• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.173-173
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• 2011

반도체 집적도의 비약적인 발전으로 복잡하고 다양한 공정이 연구되었고 공정 중 박막에서 발생되는 물리적, 화학적 반응들에 대한 연구 필요성이 대두 되었다. 박막은 다양한 공정 환경에서 박막의 특성을 잃지 않고 물성을 유지하여야 한다. 특히 공정상의 고온 환경에서 박막은 안정해야하며 물리적손상이 있어서는 안 된다. 이 논문에서는 반도체의 기판으로 사용되는 Si기판과 금속배선 물질인 Cu와의 확산을 효과적으로 방지하기 위한 W-C-N 확산방지막을 제시하였고 시료 증착을 위하여 rf magnetron sputter를 사용하여 동일한 증착조건에서 질소(N)의 비율을 다르게 하여 박막 내 질소비율(0 sccm, 2 sccm)에 따른 확산방지막을 제작하였다. 이후 시료의 열적 안정성 측정을 위하여 상온, 600도, 800도로 각각 질소 분위기에서 30분간 열처리 과정을 실시하여 열적 손상을 인가하였다. 이후 Nanoindentation기법을 이용하여 총 16 point 측정을 하였다. 이를 Weibull distribution으로 분석하여 정량화 시켜 박막의 균일도와 신뢰도를 연구하였다. 또 WET-SPM을 이용하여 AFM 표면 이미지를 확인하였다. 그 결과 고온에서 박막이 Compressive stress를 받아 박막이 일어남을 확인 하였다. 이는 질화물질이 고온에서 물성변화가 적게 나타나는 것을 알 수 있었고, 균일도와 결정성 또한 질화물질에서 더 안정적이었다.

• Economic and Environmental Geology
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• v.18 no.3
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• pp.253-261
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• 1985

Detailed chemical compositions of thirteen montmorillonites and their thermal behaviour by differential thermal and thermogravimetric analysis have been studied. Comparison of structural formulae with experimental results by thermal analysis gave evidence of that both substitutions of Fe for Al in octahedral and Al for Si in tetrahedral positions appear to affect dehydroxylation temperature, which is valid for the present samples. Further detailed study of this topic using well-known samples which have various degree of substitution will be justified.

• Economic and Environmental Geology
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• v.21 no.2
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• pp.175-184
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• 1988

Ten under 2 micron size fractions of the montmorillonite from Yongdongri area, Gyeongsangbug-Do were studied using X-ray powder diffraction, cation exchange measurement, differential thermal analysis, thermogravimetric analysis, differential thermal scanning calorimetry and chemical analysis. Montmorillonites occurring at same deposit show limited variation in chemical composition whereas in thermal properties they do not. Their dehydroxylation endothermic peaks are "abnormal" type with a small range of variation of peak temperature reflecting tetrahedral substitution of Al for Si. Data from DSC show that divalent-cation saturated montmorillonite has relatively a higher endothermic heat capacity than monovalent-cation saturated montmorillonite, indicating that cations with higher electronegativity hold more water molecules.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.271-271
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• 2011

본 논문에서는 W-N 확산 방지막을 각각 다른 질소 유입 조건 (0 sccm, 0.5 sccm, 1 sccm) 하에 Si (Silicon) (100) 기판 위에 rf (radio-frequency) magnetron sputter를 이용하여 증착하였다. 증착된 박막은 800$^{\circ}C$에서 열처리하였고, 이때 각각의 W-N 확산 방지 막의 열적 안정성을 분석하였다. 기존 W-N박막의 분석은 X-ray diffraction (XRD)와 같은 분광학적 방법을 사용하여 분석하였으나, 이는 점점 미세화 되어가는 반도체 산업의 최근 동향에는 적합하지 않다. 따라서 이번 실험에서는 박막 국부적인 영역에서 nano scale의 분석이 가능한 nano indentation을 이용하여 분석하였다. 본 연구에서는 열적 안정성을 분석하기 위하여 각각 열처리 온도가 다른 박막의 stress 분포를 XRD와 AFM를 이용하여 구한 격자상수로 먼저 박막 전체적인 영역을 분석하였다. 박막의 국부적인 영역은 앞서 언급하였던 nano indentation을 이용하여 stress 분포를 분석하였다. 실험 결과, 표면의 RMS roughness는 3.6에서 1.4 nm으로 변하였으며, 박막은 미열처리에서 열처리 온도의 증가 시 보다 tensile stress를 많이 받는 것으로 분석하였다.

• Journal of the Korean Chemical Society
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• v.43 no.3
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• pp.286-293
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• 1999

A comnprehensive process which combines chemical with thermal treatment by controlled counterflow oxidation has been developed for disposal of PCBs in transformer oil. PCBs which not completely removed by chemical treatment, after being filtered with appropriate adsorbent during the oil circulations, was thermally treated. Destruction efficiencies of better than 99.99% was obtained, with no measurable formation of PCDDs (polychlorinated dibenzo-p-dioxins) or PCDFs (polychlorinated dibenzofurans). The combination also permits high recovery of oil and inorganic supports from scrap power transformers. The process is environmentally benign, easy to use and less capital intensive than other available technologies.

• Polymer(Korea)
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• v.39 no.2
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• pp.275-280
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• 2015

Two series of copolyimides (Co-PIs) were prepared by reacting 4,4'-(hexafluoroisopropylidene) diphthalic anhydride (6FDA) and 1,2,4,5-benzentetra carboxylic dianhydride (pyromellitic dianhydride) (PMDA), as dianhydrides based on 4,4'-biphthalic anhydride (BPA) and 2,2'-bis(trifluoromethyl)benzidine (TFB) by using thermal- and chemical imidizations. Co-PIs films with different dianhydride monomer compositions were compared in terms of their thermal properties and optical transparencies. The addition of PMDA was more effective than the addition of 6FDA for improving the thermal properties. Meanwhile, 6FDA is more effective in optical transparencies.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.41 no.6
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• pp.51-60
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• 2004

In this paper, we optimized the PDT laser system to improve the therapy effects of malignancies. In order to optimize, the variation of laser output and specific wavelength shift have to reduced. To improve the PDT therapy clinician require the diverse radiation mode which irradiate the tumor surface. Continuous wave mode that general application may causes tissue thermal damage not only to tumor tissue, but also to normal tissue. In this paper, therefore, we suggested new technique for radiation method to improved PDT effects and prevented to the thermal effects for the tissue. In the experimental we verified the stability of wavelength, laser output stability and proved the reduced thermal effects to the tissue using the pulse & burst radiation modes in vitro.

• Korean Journal of Materials Research
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• v.3 no.2
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• pp.145-150
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• 1993

Abstract In order to improve the brittleness of diglycidyl ether of bisphenol A(DGEBA)/4, 4'-methylene dianiline(MDA) system, the reactive additive, succinonitrile(SN) was added to DGEBA/MDA system. In this case, thermal properties, glass transition temperature(Tg), thermal decomposition temperature(Td) and 5% weight loss temperature($T_{-5%}$)were investigated according to the different SN contents and cure temperatures. Tg, Td and $T_{-5%}$ decreased as the SN content was increased, but increased as the cure temperature was increased.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.2
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• pp.86-93
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• 2007

This paper proposes two fast calculation methods of ATC. These two methods evaluate ATC with thermal constraints(Thermal ATC) and ATC with voltage stability constraints(Voltage ATC) respectively. The ATC with thermal constraints was based on the linear incremental power flow to account for the line flow thermal loading effects when the n-1 security constraints were included. The ATC with voltage stability constraints used two-bus equivalents of the system to find the maximum load at a load bus before reaching the voltage stability problem. The methods were tested on the IEEE 30bus systems and the results obtained were compared with those found by some other methods.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.5
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• pp.1042-1046
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• 2007

In this study, we investigated the mechanism responsible for the thermal stability of CoSi by addition of a foreign chemical element. Addition of W was found to increase the heat of formation of CoSi. This increase was claimed to inhibit the glass formation, which is preferred by silicide formation kinetics depicted by the maximum system energy degradation rate. In this case, there forms at the interface between CoSi and Si wafer a crystalline structure, the effective diffusion coefficient of which is much less than the self-diffusion rate provided by the glass. It was stated that the phase transition requires a higher thermal energy as the consequence, thereby enhancing the thermal stability of CoSi.