• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
• /
• pp.273.2-273.2
• /
• 2014

Sputtering process has been widely used in Si-based semiconductor industry and it is also an ideal method to deposit transparent oxide materials for thin-film transistors (TFTs). The oxide films grown at low temperature by conventional RF sputtering process are typically amorphous state with low density including a large number of defects such as dangling bonds and oxygen vacancies. Those play a crucial role in the electron conduction in transparent electrode, while those are the origin of instability of semiconducting channel in oxide TFTs due to electron trapping. Therefore, post treatments such as high temperature annealing process have been commonly progressed to obtain high reliability and good stability. In this work, the scheme of electron-assisted RF sputtering process for high quality transparent oxide films was suggested. Through the additional electron supply into the plasma during sputtering process, the working pressure could be kept below $5{\times}10-4Torr$. Therefore, both the mean free path and the mobility of sputtered atoms were increased and the well ordered and the highly dense microstructure could be obtained compared to those of conventional sputtering condition. In this work, the physical properties of transparent oxide films such as conducting indium tin oxide and semiconducting indium gallium zinc oxide films grown by electron-assisted sputtering process will be discussed in detail. Those films showed the high conductivity and the high mobility without additional post annealing process. In addition, oxide TFT characteristics based on IGZO channel and ITO electrode will be shown.

• 한국ITS학회 논문지
• /
• 제6권1호
• /
• pp.58-71
• /
• 2007

교통약자 즉, 장애인과 노약자의 자립생활과 사회통합을 위한 장애물 없는 생활환경(Barrier-Free)의 실현은 건축, 도시, 교통, 도로 등 통합적인 측면에서 생활환경의 설계기준 재정비 등 하드웨어적인 측면과 함께 사회활동에 필요한 편의시설의 다양한 정보접근과 이용 등 소프트웨어적인 측면이 동시에 충족되어야 하며, 소프트웨어적인 측면은 편의시설의 이용성을 제고하는데 있어 매우 중요한 문제이다. 이러한 측면에서 편의시설의 이용성 향상을 위해 유비쿼터스 기술 등 정보통신기술을 활용한 지원시스템 구축이 필요하다. 대표적 교통약자인 장애인 노약자가 사회생활을 하기 위하여 주거지를 넘어 다른 장소로 이동하고자 할 경우에도 이들의 목적을 달성하기에 어려움이 없도록 정보를 제공하고 지원하는 시스템이 필요하다. 장애인, 노약자의 행태조사 및 요구조사를 통한 요구사항분석과 장애인, 노약자 중심의 생활 및 이동지원시스템관련 국외 연구동향 및 관련 기술요소파악 및 시스템 요구조건과 유즈케이스를 도출하였다.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
• /
• pp.254-255
• /
• 2012

Interest in nano-crystalline silicon (nc-Si) thin films has been growing because of their favorable processing conditions for certain electronic devices. In particular, there has been an increase in the use of nc-Si thin films in photovoltaics for large solar cell panels and in thin film transistors for large flat panel displays. One of the most important material properties for these device applications is the macroscopic charge-carrier mobility. Hydrogenated amorphous silicon (a-Si:H) or nc-Si is a basic material in thin film transistors (TFTs). However, a-Si:H based devices have low carrier mobility and bias instability due to their metastable properties. The large number of trap sites and incomplete hydrogen passivation of a-Si:H film produce limited carrier transport. The basic electrical properties, including the carrier mobility and stability, of nc-Si TFTs might be superior to those of a-Si:H thin film. However, typical nc-Si thin films tend to have mobilities similar to a-Si films, although changes in the processing conditions can enhance the mobility. In polycrystalline silicon (poly-Si) thin films, the performance of the devices is strongly influenced by the boundaries between neighboring crystalline grains. These grain boundaries limit the conductance of macroscopic regions comprised of multiple grains. In much of the work on poly-Si thin films, it was shown that the performance of TFTs was largely determined by the number and location of the grain boundaries within the channel. Hence, efforts were made to reduce the total number of grain boundaries by increasing the average grain size. However, even a small number of grain boundaries can significantly reduce the macroscopic charge carrier mobility. The nano-crystalline or polymorphous-Si development for TFT and solar cells have been employed to compensate for disadvantage inherent to a-Si and micro-crystalline silicon (${\mu}$-Si). Recently, a novel process for deposition of nano-crystralline silicon (nc-Si) thin films at room temperature was developed using neutral beam assisted chemical vapor deposition (NBaCVD) with a neutral particle beam (NPB) source, which controls the energy of incident neutral particles in the range of 1~300 eV in order to enhance the atomic activation and crystalline of thin films at room temperature. In previous our experiments, we verified favorable properties of nc-Si thin films for certain electronic devices. During the formation of the nc-Si thin films by the NBaCVD with various process conditions, NPB energy directly controlled by the reflector bias and effectively increased crystal fraction (~80%) by uniformly distributed nc grains with 3~10 nm size. The more resent work on nc-Si thin film transistors (TFT) was done. We identified the performance of nc-Si TFT active channeal layers. The dependence of the performance of nc-Si TFT on the primary process parameters is explored. Raman, FT-IR and transmission electron microscope (TEM) were used to study the microstructures and the crystalline volume fraction of nc-Si films. The electric properties were investigated on Cr/SiO2/nc-Si metal-oxide-semiconductor (MOS) capacitors.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
• /
• pp.1619-1622
• /
• 2005

The ultra thin hole injection layer (HIL) was deposited on an indium-tin-oxide (ITO) anode by using an ion beam assisted d eposition (IBAD) for the fabrication of an polymeric electroluminescence device for the first time. The device with the HIL deposited by IBAD has higher external quantum efficiency than the device with the HIL by conventional thermal evaporation. It is found that the deposited HIL by IBAD has high surface coverage on ITO anode in a few nm regions because the HIL prepared has high adatom mobility by ion beam energy.

• 한국표면공학회지
• /
• 제31권2호
• /
• pp.109-116
• /
• 1998

Highly transparent conductive pure and fluorine-doped tin oxide(FT0, $SnO_2$ : F) films have been prepared by low pressure metal organic chemical vapor deposition (LP-MOCVD) from various mixtures of tetramethyitin(TMT) with oxygen or oxygen containing ozone. The properties of TO films have been changed with the variation of gases, flow rate, and substrate temperature. The nsing of oxygen containing ozone instead of pure oxygen, reduced substrate temperature by 100-$150^{\circ}C$ while maintaining same thickness. The films prepared by using ozone showed the resistivity in the range from $10^~2$ to $10^{~3}\Omega$cm, and the mobiiity from 10 to $14\textrm{cm}^2$/Vs. Fluorine-doped tin oxide films had properties such as the resistivity about $10^{-4}\Omega$cm, and the mobility from 14 to $19\textrm{cm}^2$/Vs.

• International Journal of Contents
• /
• 제13권3호
• /
• pp.25-31
• /
• 2017

With tremendous advancement of information and communication technologies, mobile learning systems have been widely adopted in language learning contexts, and several frameworks have been developed for identifying and categorizing different factors of mobile-assisted language learning (MALL). However, pre-existing frameworks have limitations when evaluating the importance level of criteria. The purpose of this study is to develop a comprehensive hierarchical framework for identifying and categorizing success factors of MALL and prioritizing them according to the importance level. To do that, AHP method is used to quantitatively estimate weight values of MALL criteria. Results reveal that the priority of MALL criteria is ordered as follows: content, system, learner, language learning. Local weights of each criterion are also analyzed; for example, usefulness, accuracy, and authenticity are critical factors for improving MALL contents. Ease of use and mobility of MALL systems are also considered more critical than other systematic factors. In addition, availability of immediate feedback and self-directness has the highest weight values of importance. The findings of the study are discussed regarding hierarchical orders of MALL criteria and conclude that successful MALL implementation may be achieved if related elements are diversely measured and evaluated. Pedagogical implications and suggestions for further research are also presented.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2009년도 제33회 추계학술대회논문집
• /
• pp.173-176
• /
• 2009

박격포는 근거리 진지전이나 직사화기 곡사화기로는 사격할 수 없는 배사면의 적을 큰 낙각의 탄도를 그리는 포탄으로 공격할 수 있으므로 보병부대에서 효율적으로 운용되고 있다. 육군에서는 정확성, 기동성 및 사거리가 증대된 120미리 박격포의 도입 필요성을 제기하고 있으며, 관련 연구도 꾸준히 진행되고 있다. 본 연구에서는 120미리 박격포탄 중 사거리연장탄에 사용되는 로켓추진제의 조성을 설계하여 시제품을 제조한 후 지상연소시험과 발사시험을 통해 120미리 박격포용 사거리연장탄의 개발 가능성을 알아보았다.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제37권
• /
• pp.11.1-11.5
• /
• 2015

Rapid palatal expansion(RPE) with the tooth-born appliance is not sufficient to apply to the patients with periodontal problem or insufficient tooth anchorage, and it leads to tipping of the anchorage teeth and increasing teeth mobility and root resorption. To avoid these disadvantages, we present the case using palatal screws and custommade palatal expander. A 23-year-old patient underwent surgically assisted rapid maxillary expansion with the Hyrax expansion using 4 tent screws. The study models were used to measure the pre-/-post surgical width of the anterior and posterior dental arches with a digital sliding caliper. In the result, the custom-made palatal expander with 4 tent screws is suitable for delivering a force to the mid-palatal suture expansion. And it is low cost, small sized and simply applied. The results indicated that maxillary expansion with the custom-made palatal anchorage device is predictable and stable technique without significant complications in patients.

• 창의정보문화연구
• /
• 제4권2호
• /
• pp.95-101
• /
• 2018

언어교육이나 특수교육을 위하여 지능형 소셜 로봇이나 원격연결 로봇을 교육현장에 활용하는 로봇보조학습이 도입됨에 따라 기술수용모델 연구도 이루어지고 있다. 기존의 연구에서는 지능형 소셜 로봇에 대한 통합기술수용모델까지 연구되어 있으나, 원격연결형 로봇보조학습에 대한 연구는 미흡하다. 이 논문은 원격연결형 로봇보조학습이 미래학교에서 이루어질 수 있는지에 대하여 로봇보조학습을 체험한 예비교사들을 대상으로 통합기술수용모델을 추정하고자 하였다. 추정된 통합모델은 자율 지능형 로봇보다 간결한 요인으로 구성되어 있으며, 이 중에서 이동성, 커뮤니케이션, 외형의 하위요인이 영향을 끼치는 유희성의 중요도가 매우 높게 나타난 것을 알 수 있었다. 즉 예비교사들은 얼굴영상 원격연결로봇의 자유로운 이동성, 커뮤니케이션, 그리고 직접 만질 수 있는 외형으로 구성된 유희성을 높인 로봇에 대한 유의미한 수용도를 보였다.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
• /
• pp.410.1-410.1
• /
• 2014

A soft-lithographic top-down approach is combined with an epitaxial layer transfer process to fabricate high quality III-V compound semiconductor nanowires (NWs) and integrate them on Si/SiO2 substrates, using MBE-grown ultrathin InAs as a source wafer. The channel width of the InAs nanowires is controlled by using solvent-assisted nanoscale embossing (SANE), descumming, and etching processes. By optimizing these processes, the NW width is scaled to less than 50 nm, and the InAs NWFETs has ${\sim}1,600cm^2/Vs$ peak electron mobility, which indicates no mobility degradation due to the size.