• Journal of the Korean Crystal Growth and Crystal Technology
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• v.10 no.2
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• pp.100-104
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• 2000

Diamond film was deposited on Si substrate by using microwave plasma-enhanced chemical vapor deposition (MPECVD) system. After thinning the cross section between diamond film and Si substrate by ion milling method, we investigated its interface via transmission electron microscopy We could observe that the diamond film was grown either directly on Si substrate or via the interlayer between diamond film and Si substrate. Thickness of the interlayer was varied along the cross section. The interlayer might mainly composed of Sic andlor amorphous carbon. We could observe the well-developed electron diffraction pattern of both Si and diamond around the interface. Based on this result, we can conjecture the initial growth behavior of diamond film on Si substrate.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.4
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• pp.327-332
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• 2010

We report on the effect of PET substrate preheating on the characteristics of the flexible and transparent indium tin oxide (ITO) electrode grown by a specially designed roll-to-roll sputtering system for touch panel applications. It was found that electrical and optical properties of the roll-to-roll sputter grown ITO film were critically dependent on the preheating of the PET substrate. In addition, the roll-to-roll sputter-grown ITO film after post annealing test at $140^{\circ}C$ for 90 min showed stable electrical and optical properties. The low sheet resistance and high optical transmittance of the ITO film grown on the preheated PET substrate demonstrate that the preheating process before ITO sputtering is one of the effective way to improve the characteristics of ITO/PET film. Furthermore, the superior flexibility of the ITO electrode grown on the preheated PET substrate indicates that the preheating treatment is a promising technique to obtain robust ITO/PET sample for touch panel applications.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.9
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• pp.686-689
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• 2013

The carbon nanowall (CNW) is a carbon-based nanomaterials and it was constructed with vertical structure graphenes and it has the highest surface density among carbon-based nanostructures. In this study, we have checked the growth properties of CNW according to the substrate angle. Microwave plasma enhanced chemical vapor deposition (PECVD) system was used to grow CNW on Si substrate with methane ($CH_4$) and hydrogen ($H_2$) gases. And, we have changed the substrate angle from $0^{\circ}$ to $90^{\circ}$ in steps of $30^{\circ}$. The planar and vertical conditions of the grown CNWs according to the substrate angle were characterized by a field emission scanning electron microscopy (FE-SEM) and energy dispersive spectroscopy (EDS). In case of the growth angle increases, our experimental results showed that the length of the CNW was shortened and the content of carbon component was decreased.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.92-92
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• 2011

IZTO and ITO thin films with a thickness of 200nm were deposited on Corning glass substrate to investigate the effects of substrate temperature on their electrical and optical properties by using pulsed DC magnetron sputtering with a sintered ceramic target of IZTO (In2O3 70 wt.%, ZnO 15 wt.%, SnO2 15 wt.%) and ITO (In2O3 90 wt.%, SnO2 10 wt.%). We investigated the structural, electrical, and optical properties of IZTO and ITO films. The structural and electrical properties of both films are sensitive on the substrate temperature. As the substrate temperature is increased, the electrical resistivity of ITO films is improved, but that of IZTO film increase over than $100^{\circ}C$. All IZTO and ITO thin films have good optical properties, which showed an average of transmittance over 80%. As a result, IZTO films can be a possible material for flexible display due to the low processing temperature.

• Korean Journal of Materials Research
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• v.24 no.7
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• pp.344-350
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• 2014

Metal films (i.e., Ti, Al and SUH310S) were prepared in a magnetron sputtering apparatus, and their cross-sectional structures were investigated using scanning electron microscopy. The apparatus used consisted of a cylindrical metal target which was electrically grounded, and two anode rings attached to the top and to the bottom of the target. A wire was placed along the center-line of the cylindrical target to provide a substrate. When the electrical potential of the substrate was varied, the metal-film formation rate depended on both the discharge voltage and the electrical potential of the substrate. As we made the magnetic field stronger, the plasma which appeared near the target collected on the plasma wall surface and thereby decreased the bias current. The bias current on the conducting wire was different from that for cation collection. The bias current decreased because the collection of cations decreased when we increased the magnetic-coil current. When the substrate was electrically isolated, the films deposited showed a slightly coarse columnar structure with thin voids between adjacent columns. In contrast, in the case of the grounded substrate, the deposited film did not show any clear columns but instead, showed a densely-packed granular structure. No peeling region was observed between the film and substrate, indicating good adhesion.

• Journal of the Korean institute of surface engineering
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• v.29 no.5
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• pp.301-313
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• 1996

The texture of vapor deposits(PVD and CVD) changes from the orientation that places the lowest energy lattice plane parallel to the substrate under the condition of low atom or ion concentration adjacent to the deposit, to the orientation that places the higher energy crystal planes parallel to the substrate as the atom or ion concentration adjacent to the deposit increases. However, in the early stage of deposition, the deposit-substrate interface energy and the surface energy constitute the most important energies of the system. Therefore, if the lattice match is established between the substrate and the deposit without generating much strain energy, the epitaxial growth takes place to reduce the interfacial energy. When the epitaxial growth does not take place, the surface energy is dominant in the early stage of deposition and the lowest energy crystal plane tends to be placed parallel to the substrate up to a critial thickness. The thickness depends on the deposition condition. If the deposition condition does not favor placing the lowest energy crystal plane parallel to the substrate, the initial texture will change to that compatible with the deposition condition as the film thickness increases, and the texture turnover thickness will be short. The microstructure and surface topography of deposits are related to their texture.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2001.04b
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• pp.41-42
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• 2001

The objectives of this study were to investigate the effect of the physical properties of wick on the water absorption of substrate. Physical properties of wick in this study were cotton composition, width and length. The water Infiltration rate through the wick was 0.24 ㎝/s at 90 -95% cotton content, which was faster than at 80-85% (0.13 cm/s) and 70-75% (0.08 cm/s). As the cotton content increased, the water absorption of substrate became greater : the amount of absorbed water was about 5-7g higher at 90-95% than at 80-85% and 70-75% at a wick width of 1 ㎝, the velocity of water absorption through the wick was fastest with 0.25 ㎝ㆍs/sup -1/. The amount of absorbed water was higher at 3 ㎝ than at 1 and 2 ㎝. However, the water absorption rate through the cross - sectional area of wick (g H₂O /㎠/hr) was higher at a wick width of 2 ㎝ than at those of 1 and 3 ㎝. The amount of absorbed water in the substrate was higher at 2 : 1 than at 1 : 1 (length in substrate : length out of substrate). Absorbed water amount was larger at 30-40% initial moisture content than any other treatment.

• Journal of the Korean Vacuum Society
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• v.9 no.1
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• pp.30-35
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• 2000

Indium-Tin Oxide (ITO) thin films were deposited on the commercial glass substrate by rf-magnetron sputtering. The ITO films with the thickness of 2,000~2,400 $\AA$ were prepared by changing the oxygen partial pressures of 2, 3, and 5%, as well as by changing the substrate temperature of $300^{\circ}C$ and $500^{\circ}C$. spectrophotometer, XRD, SEM, AFM, 4-point probe and Hall effect system were employed to characterize the ITO films. The optimum deposition conditions were the substrate temperature of $500^{\circ}C$ and oxygen partial pressure of 2-3%. At theses conditions, the ITO film showed the transmittance of 91%, the resistivity of $5.4\times10^{-3}\Omega$cm, the carrier concentration of $1.0\times10^{19}\textrm{cm}^{-3}$, and the carrier mobility of 150$\textrm{cm}^2$/Vsec. In XRD spectra, the (222) and (400) $In_2O_3$ planes were dominant under the optimum deposition conditions When the substrate was cleaned only by the method of ultrasonic cleaning without both pre-annealing and chemical treatment of the substrate, the ITO film exhibited the transmittance of 86%, the carrier concentration of $5.4\times10^{19}\textrm{cm}^{-3}$ and the mobility of 24$\textrm{cm}^2$/Vsec.

• Journal of the Korean Ceramic Society
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• v.29 no.12
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• pp.956-962
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• 1992

The predominant sintering mechanisms of low firing temperature ceramic substrate which consists of borosilicate glass containing alumina as a filler are the rearrangement of alumina particles and the viscous flow of glass powders. In this system, sintering condition depends on the volume ratio of alumina to glass and on the particle size. When the substrate contains about 35 vol% alumina filler and the average alumina particle size is 4 $\mu\textrm{m}$, the best firing condition is obtained at the temperature range of 900∼1000$^{\circ}C$. The extensive rearrangement behavior occurs at these conditions, and the optimum sintering condition is attained by smaller size of glass particles, too. The formation of cristobalite during sintering causes the difference of thermal expansion coefficient between the substrate and Si chip. This phenomenon degradates the capacity of Si chip. Therefore, the crystallization should be prevented. In the alumina filled borosilicate glass system, the crystallization does not occur. This effect may have some relation with aluminum ions in alumina. For aluminum ions diffuse into glass matrix during sintering, functiong as network former.

• Composites Research
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• v.13 no.3
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• pp.38-47
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• 2000

The coating cracking on a substrate system was analyzed using a fracture mechanics approach. Multiple cracking in the bending configuration was analyzed using a variational mechanics approach to fracture mechanics of coatin $g_strate system. The strain energy release rate on bending geometry developed permits the prediction of crack growth in the coating layer on a substrate. Also, it can be used appropriately to the characterization of multiple cracking of coating. The obtained critical strain energy release rate (in-situ fracture toughness) will be a material property of coating and it will provide a better insight into coating cracking.ng.