• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.2
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• pp.49-56
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• 2001

Diamond thin films have been deposited on the silicon substrate by inductively coupled radio frequency plasma enhanced chemical vapor deposition system. The morphological features of thin films depending on methane concentration and deposition time have been studied by scanning electron microscopy and Raman spectroscopy. The diamond particles deposited uniformly on silicon substrate($10{\times}10[mm^2]$) at the pressure of 1[torr], a methane concentration of 1[%], a hydrogen flow rate of 60[sccm], a substrate temperature of $840\{sim}870[^{\circ}C]$, an input power of 1[kw], and a deposition time of 1[hour]. With increasing deposition time, the diamond particles grew, and than about 3 hours have passed, the graphitic phase carbon thin film with "cauliflower-like" morphology deposited on the diamond thin films.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.694-698
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• 2002

Ti films were deposited onto $100{\times}100$ mm alumina substrates using dc magnetron sputtering under the following conditions; substrate temperature of R.T. ${\sim}400^{\circ}C$, annealing temperature of $100{\sim}400^{\circ}C$ and sputtering gas pressure of $1.3{\sim}3.0{\times}10^{-2}$ Torr. And the films were examined by X-ray diffraction analysis (XRD), scanning electron microscopy(SEM) and 4-point measurement system. The best electrical and structural properties obtained by substrate temperature of ${\sim}200^{\circ}C$, target-substrate distance of ~14 cm and sputtering pressure of $1.3{\sim}1.7{\times}10^{-2}$ Torr. Also at that condition the most excellent adhesion was observed.

• Journal of Electrochemical Science and Technology
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• v.3 no.4
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• pp.178-184
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• 2012

A porous nickel (P-Ni) substrate was prepared by selective leaching of zinc from pressed pellets containing powders of Ni & Zn in 4 M NaOH solution. Anodic deposition of manganese oxide onto the porous Ni substrate ($MnO_x$/P-Ni) formed nano-flakes of manganese oxide layers as revealed in SEM studies. Pseudocapacitance of this oxide electrode was evaluated by cyclic voltammetry (CV) and chronopotentiometry (CHP) in 2 M NaOH solution. The specific capacitance of the Mn oxide electrode was as high as 1515 F $g^{-1}$, which was ten times higher than Mn oxide deposited on a flat Ni-ribbon. 80% of capacity was retained after 200 charge/discharge cycles. The system showed no loss of activity in dry form over period of days. The impedance studies indicated highly conducting $MnO_x$/P-Ni substance and the obtained specific capacitance from impedance data showed good agreement with the charge/discharge measurements.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.12
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• pp.142-148
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• 1995

Sb ${\delta}$-doped Si layers were grown by Si MBE (Molecular Beam Epitaxy) system using substrate temperature modulation technique. The Si substrate temperatures were modulated between 350$^{\circ}C$ and 600$^{\circ}C$. The doping profile was as narrow as 41$\AA$ and the doping concentration of up to 3.5${\times}10^{20}cm^{3}$ was obtained. The film quality was as good as bulk material as verified by RHEED (Reflected High Energy Electron Diffraction), SRP (Spreading Resistance Profiling) and Hall measurement. Since the film quality is not degraded after the growth a Sb ${\delta}$-doped Si layer, the ${\delta}$-doped layers can be repeated as many times as we want. The doping technique is useful for many Si devices including small scale devices and those which utilize quantum mechanical effects.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.298-303
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• 2001

The critical thickness of an epitaxial film on a substrate in electronic or optoelectronic devices is studied on the basis of equilibrium dislocation analysis. Two geometric models, a single dislocation and an array of dislocations in heteroepitaxial system, are considered respectively to calculate the misfit dislocation formation energy. The isotropic linearly elastic stress fields for the models are obtained by means of complex potential method combined with alternating technique, and are used for calculating the formation energies. As a result, the effect of elastic mismatch between film and substrate on critical thickness is presented and $Si_xGe_{1-x}/Si$ epitaxial structure is analyzed to predict the critical thickness with varying germanium concentration.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.523-525
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• 2002

The poly-Si thin film can be used in high mobility active matrix liquid-crystal display (AMLCD) and system on panel (SOP). In this paper, poly-Si thin films were grown by novel high temperature process on the molybdenum (Mo) substrate. By applying a high current above 48A on a Mo substrate. We obtained an improved crystalline Si films with the crystallinity over 80%. We exhibit the properties of structural and electrical properties of high temperature poly-Si thin film transistor on the Mo substrates.

• Journal of Surface Science and Engineering
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• v.41 no.6
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• pp.331-334
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• 2008

The replica of highly ordered nano-sphere array patterns were fabricated using hot embossing method. First, silica nano-sphere array on Si substrate was transferred to PVC film at $130^{\circ}C$ and 7 bar using hot embossing process. Then, silica nano-sphere array on PVC template was removed by soaking the PVC film in buffered oxide etcher. In order to form anti-stiction layer, the PVC template was coated with silicon dioxide layer and self-assembled monolayer. Through UV nanoimprint lithography with the fabricated flexible PVC template, highly ordered nano-sphere array pattern was imprinted on curved substrates with high fidelity.

• Laser Solutions
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• v.15 no.4
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• pp.16-19
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• 2012

Due to the fact that the dimensions of circuit lines of IC substrates have been forecast to reduce rapidly, engraving the circuit line patterns with laser has emerged as a promising alternative. To engrave circuit line patterns in an IC substrate, we used a projection ablation technique in which a metal (INVAR) mask and a DPSS UV laser instead of an excimer laser are used. Results showed that the circuit line patterns engraved in the IC substrate have a width of about 15um and a depth of $13{\mu}m$. This indicates that the projection ablation with a metal mask and a DPSS UV laser could feasibly replace the semi-additive process (SAP).

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.117-117
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• 2014

Thin $ZrO_2/Al_2O_3$ films were deposited on a tool steel substrate using Zr and Al cathodes in a cathodic arc plasma deposition system (CAPD), and then oxidized at $600-900^{\circ}C$ in air for up to 50 h. They effectively suppressed the oxidation of the substrate up to $800^{\circ}C$ by acting as a barrier layer against the outward diffusion of the substrate elements and inward diffusion of oxygen. However, rapid oxidation occurred at $900^{\circ}C$ due mainly to the increased diffusion and subsequent oxidation of steel as well as the crystallization of amorphous $Al_2O__3$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.33-36
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• 1996

AIN thin films were prepared using by Rf sputtering method on the GaAs(170) substrate and investigated by X-ray diffractometer, IR spectroscopy, n&k system. The parameters were the substrate temperature, RF power, sputtering duration and the $N_2$/Ar ratio. The AlN thin films of (101) orientation were obtained under the conditions of room temperature and the nitrogen of 60 vol.%. The crystallinity of the films, which were grown respectively under the different conditions, were determined by the comparison of the band width of an E$_1$[TO:680$cm^{-1}$ /] phonon mode. The thicknesses of AlN films were decreased dramatically in the region of the nitrogen of 40~60 vol.% according to the increment of the $N_2$/Ar ratio by which the sputter yield got lower.