• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.8
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• pp.713-719
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• 2002

In this study, the vertically well-aligned CNTs were synthesized by DC bias-assisted inductively coupled plasma hot-filament chemical vapor deposition (ICPHFCVD) using radio-frequence plasma of high density and that CNTs were vertically grown on Ni(300 )/Cr(200 )-deposited glass substrates at 58$0^{\circ}C$. This system(ICPHFCVD) added to tungsten filament in order to get thermal decompound and DC bias in order to vertically grow to general Inductively Coupled Plasma CVD. The grown CNTs by ICPHFCVD were developed to higher graphitization and fewer field emission properties than those by general ICPCVD. In this system, DC bias was effect of vortical alignment to growing CNTs. The measured turn-on fields of field emission property by general ICPCVD and DC bias-assisted ICPHFCVD were 5 V/${\mu}{\textrm}{m}$ and 3 V/${\mu}{\textrm}{m}$, respectively.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.12
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• pp.1125-1130
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• 2003

The electrophoretic deposition method using the suspension solution with additives under the electric potential was applied for the fabrication of YBCO superconductor wire. This method was able to simplify the fabrication facilities, and produce an uniform and dense thick film. To improve the critical current density of deposited films, the additive PEGs(Poly Ethylene Glycole) with the molecular weight of 600, 1000 and 3400 were used as chemical binders for the suspension solution. The organic additive (PEG) showed better effects to the properties of YBCO superconductor wire. The PEG improved the adhesion between superconductor particles and suppressed the crack on the surface, which enhanced the surface uniformity and density of YBCO deposited film. It was found that acetone suspension solution showed better deposition properties than the others. The samples fabricated in the solution with the additive, 8 vol.% of 1% PEG(1000), showed the highest critical current density measured as 2300∼2400 A/$\textrm{cm}^2$ at 77 K, 0 T.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1306-1308
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• 1998

Diamond like carbon(DLC) thin films possesed not only marvelous material charateristics such as large thermal conductivity, high hardness and being chemically inert, but also possesed negative electron affinity(NEA) properties. The NEA is an extremely desirable property of the material used in microelestronics and vacuum microelestronics device. DLC films were fabricated by pulsed laser deposition(PLD). The effect of the laser energy density and the substrate temperature on the properies of DLC films was investigated. The experiment was accomplished at temperatures in the range of room temperature to $400^{\circ}C$. The laser energy density was in the range of $6 J/cm^2$ to $16 J/cm^2$.

• Transactions on Electrical and Electronic Materials
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• v.11 no.6
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• pp.257-260
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• 2010

Zinc oxide (ZnO) bottom-contact thin-film transistors (TFTs) were prepared by the use of injector type atomic layer deposition. Two hybrid gate oxide systems of different polarity polymers with silicon oxide were examined with the aim of improving the properties of the transistors. The mobility and threshold voltage of a ZnO TFT with a poly(4-dimethylsilyl styrene) (Si-PS)/silicon oxide hybrid gate dielectric had values of 0.41 $cm^2/Vs$ and 24.4 V, and for polyimide/silicon oxide these values were 0.41 $cm^2/Vs$ and 24.4 V, respectively. The good hysteresis property was obtained with the dielectric of hydrophobicity. The solid output saturation behavior of ZnO TFTs was demonstrated with a $10^6$ on-off ratio.

• Journal of Mechanical Science and Technology
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• v.17 no.12
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• pp.1904-1911
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• 2003

In order to determine the wear properties of AIP (Arc Ion Plating) deposition, wear process was evaluated by using a Falex test machine. Also, in order to determine the effects of coating material on the wear process, TiC, TiN, and TiCN coatings of thickness about 5 $\mu\textrm{m}$∼6 $\mu\textrm{m}$ coated by Arc ion plating deposition method were tested. The wear property was determined under a dry sliding condition as a function of the applied load, sliding distance, sliding velocity and temperature. The results show that when wear of the coating-layer occurred, specific wear amount increased with the wear rate. At initial state, the wear rate rapidly increased, but it gradually reduced as the velocity increased. Also, when raising the temperature, the wear rate increased in the order of TiCN, TiN and TiC due to the frictional heat.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.488.2-488.2
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• 2014

Carbon-based materials such as carbon nanotubes and graphene have emerged as promising building blocks in applications for nanoelectronics and energy devices due to electrical property, ease of processability, and relatively inert electrochemistry. In recent years, there has been considerable interest in core-shell nanomaterials, in which inorganic nanowires are surrounded by inorganic or organic layers. Especially, carbon encapsulated semiconductor nanowires have been actively investigated by researchers in lithium ion batteries. We report a method to synthesize silicon nanowire (SiNW) core/carbon shell structures by chemical vapor deposition (CVD), using methane (CH4) as a precursor at growth temperature of $1000{\sim}1100^{\circ}C$. Unlike carbon-based materials synthesized via conventional routes, this method is of advantage of metal-catalyst free growth. We characterized these materials with FE-SEM, FE-TEM, and Raman spectroscopy. This would allow us to use these materials for applications ranging from optoelectronics to energy devices such as solar cells and lithium ion batteries.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.6
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• pp.582-586
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• 2005

We have grown GaN layers with in-situ SiN mask by metal organic chemical vapor deposition (MOCVD) and study the physical properties of the GaN layer. We have also investigate the effect of the SiN mask on its optical property. By inserting a SiN mask, (102) the full width at half maximum (FWHM) decreased from 480 arcsec to 409 arcsec and threading dislocation (TD) density decreased from $3.21\times10^9\;cm^{-2}\;to\;9.7\times10^8\;cm^{-2}$. The PL intensity of GaN with SiN mask improved 2 times to that without SiN mask. We have thus shown that the SiN mask improved significantly the physical and optical properties of the GaN layer.

• Journal of Surface Science and Engineering
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• v.29 no.6
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• pp.803-808
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• 1996

Material and electrical characteristies of copper thin films prepared by metal organic chemical vapor deposition (MOCVD) have been investigated for interconnection applications in ultra large scale integration circuits (ULSI). The copper films have been deposited a TiN substrates using a metal organic precursor, hexafluoro acetylacetonate trimethyvinylsilane copper, VTMS(hfac)Cu (I). Deposition rate, grain size, surface morphology, and electrical resistvity of the copper films have been measuredfrom samples prepared at various experimental conditions, which include substrate temperature, chamber pressure, and carrier gas flow rate. Results of the experiment showed that the electrical property of the copper films is closely related to the crystallinity of the films. Lowest electrical resistivity, $2.4{\mu}{\Omega}.cm$ was obtained at the substrate temperature of $180^{\circ}C$, but the resistivity slightly increased with increasing substrate temperature due to the carbon content along the copper grain boundaries.

• Journal of Korean Vacuum Science & Technology
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• v.3 no.1
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• pp.49-53
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• 1999

We have studied the field emission characteristics of diamond-like-carbon (DLC) films deposited by a layer-by-layer technique using plasma enhanced chemical vapor deposition, in which the deposition of a thin layer of DLC and a CH4 plasma exposure on its surface were carried out alternatively. The hydrogen-free DLC can be deposited by CH4 plasma exposure for 140 sec on a 5 nm DLC layer. N2 gas-phase doping in the CH4 plasma was also carried out to reduce the work function of the DLC. The optimum [N2]/[CH4] flow rate ratio was found to be 9% for the efficient electron emission, at which the onset-field was 7.2 V/$\mu\textrm{m}$. It was found that the hydrogen-free DLC has a stable electron emitting property.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.57-57
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• 2018

Zinc-oxide (ZnO), II-VI semiconductor with a wide and direct band gap (Eg: 3.2~3.4 eV), is one of the most potential candidates to substitute for ITO due to its excellent chemical, thermal stability, specific electrical and optoelectronic property. However, the electrical resistivity of un-doped ZnO is not low enough for the practical applications. Therefore, a number of doped ZnO films have been extensively studied for improving the electrical conductivities. In this study, Ti-doped ZnO films were successfully prepared by atomic layer deposition (ALD) techniques. ALD technique was adopted to careful control of Ti doping concentration in ZnO films and to show its feasible application for 3D nanostructured TCO layers. Here, the structural, optical and electrical properties of the Ti-doped ZnO depending on the Ti doping concentration were systematically presented. Also, we presented 3D nanostructured Ti-doped ZnO layer by combining ALD and nanotemplate processes.