• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.4
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• pp.323-326
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• 2010

$(Zn_{1-x}Ca_x)_2SiO_4$:Mn phosphors doped with Ca were synthesized by solid state reaction method. $(Zn_{1-x}Ca_x)_2SiO_4$:Mn phosphors showed XRD patterns of Willemite structure. Also, $CaSiO_3$ structure and new peak near 610 nm in $(Zn_{1-x}Ca_x)_2SiO_4$:Mn with increasing value of x were observed from XRD and PL. The new peak near 610 nm in $(Zn_{1-x}Ca_x)_2SiO_4$:Mn with doping Ca was attributed to formation of $CaSiO_3$.

• Korean Chemical Engineering Research
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• v.44 no.6
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• pp.609-613
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• 2006

Ba2-xSrxSiO4:Eu2+ phosphor particles with the high photoluminescence (PL) intensity under long wavelength ultraviolet (UV) were prepared by spray pyrolysis. The photoluminescence, morphological and crystalline characteristics of $Ba_{2-x.}Sr_{x.}SiO_4:Eu^{2+}$ phosphor particles prepared by spray pyrolysis were investigated. $Ba_{2-x.}Sr_{x.}SiO_4:Eu^{2+}$ phosphor particles prepared by spray pyrolysis had various colors from bluish green to yellow by changing the ratio of barium and strontium of the host material. In case of x=0, the main emission peak of $Ba_2SiO_4:Eu^{2+}$ phosphor was 500 nm. In case of x=2, the main emission peak of $Sr_2SiO_4:Eu^{2+}$ phosphor was 554nm. $Ba_{2-x.}Sr_{x.}SiO_4:Eu^{2+}$ phosphor particles obtained by spray pyrolysis had spherical shape and hollow structure. On the other hand, the post-treated $Ba_{2-x.}Sr_{x.}SiO_4:Eu^{2+}$ phosphor particles had large size and irregular shape. The $Ba_{1.488}Sr_{0.5}SiO_4:Eu_{0.012}{^{2+}}$ phosphor particles had the maximum PL intensity after post-treatment at temperature of $1300^{\circ}C$ for 3h under reduction atmosphere.

• Journal of the Korean Ceramic Society
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• v.38 no.9
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• pp.794-798
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• 2001

$Y_{2-x}SiO_5:Ce_x^{3+}$(x=0.002∼0.04) phosphors were prepared by sol-gel process, amorphous crystal phase was observed in calcining dry gel at 800$^{\circ}$C, but pure $X_2$ type of type $Y_2SiO_5$ phase appeared from heat treatment above 1000$^{\circ}$C. Light absorption of tye $Y_2SiO_5$ host lattice occurred at 230∼360nm, and light absorption of the $Y_{2-x}SiO_5:Ce_x^{3+}$ phosphors was observed at 300∼400nm in adding $Ce^{3+}$. $Y_{2-x}SiO_5:Ce_x^{3+}$ phosphors showed maximum emission shoulder at 436nm. Maximum CL intensities of $Y_{2-x}SiO_5:Ce_x^{3+}$ were observed in adding 0.025 $Ce^{3+}$ and the phosphor showed x=0.161, y=0.124 in color coordinate of CIE1931.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.2
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• pp.98-103
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• 2013

In this work, we investigated the enhanced performance of IZO-based TFTs with $HfSiO_x$ gate insulators. Four types of $HfSiO_x$ gate insulators using different diposition powers were deposited by co-sputtering $HfO_2$ and Si target. To simplify the processing sequences, all of the layers composing of TFTs were deposited by rf-magnetron sputtering method using patterned shadow-masks without any intentional heating of substrate and subsequent thermal annealing. The four different $HfSiO_x$ structural properties were investigated x-ray diffraction(XRD), atomic force microscopy(AFM) and also analyzed the electrical characteristics. There were some noticeable differences depending on the composition of the $HfO_2$ and Si combination. The TFT based on $HfSiO_x$ gate insulator with $HfO_2$(100W)-Si(100W) showed the best results with a field effect mobility of 2.0[$cm^2/V{\cdot}s$], a threshold voltage of -0.5[V], an on/off ratio of 5.89E+05 and RMS of 0.26[nm]. This show that the composition of the $HfO_2$ and Si is an important factor in an $HfSiO_x$ insulator. In addition, the effective bonding of $HfO_2$ and Si reduced the defects in the insulator bulk and also improved the interface quality between the channel and the gate insulator.

• Journal of the Korean Vacuum Society
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• v.19 no.5
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• pp.341-346
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• 2010

In this paper, anti-reflection coating was investigated for decreasing the reflection in visible range of 400~650 [nm] through four staked layers of $Si_xO_y$ and $Si_xN_y$ thin films prepared by reactive sputtering method. Si single crystal of 6 [inch] diameter was used as a sputtering target. Ar and $O_2$ gases were used as sputtering gases for reactive sputtering for the $Si_xO_y$ thin film, and Ar and $N_2$ gases were used for reactive sputtering for the $Si_xN_y$ thin film. DC pulse power of 1900 [W] was used for the reactive sputtering. Refractive index and deposition rate were 1.50 and 2.3 [nm/sec] for the $Si_xO_y$, and 1.94 and 1.8 [nm/sec] for the $Si_xN_y$ thin film, respectively. Considering the simulation of the four layer anti-reflection coating structure with the above mentioned films, the $Si_xO_y-Si_xN_y$ stacked four-layer structure was prepared. The reflection measurement result for that structure showed that a "W" shaped anti-reflection was obtained successfully with a reflection of 1.7 [%] at 550 [nm] region and a reflection of 1 [%] at 400~650 [nm] range.

• 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 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 Ceramic Society
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• v.23 no.4
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• pp.23-26
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• 1986

The synthetic conditions of $ ZrSiO_4-Cd(S_xS_{1-x})$ stains from CdS, Se, $SiO_2$ , 4ZrO_2$ and Lif were investigated and the colors were examined. Colors of the stains prepared were yellow orange red pink ruby and violet in relation to both the content of CdS-Se in $ZrSiO_4$ and firing temperature. Colors of these series stains were thermally stabilized probably by the structural stability of zirconium silicate. Furthermore by the result of X-ray diffraction analysis it is assumed that color of the zircon cadmium sulphoselenide $ ZrSiO_4-Cd(S_xS_{1-x})$ stain is developed by neither the coloring ions in $ZrSiO_4$ lattice nor the solid solution of $ZrSiO_4$ and $Cd(S_xS_{1-x})$ but by the small crystals of $Cd(S_xS_{1-x})$ being occluded by the zirconium silicate during sintering process.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.12
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• pp.1028-1032
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• 2009

In this study, the influences of silicon-based gas barrier films fabricated by using a facing target sputtering(FTS) system on the gas permeability for flexible displays have been investigated. Under these optimum conditions on the $SiO_x$ film with oxygen concentration($O_2/Ar+O_2$) of 3.3% and the $SiO_xN_y$ film with nitrogen concentration($N_2/Ar+O_2+N_2$) of 30% deposited by the FTS system, it was found that the films were grown about 4 times higher deposition rate than that of the conventional sputtering system and showed high transmittance about 85% in the visible light range. Particularly, the polyethylene naphthalate(PEN) substrates with the $SiO_x$ and/or $SiO_xN_y$ films showed the enhanced properties of decreased water vapor transmission rate (WVTR) over $10^{-1}\;g/m^2{\cdot}day$ compared with the PEN substrate without any gas barrier films, which was due to high packing density in the Si-based films with high plasma density by FTS process and/or the denser chemical structure of Si-N bond in the $SiO_xN_y$ film.

• Journal of the Korean Vacuum Society
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• v.9 no.4
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• pp.346-352
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• 2000

We investigated the oxidation behavior of poly $Si_{1-x}Ge_x$ films (X=0.15, 0.42) at $700^{\circ}C$ in wet oxidation ambients and analyzed the oxide by XPS, RBS, and cross-sectional TEM. In the case of poly $Si_{0.85}Ge_{0.15}$ films, $SiO_2$ was formed on the poly $Si_{1-x}Ge_x$ films and Ge was rejected from growing oxide, subsequently leading to the increase of Ge content. In the case of poly $Si_{0.58}Ge_{0.42}$ films, we found that $SiO_2-GeO_2$ were formed on the poly $Si_{1-x}Ge_x$ films due to high Ge content. Finally, we proposed the oxidation model of poly $Si_{1-x}Ge_x$ films.