• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
• /
• pp.450-450
• /
• 2012

In recent days, advances in ZnO-based oxide semiconductor materials have accelerated the development of thin-film transistors (TFTs), which are the building blocks for active matrix flat-panel displays including liquid crystal displays (LCD) and organic light-emitting diodes (OLED). In particular, the development of high-mobility ZnO-based channel materials has been proven invaluable; thus, there have been many reports of high-performance TFTs with oxide semiconductor channels such as ZnO, InZnO (IZO), ZnSnO (ZTO), and InGaZnO (IGZO). The reliability of oxide TFTs can be improved by examining more stable oxide channel materials. In the present study, we investigated the effects of an ALD-deposited water vapor permeation barrier on the stability of ZnO and HfZnO (HZO) thin film transistors. The device without the water vapor barrier films showed a large turn-on voltage shift under negative bias temperature stress. On the other hand, the suitably protected device with the lowest water vapor transmission rate showed a dramatically improved device performance. As the value of the water vapor transmission rate of the barrier films was decreased, the turn-on voltage instability reduced. The results suggest that water vapor related traps are strongly related to the instability of ZnO and HfZnO TFTs and that a proper combination of water vapor permeation barriers plays an important role in suppressing the device instability.

• 공업화학
• /
• 제29권4호
• /
• pp.484-487
• /
• 2018

본 논문에서는 유기전자소자에서 사용되는 수분 차단막의 투습도 분석을 위하여 ytterbium의 광학적 전기적 특성을 연구하였다. Ytterbium 박막은 다양한 성막 두께(20-100 nm)에 따라 넓은 범위의 광투과도(70-10%)와 비저항($6.0-0.16m{\Omega}{\cdot}cm$) 값을 나타내었다. 25 nm의 ytterbium 박막은 수분과 반응하여 산화되며 투과도와 저항이 실시간으로 변화하였고 이를 통해 parylene 고분자와 aluminum nitride 적층형 박막 봉지 필름을 분석한 결과 $4.3{\times}10^{-3}g/m^2{\cdot}day$의 투습도를 측정할 수 있었다.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2011년도 춘계학술대회 논문집
• /
• pp.1099-1100
• /
• 2011

• 한국세라믹학회지
• /
• 제56권6호
• /
• pp.601-605
• /
• 2019

This work reports the preparation of ceramic hybrid films with illite-polyethylene composites analyzed as a function of concentration of added illite in polyethylene. The enhancement of oxygen and water-vapor transmission rate of illite-polyethylene film was evaluated to determine its influence on the freshness in fruit packaging. Particle size of illite materials was controlled in the range of 1~10 ㎛ and then mixed with LDPE to form the masterbatch. Ceramic hybrid films were prepared through a blown film making process. To determine the dispersity and abundancy of illite materials in the polyethylene matrix, various characterizations of illite-PE hybrid masterbatch and films were performed using SEM, TGA, and FT-IR. The oxygen and water-vapor transmission rate of illite-polyethylene film was found to be two times higher than that of LDPE film.

• 대한금속재료학회지
• /
• 제47권12호
• /
• pp.873-880
• /
• 2009

Water-vapor permeation through metallic barriers deposited on polymer substrates has been an important technological issue because the performance of the barrier is critical to the reliability of flexible organic devices. For the development of long-lifetime flexible organic devices, two different sets of samples were designed and demonstrated from the viewpoint of the water-vapor transmission rate (WVTR). Aluminum (Al) and polyethylene terephthalate (PET) were chosen for the barrier layer and the polymer substrate, respectively. Two stacking structures, a single-layer (Al/PET) structure and a double-layer (Al/PET/Al) structure, were used for the WVTR measurement. For the single-layer structure, the WVTR decreases as the thickness of the barrier layer increases. Compared to the single-layer sample, the double-layer sample showed superior WVTR performance (by nearly three times) when the total thickness of the Al barrier was greater than 100 nm.

• Journal of Pharmaceutical Investigation
• /
• 제39권2호
• /
• pp.93-95
• /
• 2009

To compare the water vapor transmission rate (WVTR) of PVA/Dextran blended hydrogel obtained by European Pharmacopiea (EP) and Japanese Industrial Standards 1099 (JIS) method, the hydrogels with various PVA/Dextran rates were prepared and their WVTR values were then checked. As dextran in the hydrogel was increased, the WVTR of hydrogel was increased. The WVTR of hydrogels were 660-1500 and $730-1900\;g/m^2$-day in EP and JIS method, respectively. There were no significant differences between the WVTRs of the hydrogels obtained by EP and those obtained by JIS method. Thus, JIS method was recommended as a WVTR method of hydrogel due to relatively simpler and shorter time.

• 한국전자통신학회논문지
• /
• 제5권1호
• /
• pp.81-87
• /
• 2010

본 논문에서는 유기발광다이오드 적용을 위한 보호막 혹은 barrier 적용을 위하여 화학증착방법(CVD)를 이용한 실리콘 산화막을 형성하고, 산화막의 특성에 영향을 미치는 공정조건을 변화시켰다. 이로부터 HDP-CVD를 활용한 $SiO_2$박막 증착을 위한 최적의 공정조건은 $SiH_4:O_2$=30:60[sccm]유량, 소스와 기판과의 거리가 70 [mm], 기판에 Bias를 가하지 않은 조건인 경우 8~10[mtorr] 공정압력에서 매우 안정된 플라즈마 형성이 가능한 최적의 공정조건을 얻었다. 얻어진 공정조건으로 제작된 $SiO_2$산화막의 모콘테스트를 통한 투습율(WVTR)을 조사한 결과 2.2 [$g/m^2$_day]값으로 HDP-CVD로 제작된 $SiO_2$산화막은 유기발광다이오드용 보호막으로의 적용이 어려울 것으로 생각된다.

• 반도체디스플레이기술학회지
• /
• 제21권2호
• /
• pp.11-14
• /
• 2022

In this work, we evaluated the Al₂O₃ film, which was deposited by atomic layer deposition, degraded by exposure to harsh environments. The Al₂O₃ films deposited by atomic layer deposition have long been used as a gas diffusion barrier that satisfies barrier requirements for device reliability. To investigate the barrier and mechanical performance of the Al₂O₃ film with increasing temperature and relative humidity, the properties of the degraded Al₂O₃ film exposed to the harsh environment were evaluated using electrical calcium test and tensile test. As a result, the water vapor transmission rate of Al₂O₃ films stored in harsh environments has fallen to a level that is difficult to utilize as a barrier film. Through water vapor transmission rate measurements, it can be seen that the water vapor transmission rate changes can be significant, and the environment-induced degradation is fatal to the Al₂O₃ thin films. In addition, the surface roughness and porosity of the degraded Al₂O₃ are significantly increased as the environment becomes severer. the degradation of elongation is caused by the stress concentration at valleys of rough surface and pores generated by the harsh environment. Becaused the harsh envronment-induced degradation convert amorphous Al₂O₃ to crystalline structure, these encapsulation properties of the Al₂O₃ film was easily degraded.

• 한국의류학회지
• /
• 제41권1호
• /
• pp.84-97
• /
• 2017

Water vapor and thermal transmission properties of high emotional garments are important to evaluate wear comfort; in addition, the measuring methods of these properties are also critical for breathable and warm suit fabrics. In this study, the water vapor and thermal properties of composite yarn fabrics made of CoolMax, Tencel, and Bamboo fibers with filaments were measured and compared according to the measuring method. Water Vapor Transmittance (WVT) of the fabric woven by the sheath/core composite yarn in the warp direction was the highest due to the small staple fiber volume in the sheath/core yarn structure and high air voids in the sheath/core yarn fabrics. This property was also the highest in fabrics woven by bamboo staple yarns in the weft direction, and was the lowest on hi-multi filament fabrics. However, water vapor resistance ($R_{ef}$) of these fabrics by KSK ISO 11092 showed the opposite results to the water vapor transmittance method ($CaCl_2$ method); in addition, its correlation coefficient was low. The correlation coefficient between $R_{ef}$ and the drying rate was 0.719; therefore, the measurement mechanism of $R_{ef}$ is analogous to the drying property measurement. The thermal conductivity of the fabrics woven with compact staple yarn showed a high value; however, the hi-multi filament fabric showed low thermal conductivity. Therefore, fiber characteristics affect thermal properties more than yarn structure. The correlation between thermal property and moisture transport was also low. This study showed that: water vapor transmittance was active at the loose yarn structure, dry heat transport was vigorous at the compact yarn structure, and heat transport was affected more by fiber characteristics than yarn structure. In conclusion, sheath/core composite yarns were relevant to the high absorptive cool suit along with siro-fil and CoolMax/Bamboo staple yarns that were relevant to the heat diffusive cool suit.

• 한국식품과학회지
• /
• 제28권1호
• /
• pp.1-7
• /
• 1996

Hydrocolloid film에 lipid 액을 입혀 제조한 film A와 hydrocolloid 용액에 beeswax의 함량과 용해 상태를 달리하여 제조한 film B와 C의 물리적 특성을 검토해 본 결과, 제조에 있어서는 film A보다 film B와 C의 제조가 용이하였다. 세가지 film의 두께는 0.03 mm 정도로 유의적인 차이를 나타내지 않았으며, 1-3%의 수분함량과 59-68%의 지방을 함유한 film으로 세 film 모두 백색을 나타내었다. 인장강도는 film A가 우수하였으며, 투습도에서는 lipid 액의 뚜렷한 효과로 감소하였으며 film A와 B는 유의적인 차이를 나타내지 않았다. 한편 냉동전후의 투습도에서 film A는 유의적인 차이를 나타내지 않았으나, film B와 C는 냉동 후의 투습도가 유의적으로 감소하였다. 산소투과도는 film A와 C가 유의적인 차이를 나타내지 않았다. 전자현미경으로 film의 표면특성을 관찰한 결과, film A는 지방구의 분포가 일정하였으나 B와 C는 지방구의 편재를 볼 수 있었으며 1년 저장 후 film A는 bilayer층의 delamination을 나타내는 것으로 보아 전반적인 물리적 특성은 film A가 우수하나 장기저장에 있어서는 보다 제조법이 용이한 film B와 C를 선택하는 것이 바람직할 것으로 보이며, film B와 C의 균일하지 못한 표면 형상을 개선하는 방법과 투습도 및 산소투과도를 감소시키는 것이 앞으로 개선할 과제로 여겨진다.