• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.123-123
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• 2015

Al doped ZnO(AZO) films as a transparent conductive oxide (TCO) electrode were deposited on glass, polyethylene naphthalate (PEN) and polyethylene terephthalate (PET) at room temperature by a conventional rf-magneton sputtering (CMS) and a facing target sputtering (FTS) using Al2O3 and ZnO targets. In order to investigation of AZO properties, the structural, surface morphology, electrical, and optical characteristics of AZO films were respectively analyzed. The resistivities of AZO films using FTS system were $6.50{\times}10-4{\Omega}{\cdot}cm$ on glass, $7.0{\times}10-4{\Omega}{\cdot}cm$ on PEN, and $7.4{\times}10-4{\Omega}{\cdot}cm$ on PET substrates, while the values of AZO films using CMS system were $7.6{\times}10-4{\Omega}{\cdot}cm$ on glass, $1.20{\times}10-3{\Omega}{\cdot}cm$ on PEN, and $1.58{\times}10-3{\Omega}{\cdot}cm$ on PET substrates. The AZO-films deposited by FTS system showed uniform surface compared to those of the films by CMS system. We thought that the films deposited by FTS system had low stress due to bombardment of high energetic particles during CMS process, resulted in enhanced electrical conductivity and crystalline quality by highly c-axis preferred orientation and closely packed nano-crystalline of AZO films using FTS system.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.163-163
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• 2015

The effect of nematic liquid crystal(5CB-4-Cyano-4'-pentylbiphenyl) on the amorphous indium gallium zinc oxide thin film transistors(a-IGZO TFTs) was investigated. Through dropping the 5CB on the a-IGZO TFT's channel layer which is deposited by RF-magnetron sputtering, properties of a-IGZO TFTs was dramatically improved. When drain bias was induced, 5CB molecules were oriented by Freedericksz transition generating positive charges to one side of dipoles. From increment of the capacitance by orientation of liquid crystals, the drain current was increased, and we analyzed these phenomena mathematically by using MOSFET model. Transfer characteristic showed improvement such as decreasing of subthreshold slope(SS) value 0.4 to 0.2 and 0.45 to 0.25 at linear region and saturation region, respectively. Furthermore, in positive bias system(PBS), prevention effect for electron trapping by 5CB liquid crystal dipoles was observed, which showing decrease of threshold voltage shift [(${\delta}V$]_TH) when induced +20V for 1~1000sec at the gate electrode.

• Korean Journal of Applied Biomechanics
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• v.17 no.2
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• pp.197-205
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• 2007

The purpose of this study is to analyze the muscle activations and Ground Reaction Force(GRF) in university judo players, and provide the guide of training in Judo. Using surface electrode electromyography(EMG), we evaluated muscle activity in 5 university judo players during the Judo Uke Movements. Surface electrodes were used to record the level of muscle activity in the Tibialis Anterior, Rectus Femoris, Elector Spinae, Gluteus Maximus, Gastrocnemius muscles during the Uke. These signals were compared with %RVC(Reference voluntary contraction) which was normalized by IEMG(Integrated EMG). The Uke was divided into four phases : Kuzushi-1, Kuzushi-2, Tsukuri, Kake. The results can be summarized as follows: 1. The effective Uke Movements needs to short time in the Kake Phase 2. The Analysis of Electromyography of Uke Movements in Supporting Leg; TA(Tibialis anterior) had Higher %RVC in the Kuzushi Phase, RF(Rectus Femoris) had Higher %RVC in the Tsukuri Phase, GM(Gluteus Maximus) had Higher %RVC in the Kake Phase 3. The ground reaction force for Z(vertical) direction was showed increase tendency in Kuzushi phase, Tsukuri phase and decrease tendency in Kake phase.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.10
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• pp.901-906
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• 2006

The transparent conductive oxide(TCO) has been used in necessity as front electrode for increasing efficiency of LED. In our paper, aluminium-doped zinc oxide films(AZO), which has transparent conducting were prepared with RF magnetron sputtering system on glass substrate(corning 1737) and annealed at $400^{\circ}C$ for 2 hr in vacuum ambient and $600^{\circ}C$ for 2hr with $O_2$ ambient respectively. The smooth AZO films were etched in diluted HCL(0.5 %) to examine the surface properties, which in ambient post-annealing process. We confirmed that the electric, structural and optical properties of textured AZO thin films, which implemented using the methods of XRD, FWHM, AFM and Hall measurement. The properties of textured AZO thin films especially depended on the ambient post-annealing process. We presumed that the change of transmittances as R G B LED and the ambient post-annealing process will be increasing the efficiency of LED.

• Textile Coloration and Finishing
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• v.5 no.3
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• pp.194-205
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• 1993

Plasma polymerization in prepared glow discharge was carried out to improve the bathochromic of dyed PET fabrics by using silicon containing vinyl monomer in plasma polymerization equipment which consists of a pair of electrodes was connected to the 13.56MHz RF generator. The optimum condition for the bathochromic effect was investigated on various plasma polymeriztion parameters. By plasma polymerization used silicon containing vinyl monomer, the bathochromic of dyed PET fabrics was very enhanced. The optimum conditions on this equipment were as follows ; electrode distance : 3cm, discharge output : 60W, gas pressure : 0.3 Torr, monomer flow rate : 30㎤/min. plasma polymerization time : 60sec. The apparent strength of plasma polymerized PET fabrics was increased about 40∼47% with decreasing about 3 of L value.

• Proceedings of the KIEE Conference
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• 2008.10a
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• pp.131-132
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• 2008

We describe a fabrication method of submicron glass trenches which have embedded metal lines for the future application of nano-scale RF MEMS devices. The glass wafer was etched using two different conditions to identify the relationship between the slope of glass trenches and the slope of photroresist. A self-aligned metal photomask and negative photroresist (PR) slope were used to insert metal lines inside the glass trenches. The PR slope patterned by backside photolithography was affected by the profile of preformed glass trenches. Gold was well fabricated in the $0.7{\mu}m$ wide trench thanks to the negative PR slope. Nano-scale glass trenches with embedded metal lines can be used as a bottom electrode in submicron beam resonators operating with a high resonant frequency.

• Journal of the Korean Society for Heat Treatment
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• v.28 no.6
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• pp.296-299
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• 2015

$In_2O_3/Ti$ bi-layered films were deposited on glass substrate at room temperature with radio frequency (RF) and direct current (DC) magnetron sputtering to consider the effect of Ti buffer layer on the electrical and optical properties. In a comparison of figure of merit, $In_2O_3$ 90 nm/Ti 10 nm thin films show the higher opto-electrical performance of $3.0{\times}10^{-4}{\Omega}^{-1}$ than that of the $In_2O_3$ single layer films ($2.6{\times}10^{-4}{\Omega}^{-1}$). From the observed results, it is supposed that the $In_2O_3\;90nm/TiO_2$ 10 nm bi-layered films may be an alternative candidate for transparent electrode in a transparent thin film transistor device.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.4
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• pp.373-378
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• 2006

We report on plasma damage free-sputtering technologies for organic light emitting diodes (OLEDs), organic thin film transistor (OTFT) and flexible displays by using a box cathode sputtering (BCS) method. Specially designed BCS system has two facing targets generating high magnetic fields ideally entering and leaving the targets, perpendicularly. This target geometry allows the formation of high-density plasma between targets and enables us to realize plasma damage free sputtering on organic layer without protection layer against plasma. The OLED with Al cathode prepared by BCS shows electrical and optical characteristics comparable to OLED with thermally evaporated Mg-Ag cathode. It was found that OLED with Al cathode layer prepared by BCS has much lower leakage current density ($1{\times}10^{-5}\;mA/cm^2$ at -6 V) than that $(1{\times}10^{-2}{\sim}-10^0\;mA/cm^2)$ of OLED prepared by conventional DC sputtering system. This indicates that BCS technique is a promising electrode deposition method for substituting conventional thermal evaporation and DC/RF sputtering in fabrication process of organic based optoelectronics.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.04a
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• pp.183-187
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• 1997

The Thin films were obtained by plasma polymerization of phenyl isothiocyanate. Polymerizations were carried out in rf(13.56 [MHz]) glow discharge generated in an inter-electrode capacitively coupled gas flow system. It was fecund that this monomer produces uniform films with a wide range of thicknesses, from hundreds of nanometers to tens of micrometers. The deposition rate appeared to be dependent on the substrate distance from the monomer inlet. The IR data revealed significant decrease in -NCS groups content in the polymer as compared with the monomer spectrum and indicated for the appearance of new absorption bands corresponding to the -CN and C-H aliphatic groups. The soluble fraction by GC was found to be composed of numerous low molecular-weight compounds.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.788-791
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• 2002

Tin doped indium oxide(ITO) films are highly conductive and transparent in the visible region whose property leads to the applications in solar cell, liquid crystal display, thermal heater, and other sensors. This paper investigated ITO films as a transparent conducting films for application of PDP. ITO films were grown on glass substrate by RF magnetron sputtering method. To achieve high transmittance and low resistivity, we examined the various film deposition such as substrate temperature, gas pressure, annealing temperature, and deposition time. We recommend the substrate temperature of $500^{\circ}C$ and post annealing of $200^{\circ}C$ in $O_2$ atmosphere for good conductivity and transmittance. From XRD examination, ITO films showed a preferred(222) orientation. As substrate temperature increased from RT to $500^{\circ}C$, the intensity of the (222) peak increased. The highest peak intensity was observed at a substrate temperature of $500^{\circ}C$. with the optimum growth conditions, ITO films showed resistivity of $1.04{\times}10^{-4}{\Omega}-cm$ and transmittance of 81.2% for a film 300nm thick in the wavelength range of the visible spectrum.