• 한국재료학회지
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• 제21권4호
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• pp.202-206
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• 2011

We have investigated the structural and electrical properties of Ga-doped ZnO (GZO) thin films deposited by an RF magnetron sputtering at various RF powers from 50 to 90W. All the GZO thin films are grown as a hexagonal wurtzite phase with highly c-axis preferred parameters. The structural and electrical properties are strongly related to the RF power. The grain size increases as the RF power increases since the columnar growth of GZO thin film is enhanced at an elevated RF power. This result means that the crystallinity of GZO is improved as the RF power increases. The resistivity of GZO rapidly decreases as the RF power increases up to 70 W and saturates to 90W. In contrast, the electron concentration of GZO increases as the RF power increases up to 70 W and saturates to 90W. GZO thin film shows the lowest resistivity of $2.2{\times}10^{-4}{\Omega}cm$ and the highest electron concentration of $1.7{\times}10^{21}cm^{-3}$ at 90W. The mobility of GZO increases as the RF power increases since the grain boundary scattering decreases due to the reduced density of the grain boundary at a high RF power. The transmittance of GZO thin films in the visible range is above 90%. GZO is a feasible transparent electrode for application as a transparent electrode for thin film solar cells.

• 대한화학회지
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• 제61권2호
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• pp.57-64
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• 2017

Monoclinic $VO_2(M)$ nanoparticles codoped with 1.5 at. % W and 2.9 at. % Mg were synthesized by the hydrothermal treatment and post-thermal transformation method of $V_2O_5-H_2C_2O_4-H_2O$ with $Na_2WO_4$ and $Mg(NO_3)_2$. The composite thin film of the W/Mg-codoped $VO_2(M)$ with a commercial acrylic block copolymer was also prepared on PET substrate by wet-coating method. The reversible phase transition characteristics of the codoped $VO_2(M)$ nanoparticles and the composite film were investigated from DSC, resistivity and Vis-NIR transmittance measurements compared with the undoped and Wdoped $VO_2(M)$ samples. Mg-codoping into W-doped $VO_2(M)$ nanoparticles synergistically enhanced the transition characteristics by increasing the sharpness of transition while the transition temperature ($T_c$) lowered by W-doping was maintained. The codoped composite film showed the prominently enhanced NIR switching efficiency compared to only W-doped $VO_2(M)$ film with a lowered $T_c$.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 Techno-Fair 및 추계학술대회 논문집 전기물성,응용부문
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• pp.117-118
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• 2008

The $V_{1.85}W_{0.15}O_5$ thin films deposited on Pt/Ti/$SiO_2$/Si substrates by RF sputtering method exhibited fairly good TCR and dielectric properties. It was found that film crystallinity, dielectric properties, and TCR properties were strongly dependent upon the annealing temperature. The dielectric constants of the $V_{1.85}W_{0.15}O_5$ thin films annealed at $400^{\circ}C$ were 38.11, with a dielectric loss of 1%, respectively. Also, the TCR values of the $V_{1.85}W_{0.15}O_5$ thin films annealed at $400^{\circ}C$ were about -3.45%/K.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1248-1249
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• 2008

The $V_{1.8}W_{0.2}O_5$ thin films deposited on $Pt/Ti/SiO_2/Si$ substrates by RF sputtering method exhibited fairly good TCR and dielectric properties. It was found that film crystallinity, dielectric properties, and TCR properties were strongly dependent upon the annealing temperature. The dielectric constants of the $V_{1.8}W_{0.2}O_5$ thin films annealed at 400$^{\circ}C$ were 38.11, with a dielectric loss of 0.134, respectively. Also, the TCR values of the $V_{1.8}W_{0.2}O_5$ thin films annealed at 400$^{\circ}C$ were about -3.15%/K.

• E2M - 전기 전자와 첨단 소재
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• 제7권2호
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• pp.117-122
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• 1994

The role of ZnS buffer layer not only suppresses chemical reactions between emission material and insulating material but also alters the luminescence and the crystallinity of the emission layer, if ZnS buffer layer was sandwiched between emission layer and insulating layer of electroluminescent device. In this research, we fabricated ZnS thin film with rf magnetron sputter system by varying rf power 100, 200W, substrate temperature 100, 150, 200, 250.deg. C and post-annealing temperature 200, 300, 400, 500.deg. C and analysed X-ray diffraction pattern, transmission spectra and cross section by SEM photograph for seeking the optimal crystallization condition of ZnS buffer layer. As a result, increasing the rf power, the crystallinity of ZnS thin film was improved. It was found that the ZnS thin film had better properties than anything else when fabricated with the following conditions ; rf power 200W, substrate temperature 150.deg. C, and post-annealing temperature 400.deg. C. ZnS thin film had the transmittance more than 80% in visible range. So it is suitable to use as a buffer layer of electroluminescent devices.

• 센서학회지
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• 제19권3호
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• pp.197-201
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• 2010

This paper describes the fabrication and characteristics of a NO sensor using ZnO thin film integrated 3C-SiC micro heater based on polycrystalline 3C-SiC thin film of operation in harsh environments. The sensitivity, response time, and operating properties in high temperature and voltages of NO sensors based SiC MEMS are measured and analyzed. The sensitivity of device with pure ZnO thin film at the heater operating power of 13.5 mW ($300^{\circ}C$) is 0.875 in NO gas concentration of 0.046 ppm. In the case of Pt doping, the sensitivity of at power consumption of 5.9 mW ($250^{\circ}C$) was 1.92 at same gas flow rate. The ZnO with doped Pt was showed higher sensitivity, lower working temperature and faster adsorption characteristics to NO gas than pure ZnO thin film. The NO gas sensor integrated SiC micro heater is more strength than others in high voltage and temperature environments.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2008년도 High Temperature Superconductivity Vol.XVIII
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• pp.51-51
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• 2008

• E2M - 전기 전자와 첨단 소재
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• 제8권1호
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• pp.13-20
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• 1995

To develope a high precision TiAIN thin film resistor, TiAIN films were deposited on A1$_{2}$03 substrates by reactive planar magnetron cosputtering from Ti and Al targets in an Ar-N$_{2}$ atmosphere. The characteristics of the TiAIN thin film were controlled by changing of the R.F. power on Ti and Al targets, and the N$_{2}$ partial pressure. The high precision TiAIN thin film resistor with TCR(Temperature Coefficient of Resistance) of less than 10ppm/.deg. C was obtained under the R.F. power condition of 160(w)/240(w) to Ti and Al targets at the N$_{2}$ partial pressure of 7*10$^{-5}$ Torr. The composition of these films were investigated by XRD, SEM and EDS.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1997년도 추계학술대회 논문집
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• pp.343-346
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• 1997

This paper presents the basic characteristics of Cr thin-film, which were deposited on glass by DC magnetron sputtering. The optimized deposition condition of Cr thin-film strain gauges were input power 7w/cm$^2$and the Ar working pressure was 9mtorr. GF(Gauge Factor), TCR(Temperature Coefficient of Resistance) and TCS(Temperature Coefficient of Sensitivity) of Cr thin-film strain gauges were 5.86, 400 ppm/$^{\circ}C$ and 0 ppm/$^{\circ}C$, respectively.

• 한국자기학회지
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• 제15권2호
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• pp.130-132
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• 2005

Tungsten carbon nitride (W-C-N) thin films were produced by reactive radio frequency (RF) magnetron sputter-ing of tungsten in $Ar-N_2$ gas mixture. The effects of the variation of nitrogen partial pressure on the composition, and structural properties of these films as well as the influence of post-deposition annealing have been studied. When $La_{0.67}Sr_{0.33}MnO_3$ was coated on the W-C-N/Si substrate, coercivity ($H_c$) and magnetization at room temperature shows 58.73 Oe, and 29.4 emu/cc, respectively. In order to improve the diffusion barrier characteristics, we have studied the impurity behaviors to control the ratios of nitrogen and carbon concentrations.