• Proceedings of the Materials Research Society of Korea Conference
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• 1999.11a
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• pp.25-25
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• 1999

• Korean Journal of Materials Research
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• v.11 no.9
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• pp.751-758
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• 2001

Anatase $TiO_2$ thin films as a photocatalyst were prepared by the D.C reactive magnetron sputtering process. The $TiO_2$ thin films were deposited on Si(100) substrates under the various conditions : oxygen partial pressure, working pressure, substrate temperature, D.C power, and deposition time. The morphology of the TiO$_2$ thin films showed an island structure. At early stages of film growth, amorphous phase formed. However, during the further growth, columnar crystalline $TiO_2$grains evolved. The crystallinity of the thin films depended on the oxygen partial pressure, the working pressure and the D.C. powers.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.8
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• pp.8-14
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• 1997

RuO$_{2}$ thin films are prepared by RF magnetron reactive sputtering and their characteristics of crystallization, microstructue, surface roughness and resistivity are studied with various O$_{2}$/(Ar+O$_{2}$) ratios and substrate temperatures. As O$_{2}$/(Ar+O$_{2}$) ratio decreas and substrate temperature increases, the preferred growing plane of RuO$_{2}$ thin films are changed from (110) to (101) plane. With increase of the O$_{2}$/(Ar+O$_{2}$) ratio from 20% to 50%, the surface roughness and the resistivity of RuO$_{2}$ thin films increase form 2.38nm to 7.81 nm, and from 103.6.mu..ohm.-cm to 227.mu..ohm.-cm, resepctively, but the deposition rate decreases from 47 nm/min to 17nm/min. On the other hand, as the substrate temperature increases form room temperature to 500.deg. C, resistivity decreases from 210.5.mu..ohm.-cm to 93.7.mu..ohm.-cm. RuO$_{2}$ thin film deposited at 300.deg. C shows a execellent surface roughness of 2.38nm. As the annealing temperature increases in the range between 400.deg. C and 650.deg. C, the resistivity decreases because of th improvement of crystallinity. We find that RuO$_{2}$ thin film deposited at 20% of O$_{2}$/(Ar+O$_{2}$) ratio and 300.deg. C of substrate temperature shows execellent combination of surface smoothness and low resistrivity so that it is well qualified for bottom electrodes for ferroelectric thin films.

• Journal of the Korean Ceramic Society
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• v.40 no.8
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• pp.739-745
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• 2003

In $N_{x}$ films were deposited on soda-lime glass without substrate heating by reactive dc magnetron sputtering using indium (In) metal target. Depositions were carried out under various total gas pressures ( $P_{tot}$) of mixture gases (Ar+$N_2$ or He+$N_2$). He gas was introduced to $N_2$ gas in order to enhance the reactivity of nitrogen on film surface by the "penning ionization". Plasma impedance decreased greatly when 20% or more introduced the $N_2$ gas. This is due to the In $N_{x}$ layers formed on target surface because a secondary electron emission rate of InN is small compared with In metal. XRD patterns of the films revealed that <001> preferred oriented polycrystalline In $N_{x}$ films, where the crystallinity of the films was improved with decrease of $P_{tot}$ and with increase of $N_2$ flow ratio. The improvement of the crystallinity and stoichimetry of the In $N_{x}$ films were considered to be caused by an increase in the activated nitrogen radicals and also by an increase in the kinetic energy of sputtered In atoms arriving at growing film surface, which should enhance the chemical reaction and surface migration on the growing film surface, respectively. Furthermore, the films deposited using mixture gases of He+$N_2$ showed higher crystallinity compared with the film deposited by the mixture gases of Ar+$N_2$.$.EX>.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.5
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• pp.696-702
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• 2002

The BST $({Bal-xSrxTiO_3})$ (50/50) thin film has been grown by RF magnetron reactive sputtering and its characteristics such as crystallization, surface roughness, and electrical properties have been investigated with varying the film thickness. The crystallization and surface roughness of BST thin film are investigated by using XRD and AFM, respectively. The BST thin film annealed at $800^{\circ}C$ for 2 min has pure perovskite structure and good surface roughness of 16.1$\AA$. As the film thickness increases from 80 nm to 240 nm, the dielectric constant at 10 KHz increases from 199 to 265 and the leakage current density at 250 ㎸/cm decreases from $0.779 {\mu}A/{cm^2} to 0.184 {\mu}A/{cm^2}$. In the case of 240 nm-thick BST thin film, the charge storage density and leakage current density at 5V are 50.5 fC/${{\mu}m^2} and 0.182 {\mu}A/{cm^2}$, respectively. The values indicate that the BST thin film is a very useful dielectric material for the DRAM capacitor.

• Korean Journal of Crystallography
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• v.11 no.3
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• pp.167-172
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• 2000

CaTiO₃:Pr phosphor thin films were prepared on Si(100), ZnO/glass, Corning glass and ITO/glass by rf magnetron reactive sputtering. The effects of deposition parameters such as oxygen partial pressure, substrate temperature, and annealing conditions on crystallinity and compositional variation of the films were investigated. PL spectra of CaTiO₃:Pr phosphor thin films exhibited red regime peaking at 613 nm and enhanced PL intensity was observed for the film annealed in vacuum atmosphere as compared to the deposit annealed in N₂ environment.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.05a
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• pp.35-38
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• 1995

Indium Tin Oxide(ITO) thin film is transparent to visible ray and conductive in electricity. It is seen that the samples made by the sputtering process have high transmission rate to visible ray and high adhesion , but the planar type magnetron sputtering process with is very well known in industrial region have a defect of partial erosion on the surface of target and a high loss of target and also since the substrate is positioned in plasma, the damage on thin film surface is caused by the reaction with plasma. In cylindrical magnetron sputtering system. it is known that the loss of target is little , the damage of thin film is very little and the adhesion of thin film with substrate is strong. In this study, we have made ITO thin film in the cylindrical DC magnetron system with the variable of substrate temperature , magnetic field, vacuum condution and the applied voltage. The general temperature for formation on ITO is asked at 350 $^{\circ}C$~400$^{\circ}C$ but we have made ITO is low temperature(80-150$^{\circ}C$) By studing electrical and optical properties of ITO thin fims made by varing several condition, we have searched the optimal condition for formation in the best ITO in low temperature.

• Journal of the Korean Vacuum Society
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• v.7 no.3
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• pp.201-207
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• 1998

We have investigated about interface characteristics between ZnO thin films and metal electrodes when ZnO and metal electrodes were fabricated as piezoelectric vibrators. At this, ZnO thin films were deposited by rf reactive magnetron sputtering method. After fabricating piezoelectric vibrator of Cr/ZnO/Cr structure with optimum condition, we analyse interface characteristics between ZnO thin films and metal electrodes by I-V measurement. AES depth profile, SEM and C-V measurement. From these measurements we found that ZnO piezoelectric vibrators showed good property when they fabricated as Cr/$SiO_2$/ZnO/Cr structure. And we could confirm these things by driving, and measuring vibration displacement of piezoelectric vibrator with $SiO_2$diffusion barrier.

• Progress in Superconductivity and Cryogenics
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• v.17 no.3
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• pp.9-12
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• 2015

NbN thin films were deposited on thermally oxidized Si substrate at room temperature by using reactive magnetron sputtering in an $Ar-N_2$ gas mixture. Total sputtering gas pressure was fixed while varying $N_2$ flow rate from 1.4 sccm to 2.9 sccm. X-ray diffraction pattern analysis revealed dominant NbN(200) orientation in the low $N_2$ flow rate but emerging of (111) orientation with diminishing (200) orientation at higher flow rate. The dependences of the superconducting properties on the $N_2$ gas flow rate were investigated. All the NbN thin films showed a small negative temperature coefficient of resistance with resistivity ratio between 300 K and 20 K in the range from 0.98 to 0.89 as the $N_2$ flow rate is increased. Transition temperature showed non-monotonic dependence on $N_2$ flow rate reaching as high as 11.12 K determined by the mid-point temperature of the transition with transition width of 0.3 K. On the other hand, the upper critical field showed roughly linear increase with $N_2$ flow rate up to 2.7 sccm. The highest upper critical field extrapolated to 0 K was 17.4 T with corresponding coherence length of 4.3 nm. Our results are discussed with the granular nature of NbN thin films.

• Journal of the Korean institute of surface engineering
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• v.40 no.6
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• pp.245-249
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• 2007

Amorphous IZO films were deposited on PET substrate by DC magnetron sputtering without substrate heating. In order to investigate effect of reactive gas addition on film properties, 0.2-0.4% of $H_2$ or $O_2$ gas was introduced during the deposition. Deposited IZO films were evaluated with mechanical property, electrical property, and water permeability. In the case of $H_2$ gas addition, mechanical property showed clear degradation compared to $O_2$ gas. In the case of $O_2$ gas, water permeability of the IZO film was increased compared to $H_2$ gas which could be attributed to the low adhesion of the film caused by bombardment of high energy negative oxygen ion. As a result, it is confirmed that water permeability of the film could be strongly affected by adhesion of the film.