• The Journal of the Korea institute of electronic communication sciences
• /
• v.6 no.5
• /
• pp.697-702
• /
• 2011

In this paper, We have fabricated PMMA thin films by plasma polymerization method for organic thin film transistor's insulator layer. In the electrical characteristic results with deposition pressures and substrate RF bias power in thin film deposition process, we have got dielectric constant of 3.4, high deposition rate of 8.6 [nm/min] and high insulation characteristics in condition of RF100 [W], Ar20 [sccm], 5 [mtorr], RF bias 20 [W]. Therefore, the fabricated thin films are possible as insulation layer of OTFT and organic memory.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2011.05a
• /
• pp.47-48
• /
• 2011

The effect of solution acidity and organic additives, polyethylene glycol (PEG), on the trivalent chromium electroplating was systematically investigated in the view point of solution stability, electroreduction of trivalent chromium ions and characterization of deposition layer. It was found that, the concentration of fraction chromium complexes in the trivalent chromium bath containing formic acid is strongly depended on pH value. PEG molecules were stable in trivalent chromium bath containing formic acid via studies on electrospray ionization mass spectrometry (ESI-MS) and UV-Vis. However, the presence of PEG molecules decreased the reductive current of hydrogen evolution, increasing of current efficiency higher about 10 % compared with solutions without PEG. Moreover, PEG additives developed the nodular morphology during electroreduction of trivalent chromium ions with the increase of solution acidity and enhanced its current efficiency by maintaining the consumption of complexant, formic acid, at a low speed. In this study, the effect of solution acidity was emphasized important, there, it controlled the formation of complexes in the solution, cathodic film (CF) during deposition, and properties of deposited layer. By electrochemical quartz crystal microbalance (EQCM), studies show that chromium electrodeposition occurs via the formation of intermediate complexes and adsorption on the cathode surface, which hinder the penetration of ions from bulk solution to the cathode surface.

• Proceedings of the KIEE Conference
• /
• 2007.11a
• /
• pp.94-95
• /
• 2007

We have observed electrical properties of ZnO thin films for the fabrication of transparent thin film transistor. ZnO thin films were deposited on $Al_2O_3$(0001) substrate at various temperatures by pulsed laser deposition(PLD). The third of harmonic(355nm) Nd:YAG laser was used for pulsed laser deposition. X-ray diffraction(XRD), field emission-scanning electron microscope(FE-SEM), and photoluminescence were used to characterize physical and optical properties of ZnO thin film.. The results indicated the ZnO film showed good optical properties as increasing temperatures, with low FWHM of exciton-related peak and XRD(0002) peak.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.34 no.2
• /
• pp.99-104
• /
• 2021

Ion-beam sputtering (IBS) was used to deposit semiconducting IZTO (indium zinc tin oxide) thin films onto heavily-doped Si substrates using a sintered ceramic target with the nominal composition In0.4Zn0.5Sn0.1O1.5, which could work as a channel layer for oxide TFT (oxide thin film transistor) devices. The crystallization behavior and electrical properties were examined for the films in terms of deposition parameters, i.e. target tilt angle and substrate temperature during deposition. The thickness uniformity of the films were examined using a stylus profilometer. The observed difference in electrical properties was not related to the degree of crystallization but to the deposition temperature which affected charge carrier concentration (n), electrical resistivity (ρ), sheet resistance (Rs), and Hall mobility (μH) values of the films.

• Journal of the Korean Vacuum Society
• /
• v.13 no.3
• /
• pp.114-119
• /
• 2004

Silicon Nitride thin films were deposited on p-type Si (100) substrates by atomic layer deposition (ALD) method at $550^{\circ}C$ using alternating exposures of $SiH_2Cl_2$ and $NH_3$, and the physical and electrical propeties of the deposited films were characterized. The thickness of the films was linearly increased with the number of deposition cycles, and the growth rate of the films was 0.13 nm/cycle with the reactant exposures of $3.0\times10^{9}$ L. The silicon nitride thin films deposited by Alf exhibited similar physical properties with the silicon nitride thin films deposited by low-pressure chemical vapor deposition (LPCVD) method in terms of refractive index and wet etch rate, lowering deposition temperature by more than 200 $^{\circ}C$. The ALD films showed the leakage current density of 0.79 nA/$\textrm{cm}^2$ at 3 MV/cm, which is lower than 6.95 nA/$\textrm{cm}^2$ of the LPCVD films under the same condition.

• Membrane Journal
• /
• v.30 no.2
• /
• pp.97-110
• /
• 2020

CO₂ capture and storage (CCS) is one of the promising technologies that can mitigate ever-growing emission of anthropogenic carbon dioxide and resultant climate change. Among them, chemical looping combustion (CLC) and calcium looping (CaL) are getting increasing attention recently as the prospective alternatives to the existing amine scrubbing. Both methods use metal oxides in the process and consist of cyclic reactions. Yet, due to their cyclic nature, they both need to resolve sintering-induced cyclic stability deterioration. Moreover, the structure of the metal oxides needs to be optimized to enhance the overall performance of CO₂ capture and storage. Deposition of thin film coating on the metal oxide is another way to get rid of wear and tear during the sintering process. Chemical vapor deposition or atomic layer deposition are the well-known, established methods to form thin film membranes, which will be discussed in this review. Various effective recent developments on structural modification of metal oxide and incorporation of stabilizers for cyclic stability are also discussed.

• Journal of the Korean Society for Heat Treatment
• /
• v.28 no.1
• /
• pp.7-16
• /
• 2015

The fabrication of high quality graphene using chemical vapor deposition (CVD) method for application in semiconductor, display and transparent electrodes is investigated. Temperature and pressure have major impact on the growth of graphene. Graphene doping was obtained by deposition of $MoO_3$ thin films using thermal evaporator. Bilayer graphene and the metal layer graphene were obtained. According to the behavior of graphene growth P-type doping was confirmed. Graphene obtained through experiments was analyzed using optical microscopy, Raman spectroscopy, UV-visible light spectrophotometer, 4-point probe sheet resistance meter and atomic force microscopy.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
• /
• 2002.02a
• /
• pp.91-94
• /
• 2002

Textured Ce$O_{2}$ buffers for YBCO coated conductors were deposited on biaxially textured Ni substrate by metalorganic chemical vapor deposition The texture of deposited Ce$O_{2}$ films was varied with deposition temperature(T) and oxygen partial pressure($Po_{2}$). ($\ell$ 00) textured Ce$O_{2}$ films were deposited at T= 500~$520^{\circ}C$, $Po_{2}$= 0.90~3.33 Torr. The growth rate of the Ce$O_{2}$ films was 150~200 nm/min at T= $520^{\circ}C$ and $Po_{2}$= 2.30 Torr, which was much faster than that prepated by other physical deposition method.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2011.05a
• /
• pp.238.1-238.1
• /
• 2011

본 연구에서는 non-contact deposition method의 일환인 ESD (electroctatic deposition)의 박막공정을 이용하여 Conductive layer 위에 Gold nanoparticles 및 Silver nanoparticles 등 organic/inorganic nano particle conductive ink system의 단분산 2D 박막을 제조를 연구하였다. ESD head를 통해 여러가지 organic / inorganic nano particle conductive ink system을 Deposition하였으며 분산도가 높고 균일한 단분산의 2차원 박막 구조를 얻을 수 있었으며, 전도성 PEDOT과의 Hybridization을 통해 균일상의 표면 Morphology를 갖는 고 전도성 투명 필름을 제작하였다. ESD technique를 이용하는 박막공정 기술은 나노입자 및 나노구조물의 박막화 패턴화를 포함하는 새로운 Deposition 기술로써 이를 응용하여 금속 나노입자의 2차원의 패턴화된 박막 구현을 통해 유기반도체 및 전자소자에의 응용성을 증거할 수 있었다.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.23 no.2
• /
• pp.262-271
• /
• 1999

A study of aerosol dynamics has been done to obtain axially and radially varying size distributions of particles generated in the Modified Chemical Vapor Deposition process. Heat and mass transfer have also been studied since particle generation and deposition strongly depend on the temperature field in a tube. Bimodal size distributions of particles have been obtained both in the particulate flow and in the deposited particle layer for the first time using the sectional method to solve aerosol dynamics. Variations of geometric mean diameter, geometric standard deviation have been studied for various parameters; flow rates and maximum wall temperature. The comparison between one-dimensional and two-dimensional approaches has also been made.