• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2008년도 춘계학술대회 논문집 센서 박막재료연구회 및 광주 전남지부
• /
• pp.58-61
• /
• 2008

$TiO_2$ is a wide band-gap semiconductor (3.4 eV) and can only absorb about 5% of sun light in the ultraviolet light region, which largely limits its practical applications because of the lower utility of sun light and quantum yield. In order to move the absorption edge of $TiO_2$ fims to visible spectrum range, we have made the impurity level within a band-gap of $TiO_2$ thin film by introduction of oxygen vacancy. Oxygen-defected $TiO_2$ thin film have prepared by reactive sputtering with the partial pressure of $Ar:O_2=10:90{\sim}99.33:0.66$ ratio. As a result, we could have the impurity level of about 2.75 eV on condition that oxygen partial pressure is below 7%.

• 한국진공학회지
• /
• 제7권3호
• /
• pp.201-207
• /
• 1998

본 연구는 rf reactive magnetron sputtering 방법으로 증착한 ZnO 박막을 압전진동 자로 제작하였을 때 발생하는 금속전극과의 계면특성에 대해 조사하였다. 이때 ZnO 박막은 금속 아연 target을 산소분위기에서 sputtering하여 얻었다. 미리 얻은 최적성장조건으로 Cr/ZnO/Cr의 구조을 갖는 압전 진동자를 제작한 후, 금속전극과 ZnO 박막과의 계면특성을 분석하였다. 제작된 압전진동자는 I-V 측정, AES depth profile, SEM, C-V 측정등을 이용 하여 분석하였고, 이러한 분석 결과 금속전극과 ZnO 박막 사이에 $SiO_2$ 확산방지막을 쌓은 Cr/ $SiO_2$/ZnO/Cr의 구조로 ZnO 압전진동자를 제작했을 때 좋은 특성을 보임을 알 수 있었 다. 그리고, 이러한 사실은 제작된 진동자를 구동시키고 이에 대한 인가진동수에 따른 진동 변위를 측정해보므로써 확인할 수 있었다.

• Transactions on Electrical and Electronic Materials
• /
• 제16권5호
• /
• pp.280-284
• /
• 2015

Among many the oxynitrides, TiNO and AlCrNO, have diverse applications in different technological fields. We prepared TiNO/AlCrNO/Al thin films on aluminum substrates using the method of dc reactive magnetron sputtering. The reactive gas flow, gas mixture, and target potential were applied as the sputtering conditions during the deposition in order to control the chemical composition. The multi-layer films have been prepared in an Ar and O₂+N₂ gas mixture rate. The surface properties were estimated by performing scanning electron microscopy (SEM). At a wavelength range of 0.3~2.5 μm, the exact composition and optical properties of thin films were measured by Auger electron spectroscopy (AES) and Ultraviolet-visible-near infrared (UV-Vis-NIR) spectrophotometry. The optimal absorptance of multi-layer films was exhibited above 95.5% in the visible region of the electromagnetic spectrum, and the reflectance was achieved below 1.89%.

• 한국초전도ㆍ저온공학회논문지
• /
• 제17권3호
• /
• pp.9-12
• /
• 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.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
• /
• pp.164-167
• /
• 2003

Carbon nitride films with ${\beta}-C_3N_4$ crystals were grown by rf reactive magnetron sputtering system with negative DC bias. Chamber baking system to supply whole chamber with activation energy was used to reduce the contamination of H and O atoms. XRD peaks showed the existence of crystalline ${\beta}-C_3N_4$(200) and lonsdaleite structures. FTIR spectroscopy studies revealed that the film contain ${\alpha}-C_3N_4$ and ${\beta}-C_3N_4$ with $1011\;cm^{-1},\;1257\;cm^{-1}\;and\;1529\;cm^{-1}$ peaks. We could also find the grain growth of hexagonal structure from SEM photograph, which is coincident with the theoretical carbon nitride unit cell. ${\alpha}$-step was used to make the thickness profile of the grown films.

• 한국표면공학회지
• /
• 제40권6호
• /
• pp.245-249
• /
• 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.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
• /
• pp.2172-2174
• /
• 2005

MgO has been used as the material of the protecting layer for AC PDP. AC PDP is influenced by characteristics of the surface glow discharge on the MgO thin film. Because MgO thin film is practically discharge electrodes, the discharge characteristics of MgO thin film should be varied with the method of deposition. In this study, changing order and time of deposition, we use electron beam evaporation system and R.F reactive magnetron sputtering system in the MgO deposition. Particularly, after using electron beam evaporation system, we use R.F. reactive magnetron sputtering system in the MgO deposition, then we could get lower amount of charge and higher luminance efficiency than only using electron beam evaporation system.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
• /
• pp.398-399
• /
• 2006

$TiO_2$ is a wide band-gap semiconductor (3.4 eV) and can only absorb about 5% of sun light. in the ultraviolet light region, which largely limits its practical applications because of the lower utility of sun light and quantum yield. In order to move the absorption edge of $TiO_2$ films to visible spectrum range, we have made the impurity level within a band-gap of $TiO_2$ thin film by introduction of oxygen vacancy. Oxygen-defected $TiO_2$ thin film have prepared by reactive sputtering with the partial pressure of Ar:$O_2$=10:90~99.33:0.66 ratio. As a result, we could have the impurity level of about 2.75 eV on condition that oxygen partial pressure is below 7%.

• 한국표면공학회지
• /
• 제42권2호
• /
• pp.86-94
• /
• 2009

Various types of multilayer coatings including Al/$Al_2O_3$ structure have been prepared on Nd-Fe-B permanent magnet to modify the morphology of the coating and to enhance the corrosion resistance of the magnet. Magnetron sputtering has been employed to make the multilayer coatings. $Al_2O_3$sputtering conditions were optimized in reactive sputtering by varying the deposition parameters. The formation of $Al_2O_3$ film was confirmed from the binding energy shift measured by electron spectroscopy for chemical analysis. 3 types of coating structures were designed and prepared by magnetron sputtering. The coating structures consist of (1) single Al coating, (2) modified coatings having oxide or plasma treated layer in the middle of coating structure, and (3) Al/$Al_2O_3$ multilayer coatings. Surface and cross-sectional morphologies showed that Al/$Al_2O_3$ multilayer grew as a layered structure, and that very compact Zone 3 like structure were formed. X-ray diffraction peak showed that the crystal orientations of multilayer coatings were similar to that of the bulk powder pattern. Hardness increased drastically when the Al thickness was around 1im in the Al/$Al_2O_3$ multilayer. From the salt spray test and pressure cooker test, it has been shown that the multilayer coatings showed good corrosion resistance compared to Al single or modified layer coatings.

• 전기학회논문지
• /
• 제56권4호
• /
• pp.751-755
• /
• 2007

We have studied the variable conditions of reactive sputtering to prepare AM thin film. The leakage current showed below $10^{-9}A/cm^2$ at the deposition temperature of $250^{\circ}C\;and\;300^{\circ}C$ in the field of 0.1 MV/cm, and it was gradually increased and to be saturated in 0.2 MV/cm. The C-V characteristics of the above mentioned deposition temperature conditions showed a deep depletion phenomenon at inversion region. The C-V characteristics showed similarly under the DC power conditions of 100 and 150 W but were degraded at 200W. When the DC power was 100, 200, and 300 W the dielectric breakdown phenomenon was shown in 2.8, 3.2 and 5.2 MV/cm, respectively. It was found that AIN film was dominated by Poole-Frenkel conduction mechanism.