• Journal of the Korean Vacuum Society
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• v.10 no.1
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• pp.104-111
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• 2001

B-doped hydrogenated amorphous silicon carbide (a-SiC:H) thin films were prepared by plasma-enhanced chemical-vapor deposition in a gas mixture of $SiH_4, CH_4,\;and\; B_2H_6$. Physical and chemical properties of a-SiC:H films grown with varing the ratio of $B_2H_6/(SiH_4+CH_4)$ were characterized with various analysis methods including scanning electron microscopy (SEM), X-ray diffractometry (XRD), Raman spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, secondary ion mass spectroscopy (SIMS), UV absorption CH_4spectroscopy and electrical conductivity measurements. With the B-doping concentration, the doping efficiency and the micro-crystallinity were decreased and the film became amorphous when $B_2H_6/(SiH_4{plus}CH_4)$ was over $5{\times}10^{-3}$. The addition of $B_2H_6$ gas during deposition decreased the H content in the film by lowering the quantity of Si-C-H bonds. Consequently, the optical band gap and the activation energy of a-SiC:H films were decreased with increasing the B-doping level.

• Korean Journal of Materials Research
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• v.13 no.1
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• pp.43-47
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• 2003

As and BF$_2$dopants are implanted for the formation of source/drain with dose of 1${\times}$10$^{15}$ ions/$\textrm{cm}^2$∼5${\times}$10$^{15}$ ions/$\textrm{cm}^2$ then formed cobalt disilicide with Co/Ti deposition and doubly rapid thermal annealing. Appropriate ion implantation and cobalt salicide process are employed to meet the sub-0.13 $\mu\textrm{m}$ CMOS devices. We investigated the process results of sheet resistance, dopant redistribution, and surface-interface microstructure with a four-point probe, a secondary ion mass spectroscope(SIMS), a scanning probe microscope (SPM), and a cross sectional transmission electron microscope(TEM), respectively. Sheet resistance increased to 8%∼12% as dose increased in $CoSi_2$$n^{＋}$ and $CoSi_2$$p^{V}$ , while sheet resistance uniformity showed very little variation. SIMS depth profiling revealed that the diffusion of As and B was enhanced as dose increased in $CoSi_2$$n^{＋}$ and $CoSi_2$$p^{＋}$ . The surface roughness of root mean square(RMS) values measured by a SPM decreased as dose increased in $CoSi_2$$n^{＋}$ , while little variation was observed in $CoSi_2$$p^{＋}$ . Cross sectional TEM images showed that the spikes of 30 nm∼50 nm-depth were formed at the interfaces of $CoSi_2$$n^{＋}$ / and $CoSi_2$/$p^{＋}$, which indicate the possible leakage current source. Our result implied that Co/Ti cobalt salicide was compatible with high dose sub-0.13$\mu\textrm{m}$ process.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.2
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• pp.106-112
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• 2010

In order to compete with other flat display devices such as Liquid Crystal Displays (LCDs) and organic light emitting diodes (OLEDs), Plasma Display Panels (PDPs) require to have high performances like high image quality, low power consumption and high speed driving. In this paper, Fe doped MgO protective layer was introduced for higher performance. Both the surface characteristics of the deposited thin films and the electro-optical properties of 4 inch test panels were investigated. It has been demonstrated experimentally that ac PDP with Fe doped MgO protective layer has lower discharge voltage than that of undoped MgO film, which corresponds to measured secondary electron emission coefficients. The crystallinity and surface roughness of thin films were determined by XRD patterns and AFM images. In addition, ac PDP with Fe doped MgO protective layer has improved address discharge time lag for high speed driving.

• Journal of the Korean Vacuum Society
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• v.12 no.1
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• pp.16-19
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• 2003

Ni thin films on the p-InP (In) substrates were grown at room temperature by using the ion beam-assisted deposition. In order to determine the work function of the Ni thin films, the $\gamma$values were measured as functions of the acceleration voltages by using Ne, Ar, $N_2$. and Xe ion sources. The dependences of the values on various gases and on the acceleration voltages of the focused ion beam were obtained to determine the work function of the Ni thin films. The value of the work function of the Ni thin films grown on the p-InP (100) substrate was 5.8 eV ~ 5.85 eV. These results provide important information on the electronic properties of Ni thin films grown on p-InP (100) substrates at room temperature.

• Journal of Powder Materials
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• v.23 no.1
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• pp.21-25
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• 2016

The microstructural properties and electrical characteristics of sputtering films deposited with a Cu-Ga target are analyzed. The Cu-Ga target is prepared using the cold spray process and shows generally uniform composition distributions, as suggested by secondary ion mass spectrometer (SIMS) data. Characteristics of the sputtered Cu-Ga films are investigated at three positions (top, center and bottom) of the Cu-Ga target by X-ray diffraction (XRD), SIMS, 4-point probe and transmission electron microscopy (TEM) analysis methods. The results show that the Cu-Ga films are composed of hexagonal and unknown phases, and they have similar distributions of composition and resistivity at the top, center, and bottom regions of the Cu-Ga target. It demonstrates that these films have uniform properties regardless of the position on the Cu-Ga target. In conclusion, the cold spray process is expected to be a useful method for preparing sputter targets.

• The Korean Journal of Pesticide Science
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• v.18 no.4
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• pp.439-442
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• 2014

Cinnamyl derivatives are abundant secondary metabolite in biomass, and they have been studied on their biological activities. However, little information was available for plant growth regulation of the cinnamyl derivatives. In here, the acid, amide, alcohol, aldehyde and ester of cinnamyl derivatives were screened for their root growth inhibition properties including germination. The aldehyde, amide and ester derivatives showed better the root growth inhibition than the carboxylic acid, and the meta-positioned electron withdrawing group on cinnamyl derivatives enhanced the inhibition activity. 3-Chlorocinnamic acid, cinnamaimde and 4-methoxycinnamaldehyde were highlighted with the early stage root development inhibition ($GR_{50}$ < 100 mg/L) on Brassica campestris.

• Journal of Powder Materials
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• v.18 no.2
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• pp.105-111
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• 2011

This study investigated the effect of wire diameter and applied voltage on the fabrication of Ni-free Fe-based alloy nano powders by employing the PWE (pulsed wire evaporation) in liquid, for high temperature oxidation-resistant metallic porous body for high temperature particulate matter (or soot) filter system. Three different diameter (0.1, 0.2, and 0.3 mm) of alloy wire and various applied voltages from 0.5 to 3.0 kV were main variables in PWE process, while X-ray diffraction (XRD), field emission scanning microscope (FE-SEM), and transmission electron microscope (TEM) were used to investigate the characteristics of the Fe-Cr-Al nano powders. It was controlled the number of explosion events, since evaporated and condensed nano-particles were coalesced to micron-sized secondary particles, when exceeded to the specific number of explosion events, which were not suitable for metallic porous body preparation. As the diameter of alloy wire increased, the voltage for electrical explosion increased and the size of primary particle decreased.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.5 no.2
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• pp.1-6
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• 2009

Nuclear power plants (NPP) using Alloy 600 (Ni 75wt%, Cr 15wt%, Fe 10wt%) as a heat exchanger tube of the steam generator (SG) have experienced various corrosion problems by ageing such as pitting, intergranular attack (IGA) and stress corrosion cracking (SCC). In spite of much effort to reduce the material degradations, SCC is still one of important problems to overcome. Especially lead is known to be one of the most deleterious species in the secondary system that cause SCC of the alloy. Even Alloy 690 (Ni 60wt%, Cr 30wt%, Fe 10wt%) as an alternative of Alloy 600 because of outstanding superiority to SCC is also susceptible to leaded environment. An oxide on SG tubing materials such as Alloy 600 and Alloy 690 is formed and modified expanding to complex sludge throughout hideout return (HOR) of various impurities including Pb. Oxide formation and breakdown is requisite for SCC initiation and propagation. Therefore it is expected that an oxide property such as a passivity of an oxide formed on steam generator tubing materials is deeply related to PbSCC and an inhibitor to hinder oxide modification by lead efficiently can be found. In the present work, the SCC susceptibility obtained by using a slow strain rate test (SSRT) in aqueous solutions with and without lead was discussed in view of the oxide property. The oxides formed on Alloy 600 and Alloy 690 in aqueous solutions with and without lead were examined by using a transmission electron microscopy (TEM), an energy dispersive x-ray spectroscopy (EDXS), an x-ray photoelectron spectroscopy (XPS) and an electrochemical impedance spectroscopy (EIS).

• Journal of Chest Surgery
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• v.33 no.1
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• pp.7-19
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• 2000

Background :To assess the accuracy of Electron-Beam Tomography(EBT) in following evaluation of the pulmonary vascular system after a shunt operation in the cyanotic con-genital heart disease with pulmonary stenosis or pulmonary atresia. Material and Method : Sixteen patients(M:F=11:5) who received Blalock-Taussig(n=8) bidirectional cavo-pulmonary shunt(n=10) and unifocalization (n=2) were ncluded in the study. We evaluated the patency of the shunt the morphology of intrapericardial and hilar pulmonary arteries(PA) peripheral pulmonary vascularity by background lung attenuation and the abundance of arterial & venous collateral. Angiography(n=12) and echocardiography(n=20) were used as the gold standard for the comparison of EBT results. Result: EBT was consistent with angiogram/ echo in 100% of the evaluation for the patency of the shunt and in 12(by angiogram 100%) and 19(by echo 95%) for the detection the hypoplasia stenosis or interruption of central PA In measuring of PA EBT and angiogram corrlated(r=0.91) better than EBT-echo(r=0.88) or echo-angiogram(r=0.72) Abundant systemic arterial collateral were noted in 4 and venous collateral in 3 cases. In evaluating the peripheral pulmonary vascularity the homogenous and normal-ranged lung attenuation(m=6) decreased but homo-genous attenuation(n=1) segment-by-sgment heterogeneous attenuation(n=3) homogenous but asymmetrical attenuation(n=3) segment-by-segment heterogeneous attenuation(n=3) homogenous but asymmetrical attenuation(n=3) and venous congestion(n=2) were observed nd 12 of them were compatible with the blood flow pattern revealed by cardiac catheterization. Conclusion: EBT was accurate in the integrated evaluation of the pulmonary vascular system after the shunt including the patency of the shunt operaion the morphology and dimension of the central and hilar PAs and the loco-regional pulmonary flow in the lung parenchyma. It suggests the useful information about the need of secondary shunt operation the proper timing time for total repair and the need of interventional procedure prior to total repair.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1441-1444
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• 2008

We developed ultra-accelerated quantum chemical molecular dynamics and spectroscopic characterization simulators for development of PDP materials. By combination of these simulators, realistic structure of PDP materials is drawn on the computer. Furthermore, based on the structures, various properties such as cathode luminescence spectrum and secondary electron emission, is successfully evaluated. The strategy of "Experiment integrated Computational Chemistry" using developed simulators will presented that has the potential in being powerful tool for designing the PDP materials.