• Korean Journal of Materials Research
• /
• v.11 no.1
• /
• pp.15-19
• /
• 2001

Transparent and conducting tin oxide thin films were prepared on soda lime silicate glass by thermal chemical vapour deposition. Thin films were fabricated from mixtures of tetramethyltin (TMT) as a precursor, oxygen or oxygen containing ozone as an oxidant. The properties of fabricated tin oxide films are highly changed with variations of substrate temperature. Optimized thin films could be prepared on TMT, which flow rate of 8 sccm, oxygen flow rate of 150 sccm and substrate temperature of 38$0^{\circ}C$. We reduced deposition temperature about$ 180^{\circ}C$ by using of oxygen containing ozone instead of pure oxygen and resistivity of thin films was decreased from ~ ${\times}10^{-2}{\Omega}cm$ to ~${\times}10^{-3}{\Omega}cm$.

• Journal of Surface Science and Engineering
• /
• v.53 no.1
• /
• pp.15-21
• /
• 2020

In this study, growth and burning behavior of 6061 aluminum alloy was studied under constant anodic voltages at various temperatures and magnetic stirring rates in 20% sulfuric acid solution by analysing I-t curves, measuring thickness and hardness of aluminum anodic oxide (AAO) films, observations of surface and cross-sectional images of AAO films. AAO films were grown continuously at lower voltages than 18.5V but burning occurred when a voltage more than 19V was applied in 20% H₂SO₄ solution at 20±0.5℃ and 200 rpm of magnetic stirring. The burning was always related with an extremely large increase of anodic current density with anodizing time, suggesting that high heat generation during anodizing causes deteriorations of AAO films by chemical reaction with acidic solutions. The burning resulted in decreases of film thickness and hardness, surface color brightened and formation of porous defects in the AAO films. The burning voltage was found to decrease with increasing solution temperature and decreasing magnetic stirring rate. The decreased burning voltages seem to be closely related with increased chemical reactions between AAO films and hydrogen ions.

• Transactions on Electrical and Electronic Materials
• /
• v.11 no.1
• /
• pp.29-32
• /
• 2010

In this study, transparent and conductive Al-doped zinc oxide (AZO) films were prepared on a glass substrate by an radio frequency (RF) magnetron sputtering method using a 150-nm-thick AZO target (Al: 2 wt.%) at room temperature. We investigated the effects of RF power between 100-350 W (in steps of 50 W) on the structural, electrical, and optical properties of the AZO films. The thickness and cross-sectional images of the films were observed by field emission scanning electron microscopy. The thicknesses of all films were kept constant at 150 nm and grown on a glass substrate. The grain sizes of the AZO films were determined with the X-ray diffraction by using the Scherrer' equation, and their electrical properties were investigated using a Hall effect electronic transport measurement system. The transmittance of the AZO films was also measured by an ultraviolet-visible spectrometer.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.20 no.4
• /
• pp.289-293
• /
• 2007

ZnO thn films are grown on five kinds of oxide substrates including $c-Al_2O_3(0001),\;r-Al_2O_3(01-12)$, MgO(100), MgO(111), $NdGaO_3(110)$ by rf magnetron sputtering and effects substrate types on properties of ZnO thin films ate investigated. In order to compare the substrate effects one growth condition is selected and all the films are grown by the same growth condition. Structural and optical properties of the ZnO films ate different depending on the substrates although the films ate not epitaxial but polycrystalline. The ZnO film grown on $NdGaO_3(100)$ substrate shows the best overall properties among the films grown on substrates investigated in this study.

• Macromolecular Research
• /
• v.15 no.6
• /
• pp.553-559
• /
• 2007

Nanocomposite films were prepared by sol-gel synthesis from vanadium triisopropoxide with $poly((oxyethylene)_9$ methacrylate)-graft-poly(dimethyl siloxane), POEM-g-PDMS, producing in situ growth of vanadium oxide within the continuous ion-conducting POEM domains of micro phase-separated graft copolymer. The formation of vanadium oxide was confirmed by wide angle x-ray scattering (WAXS) and Fourier transform infrared (FT-IR) spectroscopy. Small angle x-ray scattering (SAXS) revealed the spatially-selective incorporation of vanadium oxide in the POEM domains. Upon the incorporation of vanadium oxide, the domain periodicity of the graft copolymer monotonously increased from 17.2 to 21.0 nm at a vanadium content 14 v%, above which it remained almost invariant. The selective interaction of vanadium oxide with POEM was further verified by differential scanning calorimetry (DSC) and FT-IR spectroscopy. The nanocomposite films exhibited excellent mechanical properties $(l0^{-5}-10^{-7}dyne/cm^2)$, mostly due to the confinement of vanadium oxide in the POEM chains as well as the interfaces created by the microphase separation of the graft copolymer.

• Journal of the Korean Ceramic Society
• /
• v.43 no.11 s.294
• /
• pp.715-723
• /
• 2006

Perovskite oxide materials are very important for the electronics industry, because they exhibit promising properties. With an interest in the obvious applications, significant effort has been invested in the growth of highly crystalline epitaxial perovskite oxide thin films in our laboratory. And the desired structure of films was formed to achieve excellent properties. $Y_1Ba_2Cu_3O_{7-x}$ (YBCO) superconducting thin films were simultaneously deposited on both sides of 3 inch wafer by inverted cylindrical sputtering. Values of microwave surface resistance R$_2$ (75 K, 145 GHz, 0 T) smaller than 100 m$\Omega$ were reached over the whole area of YBCO thin films by pre-seeded a self-template layer. For implementation of voltage tunable high-quality varactor, A tri-layer structured SrTiO$_3$ (STO) thin films with different tetragonal distortion degree was prepared in order to simultaneously achieve a large relative capacitance change and a small dielectric loss. Highly a-axis textured $Ba_{0.65}Sr_{0.35}TiO_3$ (BST65/35) thin films was grown on Pt/Ti/SiO$_2$/Si substrate for monolithic bolometers by introducing $Ba_{0.65}Sr_{0.35}RuO_3$ (BSR65/35) thin films as buffer layer. With the buffer layer, the leakage current density of BST65/35 thin films were greatly reduced, and the pyroelectric coefficient of $7.6\times10_{-7}$ C $cm^{-2}$ $K^{-1}$ was achieved at 6 V/$\mu$m bias and room temperature.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.02a
• /
• pp.699-700
• /
• 2013

Aluminum and hydrogen doped zinc oxide (AZHO) films were prepared by r.f. magnetron sputtering. The structural, electrical, and optical properties of the AHZO films were investigated in terms of the annealing conditions to study the thermal stability. The XRD measurements revealed that the degree of c-axis orientation was decreased and the crystallintiy of the films was deteriorated by the heat treatment. The electrical resistivity was significantly increased when the films were annealed at higher temperature. Although the optical transmittance of AHZO films didn't highly changed by heat treatment, the optical band gap was reduced, regardless of annealing temperature and duration. The thermal stability of AHZO films was worse compared to AZO films.

• Journal of Surface Science and Engineering
• /
• v.38 no.5
• /
• pp.179-182
• /
• 2005

Indium Tin Oxide (ITO) thin films were deposited from various target densities ($98.7\%\~99.6\%$) using RF magnetron sputtering. Effect of the sputtering target densities on the structural, electrical and optical properties of deposited ITO thin films was investigated. The preferable (400) crystalline orientation peak was observed on the films deposited from > $99.0\%$ target density. Higher target density produced films with higher roughness but lower resistivity. All of the deposited films showed optical transmittance more than $85\%$ in the visible wavelength region. It is necessary to use the highest target density for sputtering deposition of ITO thin films.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.28 no.2
• /
• pp.423-428
• /
• 1999

Potato starches were hydroxypropylated with 2.5, 5.0, 7.5, and 10.0% propylene oxide(PO) to improve mechanical properties of starch polyethylene film. Starch polyethylene cast films were prepared that contained 5% or 10% of the hydroxypropylated potato starch. Mechanical properties of these films were measured and compared to those of the films containing native potato starch. DS(degree of substitution) increased proportionally as propylene oxide concentration increased. Relative crystallinity in X ray diffraction patterns was decreased and starch granule observed by scanning electron micro scopy was destroyed by severe hydroxypropylation. In color properties of films, b value was not significantly different in the films but 5% starch polyethylene films with 2.5 PO starch showed the lowest L and a value. Tensile strength and strain energy of the films except the film containing 10.0 PO starch were higher than those of the containing native starch.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2000.07a
• /
• pp.427-431
• /
• 2000

ITO (indium tin oxide) thin films on PET (polyethylene terephthalate) and glass substrates have been deposited by a dc magnetron sputtering without heat treatments such as substrate heater and post heat treatment. Each sputtering parameter during the sputtering deposition is an important factor for the high quality of ITO thin films deposited on polymeric substrate. Particularly, the material, electrical and optical properties of as-deposited ITO oxide films are dominated by sputtering power, oxygen partial pressure and films thickness. As the experimental results, the XRD patters of ITO films are influenced by sputtering power and pressure. As the power and pressure are increased, (411) peak is grown suddenly. the electrical resistivity is also increased, as the sputteing power and pressure are increased. Transmittance of ITO thin films in visible light ranges is lowered with increasing the sputtering power and film thickness. Reflectance of ITO films in infia-red region is decreased, as the power and pressure is increased.