• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.484-487
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• 2001

Amorphous carbon thin films were deposited using laser ablation technique on Si(100) substrates at different temperatures. In this study, effects of the substrate temperature on the properties of amorphous carbon films were systematically investigated. The surface morphologic and structural properties of the films were studied by scanning electron microscopy (SEM) and raman spectroscope, respectively. With increasing of the substrate temperature, the surface morphologies were changed singnificantly. Moreover the intensity ratio of D-band and G-band and the full width at half maximum of these bands were dependent on substrate temperatures.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.406-408
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• 1999

Amorphous carbon nitride thin films were prepared on pretreated silicon(100) substrate in sputtering graphite target by activated gas phase using RF reactively sputtering. We measured the FT-IR spectrum to identify C=N(nitrile)stretching mode(2200cm$\^$-1/), C-H stretching mode(2800cm$\^$-1/), C-H bending mode, C=C stretching mode C=N(imino) mode(1680cm$\^$-1/ ), and the XPS to investigate chemical structure of surface. By the results of FT-H and XPS spectrum, We confirmed that amorphous carbon nitride films with typel (C(1s): 285.9[eV], N(1s): 398.5[ev]) and type 2(C1s): 287.5[eV, N(1s): 400.2[eV]) successfully were synthesized by RF reactively sputtering

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.6
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• pp.465-471
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• 1998

Diamond-like carbon (DLC) films have been prepared by means of the plasma enhanced chemical vapor deposition (PECVD) method using vertical-capacitor electrodes. The deposition rata in our experiment is relatively small compared with that in the conventional PECVD methods, which implies that the accumulation of the neutral $CH_n$ radicals on the substrates due to the gravitational movement may not contribute to the deposition of DLC films. The hardness and the transparency were measured as a function of the ratio of the partial pressure of $CH_4-H_2$ mixtures or the hydrogen contents of specimens. The coefficients of friction between DLC films and a $Si_3N_4$ tip measured by using a lateral force microscope are in the range of 0.024 to 0.033 which depend on the hydrogen contents in DLC, and the surface roughness depends mainly on the deposition rate. The optical gaps increase with increasing the hydrogen contents. DCL films deposited on Pt-coated Si wafers show the stable emission characteristics, and the turn-on fields are in the range of 11 to 20 $V/\mu$m.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.1
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• pp.23-26
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• 2017

Mo doped carbon (C:Mo) thin films were fabricated with various Mo target power densities by unbalanced magnetron sputtering (UBM). The effects of target power density on the surface, structural, and electrical properties of C:Mo films were investigated. UBM sputtered C:Mo thin films exhibited smooth and uniform surfaces. However, the rms surface roughness of C:Mo films were increased with the increase of target power density. Also, the resistivity value of C:Mo film as electrical properties was decreased with the increase of target power density. From the performance of organic thin filml transistor using conductive C:Mo gate electrode, the carrier mobility, threshold voltage, and on/off ratio of drain current (Ion/Ioff) showed $0.16cm^2/V{\cdot}s$, -6.0 V, and $7.7{\times}10^4$, respectively.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.135-135
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• 2016

Recently flexible electrode materials have attracted attention in various electrical devices. In general, copper(Cu) is widely used electrical conductive material. However, Cu film showed drastically reduction of electrical conductivities under an applied tensile strain of 10%. These poor mechanical characteristics of Cu have difficulty applying in flexible electronic applications. In this study, mechanical flexibilities of Cu thin film were improved by hybridization with carbon nanotubes(CNTs) and laser sintering. First, thin carbon nanotube films were fabricated on a flexible polyethylene terephthalate(PET) substrate by using ultrasonic spray coating of CNT dispersed solution. After then, physically connected CNT-Cu NPs films were formed by utilizing ultrasonic spray coating of Cu nanoparticles dispersed solution on prepared CNT thin films. Finally, CNT-Cu thin films were firmly connected by laser sintering. Therefore, electrical stabilities under mechanical stress of CNT-Cu hybrid thin films were compared with Cu thin films fabricated under same conditions to confirm improvement of mechanical flexibilities by hybridization of CNT and Cu NPs.

• Journal of Sensor Science and Technology
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• v.26 no.1
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• pp.24-27
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• 2017

In this study, I developed a simple and low cost process-printing a silver, carbon, dielectric, adhesive layer on PET films using screen printing technology and bonding the two films face-to-face-to fabricate a low price capacitive pressure-mapping sensor. Both electrodes forming the pressure measuring capacitor are arranged between the two PET films similar to a sandwich. Therefore, the sensor has the advantage of minimizing the influence of external noise. In this study, a $10{\times}10$ capacitance-type pressure-mapping sensor was fabricated and its characteristics were analyzed.

• Journal of Sensor Science and Technology
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• v.16 no.2
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• pp.97-103
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• 2007

Crystallized carbon nitride film that has many stable physical and/or chemical properties has been expected potentially by a new electrical material. However, one of the most significant problems degrading the quality of carbon nitride films is an existence of N-H and C-H bonds from the deposition environment. The possibility of these reactions with hydroxyl group in carbon nitride films, caused by a hydrogen attack, was suggested and proved in our previous reports that this undesired effect could be applied for fabricating micro-humidity sensors. In this study, MIS capacitor and MIM capacitor with $5{\mu}m{\times}5{\mu}m$ meshes were fabricated. As an insulator, carbon nitride film was deposited on a $Si_{3}N_{4}/SiO_{2}/Si$ substrate using reactive magnetron sputtering system, and its dielectric constant, C-V characteristics and humidity sensing properties were investigated. The fabricated humidity sensors showed a linearity in the humidity range of 0 %RH to 80 %RH. These results reveal that MIS and MIM $CN_{X}$ capacitive humidity sensors can be used for Si based micro-humidity sensors.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.145-146
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• 2002

Tribological properties of co-sputtered Molybdenum disulfide $(MoS_2)/Carbon\;(C)$ films were studied and compared with those of sputtered $MoS_2$ films. Friction tests were carried out using pin-on-disk friction testers to evluated their friction and wear behaviors in a vacuum ($10^{-5}Pa$), air and humid air of 30, 50, 80% RH. $MoS_2/C$ (14%) composite films exhibited about 9 times longer wear life in a vacuum and about 6 times longer wear life in dry air than $MoS_2$ films did. They also showed stable low friction coefficient of about 0.02 in a vacuum. In humid air, however, $MoS_2/C$ composite films hardly showed good tribological properties.

• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.133-134
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• 2000

Effect of nitrogen doping on field emission characteristics of patterned Diamond-like Carbon (DLC) films was studied. The patterned DLC films were fabricated by the method reported previously[1]. Nitrogen doping in DLC film was carried out by introducing $N_2$ gas into the vacuum chamber during deposition. Higher emission current density of $0.3{\sim}0.4$ $mA/cm^2$ was observed for the films with 6 at % N than the undoped films but the emission current density decreased with further increase of N contents. Some changes in CN bonding characteristics with increasing N contents were observed. The CN bonding characteristics which seem to affect the electron emission properties of these films were studied by Raman spectroscopy, x-ray photoemission spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR). The electrical resistivity and the optical band gap measurements showed consistence with the above analyses.

• Journal of the Korean Vacuum Society
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• v.4 no.S2
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• pp.163-169
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• 1995

Ion beam assisted deposition(IBAD) technique was used to synthesize hard coatings including diamond-like carbon(DLC), carbon nitride(CN) and metal-ceramic multilayered films. It was found that DLC films formed at low energy ion bombardment possess more $Sp^3$ bonds and much higher hardness. The films exhibited an excellent wear resistance. Nanometer multialyered Fe/TiC films was deposited by ion beam sputtering. The structure and properties were strongly dependent on the thickness of the individual layers and modulation wave length. It was disclosed that both hardness and toughness of the films could be enhanced by adjusting the deposition parameters. The CN films synthesized by IBAD method consisted of tiny crystallites dispersed in amorphous matrix, which were identified by electron diffraction pattern to be $\beta -C_3N_4$.