• Journal of the Microelectronics and Packaging Society
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• v.10 no.3
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• pp.89-98
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• 2003

The electrical and mechanical properties of sputtered Cu(Mg) films are investigated for highly reliable interconnects. The roughness, adhesion, hardness and resistance to thermal stress of Cu(Mg) film annealed in vacuum at $400^{\circ}C$ for 30min were improved than those of pure Cu film. Moreover, the flat band voltage(V$_{F}$ ) shift in the Capacitance-Voltage(C-V) curve upon bias temperature stressing(BTS) was not observed and leakage currents of Cu(Mg) into $SiO_2$ were three times less than those of pure Cu. Because Mg was easy to react with oxide than Cu and Si after annealing, the Mg Oxide which formed at surface and interface served as a passivation layer as well.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.281-284
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• 2007

Recently, we have developed p-i-n a-Si:H single junction thin film solar cells with RF (13.56MHz) plasma enhanced chemical vapor deposition (PECVD) system, and also successfully fabricated the mini modules ($>300cm^2$), using the laser patterning technique to form an integrated series connection. The efficiency of a mini module was 7.4% ($Area=305cm^2$, Isc=0.25A, Voc=14.74V, FF=62%). To fabricate large area modules, it is important to optimise the integrated series connection, without damaging the cell. We have newly installed the laser patterning equipment that consists of two different lasers, $SHG-YVO_4$ (${\lambda}=0.532{\mu}m$) and YAG (${\lambda}=1.064{\mu}m$). The mini-modules are formed through several scribed lines such as pattern-l (front TCO), pattern-2 (PV layers) and pattern-3 (BR/back contact). However, in the case of pattern-3, a high-energy part of laser shot damaged the textured surface of the front TCO, so that the resistance between the each cells decreases due to an incomplete isolation. In this study, the re-deposition of SnOx from the front TCO, Zn (BR layer) and Al (back contact) on the sidewalls of pattern-3 scribed lines was observed. Moreover, re-crystallization of a-Si:H layers due to thermal damage by laser patterning was evaluated. These cause an increase of a leakage current, result in a low efficiency of module. To optimize a-Si:H single junction thin film modules, a laser beam profile was changed, and its effect on isolation of scribed lines is discussed in this paper.

• Journal of the Microelectronics and Packaging Society
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• v.12 no.4 s.37
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• pp.359-363
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• 2005

The organic insulation devices with MIM (metal-insulator-metal) structures as PVP gate insulation films were prepared for the application of organic thin film transistors (OTFT). The co-polymer organic insulation films were synthesized by using PVP(poly-4-vinylphenol) as solute and PGMEA (propylene glycol monomethyl ether acetate) as solvent. The cross-linked PVP insulation films were also prepared by addition of poly (melamine-co-formaldehyde) as thermal hardener. The leakage current of the cross-linked PVP films was found to be about 300 pA with low current noise. and showed better property in electrical properties as compared with the co-polymer PVP insulation films. In addition, cross-linked PVP insulation films showed better surface morphology (roughness), showing about 0.11${\~}$0.18 nF in capacitance for all PVP film samples.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.3
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• pp.388-402
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• 2000

The radiation characteristics of leaky antenna from the dielectric-coated conducting cylinder with periodic corrugation are investigated theoretically for the infinite and finite periodic structures. For the infinite periodic structure, mode-matching method is applied. The integral equation is derived for the finite periodic structure by use of the Fourier transform and mode expansion and a simultaneous linear equation is obtained. The influences of the corrugation slot width, corrugation depth, dielectric thickness, cylinder radius, and finite corrugation number on the radiation characteristics (leakage constant, phase constant, and radiation pattern) are investigated. The results of the finite periodic corrugations are compared with those of the infinite extent structure and good agreement is found. To reduce high side lobe levels of the uniform finite periodic structure, tapering process on the beginning and end section of antenna and nonuniform quasi-period slot arrays are considered. Especially, for the corrugation period, width and depth used for a corrugated surface wave antenna, through the proper tapering process, end-fire radiation pattern with reduced side lobe levels is given.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.462-462
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• 2014

The effect of rear passivation for passivated emitter and rear cell (PERC) using ozone and H2O oxidant of atomic layer deposited (ALD) Al2O3 was studied by post-annealing in N2 and forming gas ambients. Rear surface of PERC solar cell was passivated by Al2O3 grown by ALD with ozone and H2O oxidant. Al2O3 grown by ALD with ozone oxidant has been known to have many advantages, such as lower interface defects, low leakage current density. Its passivation quality is better than Al2O3 with H2O. Al2O3 layer with 10 nm and 20 nm thickness was grown at $150^{\circ}C$ with ozone oxidant and at $250^{\circ}C$ with H2O oxidant. And then each samples were post-annealled at $450^{\circ}C$ in N2 ambients and at $850^{\circ}C$ in forming gas ambients. The passivation quality was investigated by measuring the minority carrier lifetime respectively. We examined atomic layer deposited Al2O3 such as growth rate, film density, thickness, negative fixed charge density at AlOx/Si interface, and reflectance. The influences of process temperature and heat treatment were investigated using Sinton (WCT-120) by Quasi-Steady State Photoconductance (QSSPC) mode. Ozone-based ALD Al2O3 film shows the best carrier lifetime at lower deposition temperature than H2O-based ALD.

• Restorative Dentistry and Endodontics
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• v.20 no.1
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• pp.152-163
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• 1995

This experiment was performed to observe the adhesion pattern and microleakage in the gingival margin according to variation in the resin cement thickness which results from thickness of Die spacer. which is considered to effect the adaptability of the composite resin inlays. Clearfil CR inlays were fabricated on stone models with CR Sep applicated once and Nice fit twice, 4 times, and 6 times each. After 2nd curing within the CRC-100 oven, CR inlays were cemented with CR inlay cement. Dye(2% methylene blue) penetration and adhesion pattern were evaluated after sectioning of gingival margin into :3 pieces. The results were as follows ; 1. The thickness of resin cement showed unevenchanging pattern with that of die spacer, namely, it was increased until 4 times' application of Nice-Fit but was decreased with 6 times' application of that. 2. The degree of dye penetration wasn't affected by cement thickness within a limited value. 3. Most of dye penetration was shown through the interface between cement and enamel rather than the interface between cement and CR inlay. This shows that the affinity of resin cement for CR inlay was superior to the adhesive strength with tooth structure. 4. No gap was found at the interface between enamel and cement but some showed separation between dentin and cement. It is concidered that the contraction force of cement was less than the bond strength with the enamel. 5. Lots of voids were found in the CR inlay and resin cement. There was a pooling tendency of bonding agent and cement in the axiogingival line angle portion. 6. In some specimens, cracks were shown in enamel margin. From this it could be considered that cavity preparation and surface treatment weakened the tooth structure.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.54-57
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• 2003

[ $HfO_xN_y$ ] films using a hafnium tertiary-butoxide $(Hf[OC(CH_3)_3]_4)$ in plasma and $N_2$ ambient were prepared to improve the thermal stability of hafnium-based gate dielectrics. A 10% nitrogen incorporation into $HfO_2$ films showed a smooth surface morphology and a crystallization temperature as high as $200^{\circ}C$ compared with pure $HfO_2$ films. The $TaN/HfO_xN_y/Si$ capacitors showed a stable capacitance-voltage characteristics even at post-metal annealing temperature of $1000^{\circ}C$ in $N_2$ ambient and a constant value of 1.6 nm EOT (equivalent oxide thickness) irrespective of an increase of PDA and PMA temperature. Leakage current densities of $HfO_xN_y$ capacitors annealed at PDA temperature of 800 and $900^{\circ}C$, respectively were approximately one order of magnitude lower than that of $HfO_2$ capacitors.

• International Journal of Fluid Machinery and Systems
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• v.2 no.4
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• pp.439-448
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• 2009

Three inducers were designed to avoid cavitation instabilities. This was accomplished by avoiding the interaction of tip cavity with the leading edge of the next blade. The first one was designed with extremely larger leading edge sweep, the second and third ones were designed with smaller incidence angle by reducing the inlet blade angle or increasing the design flow rate, respectively. The inducer with larger design flow rate has larger outlet blade angle to obtain sufficient pressure rise. The inducer with larger sweep could suppress the cavitation instabilities in higher flow rates more than 95% of design flow coefficient, owing to weaker tip leakage vortex cavity with stronger disturbance by backflow vortices. The inducer with larger outlet blade angle could avoid the cavitation instabilities at higher flow rates, owing to the extension of the tip cavity along the suction surface of the blade. The inducer with smaller inlet blade angle could avoid the cavitation instabilities at higher flow rates, owing to the occurrence of the cavity first in the blade passage and its extension upstream. The cavity shape and suction performance were reasonably simulated by three dimensional CFD computations under the steady cavitating condition, except for the backflow vortex cavity. The difference in the growth of cavity for each inducer is explained from the difference of the pressure distribution on the suction side of the blades.

• Journal of the Korean Vacuum Society
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• v.9 no.4
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• pp.341-345
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• 2000

We investigated the microstructures and the electrical properties of $ZrO_2$thin films deposited by reactive DC magnetron sputtering on (100) Si with different deposition conditions and annealing treatments. The refractive index of the $ZrO_2$ thin films increased with annealing temperatures and deposition powers, and approached to the ideal value of 2.0~2.2. The $ZrO_2$thin films deposited at the room temperature are amorphous, and the films are polycrystalline at the deposition temperature of $300^{\circ}C$. Both the thickness of the interfacial oxide layer and the root-mean-square (RMS) value of surface roughness increased upon annealing in the oxygen ambient. The Cmax value and leakage current value decreased with the increase of thickness of the interfacial oxide thickness.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.4
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• pp.312-317
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• 2000

Ferroelectric S $r_{0.9}$/B $i_{2.1}$/T $a_{2}$/ $O_{9}$ solutions were synthesized using sol-gel process in which strontinum ethoxide bismuth ethoxide trantalum ethoxide were used a s startring materials. SBT thin films were coated on Pt/Ti/ $SiO_2$/Si substrates by spin-coating. rapid thermal annealing (RTA) was used to promote crystallization. Thin films were annealed at $700^{\circ}C$ for 1 hr in an oxygen atmosphere. This temperature is about 10$0^{\circ}C$ lower than the usual annealing temperature for SBT thin films. Pt top-electrode was deposited by sputtering and thin films were post-annealed at $700^{\circ}C$ for 30 min. to enhance electrical properties. As the RTA temperature increased the higher 2 $P_{r}$ values were obtained. At RTA temperature being 78$0^{\circ}C$ remanent polarization of S $r_{0.9}$/B $i_{2.1}$/T $a_{2}$/ $O_{9}$ thin film was 7.73 $\mu$C/cm $_2$ and the leakage current density was 1.14$\times$10$^{-7}$ A/c $m^2$ at 3 V. As RTA temperature increased the breakdown voltage was decreased. It is considered that the low-field breadown is caused by the rough surface of SBT films and forming bismuth metal in SBT thin films.films.lms.