversion and product yield according to the catalyst components in the $H_2$-SCR of NO were discussed in relation to their catalytic roles.

• Korean Journal of Optics and Photonics
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• v.9 no.3
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• pp.162-167
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• 1998

$SiO_xF_y$ optical thin films of lower refractive indices than glass substrates were fabricated by the CF$_4$ ion beam assisted deposition method and the optical, structural and chemical properties of them were investigated. Refractive index of $SiO_xF_y$ films was varied from 1.455 to 1.394 by decreasing the anode voltage or from 1.462 to 1.430 by increasing the current density of end-Hall ion source. FT-IR and XPS analyses show that as the F concentration increases, the Si-O bond at $1080m^{-1}$ shifts to higher wavenumber, the OH bonds are reduced drastically, and the fluorine atoms at the air-film interface are desorbed out by reacting with $H_2O$ in the atmosphere. $SiO_xF_y$ thin films are amorphous by the XRD analysis and have the compressive stress below 0.3 GPa. As an application of $SiO_xF_y$ thin films a two-layer antireflection coating was fabricated using a $SiO_xF_y$ film as a low refractive index layer and a Si film as an absorbing one.

• Journal of the Microelectronics and Packaging Society
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• v.15 no.4
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• pp.25-29
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• 2008

Reliability and performance in metal gate/high-k device with multiple gate dielectrics were investigated. MOSFETs with a thin $HfSiO_x$ layer on a thermal Si02 dielectric as gate dielectrics exhibit excellent mobility and low interface trap density. However, the distribution of threshold voltages of $HfSiO_x/SiO_2$ stack devices were wider than those of $SiO_2$ and $HfSiO_x$ single layer devices due to the penetration of Hf and/or intermixing of $HfSiO_x$ with underlying $SiO_2$. The results of TZDB and SILC characteristics suggested that a certain portion of $HfSiO_x$ layer reacted with the underlying thick $SiO_2$ layer, which in turn affected the reliability characteristics.

• Journal of the Korean Chemical Society
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• v.47 no.6
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• pp.619-624
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• 2003

The $Gd_{1.9-x}Li_{0.1}Eu_xO_3$ (x=0.02, 0.05, 0.08, and 0.12) powders (${\thickapprox}1{\mu}m$) synthesized by sol-gel method, whose surfaces are modified in a colloidal silica suspension (size of $SiO_2$ particles: ${\sim}30$ nm), have been fabricated to highly stable and effective luminescent films on the glass substrates. Thanks to the fused $SiO_2$ nano particles in the vicinity of the glass softening temperature (at around $700^{\circ}C$), $Gd_{1.9-x}Li_{0.1}Eu_xO_3$ powders are strongly attached onto the surface of glass substrate (>9H, pencil hardness tester). This simple and low-cost method to get $Gd_{1.9-x}Li_{0.1}Eu_xO_3$ phosphor films without any loss of luminescence brightness would promise for applications to display devices.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.6
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• pp.603-609
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• 2022

Passivation quality is mainly governed by epitaxial growth of crystalline silicon wafer surface. Void-rich intrinsic a-Si:H interfacial layer could offer higher resistivity of the c-Si surface and hence a better device efficiency as well. To reduce the resistivity of the contact area, a modification of void-rich intrinsic layer of a-Si:H towards more ordered state with a higher density is adopted by adapting its thickness and reducing its series resistance significantly, but it slightly decreases passivation quality. Higher resistance is not dominated by asymmetric effects like different band offsets for electrons or holes. In this study, multilayer of intrinsic a-Si:H layers were used. The first one with a void-rich was a-Si:H(I₁) and the next one a-SiO_x:H(I₂) were used, where a-SiO_x:H(I₂) had relatively larger band gap of ~2.07 eV than that of a-Si:H (I₁). Using a-SiO_x:H as I₂ layer was expected to increase transparency, which could lead to an easy carrier transport. Also, higher implied voltage than the conventional structure was expected. This means that the a-SiO_x:H could be a promising material for a high-quality passivation of c-Si. In addition, the i-a-SiO_x:H microstructure can help the carrier transportation through tunneling and thermal emission.

• Corrosion Science and Technology
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• v.11 no.1
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• pp.1-8
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• 2012

The development of martensitic grades which can be processed in continuous galvanizing lines requires the reduction of the oxides formed on the steel during the hot dip process. This reduction mechanism was investigated in detail by means of High Resolution Transmission Electron Microscopy (HR-TEM) of cross-sectional samples. Annealing of a martensitic steel in a 10% $H_2+N_2$ atmosphere with the dew point of $-35^{\circ}C$ resulted in the formation of a thin $_{C-X}MnO.SiO_{2}$ (x>1) oxide film and amorphous $_{a-X}MnO.SiO_{2}$ oxide particles on the surface. During the hot dip galvanizing in Zn-0.13%Al, the thin $_{C-X}MnO.SiO_{2}$ (x>1) oxide film was reduced by the Al. The $_{a-X}MnO.SiO_{2}$ (x<0.9) and $a-SiO_{2}$ oxides however remained embedded in the Zn coating close to the steel/coating interface. No $Fe_{2}Al_{5-X}Zn_{X}$ inhibition layer formation was observed. During hot dip galvanizing in Zn-0.20%Al, the $_{C-X}MnO.SiO_{2}$ (x>1) oxide film was also reduced and the amorphous $_{a-X}MnO.SiO_{2}$ and $a-SiO_{2}$ particles were embedded in the $Fe_{2}Al_{5-X}Zn_{X}$ inhibition layer formed at the steel/coating interface during hot dipping. The results clearly show that Al in the liquid Zn bath can reduce the crystalline $_{C-X}MnO.SiO_{2}$ (x>1) oxides but not the amorphous $_{a-X}MnO.SiO_{2}$ (x<0.9) and $a-SiO_{2}$ oxides. These oxides remain embedded in the Zn layer or in the inhibition layer, making it possible to apply a Zn or Zn-alloy coating on martensitic steel by hot dipping. The hot dipping process was also found to deteriorate the mechanical properties, independently of the Zn bath composition.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2011.05a
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• pp.171-171
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• 2011

Atmospheric pressure- plasma enhanced chemical vapor deposition(AP-PECVD)Processes are recognized as promising and cost effective methods for wide-area coating on sheets of steel, glass, polymeric web, etc. In this study, $SiO_xC_y$ thin films were deposited by using AP-PECVD with a dielectric barrier discharge(DBD). The characteristic of $SiO_xC_y$ thin films were investigated as afunction of the HMDSO/O2/He flow rate. And the moisture permeability of $SiO_xC_y$ thin films was studied. The $SiO_xC_y$ thin films were characterized by the Fourier-transformed Infrared(FT-IR) spectroscopy and also investigated by X-ray photo electron spectroscopy(XPS), Auger Electron Spectroscopy(AES). The moisture permeability of $SiO_xC_y$ thin films was investigated by $H_2O$ permeability tester Detailed experimental results will be demonstrated through th present work.

• Electrical & Electronic Materials
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• v.16 no.9
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• pp.65.1-65
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• 2003

The interface of zirconium oxide thin films on silicon is analyzed in detail for their potential applications in the microelectronics. The formation of an interfacial layer of ZrSi$\sub$x/O$\sub$y. with graded Zr concentration is observed by the x-ray photoelectron spectroscopy and secondary ion mass spectrometry analysis. The as-deposited ZrO$_2$/ZrSi$\sub$x/O$\sub$y//Si sample is thermally stable up to 880$^{\circ}C$, but is less stable compared to the ZrO$_2$/SiO$_2$/Si samples. Post-deposition annealing in oxygen or ammonia improved the thermal stability of as-deposited ZrO$_2$/ZrSi$\sub$x/O$\sub$y/Si to 925$^{\circ}C$, likely due to the oxidation/nitridation of the interface. The as-deposited film had an equivalent oxide thickness of∼13 nm with a dielectric constant of ∼21 and a leakage current of 3.2${\times}$10e-3 A/$\textrm{cm}^2$ at 1.5V. Upon oxygen or ammonia annealing, the formation of SiO$\sub$x/ and SiH$\sub$x/N$\sub$y/O$\sub$z/ at the interface reduced the overall dielectric constants.