• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.23 no.5
• /
• pp.224-229
• /
• 2013

Vanadium oxide thin films were deposited on $c-Al_2O_3$ (001) substrate by in-situ RF magnetron sputtering. Oxygen partial pressure was adjusted to prepare thermochromic $VO_2$ phase. X-ray diffraction patterns and scanning electron microscopy convincingly showed that plate-like $V_2O_5$ grains were changed into round-shape $VO_2$ grains as oxygen partial pressure decreased. After the optimized deposition conditions were fixed, the effect of substrate temperature and orientation on the optical properties of $VO_2$ thin films was analyzed.

• Journal of IKEEE
• /
• v.22 no.2
• /
• pp.302-308
• /
• 2018

Multi-Layer Sputtering is aim to develop desired thickness thin film multi-layer with different materials. The multi-layer thin film deposition process occupies a relatively large portion in the process time, because the main reason is that it takes much time to move the substrate to be deposited and to make the chamber into a high vacuum state compared to the process time. Most of semiconductor and display industries sputter a single substance in one chamber and move boards through multi-continuous robots to another chamber to sputter other materials. This will inevitably require multiple chambers, vacuum pumps, and multi-contamination robots within the process facility. To solve these problems, this paper proposes a control system for multi-layer thin film sputtering devices that deposit different materials within a single vacuum chamber and is applied in TFT process. The manufacture and experiment of the control system proved its validity.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 1998.08a
• /
• pp.135.2-135
• /
• 1998

• Journal of the Korean Ceramic Society
• /
• v.42 no.1
• /
• pp.28-32
• /
• 2005

The optical properties and intrinsic stress of $Ta_{2}O_{5}$ thin films deposited by Dual ion-Beam Sputtering: (DIBS) and Single ion-Beam Sputtering (SIBS) were studied as a function of the substrate temperature and assist ion beam voltage. The refractive index showed the maximum value (n = 2.144) at $150^{circ}C$ in the SIBS process. When the substrate temperature has above $150^{circ}C$ in the SIBS process the refractive index decreased. In the DIBS process, the increase of the substrate temperature affected the increase of the refractive index at a maximum value (n = 2.1117, at $200^{circ}C$). The low temperature process $(<100^{circ}C)$ can greatly reduce residual stress with the assist ion gun, but the high temperature process was unaffected. As the assist ion beam voltage increase from 250 to 350 V the refractive index increased to 2.185. However, the refractive index was decreased at the range of 350-650 V, As the assist ion beam voltage increased, the stress of the deposited film decreased to 0.1834 GPa at 650 V.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2015.08a
• /
• pp.135-135
• /
• 2015

Tubes are of extreme importance in industries as for fluid channels or wave guides. Furthermore, some weapon systems such as cannons use the tubes as gun barrels. To increase the service life of such tubes, a protective coating must be applied to the tubes' inner surface. However, the coating methods applicable to the inner surface of the tubes are very limited due to the geometrical restriction. A small-diameter cylindrical magnetron sputtering gun can be used to deposit coating layers on the inner surface of the large-bore tubes. However, for small-bore tubes with the inner diameter of one inch (~25 mm), the magnetron sputtering method can hardly be accommodated due to the space limitation for permanent magnet assembly. In this study, a new approach to coat the inner surface of small-bore tubes with the inside diameter of one inch was developed. Instead of using permanent magnets for magnetron operation, an external electro-magnet assembly was adopted around the tube to confine the plasma and to sustain the discharge. The electro-magnet was operated in pulse mode to provide the strong axial magnetic field for the magnetron operation, which was synchronized with the negative high-voltage pulse applied to the water-cooled coaxial sputtering target installed inside the tube. By moving the electro-magnet assembly along the tube's axial direction, the inner surface of the tube could be uniformly coated. The inner-surface coating system in this study used the tube itself as the vacuum chamber. The SS-304 tube's inner diameter was 22 mm and the length was ~1 m. A water-cooled Cu tube (sputtering target) of the outer diameter of 12 mm was installed inside of the SS tube (substrate) at the axial position. The 50 mm-long electro-magnet assembly was fed by a current pulse of 250 A at the frequency and pulse width of 100 Hz and 100 usec, respectively. The calculated axial magnetic field strength at the center was ~0.6 Tesla. The central Cu tube was synchronously driven by a HiPIMS power supply at the same frequency of 100 Hz as the electro-magnet and the applied pulse voltage was -1200 V with a pulse width of 500 usec. At 150 mTorr of Ar pressure, the Cu deposition rate of ~10 nm/min could be obtained. In this talk, a new method to sputter coat the inner surface of small-bore tubes would be presented and discussed, which might have broad industrial and military application areas.

• Journal of Surface Science and Engineering
• /
• v.46 no.6
• /
• pp.248-257
• /
• 2013

It is generally recognized that thin Pd-Cu alloy films fabricated by sputtering show a wide range of microstructures and properties, both of which are highly dependent on the sputtering conditions. In view of this, the present study aims to investigate the relationship between the performance of hydrogen separation membranes and the microstructure of Pd alloy films depending on sputtering deposition conditions such as substrate temperature, working pressure, and DC power. We fabricated thin and dense Pd-Cu alloy membranes by the micro-polishing of porous Ni support, an advanced Pd-Cu sputtered multi-deposition under the conditions of high substrate temperature / low working pressure / high DC power, and a followed by Cu-reflow heat-treatment. The result of a hydrogen permeation test indicated that the selectivity for $H_2/N_2$ was infinite because of the void-free and dense surface of the Pd alloy membranes, and the hydrogen permeability was 10.5 $ml{\cdot}cm^{-2}{\cdot}min^{-1}{\cdot}atm^{-1}$ for a 6 ${\mu}m$ membrane thickness.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2008.10a
• /
• pp.613-616
• /
• 2008

We report on electrical and optical properties of flexible ITO electrode grown on PET substrate using a specially designed roll-to-roll facing target sputtering (R2R FTS) system at room temperature without conventional cooling drum. Due to effective confinement of high density plasma between ITO targets, we can grow a flexible ITO electrode without cooling drum at room temperature.

• Journal of Surface Science and Engineering
• /
• v.38 no.2
• /
• pp.55-59
• /
• 2005

ITO/Ni/ITO thin films were deposited on the PET by RF magnetron sputtering. Dependance of the process parameters such as deposition pressure, positions of Ni layer, on the transmittance, reflectance and sheet resistance of ITO/Ni/ITO film were investigated. When the Ni layer is placed at the center of ITO and deposition pressure is low, ITO/Ni/ITO films showed better optical and electrical properties. At these conditions, the transmittance, reflectance and sheet resistance of the ITO film were $90\%,\;0.38\%$ and $185\Omega/\Box$ respectively.

• Korean Journal of Materials Research
• /
• v.18 no.4
• /
• pp.181-186
• /
• 2008

In this study, tantalum (Ta) compacts were fabricated in a spark plasma sintering (SPS) process and their microstructure and mechanical properties were investigated. Ta compacts with a density of 99% were successfully fabricated by controlling the sintering conditions of the current and the temperature. The density and hardness were increased as the sintering temperature increased. The $Ta_2C$ compound was observed at the surface of the compacts due to the contact between the Ta powder and graphite mold during the sintering process. The main fracture mode showed a mixed type with intergranular and transgranular modes having some roughness.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.07a
• /
• pp.3-4
• /
• 2003