• Title/Summary/Keyword: Film Defects

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Light Effects of amorphous indium gallium zinc oxide thin-film transistor

  • Lee, Keun-Woo;Shin, Hyun-Soo;Heo, Kon-Yi;Kim, Kyung-Min;Kim, Hyun-Jae
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.531-533
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    • 2009
  • We've studied the optical and electrical properties of amorphous indium gallium zinc oxide thin-film transistor (a-IGZO TFT). When the a-IGZO TFT was illuminated at a wavelength of 660 nm, the offstate drain current was slightly increased, while below 550 nm it was increased significantly. The a-IGZO TFT was extremely sensitive, with deep-level defects at approximately 2.25 eV near the midgap.

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Fabrication of Micro Solid Oxide Fuel Cell by Thin Film Processing Hybridization: I. Multilayer Structure of Sputtered YSZ Thin Film Electrolyte and Ni-Based Anodes deposited by Spray Pyrolysis (박막공정의 융합화를 통한 초소형 고체산화물 연료전지의 제작: I. Spray Pyrolysis법으로 증착된 Ni 기반 음극과 스퍼터링으로 증착된 YSZ 전해질의 다층구조)

  • Son, Ji-Won;Kim, Hyoung-Chul;Kim, Hae-Ryoung;Lee, Jong-Ho;Lee, Hae-Weon;Bieberle-Hutter, A.;Rupp, J.L.M.;Muecke, U.P.;Beckel, D.;Gauckler, L.J.
    • Journal of the Korean Ceramic Society
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    • v.44 no.10
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    • pp.589-595
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    • 2007
  • Physical properties of sputtered YSZ thin film electrolytes on anode thin film by spray pyrolisis has been investigated to realize the porous electrode and dense electrolyte multilayer structure for micro solid oxide fuel cells. It is shown that for better crystallinity and density, YSZ need to be deposited at an elevated temperature. However, if pure NiO anode was used for high temperature deposition, massive defects such as spalling and delamination were induced due to high thermal expansion mismatch. By changing anode to NiOCGO composite, defects were significantly reduced even at high deposition temperature. Further research on realization of full cells by processing hybridization and cell performance characterization will be performed in near future.

Analysis of Photoluminescence for N-doped and undoped p-type ZnO Thin Films Fabricated by RF Magnetron Sputtering Method

  • Liu, Yan-Yan;Jin, Hu-Jie;Park, Choon-Bae;Hoang, Geun C.
    • Transactions on Electrical and Electronic Materials
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    • v.10 no.1
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    • pp.24-27
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    • 2009
  • N-doped ZnO thin films were deposited on n-type Si(100) and homo-buffer layer, and undoped ZnO thin film was also deposited on homo-buffer layer by RF magnetron sputtering method. After deposition, all films were in-situ annealed at $800^{\circ}C$ for 5 minutes in ambient of $O_2$ with pressure of 10Torr. X -ray diffraction shows that the homo-buffer layer is beneficial to the crystalline of N-doped ZnO thin films and all films have preferable c-axis orientation. Atomic force microscopy shows that undoped ZnO thin film grown on homo-buffer layer has an evident improvement of smoothness compared with N-dope ZnO thin films. Hall-effect measurements show that all ZnO films annealed at $800^{\circ}C$ possess p-type conductivities. The undoped ZnO film has the highest carrier concentration of $1.145{\times}10^{17}cm{-3}$. The photoluminescence spectra show the emissions related to FE, DAP and many defects such as $V_{Zn}$, $Zn_O$, $O_i$ and $O_{Zn}$. The p-type defects ($O_i$, $V_{Zn}$, and $O_{Zn}$) are dominant. The undoped ZnO thin film has a better p-type conductivity compared with N-doped ZnO thin film.

Measurements of simulated periodontal bone defects in inverted digital image and film-based radiograph: an in vitro study

  • De Molon, Rafael Scaf;Morais-Camillo, Juliana Aparecida Najarro Dearo;Sakakura, Celso Eduardo;Ferreira, Mauricio Goncalves;Loffredo, Leonor Castro Monteiro;Scaf, Gulnara
    • Imaging Science in Dentistry
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    • v.42 no.4
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    • pp.243-247
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    • 2012
  • Purpose: This study was performed to compare the inverted digital images and film-based images of dry pig mandibles to measure the periodontal bone defect depth. Materials and Methods: Forty 2-wall bone defects were made in the proximal region of the premolar in the dry pig mandibles. The digital and conventional radiographs were taken using a Schick sensor and Kodak F-speed intraoral film. Image manipulation (inversion) was performed using Adobe Photoshop 7.0 software. Four trained examiners made all of the radiographic measurements in millimeters a total of three times from the cementoenamel junction to the most apical extension of the bone loss with both types of images: inverted digital and film. The measurements were also made in dry mandibles using a periodontal probe and digital caliper. The Student's t-test was used to compare the depth measurements obtained from the two types of images and direct visual measurement in the dry mandibles. A significance level of 0.05 for a 95% confidence interval was used for each comparison. Results: There was a significant difference between depth measurements in the inverted digital images and direct visual measurements (p>|t|=0.0039), with means of 6.29 mm ($IC_{95%}$:6.04-6.54) and 6.79 mm ($IC_{95%}$:6.45-7.11), respectively. There was a non-significant difference between the film-based radiographs and direct visual measurements (p>|t|=0.4950), with means of 6.64mm($IC_{95%}$:6.40-6.89) and 6.79mm($IC_{95%}$:6.45-7.11), respectively. Conclusion: The periodontal bone defect measurements in the inverted digital images were inferior to film-based radiographs, underestimating the amount of bone loss.

Packaging technology of fresh-cut produce (신선편의식품 포장기술)

  • Kim, Ji Gang
    • Food Science and Industry
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    • v.50 no.2
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    • pp.12-26
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    • 2017
  • Processing steps such as washing and cutting, involved in preparing fresh-cut produce causes tissue damage, leading to rapid quality deterioration. Major defects of fresh-cut produce are discoloration, softening, off-odor development, and microbial growth. Packaging of fresh-cut produce has been changed to reduce these quality problems. Flexible packaging film is widely used to pack fresh-cut produce. Vacuum packaging was the popular packaging method in the beginning of fresh-cut industry in Korea. Vacuum packaging creates high $CO_2$ and low $O_2$ levels to control browning of fresh-cut produce. However, these conditions induce some visual defects and off-odor development. Discoloration problem was also found when fresh-cut produce was packaged with conventional packaging film or plastic tray. Modified atmosphere (MA) packaging is effective for prolonging shelf-life of fresh-cut produce by decreasing $O_2$ and increasing $CO_2$ concentration in the package. Retail MA packaging using different oxygen transmission rate (OTR) film and micro-perforated film has started to be applied to fresh-cut produce in Korea. Proper MA package design that provides optimum range of $O_2$ and $CO_2$ partial pressures is one of the major challenges in the industry. An initial package flushing with $N_2$ or an low $O_2$/high $CO_2$ atmosphere is also used to more rapidly establish steady-state MA condition. Film OTR and $O_2$ flushing affects the fermentative volatile production, off-odor development, electrolyte leakage, discoloration, $CO_2$ injury, microbial population of fresh-cut produce. There is also a demand for convenient packaging to attract consumers. Rigid fresh-cut produce container for retail market has increased since the packaging provides excellent protection from physical damage during transport. Rigid tray used as actual serving vessel for the consumer is increasing in Korea. The tray with flexible lid to wrap or seal fresh-cut produce is more and more gaining popularity. Further practical technology to control quality change and microbial growth for each fresh-cut product has been studied since various fresh-cut items were required. The fresh-cut industry also focuses on searching for more convenient and environmentally friendly packaging.

Temperature dependence of Heteroeptaxial $Y_2O_3$ films grown on Si by ionized cluster beam deposition

  • Cho, M.-H.;Ko, D.-H.;Whangbo, S.W.;Kim, H.B.;Jeong, K.H.;Whang, C.N.;Choi, S.C.;Cho, S.J.
    • Journal of the Korean Vacuum Society
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    • v.7 no.s1
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    • pp.57-77
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    • 1998
  • Heteroepitaxial $Y_2O_3$ films were grown on a Si(111) substrate by ionized cluster beam deposition(ICBD) in ultra high vacuum, and its qualities such as crystllitnity, film stress, and morphological characteristics were investigated using the various measurement methods. The crystallinity was investigated by x-ray diffraction (XRD) and reflection high energy electron diffraction (RHEED). Interface crystallinity was also examined by Rutherford backscattering spectroscopy(RBS) channeling, transmission electron microscopy(TEM). The stress of the films was measured by RBS channeling and XRD. Surface and interface morphological characteristics were investigated by atomic force microscopy (AFM) and x-ray scattering method. Comparing the interface with the surface characteristics, we can conclude that many defects at the interface region were generated by interface reaction between the yttrium metal and SiO2 layer and by ion beam characteristic such as shallow implantation, so that they influenced the film qualities. The film quality was dominantly depended on the characteristic temperature range. In the temperature range from $500^{\circ}C$ to $600^{\circ}C$, the crystallinity was mainly improved and the surface roughness was drastically decreased. On the other hand, in the temperature range from $600^{\circ}C$ to $700^{\circ}C$, the compressive stress and film density were dominantly increased, and the island size was more decreased. Also the surface morphological shape was transformed from elliptical shape to triangular. The film stress existed dominantly at the interface region due to the defects generation.

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A Scope of Functional Molecular Materials (기능성 분자재료의 발전 방향)

  • Shin, Dong-Myung;Kang, Dou-Yol
    • Proceedings of the KIEE Conference
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    • 1990.11a
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    • pp.136-138
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    • 1990
  • In developing, microscopic scale electrical and electronic devices, molecular level Insulators and functional electric conductors are fundamental. The properties of the electrical-insulating thin film materials are very much dependent on defects and electron transfer rate. There are number of companies which try to reduce defects and control electrical conductivity. Functional electrical conductors are more demanding subject in electrical fields. Reorganization energy around the sites that generate the electrons and holes are very important for the electron transfer in the organic thin layers.

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Effect of AIN Buffers by R. F. Sputter on Defects of GaN Thin films (R. F. Sputter법으로 성장된 AIN 완충층이 GaN 박막결함에 미치는 영향)

  • 이민수
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.17 no.5
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    • pp.497-501
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    • 2004
  • The crystal structure of the GaN film on the AIN buffer layer grown by R. F sputtering with different thickness has been studied using X-ray scattering and transmission electron microscopy(TEM). The interface roughness between the AIN buffer layer and the epitaxial GaN film, due to crossover from planar to island grains, produced edge dislocations. The strain, coming from lattice mismatch between the AIN buffer layer and the epitaxial GaN film, produced screw dislocations. The density of the edge and screw dislocation propagating from the interface between the GaN film and the AIN buffer layer affected the electric resistance of GaN film.

Reliability Evaluation of Atomic layer Deposited Polymer / Al2O3 Multilayer Film for Encapsulation and Barrier of OLEDs in High Humidity and Temperature Environments (OLED Barrier와 Encapsulation을 위한 원자층 증착 Polymer / Al2O3 다층 필름의 온습도 신뢰도 평가 분석)

  • Lee, Sayah;Song, Yoon Seog;Kim, Hyun;Ryu, Sang Ouk
    • Journal of the Semiconductor & Display Technology
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    • v.16 no.4
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    • pp.1-4
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    • 2017
  • Encapsulation of organic based devices is essential issue due to easy deterioration of organic material by water vapor. Atomic layer deposition (ALD) is a promising solution because of its low temperature deposition and quality of the deposited film. Moisture permeation has a mechanism to pass through defects, Thin Film Encapsulation using inorganic / organic / inorganic hybrid film has been used as promising technology. $Al_2O_3$ / Polymer / $Al_2O_3$ multilayer film has shown excellent environmental protection characteristics despite of thin thicknesses of the films.

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Cavity and Interface effect of PI-Film on Charge Accumulation and PD Activity under Bipolar Pulse Voltage

  • Akram, Shakeel;Wu, Guangning;Gao, GuoQiang;Liu, Yang
    • Journal of Electrical Engineering and Technology
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    • v.10 no.5
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    • pp.2089-2098
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    • 2015
  • With the continuous development in insulation of electrical equipment design, the reliability of the system has been enhanced. However, in the manufacturing process and during operation under continues stresses introduce local defects, such as voids between interfaces that can responsible to occurrence of partial discharge (PD), electric field distortion and accumulation of charges. These defects may lead to localize corrosion and material degradation of insulation system, and a serious threat to the equipment. A model of three layers of PI film with air gap is presented to understand the influence of interface and voids on exploitation conditions such as strong electrical field, PD activity and charge movement. The analytical analysis, and experimental results are good agreement and show that the lose contact between interfaces accumulate more residual charges and in consequences increase the electric field intensity and accelerates internal discharges. These residual charges are trapped charges, injected by the electrodes has often same polarity, so the electric field in cavities increases significantly and thus partial discharge inception voltage (PDIV) decreases. Contrary, number of PD discharge quantity increases due to interface. Interfacial polarization effect has opposite impact on electric field and PDIV as compare to void.