• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.3 s.357
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• pp.1-5
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• 2007

SiOC films were made using the oxygen and bistrimethylsilylmethane mixed precursor. The chemical properties of SiOC films divided into three properties, organic, hybrid and inorganic depending on the flow rate ratio between oxygen and bistrimethylsilylmethane precursor. The films with organic properties decreased dielectric constant, because of pore incorporation in final materials. In this study, the porosity of SiOC films with organic properties was investigated using the Makwell-Garnett equation. The porosity of the films could be correlated with the blue shift in the infrared spectra scopy, and increased with the decreasing the dielectric constant of the film.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.2
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• pp.13-20
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• 2008

This paper describes the methods of spacer-fabrication for wafer-level CIS(CMOS Image Sensor) assembly. We propose three methods using SU-8, PDMS and Si-interposer for the spacer-fabrication. For SU-8 spacer, novel wafer rotating system is developed and for PDMS(poly-dimethyl siloxane) spacer, new fabrication-method is used to bond with alignment of glass/PDMS/glass structure. And for Si-interposer, DFR(Dry Film Resist) is used as adhesive layer. The spacer using Si-interposer has the strongest bonding strength and the strength is 32.3MPa with shear.

• Advanced Composite Materials
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• v.18 no.4
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• pp.351-364
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• 2009

The thermal stability and elevated temperature mechanical properties of $SiC_P$/Al-11.7Fe-1.3V-1.7Si (Al-11.7Fe-1.3V-1.7Si reinforced with SiC particulates) composites sheets prepared by spray deposition (SD) $\rightarrow$ hot pressing $\rightarrow$ rolling process were investigated. The experimental results showed that the composite possessed high ${\sigma}_b$ (elevated temperature tensile strength), for instance, ${\sigma}_b$ was 315.8 MPa, which was tested at $315^{\circ}C$, meanwhile the figure was 232.6 MPa tested at $400^{\circ}C$, and the elongations were 2.5% and 1.4%, respectively. Furthermore, the composite sheets exhibited excellent thermal stability: the hardness showed no significant decline after annealing at $550^{\circ}C$ for 200 h or at $600^{\circ}C$ for 10 h. The good elevated temperature mechanical properties and excellent thermal stability should mainly be attributed to the formation of spherical ${\alpha}-Al_{12}(Fe,\;V)_3Si$ dispersed phase particulates in the aluminum matrix. Furthermore, the addition of SiC particles into the alloy is another important factor, which the following properties are responsible for. The resultant Si of the reaction between Al matrix and SiC particles diffused into Al matrix can stabilize ${\alpha}-Al_{12}(Fe,\;V)_3Si$ dispersed phase; in addition, the interface (Si layer) improved the wettability of Al/$SiC_P$, hence, elevated the bonding between them. Furthermore, the fine $Al_4C_3$ phase also strengthened the matrix as a dispersion-strengthened phase. Meanwhile, load is transferred from Al matrix to SiC particles, which increased the cooling rate of the melt droplets and improved the solution strengthening and dispersion strengthening.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.3
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• pp.75-75
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• 2001

Si₃N₄/SiO₂/Si₃N₄ 멤브레인에 의해 실리콘 기판으로부터 열차단된 비냉각 초전형 박막 (Ba,Sr)TiO₃ 적외선 검지기를 제작하고, 적외선 검지기의 특성을 논의하였다. 25℃의 공기중에서 쵸핑주파수가 1 ㎐일 때 적외선 검지기는 약 168.8 V/W의 비교적 높은 전압 감응도를 나타내었으나, 매우 작은 신호대잡음비 때문에 약 2.6×10⁴㎝·㎐/sup 1/2//W의 낮은 비검지도를 나타내었다. 또한 출력파형의 쵸핑주파수 및 온도 의존성에 대한 정성적인 해석으로부터 적외선 검지기의 열잡음전압 및 열시정수가 모두 상당히 크다는 것을 알 수 있었다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.10 s.340
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• pp.9-18
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• 2005

Analytical expressions for breakdown voltages of abrupt $p^{+}n$ junction of Si, GaAs, InP and In$In_{0.53}Ga_{0.47}AS$ were induced. Getting analytical breakdown voltages, effective ionization coefficients were extracted using lucky drift parameters of Marsland for each materials. The results of analytical breakdown voltages followed by ionization integral agreed well with experimental result within 10$\%$ in error for the doping concentration in the range of $10^{14}cm\;^{-3}\~5\times10\;^{17}cm\;^{-3}$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.71-74
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• 2000

Pt/Pb$TiO_3$/$SrTiO_3$/p-Si films were prepared by metallo-organic solution deposition(M0SD) method and investigated its structure and ferroelectric properties. Crystallinity of specimen as a funtions of post annealing temperature and the thickness of $SrTiO_3$(STO) buffer layer was studied using XRD and AFM. Based on C-V and P-E curve, $PbTiO_3$(PTO) capacitors showed good ferroelectric hysteresis arising from the polarization switching properties. When the thickness of ST0 buffer layer between PTO and Si substrate was 260 nrn and the post annealing temperature was $650^{\circ}C$, it was showed that production of the pyrochlore phase due to interdiffusion of Si into FTO was prevented. The dielectric constant of FTO thin films calculated from a maximum Cma in the accumulation region was 180 and the dielectric loss was 0.30 at 100 kHz frequency. The memory window in the C-V curve is 1.6V at a gate voltage of 5V.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.10
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• pp.1-7
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• 2004

In order to enhance the electron mobility in SOI n-MOSFET, we fabricated fully depletion(FD) n-MOSFET on the strained Si/relaxed SiGa/SiO$_2$/Si structure(strained Si/SGOI) formed by inserting SiGe layer between a buried oxide(BOX) layer and a top silicon layer. The summated thickness of the strained Si and relaxed SiGe was fixed by 12.8 nm and then the dependency of electron mobility on strained Si thickness was investigated. The electron mobility in the FD n-MOSFET fabricated on the strained Si/SGOI enhanced about 30-80% compared to the FD n-MOSFET fabricated on conventional SOI. However, the electron mobility decreased with the strained Si thickness although the inter-valley phonon scattering was reduced via the enhancement of the Ge mole fraction. This result is attributed to the increment of intra-valley phonon scattering in the n-channel 2-fold valley via the further electron confinement as the strained Si thickness was reduced.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.7
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• pp.1-6
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• 2000

In this study, the effects of the addition of $N_2$ gas into the $Cl_2$ (90)/Ar(10) gas mixture, which has been proposed as the optimized etching gas combination, for etching of platinum was performed. The selectivity of platinum film to $SiO_2$ film etch mask increased with the addition of $N_2$ gas, and etch profile over 75 $^{\circ}$ could be obtained when 20 % additive $N_2$ gas was added. These phenomena were interpreted as the results of a formation of blocking layer such as Si-N or Si-O-N on the $SiO_2$ mask. The maximum etch rate of Pt film and selectivity of Pt to $SiO_2$ are 1425 ${\AA}$/min and 1.71, respectively. These improvements were considered to be due to the formation of more volatile compounds such as Pt-N or Pt-N-Cl.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.5 s.347
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• pp.11-16
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• 2006

This paper reports the correlation between dielectric constant and degree of amorphism of the hybrid type SiOC thin films. SiOC thin films were deposited by high density plasma chemical vapor deposition using bistrimethyl- silylmethane(BTMSM,$H_{9}C_{3}-Si-CH_{2}-Si-C_{3}H_{9}$) and oxygen precursors with various flow rate ratio. As-deposited film and annealed films at $400^{\circ}C$ were analyzed by XRD. The SiOC thin films were amorphous from XRD patterns. For quantitative analysis, the diffraction pattern of the samples was transformed to radial distribution function by Fourier analysis, and then compared with each other. The degree of amorphism of annealed films was higher than that of as-deposited ones. The dielectric constant varied in accordance with flow rate ratio of precursors. The lowest dielectric constant was obtained from the as-deposited film which has the highest degree of amorphism after annealing.

• Analytical Science and Technology
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• v.16 no.4
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• pp.299-308
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• 2003

The purpose of this study is to investigate cadmium concentrations among metals in ETS (Environmental Tobacco Smoke) of indoor environments and to evaluate the cadmium as a marker of ETS. The correlations of cadmium concentrations and nicotine, 3-EP, RSP, SD (Smoking Density), and SI (Smoking Index). Air samples of metals, nicotine, 3-EP, and RSP were taken in smoking room, smoking allowed office, corridor outside smoking room, and non-smoking office respectively. The SD, ACH, and SI were investigated during sampling. Airborne concentration of cadmium known as human carcinogen were qualified and quantified. The SD was 0.2 to $2.6cig/m^2{\cdot}hr$, and the mean value of SD in smoking rooms was $1.2cig/m^2{\cdot}hr$ that is higher than other researches. The mean of ACH in smoking rooms was 11.1. The concentrations of cadmium showed log-normal distributions and the geometric mean concentrations of cadmium in smoking rooms, corridor outside smoking rooms, smoking allowed offices, and non-smoking offices were $0.045{\mu}g/m^3$, $0.018{\mu}g/m^3$, $0.021{\mu}g/m^3$, and $0.017{\mu}g/m^3$ respectively. The concentrations of cadmium in smoking room showed significant difference according to category of indoor office environments (p<0.05) and showed compliance with occupational exposure limits. The correlation coefficients between cadmium and nicotine, 3-EP, and RSP were 0.53, 0.41, 0.43 respectively. The cadmium among metals showed the highest correlations (r=0.63) with SI. It was recommended cadmium among metals is a good indicator for ETS.