• 한국진공학회지
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• 제4권S2호
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• pp.79-82
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• 1995

$N^+$ beam modified diffusion barriers have been proposed for Cu metallization . The crystalline phases of W and Ti thin films change from polycrytalline to amorphous phase by the N ion implantation of 1~$3\times 10^{17}$atoms/$\textrm{cm}^2$. The comparison between these amorphized diffusion barriers and the conventional W and TiN films shows that the amorphized W and Ti diffusion barriers are superior to the conventional w and TiN for protecting the Cu diffusion barriers are superior to the conventional W and TiN for protecting the Cu diffusion at the annealing temperature range $600^{\circ}C$~$800^{\circ}C$ for 30min. This is a worldwidely new and excellent result on the high temperature thermal stability of diffusion barrier.

• Nuclear Engineering and Technology
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• 제55권8호
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• pp.2879-2888
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• 2023

In fusion environments, large scales of helium (He) atoms are produced by a radical transformation along with structural damage in structural materials, resulting in material swelling and degradation of physical properties. To understand its irradiation effects, this paper investigates the stability, electronic structure, energetics, charge density distribution, PDOS and TDOS, and diffusion processes of He impurities in 6HSiC materials. The formation energy indicates that a stable, favorable position for interstitial He is the HR site with the lowest energy of 2.40 eV. In terms of vacancy, the He atom initially prefers to substitute at pre-existing Si vacancy than C vacancy due to lower substitution energy. The minimum energy paths (MEPs) with migration energy barriers are also calculated for He impurity by interstitial and vacancy-mediated diffusion. Based on its calculated energy barriers, the most possible diffusion path includes the exchange of interstitial and vacancy sites with effective migration energies ranging from 0.101 eV to 1.0 eV. Our calculation provides a better understanding of the stabilization and diffusion behaviors of He impurities in 6H-SiC materials.

• Journal of Information Technology Applications and Management
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• 제17권3호
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• pp.121-134
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• 2010

Past studies in e-commerce loyalty were mostly focused on the effects of customer satisfaction and trust on loyalty toward online vendors. Few studies investigated the impacts of switching barriers, whilst they are widely proven to affect customer loyalty in offline commerce. Even in a handful of studies that did deal with switching barriers, their treatment of the subject remained at best superficial. This may have to do with the fact that switching costs in e-commerce could be comparatively negligible, as switching to another online vendor often involves one simple mouse click. In this study, we investigated the impact of switching barriers on loyalty under the e-commerce context. Furthermore, the extent of switching barriers which could be affected by those positive factors (most constructs were adopted from IDT) was also examined. The statistical testing results revealed that combined model which includes both the positive factors and the switching barriers explains the loyalty formation process more strongly ($R^2$ = 0.543) than each separated models ($R^2$ = 0.468 for positive factor only model, and $R^2$ = 0.365 for switching barrier only model). While only the two switching barriers such as convenience and emotional were shown to be statistically significant, we found that trust strongly influences customer's emotional barrier, let alone direct impact on loyalty, which thereby influences loyalty. The results offer insights for better understanding switching barriers in e-commerce related applications.

• 한국재료학회:학술대회논문집
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• 한국재료학회 1996년도 재료학회 춘계학술발표회
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• pp.63-63
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• 1996

• Agribusiness and Information Management
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• 제3권2호
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• pp.33-42
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• 2011

Although the diffusion of mobile services appears to be occurring much more rapidly than the spread of wired services, there are risks of a new type of digital divide: the mobile divide. The mobile divide, which refers to a specific digital divide that involves the unbalanced diffusion of mobile technologies, must be concretely studied. Thus, this study focuses on the mobile divide with respect to disadvantaged populations. Although various studies suggest that the diffusion of mobile devices may reduce the digital divide, somestudies argue against the positive effect of mobile devices in addressing traditional digital devices. Low and O'Connell (2006) insisted that equity of access to mobile technologies should be considered in the contextof the traditional digital divide; they argued that there may be socio-economic barriers to accessing mobile devices and the mobile Internet that are similar to the socio-economic barriers to accessing stationary computers and the stationary use of the Internet. Focusing on the smartphone divide, this study suggests that emphasizing utilization is an appropriate manner in which to bridge the mobile divide rather than focusing on other factors, such as accessibility and capability, thatprevious studies have used to measure the traditional digital divide.

• 디지털융복합연구
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• 제3권1호
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• pp.9-25
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• 2005

The purpose of this study is to explore conquest plans of the barrier and resistance in innovation management. In addition, this study is to describe the model of innovation resistance that reflects adoption process stages and identify the factors that drive the resistance of consumers and the barriers. Whenever organizations try to plan and implement some kind of innovation in organizations, they confront the resistance and barriers in many ways. By understanding innovation resistance and barrier, organizations can not only design better innovations but can develop strategies to reduce resistance and conquer the barriers. Thus they accelerate innovation. Also, these results indicate that people resist innovation strongly when it betrays their value, needs and beliefs or when they felt the pressure on self-conviction and mental risk, loss, and lack of knowledge. Understanding the factors that drive the innovation resistance and barrier has important implications for both theoretical development and managerial action.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.118-119
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• 2013

High power, short wavelength red laser diodes (LDs) have attracted significant interests in a variety of fields due to their advantages in terms of reliability, compactness and cost. The higher brightness for human eyes is required, the shorter wavelength like 630 nm is necessary with higher output power. In this respect, LDs are promising as alternative candidates of gas or dye lasers for such applications due to their small size, high optical/electrical power conversion efficiency, robustness and so on. The crystalline quality of GaInP-AlGaInP multiple quantum wells (MQWs) and AlInP cladding layers is a crucial part in the device performance of GaInP red LDs. Here, we first investigated the effect of Si diffusion on the optical properties of GaInP-AlGaInP MQWs grown with different growth temperatures. Secondary ion mass spectroscopy (SIMS) measurements revealed that both the Mg and Si diffusion into MQW active region was significant. To reduce such diffusion, we employed undoped Mg and Si diffusion barrier and could improve the properties.Without both Mg and Si diffusion barriers, no lasing emission was observed. However, lasing emission was observed clearly for the red LDs with both Mg and Si diffusion barriers. We then investigated the temperature dependent optical properties of MQW layers grown with different well thicknesses (6, 8 and 10 nm). When the well thickness was 10 nm, the better crystalline quality was obtained. However, the observed LD performances were similar, probably due to the defects and impurities in the AlGaInP layer. Further investigation with the detailed analyses will be presented later.

• 한국막학회:학술대회논문집
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• 한국막학회 1997년도 추계 총회 및 학술발표회
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• pp.27-30
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• 1997

1. Introduction : Molecular diffusion of small molecules in polymers plays an important role in many areas where polymers are acting as barriers, and in separation processes, such as selective diffusion. Different applications of polymers have different requirements on their transport properties. Therefore, reliable predictions of diffusion coefficients for small molecules in polymeric materials could be a useful tool to design appropriate materials. For many years, the theories based on free-volume concepts have been widely used to correlate and predict diffusion behavior in polymer/solvent systems. In the theory derived by Vrentas and Duda, the empty space between molecules that is available for molecular transport, referred to as hole free-volume, is being redistributed. Molecular transport will occur only when a free-volume of sufficient size appears adjacent to a molecule and the molecule has enough energy to jump into this void. The diffusive jump is considered complete when the void left behind is closed before the molecule returns to its original position. In this paper, the Vrentas-Duda free-volume theory is presented and the methods to estimate free-volume parameters for predicting polymer/ solvent diffusion coefficients are described in detail.

• Restorative Dentistry and Endodontics
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• 제35권5호
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• pp.368-373
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• 2010

연구목적: 본 연구는 감염 조절용 차단막을 여러 겹으로 사용했을 때 광중합기의 광강도와 파장, light diffusion 등에 미치는 영향에 대해 조사하였다. 연구 재료 및 방법: 감염 조절용 차단막은 투명 랩 (크린랩)을 사용하였고 광중합기는 할로겐 광중합기 (Optilux 360)와 LED 광중합기 (Elipar FreeLight 2)를 사용하였다. 차단막을 1겹, 2겹, 4겹, 8겹으로 광중합기의 광섬유말단을 감싸고 휴대용 광강도 측정기 (Cure Rite)로 광중합기의 광강도를 측정하였다. 광중합기를 주문제작한 optical breadboard에 고정시킨 후 휴대용 spectroradiometer (CS-1000)를 이용하여 광중합기의 파장을 측정하였고, DSLR (Nikon D70s)을 이용하여 광중합기의 light diffusion을 사진 촬영하였다. 결과: 광강도 측정 결과는 차단막의 두께가 증가할수록 광강도가 유의하게 감소하였으나 할로겐 광중합기에서 1겹과 2겹 사이에는 유의차가 없었으며, 4겹 이상의 차단막을 투과할 때 광강도가 더 많이 감소하였다. 여러 겹의 차단막을 투과한 광중합기의 전체적인 파장 형태와 peak wavelength의 변화는 관찰되지 않았다. Light diffusion 사진 촬영 시, LED 광중합기에서는 차단막의 두께가 미치는 영향이 없었으나 할로겐 광중합기에서는 차단막을 4겹 사용했을 때부터 중합광이 조사되는 각도가 감소하기 시작하여 8겹 사용했을 때 통계적으로 유의하게 감소하는 것을 볼 수 있었다 (p < 0.05). 결론: 광중합형 복합레진을 광중합할 경우 감염 조절용 차단막이 찢어지는 경우를 대비하여 1겹으로 사용하기 보다는 2겹으로 사용하는 것이 환자간의 교차감염을 예방하는데 유리할 것으로 사료된다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.214.2-214.2
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• 2013

Device performance for the 45 and 32 nm node CMOS technology requires the integration of ultralow-k materials. To lower the dielectric constant for PECVD and spin-on materials, partial replacement of the solid network with air (k=1.01) appears to be more intuitive and direct option. This can be achieved introducting of second "labile" phase during depositoin that is removed during a subsequent UV curing and annealing step. Besides, with shrinking line dimensions the resistivity of barrier films cannot meet the International Technology Roadmap for Semiconductors (ITRS) requirements. To solve this issue self-forming diffusion barriers have drawn attention for great potential technique in meeting all ITRS requirments. In this present work, we report a Cu-V alloy as a materials for the self-forming barrier process. And we investigated diffusion barrier properties of self-formed layer on low-k dielectrics with or without UV curing treatment. Cu alloy films were directly deposited onto low-k dielectrics by co-sputtering, followed by annealing at various temperatures. X-ray diffraction revealed Cu (111), Cu (200) and Cu (220) peaks for both of Cu alloys. The self-formed layers were investigated by transmission electron microscopy. In order to compare barrier properties between V-based interlayer on low-k dielectric with UV curing and interlayer on low-k dielectric without UV curing, thermal stability was measured with various heat treatment temperature. X-ray photoelectron spectroscopy analysis showed that chemical compositions of self-formed layer. The compositions of the V based self-formed barriers after annealing were strongly dominated by the O concentration in the dielectric layers.