• Journal of the Korean Vacuum Society
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• v.12 no.S1
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• pp.63-66
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• 2003

It is experimentally shown that a $TiO_2$ film on Si(111) substrate was prepared by using the technique of D.C. reaction sputter deposition with $Ar^{+}$ ion beam bombardment, and a layer-like structure was observed from the depth profile of the interface between $TiO_2$ film and Si substrate with Scanning Electron Microscopy and Electron Probe. It was also surprisingly discovered that Ti atoms could be detected at about 9 $\mu$m depth. The $TiO_2$-Si interface bombarded by $Ar^{+}$ ion beams revealed multi-layer structures, a mechanism might be caused by defect diffusion, impurity and matrix relocation. Multi-relocations of impurity and matrix atoms were as a result of profile broadening of the $TiO_2$-Si interface, and the spread due to matrix relocation in this system is shown to exceed much more the spread due to impurity relocation.

• Journal of Korean Vacuum Science & Technology
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• v.6 no.1
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• pp.16-21
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• 2002

Ti-0 film is a kind of biocompatible surface materials. In this paper, a new method, glow discharge plasma oxidizing, has been used in synthesizing Ti-O gradient films on Ti6A14V substrates. The effects of ion bombardment and process parameters on the structures of titanium oxide layers have been investigated. The results demonstrate that DC glow plasma oxidizing is more efficient in preparation of dense, hard, and high adhesive Ti-O biomedical films on titanium and its alloys. Samples treated by this method show higher hardness values than by others. Especially, in the condition of hollow cathode discharge, the ion bombardment enhances ionization of oxygen, promotes the oxygen permeation and facilitates the formation of the oxide of low valence states of titanium.

• Journal of the Korean Society for Heat Treatment
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• v.22 no.3
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• pp.143-148
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• 2009

We have fabricated Ti metal films on Cu wire substrates by using a RF magnetron sputtering method at different RF powers (0, 30 and 60 W) in a high vacuum, and we have investigated the thin film characteristics and resistivity. The ion bombardment effect is increased by the method to superimpose RF power to DC power applied to two poles of the base; thus, the thin film is deposited at sputtering gas pressures below 1 Pa. Moreover, the thin film formation of the multilayer structure becomes possible by gradually injecting the RF power, and the thin film quality is improved.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.476-479
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• 2000

In this study, mesh-type PECVD system was suggested to minimize the hydrogen concentration. The main structural difference between the triode system and a conventional system is that a mesh was attached to the substrate holding electrode. We investigated several conditions to compare with conventional PECVD. The main effect of mesh was to minimize the substrate damage by ion bombardment and to enhance the surface reaction to induce hydrogen desorption. It was also found that hydrogen concentration decreased but deposition rate increased as increasing applied dias. Applied DC bias enhanced sputtering process. Intense ion bombardment causes the weakly bonded hydrogen or hydrogen-containing species to leave the growing film and increased adatom mobility. Furthermore, addition of hydrogen gas enhance the surface diffusion of adatom. The structural properties of poly-Si films were analyzed by scanning electron microscopy(SEM).

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.9
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• pp.527-532
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• 2000

The performance of ac plasma display panels (PDP) is influenced strongly by the surface glow discharge characteristics on the MgO thin films. This paper deals with the surface glow discharge characteristics and some physical properties of MgO thin films prepared by reactive RF planar unbalanced magnetron sputtering in connection with ac PDP. The samples prepared with dc bias voltage of -10V showed lower discharge voltage and lower erosion rate byion bombardment than those samples prepared by conventional magnetron sputtering or E-beam evaporation. The main factor that improves the discharge characteristics by bias voltage is considered to be due to the morphology changes or crystal structure of the MgO thin film by ion bombardement during deposition process.

• Journal of the Korean institute of surface engineering
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• v.50 no.5
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• pp.352-359
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• 2017

The growth of nanocrystalline diamond films on a p-type poly silicon substrate was studied using microwave plasma chemical vapor deposition method. A 6 mm thick poly silicon plate was mirror polished and scratched in an ultrasonic bath containing slurries made of 30 cc ethanol and 1 gram of diamond powders having different sizes between 5 and 200 nm. Upon diamond deposition, the specimen scratched in a slurry with the smallest size of diamond powder exhibited the highest diamond particle density and, in turn, fastest diamond film growth rate. Diamond deposition was carried out applying different DC bias voltages (0, -50, -100, -150, -200 V) to the substrate. In the early stage of diamond deposition up to 2 h, the effect of voltage bias was not prominent probably because the diamond nucleation was retarded by ion bombardment onto the substrate. After 4 h of deposition, the film growth rate increased with the modest bias of -100 V and -150 V. With a bigger bias condition(-200 V), the growth rate decreased possibly due to the excessive ion bombardment on the substrate. The film grown under -150V bias exhibited the lowest contact angle and the highest surface roughness, which implied the most hydrophilic surface among the prepared samples. The film growth rate increased with the apparent activation energy of 21.04 kJ/mol as the deposition temperature increased in the range of $300{\sim}600^{\circ}C$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.116-116
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• 2009

This paper focuses on improving organic thin film transistor (OTFT) characteristics by controlling the self-organization of pentacene molecules with an alignable high-dielectric-constant film. The process, based on the growth of pentacene film through high-vacuum sublimation, is a method of self-organization using ion-beam (IB) bombardment of the $HfO_2/Al_2O_3$ surface used as the gate dielectric layer. X-ray photoelectron spectroscopy indicates that the IB raises the rate of the structural anisotropy of the $HfO_2/Al_2O_3$ film, and X-ray diffraction patterns show the possibility of increasing the anisotropy to create the self-organization of pentacene molecules in the first polarized monolayer.

• Journal of Satellite, Information and Communications
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• v.9 no.1
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• pp.33-37
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• 2014

This paper introduces homogeneous liquid crystal (LC) orientations on chemically modulated polystyrene (PS) surfaces using various ion beam (IB) exposure time. Transparent PS was replaced with conventional polyimide material. As a non-contact process, IB bombardment process induced LC orientation in the direction parallel to the IB process. Through x-ray photoelectron spectroscopy, it was shown that the chemical compositional changes of the IB-irradiated PS surfaces were determined as a function of IB exposure time.Using this analysis, the optimal IB bombardment condition was determined at IB exposure time of up to 15 s. Moreover, thermal stability on IB-irradiated PS surfaces were carried out which showed that a relatively high IB exposure time induced a thermally stable LC alignment property.

• Journal of Electrochemical Science and Technology
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• v.2 no.4
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• pp.193-197
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• 2011

The influences of the thickness and microstructure of Fe layer on the electrochemical performances of Fe/Si multilayer thin film anodes were investigated. The Fe/Si multilayer films were prepared by electron beam evaporation, in which Fe layer was deposited with/without simultaneous bombardment of Ar ion. The kinetics of Li insertion/extraction reactions in the early stage are slowed down with increasing the thickness of Fe layer, but such a slowdown seems to be negligible for thin Fe layers less than about $500{\AA}$. When the Fe layer was deposited with ion bombardment, even the $300{\AA}$ thick Fe layer significantly suppress Li diffusion through the Fe layer. This is attributed to the dense microstructure of Fe layer, induced by ion beam assisted deposition (IBAD). It appears that the Fe/Si multilayer films prepared with IBAD show good cyclability compared to the film deposited without IBAD.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.3
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• pp.183-187
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• 2000

In this study the SrBi$_2$Ta$_2$$O_{9}$ (SBT) thin films were etched by using magnetically enhanced inductively coupled Ar/CHF$_3$plasma as function of CHF$_3$/(Ar+CHF$_3$)gas mixing ratio. Maximum etch rate of SBT thin films was 1650 $\AA$/min and the selectivities of SBT to Pt and photoresist(PR) were 1.35 and 0.94 respectively under CHF$_3$/(Ar+CHF$_3$) of 0.1 For study on etching mechanism of SBT thin film X-ray photoelectron spectroscopy (XPS) surface analyses and secondary ion mass spectrometry (SIMS) mass analysis of etched SBT surfaces were performed. Among the elements of SBT thin film. M(Sr, Bi, Ta)-O bonds are broken by Ar ion bombardment and form SrF and TaF$_2$by chemical reaction with F. SrF and TaF$_2$are removed more easily by Ar ion bombardment. Scanning electron microscopy(SEM) was used for the profile examination of etched SBT film and the cross-sectional SEM profile of etched SBT film under CHF$_3$(Ar+CHF$_3$) of 0.1 was about 85$^{\circ}$X>.