• Journal of Information Display
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• v.13 no.3
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• pp.97-100
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• 2012

We have conducted two kinds of the so-called charge-compensated aliovalent element substitutions to control the photoluminescence properties of $NaAlSiO_4:Eu^{2+}$ with a special focus on the enhancement of the excitation intensity at 400 nm. The aliovalent element substitutions include cation-cation and cation-anion co-substitutions according to the general formulas $Na_{1-x}M_xAl_{1+x}Si_{1-x}O_4:Eu^{2+}$ and $Na_{1-x}M_xAlSiO_{4-x}N_x:Eu^{2+}$ (M = $Mg^{2+}$, $Ca^{2+}$, and $Sr^{2+}$), respectively. The increase in the relative excitation intensity at 400 nm has been achieved in both types of the co-substitutions. Thus, the present research has demonstrated the effectiveness of the charge-compensated element substitution.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.5
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• pp.295-299
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• 2015

In this paper to improve the ionic conduction properties, lanthanum silicate apatite $La_{9.33}(SiO_4)_6O_2$ ceramic, which substituted by V ions at Si-site, were fabricated by the mixed-oxide method. And we investigated the structural and electrical properties of $La_{9.33}(Si_{6-x}V_x)O_{26}$ specimens with variation of dopants for the application of solid oxide fuel cells. The sintering temperature of $La_{9.33}(Si_{6-x}V_x)O_{26}$ specimens decreased from $1,600^{\circ}C$ to $1,400^{\circ}C$. As results of X-ray diffraction patterns, all $La_{9.33}(Si_{6-x}V_x)O_{26}$ specimens showed the formation of a complete solid solution in a apatite polycrystallin structure. But the specimens doped with more than 1.5mol% showed the second phase, $La_2SiO_5$ and $SiO_2$. The specimen dopants with 1.0 mol% showed the maximum ion conductivity. Ion conducting and activation energy of the $La_{9.33}(Si_5V_1)O_26$ specimens were about $7.8{\times}10^{-4}S/cm$ 1.62 eV at $600^{\circ}C$, respectively.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.32 no.1
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• pp.78-85
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• 2019

The effect of various lithium sources such as LiCl, LiOH, and Li-metal on the microstructure and electrochemical properties of granulated $SiO_x$ powders were investigated. Various lithium sources were metallurgically added for a passive pre-lithiation of $SiO_x$ to improve its low initial coulombic efficiency. In spite of using the same amount of Li in various sources, as well as the same process conditions, different lithium silicates were obtained. Moreover, irreversible phases were formed without reduction of $SiO_x$, which might be from additional oxygen incorporation during the process. Accordingly, there were no noticeable electrochemical enhancements. Nevertheless, the $Li_4SiO_4$ phase changes the initial electrochemical reaction, and consequently the relationship between the microstructure and electrochemical properties of metallurgically pre-lithiated $SiO_x$ could provide a guideline for the optimization of the performance of lithium ion batteries.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.138-138
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• 2010

플렉서블 디스플레이에 사용되고 있는 기판은 광학적 투과율이 우수하고 휘어지는 폴리머 기판이 많이 활용되고 있으나 대기중의 수분 및 산소와 같은 가스성분들이 기판을 통해 침투하여 디스플레이의 수명을 감소시킨다. 이러한 문제점을 해결하기 위해 투명하면서 절연특성이 뛰어나고 수분투과 방지 특성이 뛰어난 실리콘 화합물을 기반으로 하는 가스차단막의 연구가 활발히 진행되고 있다. 본 실험에서는 기존의 스퍼터링 장치에 비해 저온공정이면서 구조적으로 뛰어난 박막특성을 얻을 수 있는 대향타겟식 스퍼터링(Facing Targets System, FTS)법을 이용하여 PEN기판 위에 $SiO_x$, $SiO_xN_y$, $(SiO_2)_x(ZnO)_{100-x}$ (SZO)를 단일층또는 다층으로 증착한 박막들의 광학적, 구조적 및 수분 투과 방지 특성들을 알아보았다. $SiO_x$, $SiO_xN_y$, SZO박막들의 광학적 특성을 알아보기 위해 Shimadzu사의 UV-VIS spectrophotometer 장비를 사용하여 측정한 결과 가시광 영역에서 80%이상의 높은 광투과율을 나타내었다. 박막의 수분투과 방지 특성으로 Mocon사의 Permatran W3/31 system을 이용한 투습율을 측정결과 가스 차단막이 없는 Bare PEN에 비해 PEN기판 위에 $SiO_x$와 $SiO_xN_y$ 박막들을 단층 또는 다층으로 증착한 박막의 투습율이 감소한 것을 확인 할 수 있었다. 특히 SZO 박막의 경우 다른 가스차단막들과 비교해 가장 낮은 수분투과율을 나타내었다. 이는 향후 SZO를 기반으로 한 단층박막이나 무기/무기 또는 유기/무기의 다층 박막 형태를 가지는 가스차단막이 플렉서블 디스플레이에 적용 가능할 것이라 사료된다.

• Electrical & Electronic Materials
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• v.7 no.4
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• pp.294-299
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• 1994

CHF$_{3}$/CH$_{4}$Ar 플라즈마에 의해 형성된 산화막 식각 잔류물의 화학구조와 이 잔류물의 제거를 위한 세정방법을 x-ray photoelectron spectroscopy를 이용하여 조사하였다. 잔류무르이 구조는 CF$_{x}$-polymer와 Si-C, Si-O 결합으로 이루어진 SiO$_{y}$ C$_{z}$ 이었다. CF$_{4}$O$_{2}$ 플라즈마에 의한 silicon light etch는 산화막 식각 잔류물인 SiO$_{y}$ C$_{z}$ 층과 손상된 실리콘 표면을 제거하엿으며 NH$_{4}$OH-H$_{2}$O$_{2}$과 HF용액으로 완전히 제거되는 CF$_{x}$-polymer/SiO$_{x}$층을 남겼다. 100.angs.정도의 silicon light etch는 minority carrier life time과 thermal wave signal값을 초기 웨이퍼 수준까지 회복시켰으며 접합누설 전류도 거의 습식 식각 공정수준까지 감소시켰다.

• Korean Journal of Materials Research
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• v.11 no.2
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• pp.71-75
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• 2001

The reaction stability of nickel with side-wall materials of SiO$_2$ and Si$_3$N$_4$ on p-type 4"(100) Si substrate were investigated. Ni on 1300 $\AA$ thick SiO$_2$ and 500 $\AA$ - thick Si$_3$N$_4$ were deposited. Then the samples were annealed at 400, 500, 750 and 100$0^{\circ}C$ for 30min, and the residual Ni layer was removed by a wet process. The interface reaction stability was probed by AES depth Profiling. No reaction was observed at the Ni/SiO$_2$ and Ni/Si$_3$N$_4$, interfaces at 400 and 50$0^{\circ}C$. At 75$0^{\circ}C$, no reaction occurred at Ni/SiO$_2$ interface, while $NiO_x$ and Si$_3$N$_4$ interdiffused at Ni/Si$_3$N$_4$ interface. At 100$0^{\circ}C$, Ni layers on SiO$_2$ and Si$_3$N$_4$ oxidized into $NiO_x$ and then $NiO_x$ interacted with side-wall materials. Once $NiO_x$ was formed, it was not removed in wet etching process and easily diffused into sidewall materials, which could lead to bridge effect of gate-source/drain.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.453-456
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• 1998

The electrical properties of $Si_{1-x}Ge_{x}$ samples have been investigated. The sample structures were grown by MBE (molecular geam epitaxy) with Ge mole-fraction of x=0.0, x=0.05, x=0.1, and x=0.2. To examine the influence of the thermal processing, the $O_{2}$ and N$_{2}$ process were performed at 800[.deg. C] and 900[.deg. C], respectively. After this thermal process, hall measurements have been done over a wide range of the ambient temperature between 320[.deg. K] and 10[.deg. K] to find the temperature dependence using the comparessed-He gas system. The Ge-rich layer has been formed at the $SiO_{2}$/SiGe interface and it has an effect on the hall mobility. And it has been found that hall mobility was increased by the $N_{2}$ annealing process comparing with dry oxidation process at both 800[.deg.C] and900[.deg. C].

• Journal of the Korean Vacuum Society
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• v.11 no.4
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• pp.207-211
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• 2002

Band gap tuning by quantum well disordering in $In_{0.53}Ga_{0.47}As/InGaAsP(Q1.25)$ quantum well structure has been investigated using photoluminescence. The threshold temperature for the blue shift was about $750^{\circ}C$ , and the blue shift became larger as the annealing temperature increased. $SiO_2$ showed saturation as the annealing temperature increased. $SiN_x$caused larger blue shift than $SiO_2$, which is considered to be related to the low growth temperature of $SiN_x$. The diffusion of P and Ga are thought to be responsible for the blue shift of the $SiN_x$ and $SiO_2$capped quantum well disordering , respectively.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.11a
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• pp.186-186
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• 2012

최근 Flexible organic electronics 분야에 대한 관심과 더불어 소자의 산소 및 수분의 침투를 방지하기 위한 투습방지막 연구가 활발히 진행되고 있다. 이에 본 연구에서는 Closed Drift Linear Source(CDLPS) 플라즈마 공정을 이용하여 저온 고속의 $SiO_xC_yH_z$ barrier flims 형성 연구를 진행하였다. HMDSO(hexamethyldisiloxane), TMS(trimethylsilane)와 산소를 기반으로 HMDSO/HMDSO+산소의 비율에 따라 $Si(-O_x)$ 변화에 따른 특성 평가를 진행하였다. X-ray photoelectrom spectroscopy(XPS) 및 Ft-IR spectrometer 측정 시 3.7% 비율에서 실리콘 원소가 산소 라디칼과 효율적인 반응을 함으로써 단일한 $SiO_2$ 박막이 형성됨을 확인 하였다. 그와 반면에 비율의 증가로 인해 다량의 HMDSO 물질이 주입 되었을 시 산소 라디칼과 충분히 반응 되지 못하여 $SiO_2$에 비해 $Si(CH)_x$ 가 많이 함량 된 Polymer like한 $SiO_x$가 많이 형성되었다. 박막의 증착율의 경우에는 3.7%에서 18%로 증가함에 따라 35 nm/min에서 180 nm/min의 증착율을 가지는 것을 확인 하였다. 3.7% 비율의 단일 $SiO_2$ 공정 조건으로 유기태양전지에 형성 하였을 시 소자의 에너지 변환 효율(PCE)이 변화 없는 것을 확인하였다. 이는 기존 공정에 비해 CDLPS 플라즈마 공정의 경우 유기소자에 플라즈마로 인한 열에너지나 이온 충격 에너지로 인한 영향 없는 것을 확인 할 수 있다. 이런 장점을 통해 CDSPS를 이용한 공정 기술은 다양한 유기 소자의 barrier 형성 연구에 큰 도움이 될 것이다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.11
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• pp.969-973
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• 2009

In this study, the electrical and optical properties of $(SiO_2)_x(ZnO)_{100-x}$ (SZO) films prepared on the coming 7059 glass substrates by using rf-magnetron sputtering method are investigated. The deposition rate becomes maximum near 3 wt.% and gradually decreases when the $SiO_2$ content further increases. The growth rates of the SZO film with $SiO_2$ content of 3 wt.% is $4\;{\AA}/s$. We found that the average transmittance of all films is over 80% in the wavelength range above 500 nm. The optical band gap were decreased from 3.52 to 3.33 eV as an increase the deposition thickness. X-ray diffraction patterns showed that the film with a relatively low $SiO_2$ content (< 4 wt.%) is amorphous. SZO film with the $SiO_2$ contents of 2 wt.% showed the resistivity of about $3.8{\times}10^{-3}\;{\Omega}{\cdot}cm$. The sheet resistance decreases with increasing the heat treatment temperature.