• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.07a
• /
• pp.655-656
• /
• 2005

In the future, plastic based system will play a crucial role in modem life, for examples, transparent display or disposable electronics and so on. In this paper, we introduced a new method to fabricate the metal line on the plastic substrate. Metal lines were fabricated by hot embossing and CMP process on PMMA (polymethylmethacrylate) substrates. A Si mold was made by wet etching process and a PMMA wafer was cut off from I mm thick PMMA sheet. A 100 nm thick Al was deposited on PMMA wafers. The Al deposited PMMA wafer and the Si mold carefully sandwiched which was directly imprinted by hot embossing. After imprinting process, a residual Al layer was removed by CMP process. Finally, we found the entire process may be very useful to fabricate the metal line on plastic substrates.

• Journal of the Korean Society for Heat Treatment
• /
• v.29 no.5
• /
• pp.216-219
• /
• 2016

$SnO_2$ single layer films (100 nm thick) and 2 nm thick Ni intermediated $SnO_2$ films were deposited on glass substrate by RF and DC magnetron sputtering without intentional substrate heating and then the influence of the Ni interlayer on the electrical and optical properties of the films were investigated. As deposited $SnO_2$ single layer films show the optical transmittance of 82.6% in the visible wavelength region and a resistivity of $6.6{ \times}10^{-3}{\Omega}cm$, while $SnO_2/Ni/SnO_2$ trilayer films show a lower resistivity of $2.7{ \times}10^{-3}{\Omega}cm$ and an optical transmittance of 76.3% in this study. Based on the figure of merit, it can be concluded that the intermediate Ni thin film effectively enhances the opto-electrical performance of $SnO_2$ films for use as transparent conducting oxides in flexible display applications.

• Korean Journal of Metals and Materials
• /
• v.47 no.1
• /
• pp.38-43
• /
• 2009

To investigate the effect of RF power on the structural, optical and electrical properties of amorphous InGaZnO (a-IGZO), its thin films and TFTs were prepared by RF magnetron sputtering method with different RF power conditions of 40, 80 and 120 W at room temperature. In this study, as RF power during the deposition process increases, the RMS roughness of a-IGZO films increased from 0.26 nm to 1.09 nm, while the optical band-gap decreased from 3.28 eV to 3.04 eV. In the case of the electrical characteristics of a-IGZO TFTs, the saturation mobility increased from $7.3cm^2/Vs$ to $17.0cm^2/Vs$, but the threshold voltage decreased from 5.9 V to 3.9 V with increasing RF power. It is regarded that the increment of RF power increases the carrier concentration of the a-IGZO semiconductor layer due to the higher generation of oxygen vacancies.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.36 no.5
• /
• pp.463-473
• /
• 2023

In recent years, the transparent amorphous oxide thin film transistor represented by indium-gallium-zinc-oxide (IGZO) has become the first choice of the next generation of integrated circuit control components. This article contributes an overview of IGZO thin-film transistors (TFTs), including their fundamental principles and recent advancements. The paper outlines various TFT structures and places emphasis on the fabrication process of the active layer. The result showed that the size of the active layer including the length-to-width ratio and the width could have a significant effect on the mobility. And the process of TFT could influence the crystal structure of IGZO thin film. Furthermore, the article presents an overview of recent applications of IGZO TFTs, such as their use in display drivers and TFT memories. At last, the future development of IGZO TFT is forecasted in this paper.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2010.04a
• /
• pp.369-372
• /
• 2010

평판 디스플레이(flat panel display)의 크기가 커짐에 따라 다양한 기판을 이용한 제조 방법이 개발되고 있다. 디스플레이 제조 공정 중 기판의 결함을 찾아서 분류하는 검사 시스템은 최종 제품의 품질을 결정하는 매우 중요한 부분이다. 본 연구는 머신비전 기술을 이용하여 불투명하고 반사율이 높은 기판 표면의 결함을 찾아내고, 이 결함을 스크래치(scratch), 흑결함(dark defect), 백결함(white defect)으로 분류하는 장치를 구현하는데 목적이 있다. 이를 구현하기 위해 본 논문에서는 정밀 스테이지(stage)와 라인 카메라(line CCD camera)을 이용한 광학계를 활용하여 검사 시스템을 구현하였다. 구축된 시스템을 이용하여 취득한 이미지를 12 개의 영역으로 등분하여 각각의 국부 영역에 대한 문턱값 연산(thresholding)을 적용함으로써 조명의 불균일을 의한 검출 에러율을 획기적으로 낮추었다. 간단한 컴퓨터비전 알고리듬의 채용으로도 검사 시스템의 구현이 가능함을 보였다.

• Cartoon and Animation Studies
• /
• s.35
• /
• pp.347-374
• /
• 2014

The aim of this article is to consider the future of industrialization of Augmented Reality contents focusing on cinematic imagination of films that used Augmented Reality techniques and artistic imagination of Augmented Reality Arts in the 21st century. The film showing future technology through cinematic imagination plays an role in the presentation of future vision important. Augmented Reality Arts show the big picture of future arts, future aspect of society, and future culture by using technically possible present technology. I classified the researched films according to Augmented Reality technique. It is expected that Gesture Recognition will develop with transparent display device techniques, Hologram techniques will be changed into individualized communication styles, Biometrics will be able to evolve into multi-Biometrics, and Wearable Computer will develop in the aspect of physical body augmentation and then industrialize. In Augmented Reality Arts, it seems that the various utilization of avatar will be related to Hologram, the utilization of the physiological phenomenon of the human body will be related to Biometrics, the mixture of reality and virtual reality will utilize display devices through Gesture Recognition, and a new experiment of HMD(Head-Mounted Display) will industrialize with the diversification of Wearable Computer. Augmented Reality contents created through the imagination and representation in the films and arts take a role in helping human life, and, at the same time, show the future image industrialized in the way of combination between human and environment without a medium.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2009.06a
• /
• pp.311-311
• /
• 2009

Carbon nanotubes (CNTs) belong to an ideal material for field emitters because of their superior electrical, mechanical, and chemical properties together with unique geometric features. Several applications of CNTs to field emitters have been demonstrated in electron emission devices such as field emission display (FED), backlight unit (BLU), X-ray source, etc. In this study, we fabricated a CNT cathode by using filtration processes. First, an aqueous CNT solution was prepared by ultrasonically dispersing purified single-walled CNTs (SWCNTs) in deionized water with sodium dodecyl sulfate (SDS). The aqueous CNT solution in a milliliter or even several tens of micro-litters was filtered by an alumina membrane through the vacuum filtration, and an ultra-thin CNT film was formed onto the alumina membrane. Thereafter, the alumina membrane was solvated by acetone, and the floating CNT film was easily transferred to indium-tin-oxide (ITO) glass substrate in an area defined as 1 cm with a film mask. The CNT film was subjected to an activation process with an adhesive roller, erecting the CNTs up to serve as electron emitters. In order to measure their luminance characteristics, an ITO-coated glass substrate having phosphor was employed as an anode plate. Our field emitter array (FEA) was fairly transparent unlike conventional FEAs, which enabled light to emit not only through the anode frontside but also through the cathode backside, where luminace on the cathode backside was higher than that on the anode frontside. Futhermore, we added a reflecting metal layer to cathode or anode side to enhance the luminance of light passing through the other side. In one case, the metal layer was formed onto the bottom face of the cathode substrate and reflected the light back so that light passed only through the anode substrate. In the other case, the reflecting layer coated on the anode substrate made all light go only through the cathode substrate. Among the two cases, the latter showed higher luminance than the former. This study will discuss the morphologies and field emission characteristics of CNT emitters according to the experimental parameters in fabricating the lamps emitting light on the both sides or only on the either side.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.25 no.6
• /
• pp.263-271
• /
• 2015

Commercial AR(Alkali Resistant)-glass fiber has a good chemical resistant property, but also has a problem of difficulty in fiberizing process because of high viscosity in melted glass compare with E-glass fiber which is the most widely used for reinforced fiber of composite materials. In this study, we fabricated AR-glass fiber with low zirconia contents compare with commercial AR-glass fiber relatively, and measured properties against E-glass fiber. We obtained transparent clear glass with zirconia contents of 0.5~16 wt% by melting at $1600^{\circ}C$ for 2 hours. These AR-glass samples had high visible transmittance of 89~90 %, softening temperature of $703{\sim}887^{\circ}C$. And softening temperatures of them were increased according to the increasing zirconia contents. Compare with E-glass, AR-glass contains 4 wt% zirconia has different value of $-94^{\circ}C$ in softening temperature, $+68^{\circ}C$ at Log3 temperature and $-13^{\circ}C$ at Log5 temperature in viscosity. We could verify good alkali resistant property of the AR-glass fiber with SEM after dipping in alkali solution for 48~72 hours, and also high tensile strength, 1.7 times compare with E-glass fiber at 48 hours and 2.2 times at 72 hours. We conclude that this AR-glass fiber can be widely used as general alkali resistant glass fiber because of easy manufacturing condition and good properties even though it has low zirconia contents.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2006.08a
• /
• pp.421-421
• /
• 2006

The light and energy-efficiency of classical liquid crystal displays is notoriously poor due to the use of absorption-based linear polarisers and colour filters. For instance, the light efficiency of PVAL polarisers is typically between 40 and 45 % and the colour filters have a typical efficiency below 35 % which results in a total light and energy-efficiency of the display below 10 %. In the past, a variety of polarizers were developed with an enhanced efficiency in generating linearly polarized light. Typically, these polarizers are based on the polarisationselective reflection, scattering or refraction of light i.e. one polarisation direction of light is directly transmitted to the LCD/viewer and the other polarization direction of light is depolarised and recycled which results in a typical efficiency for generating linearly polarized light of 70-85 %. Also, special colour filters have been proposed based on chiral-nematic reactive mesogens which increase the efficiency of generating colour. Despite the enormous progress in this field, a need persists for improved methods for generating polarized light and colour based on low cost optical components with a high efficiency. Here, the use of holographic phase gratings is reported for the generation of polarized light and colour. The phase grating are recorded in a photopolymer which is coated onto a backor frontlight for LCDs. Typically the recording is performed in the transmisson mode or in the waveguiding mode and slanted phase gratings are generated with their refractive index modulation at an angle between 20o and 45o with the normal of the substrate. It is shown that phase gratings with a high refractive index modulation and a high efficiency can be generated by a proper selection of the photopolymer and illumination conditions. These phase gratings coupleout linearly polarized light with a high contrast (> 100) and the light is directed directly to the LCD/viewer without the need for redirection foils. Dependent on the type of phase grating, the different colours are coupled-out at a slightly different angle which potentially increases the efficiency of classical colour filters. Moreover, the phase gratings are completely transparent in direct view which opens the possibility to use them in frontlights for LCDs. Holographic polarization gratings posses a periodic pattern in the polarization state of light (and not in the intensity of light). A periodic pattern in the polarization direction of linearly polarized light is obtained upon interference of two circularly polarized laser beams. In the second part of the lecture, it is shown that these periodic polarization patterns can be recorded in a linear photo-polymerizable polymer (LPP) and that such an alignment layer induces a period rotation in the director of (reactive and non-reactive) liquid crystals. By a proper design, optical components can be produced with only first order diffraction and with a very high efficiency (>0.98). It is shown that these diffraction gratings are potentially useful in projection displays with a high brightness and energy efficiency

• Clean Technology
• /
• v.19 no.4
• /
• pp.388-392
• /
• 2013

Iindium-tin-oxide (ITO) material was had to use in display application as transparent electrode. However it would be problems comes up, the depletion of indium, tin and energy consumption of production process. Therefore recently trend was demanded alternative ITO material and recycling/reused ITO. In this conditions, the environmental impact have to express correct value about recycling/reused ITO process. The life cycle assessment was valuable method in this process. Thus first step was carried out separating in/out put (material) sources and then, exactive data base (DB) was applied. The result of environment impact was calculated by affect categories and recycling rate was set to 34% (This value was measured in previous project). The rate (g) of ITO material was calculated by chemical equivalent. In result, environmental impact were revealed acidification potential and abiotic depletion and if do not recycle/reuse ITO, $ 476 per 1 ton waste in land.