• Polymer Science and Technology
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• v.20 no.5
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• pp.472-480
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• 2009

반도체 미세화가 진행되면서, 이를 성공하기 위해 많은 재료물질이 요구되어진다. 이 중 미세 패턴의 붕괴를 막고 깊은 패턴을 새기기 위해서 필요한 hardmask 재료가 있다. Hardmask는 유기실리콘 재료와 탄소 함량이 높은 재료로 주로 구성되고, 이들은 193 nm 빛과 관련된 광학적 특성을 가지면서 특정 플라즈마에 대한 에치 저항성을 가지는 물성을 가지도록 디자인/합성/배합되어져 있다. 또한, 접합되는 다른 박막과의 compatibility및 용매에 대한 solubility 등이 적절해야만 나노미터 수준의 defect 없는 패턴을 구현할 수 있다.

• Journal of the Microelectronics and Packaging Society
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• v.23 no.1
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• pp.11-15
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• 2016

The organic light emitting diodes (OLEDs) have been studied as large flexible displays, light source and hard wares of internet of things. However, OLEDs show some drawbacks in terms of external environments due to the low work function of the metals and the reactive organic materials. In particular, the operation functions of the OLEDs tend to deteriorate rapidly by exposing the oxygen and moisture. So as to prevent it, domestic and overseas studies underway in various method such as ALD, PVD, CVD. But it has complex process and high cost. Therefore In order to protect devices from the external environments, it is important to develop the passivation thin films of low-cost and simple process which can prevent the devices from the penetration of the oxygen and moistures. In this study, to improve the reliability, passivation thin films were coated onto the green OLEDs by spin coating method and investigated the changes of the optical properties of the prepared devices at various doping concentrations of sodium alginate (SA). The passivation solutions were synthesized by using polyvinyl alcohol (PVA) host material with a dopant of SA which were added with the amounts of 10, 20 and 40 wt% into the PVA. As a result, the best barrier properties of the OLEDs were obtained for the samples with 40 wt% SA. Finally, the passivation films can be optimized by using the mixture solution of PVA and SA materials.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.399-399
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• 2008

Synthesis and characterization of ZnO structure such as nanowires, nanorods, nanotube, nanowall, etc. have been studied to multifunctional application such as optical, nanoscale electronic and chemical devices because it has a room-temperature wide band gap of 3.37eV, large exiton binding energy(60meV) and various properties. Various synthesis methods including chemical vapor deposition (CVD), physical vapor deposition, electrochemical deposition, micro-emulsion, and hydrothermal approach have been reported to fabricate various kinds of ZnO nanostructures. But some of these synthesis methods are expensive and difficult of mass production. Wet chemical method has several advantage such as simple process, mass production, low temperature process, and low cost. In the present work, ZnO nanorods are deposited on ITO/glass substrate by simple wet chemical method. The process is perfomed by two steps. One-step is deposition of ZnO seeds and two-step is growth of ZnO nanorods on substrates. In order to form ZnO seeds on substrates, mixture solution of Zn acetate and Methanol was prepared.(one-step) Seed layers were deposited for control of morpholgy of ZnO seed layers by spin coating process because ZnO seeds is deposited uniformly by centrifugal force of spin coating. The seed-deposited samples were pre-annealed for 30min at $180^{\circ}C$ to enhance adhesion and crystallinnity of ZnO seed layer on substrate. Vertically well-aligned ZnO nanorods were grown by the "dipping-and-holding" process of the substrates into the mixture solution consisting of the mixture solution of DI water, Zinc nitrate and hexamethylenetetramine for 4 hours at $90^{\circ}C$.(two-step) It was found that density and morphology of ZnO nanorods were controlled by manipulation of ZnO seeds through rpm of spin coating. The morphology, crystallinity, optical properties of the grown ZnO nanostructures were carried out by field-emission scanning electron microscopy, high-resolution electron microscopy, photoluminescence, respectively. We are convinced that this method is complementing problems of main techniques of existing reports.

• Journal of the Microelectronics and Packaging Society
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• v.14 no.3
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• pp.1-6
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• 2007

In this study, the pentacene thin films were prepared by the soluble process, and characterized fur the application of the organic thin film transistor(OTFT) device. To dissolve the pentacene material, two kinds of solvents such as toluene and chloroform were used, and the effects of these solvents on the properties of pentacene thin films coated on ITO/Glass substrate were investigated. Pentacene thin films were prepared by using spin-coating methode and characterized the surface morphology, crystalline and electrical properties. From the AFM measurement, the surface morphology of the pentacene film dissolved with chloroform was improved compared with the one dissolved with toluene solvent. XRD measurement showed that all prepared pentacene film samples were amorphous crystal phases without crystallization of the films. The electrical properties of the pentacene film dissolved with chloroform showed better results than the ones using toluene solvent by hall measurement system. The carrier concentration and the mobility values of pentacene films using chloroform solvent were found to be $-3.225{\times}10^{14}\;cm^{-3}$ and $3.5{\times}10^{-1}\;cm^2{\cdot}V^{-1}{\cdot}S^[-1}$, respectively. The resistivity was about $2.5{\times}10^2\;{\Omega}{\cdot}cm$.

• Journal of the Korean Ceramic Society
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• v.34 no.1
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• pp.79-87
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• 1997

Anti-reflective and anti-static double layered films were prepared on the VDT panel by sol-gel spin-coating method. Their electrical, opticla, and mechanical properties were investigated. The outer SiO2 film with low re-fractive index was coated over the inner ATO(Antimony-doped Tin Oxide)-SiO2 film which was prepared by mixing ATO sol with SiO2 at molar ratio of 68:32 to satisfy the interference condition of double layers. The heat treatment was conducted at 45$0^{\circ}C$ for 30 min where residual organics were completely removed. The sheet resistance of ATO single layer showed the minimum value of 6$\times$107$\Omega$/$\square$ at 3 mol% addition of Sb and that of SiO2/ATO-SiO2 increased slightly with increasing SiO2 mol% up to 30 mol%, and then increased steeply to the value of 3$\times$108$\Omega$/$\square$ at 32 mol%. The reflectance of double layered films was about 0.64% at the wavelength of 550nm and the transmittance increased about 3.20%. The hardness of double layered films was almost the same as that of uncoated VDT panel, 471.4kg.f/mm2.

• Journal of the Korean Vacuum Society
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• v.19 no.4
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• pp.281-286
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• 2010

Thickness effects on the structural and optical properties of ZnO thin films fabricated by spin coating method have been carried out. With increase in the thickness of the ZnO thin films, the width and density of striation shape are increased. The ZnO thin film with thickness of 450 nm has a smooth surface morphology. For the ZnO thin film with a smooth surface, orientation factor ${\alpha}_{(002)}$ is sharply increased and FWHM of (002) diffraction peak is decreased compared to the ZnO thin films with a striation shape surface. Thickness and surface morphology of the ZnO thin films hardly affect the NBE peak position. However, the DLE peak position is blue-shifted as the surface morphology is changed from striation to smooth surface. The PL intensity ratio of the NBE to DLE is increased and the FWHM of NBE peak is decreased as the thickness of the ZnO thin films is increased.

• Journal of the Korean Vacuum Society
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• v.19 no.6
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• pp.483-488
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• 2010

ZnO nano-fibrous thin films with various precursor concentrations ranging from 0.2 to 1.0 mol (M) were grown by spin-coating method and effects of the precursor concentration on surface and optical properties of the ZnO nano-ribrous thin films were investigated by using scanning electron microscopy (SEM) and photoluminescence (PL). ZnO nuclei were formed at the precursor concentration below 0.4 M and the ZnO nano-fibrous thin films were grown at the precursor concentration above 0.6 M. Further increase in the precursor concentration, the thickness of the ZnO nano-fibrous thin films is gradually increased. The intensity and the full-width at half-maximum (FWHM) of the near-band-edge emission (NBE) is increased as the precursor concentration is increased. The deep-level emission (DLE) is red-shifted as the precursor concentration is increased.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.11a
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• pp.247-250
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• 1998

Ferroelectric PZT(10/90)PZT(90/10) heterolayered thin films were fabricated by spin-coating method on the Pt/Ti/SiO$^2$/Si substrate alternately using PZT(10/90) and PZT(90/10) metal alkoxide solutions. The coating and heating procedure was repeated six times to form PZT heterolayered films. The surface, cross-sectional microstructures and thickness of the films were observed using scanning electron microscope(SEM). The relative dielectric constant and dielectric loss of the 5-coated PZT heterolayered films were 1331 and 4.8% respectively.

• Korean Journal of Materials Research
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• v.27 no.11
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• pp.577-582
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• 2017

Self-cleaning and photocatalytic $TiO_2$ thin films were prepared by a facile sol-gel method followed by spin coating using peroxo titanic acid as a precursor. The as-prepared thin films were heated at low temperature($110^{\circ}C$) and high temperature ($400^{\circ}C$). Thin films were characterized by X-ray diffraction(XRD), Field-emission scanning electron microscopy(FESEM), UV-Visible spectroscopy and water contact angle measurement. XRD analysis confirms the low crystallinity of thin films prepared at low temperature, while crystalline anatase phase was found the for high temperature thin film. The photocatalytic activity of thin films was studied by the photocatalytic degradation of methylene blue dye solution. Self-cleaning and photocatalytic performance of both low and high temperature thin films were compared.

• Transactions on Electrical and Electronic Materials
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• v.11 no.5
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• pp.212-215
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• 2010

$BiFeO_3/Pb(Zr_{0.95}Ti_{0.05})O_3$ (BFO/PZT) heterolayered thin films were fabricated by the spin coating method on a Pt/Ti/$SiO_2$/Si substrate using metal alkoxide solutions. The coating and heating procedure was repeated 6 times to form the heterolayered films. The thickness of the BFO/PZT films after one cycle of drying/sintering is about 30-40 nm. All BFO/PZT films show a void free uniform grain structure without the presence of rosette structures. It can be assumed that the crystal growth of the upper BFO layers can be influenced by the lower PZT layers. As the number of coatings increased, the dielectric constant increased, so that the value for the 6-layer film was 1360 at 1 KHz.