• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8679-8683
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• 2015

Using a surface modification technique, ion beam assisted deposition (IBAD) of Ti thin film it becomes possible to prepare an active ceramic surface to braze $Al_2O_3$-STS304 with conventional Ag-Cu eutectic composition filler metal. Researches on bonding formations at interfaces of ceramic joints were mainly related on the development of filler metals to ceramic, the process parameters, and clarifications of reaction products. From the results, the reactive brazing is a very convenient technique compared to the conventional Mn-Mo method. However melting point of reactive filler is still higher than that of Ag-Cu eutectic and it forms the brittle inter metallic compound. Recently several new approaches are introduced to overcome the main shortcomings of the reactive metal brazing in ceramic-metal, metal vapor vacuum arc ion source was introduced to implant the reactive element directly into the ceramics surface, and sputter deposition with sputter etching for the deposition of active material.

• Journal of the Korean Ceramic Society
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• v.35 no.8
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• pp.795-800
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• 1998

• Journal of the Korean Vacuum Society
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• v.11 no.3
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• pp.141-150
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• 2002

Titanium oxide thin films were deposited by DC reactive magnetron sputtering(RMS) with Ar ion-beam assistance using end-Hall ion source at low oxygen partial pressure and long target-to-substrate distance. The optical and structural properties of deposited films were investigated by the measurement of measured transmittance and reflectance, atomic force microscope(AFM), and X-ray diffraction(XRD). The results show that the Ax ion-beam assisted RMS for titanium oxide thin films induces the higher packing density, lower absorption, and smoother surface than the conventional RMS, suggesting that it can be employed in deposition of optical dielectric coatings.

• Journal of the Korean Ceramic Society
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• v.31 no.7
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• pp.731-738
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• 1994

TiN films were deposited on high speed steels by plasma assisted chemical vapor deposition (PACVD), cathode arc ion plating (CAIP) and reactive magnetron sputtering (RMS). The properties of the films deposited by the three different methods were compared. The preferred oriented plane of PACVD-TiN is (200) and those of CAIP-TiN and RMS-TiN are (111). PACVD-TiN shows a dome surface and a microstructure having small grains. CAIP-TiN shows the highest microhardness and the best adhesion strength of the three because it has a dense microstructure and an ill-defined interface. But is shows the greatest surface roughness due to the Ti droplet created by the arc. RMS-TiN shows a microstructure having large voids so that its properties in microhardness and adhesion are the worst of the three.

• Korean Journal of Materials Research
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• v.13 no.9
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• pp.587-592
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• 2003

The thin films of 316L stainless steel were made on glass and S45C substrate by Ion beam assisted deposition with reactive atmosphere of argon and nitrogen. The films were deposited at the various conditions of ion beam power and the ratios of Ar/$N_2$gas. Properties of these films were analyzed by glancing x-ray diffraction method(GXRD), AES, potentiodynamic test, and salt spray test. The results of GXRD showed that austenite phase could be appeared by $N_2$ion beam treatment and the amount of austenite phase increased with the amount of nitrogen gas. The films without plasma ion source treatment had the weak diffraction peak of ferrite phase. But under the Ar plasma ion beam treatment, the strong diffraction peaks of ferrite phase were appeared and the grain size was increased from 12 to 16 nm. Potentiodynamic polarization test and salt spray test indicated that the corrosion properties of the STS 316L films with nitrogen ion source treatment were better than bulk STS 316L steel and STS 316L films with Ar ion source treatment.

• Progress in Superconductivity and Cryogenics
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• v.15 no.4
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• pp.1-5
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• 2013

This paper reviews recent progress in research and development (R&D) of reactive co-evaporation for high performance REBCO coated conductors in Korea. Two types of reactive co-evaporation methods were developed for the deposition of SmBCO and GdBCO superconducting layers respectively on the IBAD (Ion Beam Assisted Deposition)-MgO template in the Korean coated conductor project. Batch type reactive co-evaporation equipment and its processing were developed for SmBCO coated conductors at Korea Electrotechnology Research Institute (KERI) in conjunction with the Korea Advanced Institute of Science and Technology (KAIST), and a very high critical current exceeding 1,000 A/cm at 77 K in the self field was achieved through the optimization of deposition parameters. Reel-to-reel type reactive co-evaporation processing with a high conversion rate was also developed, while long length GdBCO coated conductors have been routinely produced by SuNAM Co. The minimum critical current of 422 A/cm-w at 77 K in self field was confirmed for 1 km-long GdBCO tape.

• Journal of the Korean institute of surface engineering
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• v.45 no.5
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• pp.206-211
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• 2012

Process analysis was carried out during deposition of MgO by inductively coupled plasma assisted reactive magnetron sputtering in Ar and $O_2$ ambient. At the initiation of Mg sputtering with bipolar pulsed dc power in Ar ambient, total pressure showed sharp increase and then slow fall. To analyse partial pressure change, QMS was used in downstream region, where the total pressure was maintained as low as $10^{-5}$ Torr during plasma processing, good for ion source and quadrupole operation. At base pressure, the major impurity was $H_2O$ and the second major impurity was $CO/N_2$ about 10%. During sputtering of Mg in Ar, $H_2$ soared up to 10.7% of Ar and remained as the major impurity during all the later process time. When $O_2$ was mixed with Ar, the partial pressure of Ar decreased in proportion to $O_2$ flow rate and that of $H_2$ dropped down to 2%. It was understood as Mg target surface was oxidized to stop $H_2$ emission by Ar ion sputtering. With ICP turned on, the major impurity $H_2$ was converted into $H_2O$ consuming $O_2$ and C was also oxidized to evolve CO and $CO_2$.

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.60-60
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• 2000

The adhesion interface formation between copper and poly(ethylene terephthalate)(PET), poly(methyl methacrylate)(PMMA) and Polyimide films was treated using Ion assisted reaction system to sequential sputter deposition by High-Frequency ion source. The ion beam modification system used a new type of low power HF ion thruster for space application as new low thruster electric propulsion system. Low power HF ion thruster with diameter 100mm gives the opportunity to obtain beams of Ar+ with currents 20~150 mA (current density 0.5~3.5 mA/cm2) and energy 200~2500eV at HF power level 10~150 W. Using Ar as a working gas it is possible to obtain thrust within 3~8 mN. Contact angles for untreated films were over 95$^{\circ}$ and 80 for Pet, 10o for PMMA and 12o for PI samples as a condition of ion assisted reaction at the ion dose of 10$\times$1016 ions/cm2, the ion beam potential of 1.2 keV and 4 ml/min for environmental gas flow rate. 900o peel tests yielded values of 15 to 35 for PET, 18 to 40 and 12 to 36 g/min. respectively. High resolution X-ray photoelectron spectrocopy is the Cls region for Cu metal on these polymer substrates showed increases in C=O-O groups for polymide, whereas PET and PMMA treated samples showed only C=O groups with increase the ion dose. Finally, unstable polymer surface can be changed from hydrophobic to hydrophilic formation such as C-O and C=O that were confirmed by the XPS analysis, conclusionally, the ion assisted reaction is very effective tools to attach reactive ion species to form functional groups on C-C bond chains of PET, PMMA and PI.

• Proceedings of the Korean Vacuum Society Conference
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• 1998.06a
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• pp.54-54
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• 1998

• Proceedings of the Korean Vacuum Society Conference
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• 1996.02a
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• pp.173-173
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• 1996