• Journal of the Korean Society of Manufacturing Process Engineers
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• v.8 no.3
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• pp.62-67
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• 2009

Pt thin films on Cr or Ti interlayer were deposited onto a tungsten carbide(WC) substrate by the ion beam assisted DC magnetron sputtering. The various atomic percent of Cr and Ti underneath of the Pt films were prepared to examine the total thin film characteristics. The microstructure and surface analysis of the specimen were conducted by using the SEM, XRD and AFM. Mechanical properties such as hardness and adhesion strength of Pt thin film also were examined. The interlayer of pure Ti was formed with 40 nm thickness while that of pure Cr was done with 50 nm as standard reference. The growth rate of either Cr or Ti thin film was almost same under the same deposition conditions. The SEM images showed that anisotropic grain of Pt thin films consisting of dense columnar structures irrespectively grew from the different target compositions. The values of hardness and adhesion strength of Cr/Pt thin film coated on a WC substrate were higher than those of Ti/Pt thin film.

• Journal of the Korean institute of surface engineering
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• v.31 no.3
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• pp.142-150
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• 1998

Stainless steel is being used widely for various purposes due to its good corrosion resistance. There has been much research to produce colored stainless steel by several methods such as anodizing and ion plating. In this experiment, we coated TiN(C,O,H)films SUS304 substraate with the DC magnetron spttering system made by Leybold Heraeus and studied the interlater structure and abhesive strength of the films as a function of additional gases, acetylene, hydrogen and oxygen. When the acetylene gas was added into the chamber, the specimen with the interlayer phase had good adhesion due to the toughness of the $\gamma'-Fe_4N$ plase induced from a solid solution of carbon atoms, while low adhesion appeared on the specimen of the non interlayer phase. The formation of the interlayer phase($\gamma'-Fe_4N$) was due to hydrogen embrittlement and internal stress induced by $\gamma'-Fe_4N$ formation in the interlayer. We could fine the interlayer phase ($\gamma'-Fe_4N$) at the interface between the film and the substrate of the TEM image when $\gamma'-Fe_4N$ was detected by the X-ray duffraction metheod.

• Journal of the Korean institute of surface engineering
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• v.52 no.3
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• pp.145-149
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• 2019

Transparent and conductive ZnO/Ag/SnO2 (ZAS) tri-layer films were deposited onto glass substrates at room temperature by using radio frequency (RF) and direct current (DC) magnetron sputtering. The thickness values of the ZnO and $SnO_2$ thin films were kept constant at 50 nm and the value for Ag interlayer was varied as 5, 10, 15, and 20 nm. In the XRD pattern the diffraction peaks were identified as the (002) and (103) planes of ZnO, while the (111), (200), (220), and (311) planes could be attributed to the Ag interlayer. The optical transmittance and electrical resistivity were dependent on the thickness of the Ag interlayer. The ZAS films with a 10 nm thick Ag interlayer exhibited a higher figure of merit than the other ZAS films prepared in this study. From the observed results, a ZAS film with a 10 nm thick Ag interlayer was believed to be an alternative transparent electrode candidate for various opto-electrical devices.

• Korean Journal of Materials Research
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• v.20 no.5
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• pp.267-270
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• 2010

Sn doped $In_2O_3$ (ITO) and ITO/Cu/ITO (ICI) multilayer films were prepared on glass substrates with a reactive radio frequency (RF) magnetron sputter without intentional substrate heating, and then the influence of the Cu interlayer on the methanol gas sensitivity of the ICI films were considered. Although both ITO and ICI film sensors had the same thickness of 100 nm, the ICI sensors had a sandwich structure of ITO 50 nm/Cu 5 nm/ITO 45 nm. The ICI films showed a ten times higher carrier density than that of the pure ITO films. However, the Cu interlayer may also have caused the decrement of carrier mobility because the interfaces between the ITO and Cu interlayer acted as a barrier to carrier movement. Although the ICI films had two times a lower mobility than that of the pure ITO films, the ICI films had a higher conductivity of $3.6{\cdot}10^{-4}\;{\Omega}cm$ due to a higher carrier density. The changes in the sensitivity of the film sensors caused by methanol gas ranging from 50 to 500 ppm were measured at room temperature. The ICI sensors showed a higher gas sensitivity than that of the ITO single layer sensors. Finally, it can be concluded that the ICI film sensors have the potential to be used as improved methanol gas sensors.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.210-210
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• 2012

Gas barrier coating from dense thin film deposition has been one of the important applications such as food-packaging and organic display. Especially for food-packaging, plastic container has been widely used due to its low price and high through-put in mass production. However, the plastic container with low surface energy like polypropylene (PP) has been limited to apply gas barrier coating. That is because a gas barrier coating could not adhere to PP due to its too low surface energy and high porosity of PP. In this research, we applied carbon coating consisting of Si and O as an interlayer between silicon oxide (SiOx) and PP. A carbon layer was found to provide better adhesion, which was experimentally proved by oxygen transmission rate (OTR) and SEM images. However, we also found that there is a limitation in the maximum thickness of a carbon layer and SiOx film due to their high stress level. For this conflict, we obtain the optimal thickness of a carbon layer and SiOx film showing optimal gas barrier property.

• Proceedings of the Korean Vacuum Society Conference
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• 1998.06a
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• pp.93-93
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• 1998

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.935-938
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• 1997

Recently, the minimum line width shows a tendency to decrease and the multi-level increase in semiconductor. Therefore, a planarization technique is needed and chemical mechanical polishing(CMP) is considered as one of the most suitable process. CMP accomplishes a high polishing performance and a global planarization of high quality. But there are several defects in CMP such as micro-scratches, abrasive contaminations, and non-uniformity of polished wafer edges. Wet etching include of Spin-etching can improve he defects of CMP. It uses abrasive-free chemical solution instead of slurry. On this study, ILD(INterlayer-Dielectric) was removed by CMP and wet-etching methods in order to investigate the superiority of wet etching mechanism. In the thin film wafer, the results were evaluated at a viewpoint of material removal rate(MRR) and within wafer non-uniformity(WIWNU). And pattern step height was also compared for planarization characteristics of the patterned wafer.

• Journal of the Korean institute of surface engineering
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• v.24 no.2
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• pp.73-79
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• 1991

Recent studies son surface coatings have shown that the change of physical, chemical and crystallographic structure analysed and observed according to the deposition process variables has the effects on the resultant film properties. Under the same preparation condition conditions of the substrate and process variables, physical morphology variations characterized by substrate temperature and bias which offect the surface mobility of adatom and adhesion variations related to the formation of Ti interlayer were considered in the present study. Microhardness showed the highest value around 40$0^{\circ}C$ of the substrate temperature and increased with the substrate bias. Adhesion was improved with the increase of substrate temperature and bias. An interlayer of pure titanium formed prior to deposition of TiN improves the adhesion at its optimum thickness. These results were explained by the change of physical morphology and phase analysis.

• Journal of the Korean institute of surface engineering
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• v.35 no.2
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• pp.113-121
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• 2002

We have investigated insulating properties of $SiO_2$ interlayer for the thin film strain gauge, which were prepared by RF magnetron sputtering method in various deposition conditions, such as Ar pressure, gas flow rates and sputtering gases. SEM, AFM and FT-IR techniques were used to analyze its structures and composition. As the Ar pressure and the flow rate increased, the insulating interlayer showed low insulating resistance due to its porous structure and defects. Oxygen deficiency in $SiO_2$ was decreased as fabricated by hydrogen reactive sputtering. We could enhance the surface mobility of sputtered adatoms by using Ar/$H_2$ sputtering gas and obtain a good surface roughness and insulating property. The optimum insulating resistance of 9.22 G$\Omega$ was obtained in Ar/30% $H_2$ mixed gas, flow rate 10sccm, and 1mTorr.

• Progress in Superconductivity
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• v.1 no.1
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• pp.1-8
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• 1999

The magnetization and/or resistivity of high $T_c$ superconductors ($YBa_2Cu_3O_{7-\delta}$(YBCO) single crystal, $Bi_2Sr_2CaCu_2O_8$ (Bi-2212) single crystal, $Tl_2Ba_2CaCu_2O_8$ (Tl-2212) film, $HgBa_2Ca_2Cu_3O_8$ (Hg-1223) film) have been measured as a function of magnetic field H and temperature T. The extracted fluctuation part of the magnetization and conductivity exhibits a critical behavior consistent with the three-dimensional XY model. The dynamic critical exponent z does not sensitively vary with a type of the superconductors. The value of z ranges from 1.5 to $1.8{\pm}0.1$. However, the static critical exponent ${\nu}$ is the most largely increased in Tl-2212 that has a weaker interlayer coupling strength than YBCO; the value of ${\nu}$ is 0.669, 0.909, 1.19, and 1.338 for YBCO, Bi-2212, Hg-1223, and Tl-2212 respectively. The results indicate that the weak interlayer coupling along the c-axis of high $T_c$ superconductors near $T_c$ does not influence the dynamic critical exponent z (the same value of superfluid $^4He$), but significantly increases the static critical exponent ${\nu}$.