• Nuclear industry
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• v.22 no.11 s.237
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• pp.62-69
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• 2002

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.173-174
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• 2007

반도체 소자가 발달함에 따라서 박막은 더욱 다층화 되고 그 두께는 줄어들고 있다. 따라서 소자의 초고집적화를 위해서는 각 박막의 두께를 더욱 작게 하여야 한다. 또한 반도체 소자 제조 공정에서는 Si 기판과 금속 박막간의 확산이 커다란 문제로 부각되어 왔다. 특히 Cu는 높은 확산성에 의하여 Si 기판과 접합에서 많은 확산에 의한 문제가 발생하게 되며, 또한 선폭이 줄어듦에 따라 고열이 발생하여 실리콘으로 spiking이 발생하게 된다. 이러한 확산을 방지하기 위하여 금속 배선과 Si기판 사이에는 필연적으로 확산방지막을 삽입하게 되었다. 기존의 연구에서는 $1000\;{\AA}$의 W-B-C-N 확산방지막을 제작하여 연구하였다. 이 논문에서는 Cu의 확산을 방지하기 위한 W-B-C-N 확산방지막을 다양한 두께로 제작하여 그 특성을 확인하여 초고집적화를 위한 더욱 얇은 두께의 W-B-C-N 확산방지막에 대하여 연구하였다. W-B-C-N 확산방지막의 두께 변화에 대한 특성을 확인하기 위하여 $900^{\circ}C$까지 열처리 한 후 그 면저항을 측정하였다.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.1
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• pp.1-7
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• 2017

Concrete behavior in early-age is changing due to hydration reaction with time, and a resistance to chloride attack and strength development are different characterized. In the present work, changing strength and resistance to chloride attack are evaluated with ages from 28 days to 6 months. For the purpose, strength, diffusion coefficient, and passed charge are evaluated for normal concrete with 3 different mix proportions considering 28-day and 6-month curing conditions. With increasing concrete age, the changing ratio of strength falls on the level of 135.3~138.3%, while diffusion coefficient and passed charge shows 41.8%~51.1% and 53.6%~70.0%, respectively. The results of chloride diffusion coefficient and passed charge show relatively similar changing ratios since they are much dependent on the chloride migration velocity in electrical field. The changing ratios in chloride behaviors are evaluated to be much larger than those in compressive strength since the ion transport mechanism is proportional to not porosity but square of porosity.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.409-409
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• 2013

최근, 집적 소자의 미세화에 따라 늘어난 배선 신호 지연 및 상호 간섭, 그리고 소비 전력의 증가는 초고집적 소자 성능 개선에 한계를 가져온다. 이에 따라 기존의 알루미늄(Al)/실리콘 절연 산화막은 구리(Cu)/저유전율 박막(low-k)으로 대체되고 있고, 이는 소자 성능 개선에 큰 영향을 미친다. 그러나 Cu는 Si과 low-k 내부로 확산이 빠르게 일어나 소자의 비저항을 높이고, 누설 전류를 일으키는 등 소자의 성능을 저하시킬 수 있는 문제점을 가지고 있다. 이러한 Cu의 확산을 막기 위하여 Ta, TaN 등과 같은 확산방지막에 대한 연구가 활발히 진행되어 왔으나, 배선 공정의 집적화와 low-k 대체에 따른 공정 및 신뢰성 문제로 인해 새로운 확산방지막의 개발이 필요하게 되었다. 이를 위해, 본 연구에서는 Cu-V 합금을 사용하여 low-k 기판 위에 확산방지막을 자가 형성 시키는 공정에 대한 연구를 진행하였다. 다양한 low-k 기판에서 열처리조건에 따른 Cu-V 합금의 특성을 확인하기 위해 4-point probe를 통한 비저항 평가와 XRD (X-ray diffraction) 분석이 이뤄졌다. 또한, TEM (transmission electron microscope)을 이용하여 $300^{\circ}C$에서 1 시간 동안 열처리를 거쳐 자가형성된 V-based interlayer가 low-k와 Cu의 계면에서 균일하게 형성된 것을 확인하였다. 형성된 V-based interlayer의 barrier 특성을 평가하고자 Cu-V합금/low-k/Si 구조와 Cu/low-k/Si 구조의 leakage current를 비교 분석하였다. Cu/low-k/Si 구조는 비교적 낮은 온도에서 leakage current가 급격히 증가하는 양상을 보였으나, Cu-V 합금/low-k/Si 구조는 $550^{\circ}C$의 thermal stress 에서도 leakage current의 변화가 거의 없었다. 이러한 결과를 바탕으로 열처리를 통해 자가형성된 V-based interlayer의 Cu/low-k 간 확산방지막으로서 가능성을 검증하였다.

• Journal of Korean Tunnelling and Underground Space Association
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• v.17 no.3
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• pp.283-293
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• 2015

In order to evaluate corrosion resistance of steel fiber-reinforced concrete, accelerated chloride migration and surface resistivity tests were conducted. In addition air content of fresh concrete, compressive strength and water absorption were measured for investigating fundamental characteristics of concrete. Two different water-cement ratios(0.44, 0.5) and three steel fiber contents(0.25%, 0.5%, 1%) were considered as variables. Note that all specimens cast with same compaction work. As a results, corrosion resistance decreased as steel fiber contents increased regardless of water-cement ratio when the concrete was compacted with same amount of work done. However, for concrete with same steel fiber content, the lower water-cement ratio showed the better corrosion resistance. It is found that enhancement of fluidity and enough compaction should be done for corrosion resistance of SFRC.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.1
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• pp.51-58
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• 2023

The purpose of this study is to identify various variables that affect the intention to use the metaverse, which has recently attracted attention. In particular, while previous studies have focused only on the variables that have a positive effect on the spread of the metaverse, this study tried to examine both the use and resistance perspectives by examining the psychological variables of consumers who reject specific changes, such as innovation resistance. By constructing consumer characteristics and innovation characteristic variables that affect innovation diffusion, the relationship between innovation resistance, attitude toward the metaverse, and intention to use the metaverse was examined. As a result of the study, it was found that innovation propensity, social image, and conformity had a negative effect on resistance to the metaverse. In addition, innovation propensity, social image, suitability, relative advantage, complexity, and observability mediate innovation resistance and attitudes toward the metaverse, and were finally revealed as variables that have positive or negative influences on the intention to use the metaverse.

• Journal of Conservation Science
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• v.25 no.2
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• pp.147-154
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• 2009

The change of strength and water vapour diffusion resistant by soluble salts was investigated in the tuff and granite used in many stone monuments of Gyeongju area. With $Na_2SO_4$ and $CaSO_4{\cdot}2H_2O$ were treated the rock samples to understand the difference of solubility. The densities of the tested rocks were increased by the impregnation of $CaSO_4{\cdot}2H_2O$ and $Na_2SO_4$. The flexural strength was increased in the tuff samples but decreased in the granite as the salts increased in the pore. In the tuff, the uniaxial compressive strength was increased by $CaSO_4{\cdot}2H_2O$, but decreased by $Na_2SO_4$. In the granite, it was decreased slightly by $CaSO_4{\cdot}2H_2O$, but increased by $Na_2SO_4$. The water vapour diffusion resistant was increased by the salts in both rocks. As results, it was cleared that the mechanical strength colud be increased in early stage of weathering by the accumulation of salt and water vapour diffusion resistant.

• Journal of Bio-Environment Control
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• v.6 no.3
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• pp.205-215
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• 1997

An accurate transpiration model for greenhouse tomato crop, which is liable to transpiration depression and yield loss because of low solar radiation and high humidity, could be an efficient tool for the optimum control of greenhouse climate and for the optimization of Irrigation scheduling. The purpose of this study was to develop transpiration model of greenhouse tomato and to carry out the experimental verification. The formulas to calculate the canopy transpiration and temperature simultaneously were derived from the energy balance of canopy. Transpiration and microclimate variables such as net radiation, solar radiation, humidity, canopy and air temperature, etc. were simultaneously measured to estimate parameters of model equations and to verify the suggested model. Leaf boundary layer resistance was calculated as a function of Nusselt number and stomatal diffusive resistance was parameterized by solar radiation and leaf-air vapor pressure deficit. The equation for stomatal diffusive resistance could explain more than 80％ of its variation and the calculated stomatal diffusive resistance showed good agreements with the measured values in situations independent of which the constants of the equation were estimated. The canopy net radiation calculated by Stanghellini's model with slight modification agreed well with the measured values. The present transpiration model, into which afore-mentioned component equations were assembled, was found to predict the canopy temperature, instantaneous and daily transpiration with considerable accuracy in greenhouse climates.

• Journal of Bio-Environment Control
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• v.8 no.1
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• pp.42-48
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• 1999

This study was executed to see the effects of Ca : K ratios in me.L$^{-1}$ -0:9, 1.5:7.5, 3:6, 4.5:4.5, 6:3 - in the nutrient solution on the photosynthesis, transpiration, growth and incidence of tipburn in butterhead ‘Omega’and Leaf ‘Grand Rapids’lettuce (Lactuca sativa. L) grown in nutrient film technique(NFT). The photosynthesis of both lettuces showed high in the Ca : K ratios of 3:6 and 4.5:4.5 regardless of species. But stomatal resistance of Grand Rapids was higher than that of Omega. The highest transpiration rate of them was shown in the Ca : K ratio of 3:6. The transpiration rate of developing leaves was lower than that of expanded leaves. It was seemed to have relation with incidence of tipbum in the developing leaves. The nutrient solution treatment without Ca developed less growth than that of other treatments, especially growth and development of apical part were inhibited, so that in the both of them incidence of tipburn appeared 100 percent. The incidence of tipburn in Omega appeared 25 percent in the Ca/K ratio of 1.5:7.5, but Grand Rapids did not show it according to the Ca/K ratio in nutrient solution. The highest growth in two species was also shown in the Ca/K ratio of 3:6 except nutrient solution without Ca. This study suggested that the unbalanced ratio of Ca/K affected Ca transport in two species because of the increase of stomatal resistance and diffusive resistance and the decrease of photosynthesis and transpiration.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.172-172
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• 2011

현대 반도체 금속배선 연구에서는 기존에 쓰이던 Al (Aluminium) 금속배선 대신에 Cu(Copper) 금속배선 연구가 진행 되고 있다. Cu는 Al 보다 비저항이 낮고, 녹는점도 Al보다 높다는 장점이 있지만 저온에서 기판인 Si (Silicon) 과 반응하고 접착력이 우수하지 못 하다는 단점이 있다. 이런 문제를 해결하기 위하여 확산방지막을 기판과 금속배선 사이에 삽입하는 방법이 제시 되었다. 확산방지막으로는 기존에 쓰이던 Ti (Titanium) 계열의 확산방지막과 W (Tungsten) 계열의 확산방지막이 있다. 이번 연구에서는 W 계열의 확산방지막에 불순물 C (Carbon), N(Nitrogen)을 첨가한 W-C-N 확산방지막 시편을 제조하였고, N2의 비율을 변화시키며 $600^{\circ}C$ 열처리를 하였다. 실험 결과 질소의 포함 농도에 따라 확산방지막의 안정도가 변화한다는 결과를 얻었으며, 질소 첨가량에 따라 시편의 표면 보다는 시편의 중간층의 물성 변화율이 큰데 이는 시편 표면의 질소는 열처리 중 확산에 의한 시편과의 분리 현상이 일어나지만 시편의 중간층은 trap현상에 의하여 시편에 남아있어 질소의 영향을 받아 시편의 중간층이 더욱 질소 유량에 따른 영향이 큰 것을 확인하였다. 이 결과로부터 W-C-N 박막은 첨가된 질소의 유량에 따라 박막의 안정도가 결정된 다는 것을 알았다. 본 연구에서 시편은 rf magnetron sputtering 방법으로 제작하였고 연속압입 실험은 Hysitron사의 Triboindenter를 이용하였다. Indenting에 사용된 압입팁은 Berkovich tip을 사용하였다.