• Journal of Adhesion and Interface
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• v.2 no.2
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• pp.35-47
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• 2001

• Korean Journal of Materials Research
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• v.7 no.11
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• pp.964-968
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• 1997

Si(001)기판 위에 형성시킨 Zr-silicide의 전기적, 물리적 특성에 관한 연구를 하였다. Zr 박막은 전자빔 증착기를 사용하여 증착하였으며, 50$0^{\circ}C$ 열처리하여 Zr-silicide를 형성시켰다. 각 온도에서 열처리된 Zr-silicide시편의 상형성, 전기적 특성, 화학적 조성, 표면 및 계면 형상을 XRD, four-point probe, AES, TEM과 HRTEM으로 분석하였다. 분석 결과 $600^{\circ}C$부터 Zr과 Si기판의 계면에서 C49 ZrSi$_{2}$의 생성이 관찰되었다. Zr-Silicide박막의 비저항은 C49 ZrSi$_{2}$의 형성에 영향을 받는 것으로 관찰되었으며, 50$0^{\circ}C$ 열처리 후에는 184.3 $\mu$Ω-cm로 낮아졌으며, C49 ZrSi$_{2}$가 박막에 완전히 형성된 80$0^{\circ}C$ 열처리 후에는 32$\mu$Ω-cm의 낮은 저항을 나타내었다. 형성된 C49 ZrSi$_{2}$박막은 균질한 화학적 조성을 하고 있음을 AES 분석으로 확인하였다. Zr-silicide의 표면 및 계면의 형상을 TEM과 HRTEM으로 관찰하였으며, $600^{\circ}C$ 열처리 후에 계면에서 ZrSi$_{2}$의 상형성이 시작되는 것을 관찰하였다. 80$0^{\circ}C$ 열처리 후에도 계면과 표면형상은 비교적 균질한 형상이 유지되었음이 관찰되었으며, 이는 C49 ZrSi$_{2}$가 높은 온도에서도 잘 응집되지 않으며 고온 안정성을 가지는 재료임이 관찰되었다.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.163-163
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• 2010

중적외선 영역 ($3{\sim}5\;{\mu}m$)은 공기 중에 존재하는 이산화탄소나 수증기에 의해 흡수가 일어나지 않기 때문에 군사적으로 중요한 파장 영역이며, 야간에 적을 탐지하는데 응용되고 있다. InSb는 77 K에서 중적외선 파장 흡수에 적합한 밴드갭 에너지 (0.228 eV)를 갖고 있으며, 다른 화합물 반도체와 달리 전하 수송자 이동도 (전자: $10^6\;cm^2/Vs$, 정공: $10^4\;cm^2/Vs$)가 매우 빠르기 때문에 적외선 화상 감지기 재료로 매우 적합하다. 또한 현재 중적외선 영역대에서 널리 사용되는 HgCdTe (MCT)와 대등한 소자 성능을 나타냄과 동시에 낮은 기판 가격, 소자의 제작 용이성 때문에 MCT를 대체할 물질로 주목 받고 있다. 하지만, 기판과 절연막의 계면에 존재하는 결함 때문에 에너지 밴드갭 내에 에너지 준위를 형성하여 높은 누설 전류 특성을 보인다. 따라서 InSb 적외선 소자의 구현을 위하여 고품질의 절연막의 연구가 필수적이라고 할 수 있겠다. 절연막의 특성을 알아보기 위해, n형 InSb 기판에 플라즈마 화학 기상 증착법 (PECVD)을 이용하여 $SiO_2$, $Si_3N_4$를 증착하였으며, 증착 온도를 $120^{\circ}C$에서 $240^{\circ}C$까지 $40^{\circ}C$ 간격으로 변화하여 증착온도가 미치는 영향에 대하여 알아보았다. 절연막과 기판의 계면 특성을 분석하기 위하여 77 K에서 커패시턴스-전압 (C-V) 분석을 하였으며, 계면 트랩 밀도는 Terman method를 이용하여 계산하였다 [1]. $Si_3N_4$를 증착하였을 경우, $120{\sim}240^{\circ}C$의 증착 온도에서 $2.4{\sim}4.9{\times}10^{12}\;cm^{-2}eV^{-1}$의 계면 트랩 밀도를 가졌으며, 증착 온도가 증가할수록 계면 트랩 밀도가 증가하는 경향을 보였다. 또한 모든 증착 온도에서 flat band voltage가 음의 전압으로 이동하였다. $SiO_2$의 경우 $120{\sim}200^{\circ}C$의 증착온도에서 $7.1{\sim}7.3{\times}10^{11}\;cm^{-2}eV^{-1}$의 계면 트랩 밀도 값을 보였으나, $240^{\circ}C$ 이상에서 계면 트랩밀도가 $12{\times}10^{11}\;cm^{-2}eV^{-1}$로 크게 증가하였다. $SiO_2$ 절연막을 사용함으로써, $Si_3N_4$ 대비 약 25% 정도 낮은 계면 트랩 밀도를 얻을 수 있었으며, 모든 증착 온도에서 양의 전압으로 flat band voltage가 이동하였다. 두 절연막에 대한 계면 트랩의 원인을 분석하기 위하여 XPS 측정을 진행하였으며, 깊이에 따른 조성 분석을 하였다. 본 실험에서 최적화된 $SiO_2$ 절연막을 이용하여 InSb 소자의 pn 접합 연구를 진행하였다. Be+ 이온 주입을 진행하고, 급속열처리(RTA) 공정을 통하여 p층을 형성하였다. -0.1 V에서 16 nA의 누설 전류 값을 보였으며, $2.6{\times}10^3\;{\Omega}\;cm^2$의 RoA (zero bias resistance area)를 얻을 수 있었다.

• Korean Chemical Engineering Research
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• v.47 no.1
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• pp.38-45
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• 2009

In this study, interfacial properties were measured for imidazoline type cationic surfactant system which has been widely used as a fabric softener, a dispersant, an anti-static agent, a bleach activator, and an emulsifier. The CMC of imidazoline surfactant was near $6{\times}10^{-5}mol/L$ and the surface tension at CMC was about 32 mN/m. It was found that surface tension was not affected by surfactant concentration but decreased with an increase in pH. The interfacial tension between 1 wt% aqueous solution and n-dodecane was shown to be about 0.01 mN/m and equilibration time was not affected by pH. Phase behavior experiment in a binary aqueous surfactant system showed that only micellar solution of $L_1$ phase was found under conditions of temperature and pH investigated during this study. Only a two-phase region consisting of lower-phase microemulsion in equilibrium with excess oil phase existed under the same conditions, when oil was added to the binary surfactant system. The foam stability measured with 1 wt% surfactant solution increased with pH, which is consistent with surface tension measurement result. QCM(quartz crystal microbalance) measurement showed that surfactant adsorption increased with surfactant concentration but decreased with pH. According to the friction measurement, best fabric softening effect by imidazoline surfactant system was found under alkali conditions.

• Proceedings of the KIEE Conference
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• 2003.10a
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• pp.123-127
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• 2003

액상실리콘으로 이루어진 초고압전력케이블용 프리몰드 접속재의 반도전-절연체 계면접합체를 다양한 제조조건과 조합별로 제조하여 계면접착력에 대한 영향을 검토하였다. 후가교적용 시 계면접착력이 강화되며 grade조합에 따른 특성차이가 존재하였다. 하지만 고온 장시간의 후가교 조건에서는 계면간의 화학적 결합력의 저하로 인해 오히려 접착력이 낮아지기도 하였다. 절연 RTV와의 계면접착성은 S-1재료가, 절연 LSR의 경우에는 S-3 재료가 가장 우수하였으며 도전안정성 측면에서도 S-3 재료가 상대적으로 유리하였다. 매입형 전극체를 제조하여 절연파괴거동을 연구한 결과 계면접착성과의 직접적인 상관관계는 크지 않음을 알 수 있었다.

• Journal of the Korean GEO-environmental Society
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• v.12 no.10
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• pp.23-28
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• 2011

This study was conducted to investigate the adsorption characteristics of various surfactants including biosurfactant, SWA 1503, Triton X-100 and sodium dodecyl sulfate(SDS) on soil. The Freundlich adsorption isotherm equation was found to be the best to describe experimental results. The amount of adsorbed surfactant on soil increased as the content of clay increased. The results showed that surfactant was adsorbed mainly on the surface and the pores of soil since the surface area of clay was larger than that of sand. The amount of adsorbed surfactants on soil was as follows: Biosurfactant > SWA 1503 > Triton X-100 > SDS.

• Composites Research
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• v.16 no.2
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• pp.18-25
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• 2003

The tensile properties of short nylon6 fiber reinforced NR and SBR have been investigated as functions of fiber aspect ratio(AR), diameter ratio(DR), interphase condition, and fiber content. The tensile strength increased with increasing fiber AR(20 min.) and good interphase conditions. The short-fiber(DR=3 and AR=20 min.) reinforced SBR did not show the dilution effect for all interrhase conditions. And the short-fiber(DR=3 and AR=20min.) reinforced NR did not show the dilution effect except for the no-coating. The tensile moduli were significantly improved due to fiber AR. fiber content, and good interphase at same DR. The better interphase condition showed the higher pull-out force at same DR. Also, the stress analysis near the fiber end carried out using axisymmetric FEA to be convinced of the reinforcing mechanism. It is found that the fiber AR, interphase and DR have an important effect on tensile properties.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.11
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• pp.1567-1573
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• 2010

In printing systems, the reliability of printed material depends on the ability of the toner film to remain adhered to the paper surface. In order to measure the strength between the toner film and the paper surface, a peel-off test is often performed. After conducting the test, the amount of toner film remaining on the paper is measured in order to determine the interfacial strength. The results of this test can be affected by many factors such as the peeling rate, weight of the roller used, and dwell time of tape. Sensitivity analysis was performed with respect to peeling rate, weight of roller and dwell time of tape at different levels. It was found that the interfacial strength increased with an increase in these main parameters. On the other hand, the trend with respect to the percentage of toner loss was different. Further, the interfacial strength and percentage of toner loss were significantly affected by the peeling rate.

• Journal of Adhesion and Interface
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• v.5 no.1
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• pp.21-28
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• 2004

In this work, glass fiber/nylon 6 and woven glass fiber/nylon 6 composites have been fabricated using glass fiber reinforcements sized with 3-chloropropyltrimethoxysilane(CTMS) having a chloropropyl organo-functional group in the molecular chain end. The interfacial shear strength of glass fiber/nylon 6 composite was measured using a single fiber microbonding test and the interlaminar shear strength and the storage modulus of woven glass fabric/nylon 6 composites were measured using a short-warn shear test and a dynamic mechanical analysis, respectively, informing the effect of the concentration of CTMS on the properties. With increasing CTMS concentration, the interfacial properties of the composites were improved. The results on the interfacial shear strength, interlaminar shear strength, interlaminar failure pattern, and storage modulus with varying the CTMS concentration agree with each other.

• Journal of the Korean Electrochemical Society
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• v.24 no.3
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• pp.35-41
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• 2021

In this study, the effect of zwitterionic surfactant on Cu electrodeposition was investigated through cyclic voltammetry. With the addition of (dodecyldimethylammonio)propanesulfonate (DDAPS) as a representative zwitterionic surfactant in the electrolyte for Cu electrodeposition, the electrochemical Cu²⁺ reduction was inhibited on Cu and glassy carbon electrodes. Its inhibition effect was similar to that of cationic surfactant rather than anionic surfactant. Moreover, DDAPS interacted with chloride ion and exhibited the mass transfer-dependent inhibition behavior, which indicates that its inhibition function is associated with the formation of its surface aggregates on anion-covered Cu surface. In addition, adsorbed DDAPS slightly reduced the surface roughness of Cu electrodeposits. These characteristics were similar to those of cationic surfactant, but less obvious. It means the effect of DDAPS on Cu electrodeposition originates from the cationic head group which is shield by anionic head group.