• Journal of the Korean Ceramic Society
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• v.39 no.2
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• pp.171-177
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• 2002

In this study, the vertical aligned carbon nanotubes was synthesized by DC bias-assisted Inductively Coupled Plasma Hot-Filament Chemical Vapor Deposition (ICPHFCVD). The substrate used CNTs growth was Ni(300 ${\AA}$)/Cr(200 ${\AA}$)-deposited one on glass by RF magnetron sputtering. R-F, DC bias and filament power during the growth process were 150 W, 80 W, 7∼8 A, respectively. The grown CNTs showed hollow structure and multi-wall CNTs. The top of grown CNT was found to Ni-tip that the CNT end showed to metaltip. The graphitization and field emission properties of grown was better than grown CNTs by ICPCVD. The turn-on voltage of CNT grown by DC bias-assisted ICPHFCVD showed about 3 V/${\mu}m$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.2
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• pp.169-173
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• 2005

Ni oxide thin films were formed through annealing treatment in the atmosphere after Ni thin films deposited by a r.f. magnetron sputtering method and then electric and material properties were analyzed for application to thermal sensors. Resistivity of Ni thin films decreased after annealing treatment at 30$0^{\circ}C$ and 40$0^{\circ}C$ for five hours due to crystallization of Ni thin films but the value increased over 45$0^{\circ}C$ because of Ni thin film's oxidation. Resistivity values of Ni thin films were in the range of 10.5 $\mu$Ωcm/$^{\circ}C$ to 2.84${\times}$10$^4$$\mu$Ωcm/$^{\circ}C$ according to the degree of Ni oxidation. Also temperature coefficient of resistance(TCR) values of Ni oxide thin films depended on the degree of Ni oxidation such as 2,188 ppm/$^{\circ}C$ to 5,630 ppm/$^{\circ}C$ in the temperature range of 0 $^{\circ}C$∼150 $^{\circ}C$. The results demonstrate that Ni oxide thin films of annealing treatment at 40$0^{\circ}C$ for 5hours could be more advantageous than pure Ni thin films and Pt thin films from a point of output properties and TCR, applied to thermal sensors.

• Journal of the Korean Magnetics Society
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• v.8 no.4
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• pp.241-248
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• 1998

In accordance with tendency to miniaturization and high frequency operation of electronic products, extensive efforts of miniaturizing magnetic devices such as inductors, transformers and magnetic sensors are being made. In order to study on fabrication and characteristic of micro-magnetic devices, we carried out two sets of experiments. One is to develop a magnetic film that is suitable for high frequency operation, and the other is to develop the fabrication processes for realizing the micro-coil with meander shape. Magnetic films were composed of FeTa(N,C) fabricated by DC magnetron sputtering system. Their microstructures were nanocrystalline structure and magnetic properties showed Bs:13~17 kG, Hc:0.1~0.2 Oe and $\mu$':2000~4000. Cu coil pattern fabricated by selective electroplating process showed good electrical conductivity. In the case of air core inductors, inductance (L) of 50 nH, resonance frequency $(f_R)$ of 700 MHz, and quality factor (Q) of 30 at 200 MHz could be obtained. In the case of close type magnetic inductors, inductance (L) of 150 nH, resonance frequency $(f_R)$ of 100 MHz, and quality factor (Q) of 4 at 10~30 MHz could be obtained.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.2
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• pp.344-348
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• 2011

A layer of $TiO_2$ thin film less than ~200nm in thickness, as a blocking layer, was deposited by 13.56 MHz radio frequency magnetron sputtering method directly onto the anode electrode to be isolated from the electrolyte in dye-sensitized solar cells (DSCs). This is to prevent the electrons from back-transferring from the electrode to the electrolyte ($I^-/{I_3}^-$). The presented DSCs were fabricated with working electrode of F:$SnO_2$(FTO) glass coated with blocking $TiO_2$ layer, dye-attached nanoporous $TiO_2$ layer, gel electrolyte and counter electrode of Pt-deposited FTO glass. The effects of blocking layer were studied with respect to impedance and conversion efficiency of the cells. The, electrochemical impedances of DSCs using this electrode were $R_1$: 13.9, $R_2$: 15.0, $R_3$: 10.9 and $R_h$: $82{\Omega}$. The $R_2$ impedance related by electron movement from nanoporous $TiO_2$ to TCO showed lower than that of normal DSCs. The photo-conversion efficiency of prepared DSCs was 5.97% ($V_{oc}$: 0.75V, $J_{sc}$: 10.5 mA/$cm^2$, ff: 0.75) and approximately 1% higher than general DSCs sample.

• Journal of Surface Science and Engineering
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• v.47 no.4
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• pp.181-185
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• 2014

We investigated the structural, electrical and optical characteristics of IGZO thin films deposited by a room-temperature RF reactive magnetron sputtering. The thin films deposited were annealed for 2 hours at various temperatures of 300, 400, 500 and $600^{\circ}C$ and analyzed by using X-ray diffractometer, transmission electron microscopy, atomic force microscope and Hall effects measurement system. The films annealed at $600^{\circ}C$ were found to be crystallized and their surface roughness was decreased from 0.73 nm to 0.67 nm. According to XPS measurements, concentration of oxygen vacancies were decreased at $600^{\circ}C$. Optical band gap were increased to 3.31eV. The carrier concentration and Hall mobility were sharply increased at 600oC. Our results indicate that the IGZO films deposited at a room temperature can show better thin film properties through a heat treatment.

• Proceedings of the Korean Vacuum Society Conference
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• 1997.07a
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• pp.169-172
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• 1997

MgO dielectric pprotection layer is ppreppared by R.F. reactive magnetron spputtering with Mg target under various conditions of spputtering ppressure, time and substrate tempperature. Discharge characteristics of ppDpp is also studied as a pparameter of MgO pprepparation conditions. As the working ppressure and substrate tempperature was increase, the discharge voltage was decreased. Two kinds of MgO ppreppared both spputtering and E-beam methods were stable after annealing at 35$0^{\circ}C$ for 120min. discharge voltage under 3 mixed gas(He+Xe0.2%+Ne30%) was V=130V, V=102V and ${\gamma}$ coefficient was twiced as much as that of dielectric layer.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.729-732
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• 2001

In this study, the effect of oxygen partial pressure on the electrical properties of vanadium oxide(VO$_{x}$) thin films were investigated. The thin films were prepared by r.f. magnetron sputtering from V$_2$O$_{5}$ target in a gas mixture of argon and oxygen. The oxygen partial pressure ratio is changed from 0% to 8%. I-V characteristics were distinguished between linear and nonlinear region. In the low field region the conduction is due to Schottky emission, while at high fields it changes to Fowler-Nordheim tunneling type conduction. The conductivity measurements have shown an Arrhenius dependence of the conductivity on the temperature.ure.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1992.11a
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• pp.81-83
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• 1992

The superconducting thin films deposited on $SiO_x$ substrate by R.F magnetron sputter using $YBa_2Cu_3O_x$ single target have been made and annealed at $940^{\circ}C$ for 30 min. The thickness of films were 1000-2000${\AA}$ with a rate of 20-25${\AA}/min$ and superconducting properties of thin films depended on the compositions of pre-annealed the thin films. It has been analyzed by SEM photo-analysis and X-ray diffraction patterns of these samples obtained under the various conditions of this sputtering methods. and recognized the supperconducting thin films by electric properties.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.334.1-334.1
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• 2014

태양전지, 터치센서와 같이 투명한 전극(TCO: Transparent conducting oxide)이 필요로 하는 곳에는 금속 산화물 형태의 ITO, ZnO, FTO와 같은 투명 전극이 사용된다. 그중에서 FTO는 저렴한 가격과 높은 투과율, 낮은 저항으로 주목을 받고 있다. 뿐만아니라 FTO 박막은 다른 산화물 전도체에 비해 구부림에 강한 저항성을 보여 주고 있다. FTO 박막의 캐리어 전하 생성 원리는 F 원자가 O 원자의 자리를 치환하게 되면서 잉여 전자의 발생으로 전기가 흐를 수 있다. 아직까지는 화학적 조성비에 유리한 CVD를 이용한 증착 방법이 많이 사용되고 있다. 스퍼터 장비 역시 공정 가스에 따라 화학적 조성비 변화가 가능하고 CVD와 비교하여 공정이 간단하며 연속 공정이 쉽고 대면적 적용이 가능하다. 본 실험은 본사에서 R&D용으로 제작한 Daon-1000 S 장비를 사용하였으며 DaON-1000 S는 3개의 2" sputter gun이 장착 되어 있어 co-sputtering이 가능한 장비이다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.101-102
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• 2005

Cadmium telluride (CdTe) films have been prepared on Coming 7059 glass, molybdemium (Mo), and polyimide (PI) substrates by r.f. magnetron sputtering technique. The influence of the sputter pressure on the structural and optical properties of these films was evaluated. In addition, a comparison of the properties of the films deposited on different substrates was performed.