• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.328-329
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• 2005

Inorganic alignment layer (IAL) was deposited on an indium-tin-oxide (ITO) by using reactive sputtering deposition method. After deposited, IAL was irradiated by $Ar^+$ ion beam (IB) for liquid crystal (LC) alignment. IAL treated by various conditions such as IB energy, IB incident angle, and IB irradiation time had excellent alignment property and electro-optical property the same as that of PI. We investigated into the stability of ion beam treated IAL after a lapse of long time. However IAL irradiated IB did not occur degradation of electro-optical property. The results implied that IAL irradiated IB was adopted as LC alignment layer instead of rubbed polyimide.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.796-799
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• 2002

BSCCO thin films are fabricated via a co-deposition process at an ultra-low growth rate using ion beam sputtering. The sticking coefficient of Bi element exhibits a characteristic temperature dependence. This temperature dependence of the sticking coefficient was explained consistently on the basis of the evaporation and sublimation processes of Bi$_2$O$_3$.

• Proceedings of the Materials Research Society of Korea Conference
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• 1993.11a
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• pp.84-84
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• 1993

• Proceedings of the Korean Ceranic Society Conference
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• 2002.10a
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• pp.96.2-96
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• 2002

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.1218-1221
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• 2004

Bi2212 superconducting thin films fabricated by using the ion Beam Sputtering Method. As a result, although the composition of Bi2212 was set up, the phase of Bi2201, Bi2212 and Bi2223 was formed. The formation area of these stable phases is indicated as inclined line in the direction of the right lower end from the Arrhenius plot of the substrate temperature-oxidation gas pressure, and are distributed in very small area. The activation energy for the phase transformation from the Bi2201 to the Bi2212 is estimated in terms of the Avrami equation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.301-301
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• 2008

Ion beam (IB)-induced alignment of inorganic materials has been investigated intensively as it provides controllability in a nonstop process for producing high-resolution displays[1][2]. LC orientation via ion-beam (IB) irradiation on the nitrogen doped diamond like carbon (NDLC) thin film deposited by physical deposition method-sputtering was embodied. The NDLC thin film that was deposited by sputter showed uniform LC alignment at the 1200eV of the ion beam intensity. The pretilt angle of LC on NDLC thin films was measured with various IB exposure time and angle. The maximum pretilt angle were showed with IB irradiation angle of $45^{\circ}$ and exposure time of 62.5 sec, respectively. To show NDLC thin film stability in high temperature, thermal stability test was proceeded. The uppermost of the thermal stability of NDLC thin film was $200^{\circ}C$. In this investigation, the electro-optical (EO) characteristics of LC on NDLC thin film were measured.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.254-257
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• 2008

We have investigated the effect of source/drain electrode deposition method on a performance of top gate structured ZnO TFT performance. TFT using S/D of ITO film, consisted of bi-layer which deposited by ion beam assisted sputtering at the initial stage then deposited by DC magnetron sputtering, showed better performance compared to that using S/D of ITO deposited by just DC magnetron sputtering. Two ITO films exhibited different grain shapes and these resulted in different etching properties. We also suspect that charge trapping on the glass substrate (back channel) during the ITO film deposition may influence the characteristics of top gate structured ZnO TFT.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.338-338
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• 2011

The behavior of hydroxide ions on water-ice films was studied by using $Cs^+$ reactive ion scattering (RIS), low energy sputtering (LES) and temperature-programmed desorption (TPD). A $Cs^+$ beam of a low kinetic energy (<100 eV) from $Cs^+$ ion gun was scattered at the film surface, and then $Cs^+$ projectiles pick up the neutral molecules on the surface as $Cs^+$-molecule clusters form (RIS process). In LES process, the preexisting ions on the surface are desorbed by the $Cs^+$ beam impact. The water-ice films made of a thick (>50 BL) $H_2$O layer and a thin $D_2O$ overlayer were controlled in temperatures 90~140K. We prepared hydroxide ions by using Na atoms which proceeded hydrolysis reaction either on the ice film surface or at the interface of the $H_2O$ and $D_2O$ layers.[1] The migration of hydroxide ions from the $H_2O/D_2O$ interface to the top of the film was examined as afunction of time. From this experiment, we show that hydroxide ions tend to reside at the water-ice surface. We also investigated the H/D exchange reactions of $H_2O$ and $D_2O$ molecules mediated by hydroxide ions to reveal the mechanism of migration of hydroxide to the ice surface.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.440-440
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• 2012

Nanomaterials have emerged as new building blocks to construct light energy harvesting assemblies. Size dependent properties provide the basis for developing new and effective systems with semiconductor nanoparticles, quantized charging effects in metal nanoparticle or their combinations in 2 and 3 dimensions for expanding the possibility of developing new strategies for photovoltaic system. As top-down approach, we developed a simple and effective method for the large scale formation of self-assembled Cu(In,Ga)$Se_2$ (CIGS) nanostructures by ion beam irradiation. The compositional changes and morphological evolution were observed as a function of the irradiation time. As the ion irradiation time increased, the nano-dots were transformed into a nano-ridge structure due to the difference in the sputtering yields and diffusion rates of each element and the competition between sputtering and diffusion processes during irradiation. As bottom-up approach, we developed the growth of CIGS nanowires using thermal-chemical vapor deposition (CVD) method. Vapor-phase synthesis is probably the most extensively explored approach to the formation of 1D nanostructures such as whiskers, nanorods, and nanowires. However, unlike binary or ternary chalcogenides, the synthesis of quaternary CIGS nanostructures is challenging because of the difficulty in controlling the stoichiometry and phase structure. We introduced a method for synthesis of the single crystalline CIGS nanowires in the form of chalcopyrite using thermal-CVD without catalyst. It was confirmed that the CIGS nanowires are epitaxially grown on a sapphire substrate, having a length ranged from 3 to 100 micrometers and a diameter from 30 to 500 nm.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05d
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• pp.45-48
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• 2003

BiSrCaCuO thin films were fabricated by atomic layer-by-layer deposition using an ion beam sputtering method. 10 wt% and 90 wt% ozone mixed with oxygen were used with ultraviolet light irradiation to assist oxidation. At early stages of the atomic layer by layer deposition, two dimensional epitaxial growth which covers the substrate surface would be suppressed by the stress and strain caused by the lattice misfit, then three dimensional growth takes place. Since Cu element is the most difficult to oxidize, only Sr and Bi react with each other predominantly, and forms a buffer layer on the substrate in an amorphous-like structure, which is changed to $SrBi_2O_4$ by in-situ anneal.