• Proceedings of the Korean Vacuum Society Conference
• /
• 2015.08a
• /
• pp.123-123
• /
• 2015

Al doped ZnO(AZO) films as a transparent conductive oxide (TCO) electrode were deposited on glass, polyethylene naphthalate (PEN) and polyethylene terephthalate (PET) at room temperature by a conventional rf-magneton sputtering (CMS) and a facing target sputtering (FTS) using Al2O3 and ZnO targets. In order to investigation of AZO properties, the structural, surface morphology, electrical, and optical characteristics of AZO films were respectively analyzed. The resistivities of AZO films using FTS system were $6.50{\times}10-4{\Omega}{\cdot}cm$ on glass, $7.0{\times}10-4{\Omega}{\cdot}cm$ on PEN, and $7.4{\times}10-4{\Omega}{\cdot}cm$ on PET substrates, while the values of AZO films using CMS system were $7.6{\times}10-4{\Omega}{\cdot}cm$ on glass, $1.20{\times}10-3{\Omega}{\cdot}cm$ on PEN, and $1.58{\times}10-3{\Omega}{\cdot}cm$ on PET substrates. The AZO-films deposited by FTS system showed uniform surface compared to those of the films by CMS system. We thought that the films deposited by FTS system had low stress due to bombardment of high energetic particles during CMS process, resulted in enhanced electrical conductivity and crystalline quality by highly c-axis preferred orientation and closely packed nano-crystalline of AZO films using FTS system.

• Journal of the Korean institute of surface engineering
• /
• v.43 no.4
• /
• pp.194-198
• /
• 2010

Indium doped zinc oxide films (ZIO) were deposited on non-alkali glass substrates by radio frequency (RF) magnetron sputtering at room temperature. The structural, electrical and optical properties of the ZIO films were investigated as a function of their $In_2O_3$ content (3.33-15.22 wt%). The ZIO films deposited with an $In_2O_3$ content of 9.54 wt% showed a relatively low resistivity of $9.13{\times}10^{-4}{\Omega}cm$ and a highly c-axis preferred orientation. The grain size and FWHM were mainly affected by the $In_2O_3$ content. The crystallinity and resistivity were enhanced with increasing grain size. The average transmittance of the ZIO films was over 85% in the visible region and their band gap varied from 3.22 to 3.66 eV depending on their doping ratio.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.11 no.7
• /
• pp.541-545
• /
• 1998

(PZT, PST, PT)/ YBCO structured have been grown on single crystal $LaAlO_3$ using in-situ Nb:YAG pulsed laser deposition technique. The optimum conditions of fabrication for high quality films have been established under various oxygen pressure. TBCO was used as a metallic electrode for polarizing ferroelectric thin fillms. Lattice mismatch of these materials were found to be with in 3%. As a result XRD patterns and rocking curves, (PZT, PST, PT)/ YBCO multiayered thin films on $LaAlO_3$ substrates showed preferred orientation to c-axis. For invastigation on electrical properties of ferroelectric thin films, remanent polaiztion $P_r$ and coercive field $E_c$ were measured for three samples. At each optimum condition, they showed the values of P_r=60 \mu C/cm^2 and E_c=240kV/ cm for PT, 30\mu C/cm^2 and 105kV/cm for PZT, 1.5\mu C/cm^2$ and 15kV/cm for PST. Frequency dependence of dielectric properties of ferroelectric thin fillms was also investigated. As a result, it showed the frequency dependence was relatively small in the range of 10Hz~10kHz.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.05c
• /
• pp.124-130
• /
• 2003

Zinc Oxide(ZnO) thin films on Si (100) substrate were deposited by RF magnetron sputter with changing sputtering conditions such as argon/oxygen gas ratios, RF power, and substrate temperature, chamber pressure and target-substrate distance. To analyze a crystallographic properties of the films, $\theta/2\theta$ mode X-ray diffraction, SEM, and AFM analyses. C-axis preferred orientation, resistivity. and surface roughness highly depended on $Ar/O_2$ gas ratios. The resistivity of ZnO thin films rapidly increased with increasing oxygen ratio and the resistivity value of $9{\times}10^7{\Omega}cm$ was obtained at a working pressure of 10 mTorr with $Ar/O_2$=50/50. The surface roughness was also improved with increasing oxygen ratio and the ZnO films deposited with $Ar/O_2$=50/50 showed the excellent roughness value of $28.7{\AA}$.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2016.02a
• /
• pp.169-169
• /
• 2016

In this paper, we report electrical, optical and structural properties of Al-doped zinc oxide (AZO) thin films deposited at different substrate temperatures and pressures. The films were prepared by radio frequency (RF) magnetron sputtering on glass substrates in argon (Ar) ambient. The X-ray diffraction analysis showed that the AZO films deposited at room temperature (RT) and 20 Pa were mostly oriented along a-axis with preferred orientation along (100) direction. There was an improvement in resistivity ($3.7{\times}10^{-3}{\Omega}-cm$) transmittance (95%) at constant substrate temperature (RT) and working pressure (20 Pa) using the Hall-effect measurement system and UV-vis spectroscopy, respectively. Our results have promising applications in low-cost transparent electronics, such as the thin-film solar cells and thin-film transistors due to favourable deposition conditions. Furthermore our film deposition method offers a procedure for preparing highly oriented (100) AZO films.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.11b
• /
• pp.463-466
• /
• 2001

In recent year, Ferroelectric $BLT(Bi_{4-x}La_{x}Ti_{3}O_{12})$ is a promising candidate materials. This study was practiced to make good conditions of BL T targets. In this study, calcination and sintering temperature were kept at $750^{\circ}C$, $1100^{\circ}C$ for 2 hour respectively. the density obtained 7.612, 7.98, $7.877g/cm^{3}$ as $La_{2}O_{3}$ contents were 0.0mol%, 0.25mol%, 0.5mol%. Especially, the lanthanum content of 0.5 mol% measured C-axis (117) preferred orientation more than the others targets in the XRD. In $\varepsilon_{r}-f$ relationship using by HP 4194 A impedance analyzer, the 0.5 mol% observed above 200 relative dielectric constant. but the dissipation factor was higher than others targets at 100Hz~13MHz range. SEM photograph with the content of $La_{2}O_{3}$ was observed like rod and plate types.

• Journal of the Korean institute of surface engineering
• /
• v.42 no.3
• /
• pp.122-127
• /
• 2009

Ga/Al doped ZnO (GAZO) thin films were prepared on non-alkali glass substrate by co-sputtering system using two DC cathodes equipped with AZO ($Al_2O_3$:2.0 wt%) target and GZO ($Ga_2O_3$:6.65 wt%) target. This study examined the influence of Al/Ga concentration and substrate temperature on the electrical, structural and optical properties of GAZO films. The lowest resistivity $1.95{\times}10^{-3}{\Omega}cm$ was obtained at room temperature. With increasing substrate temperature, resistivity of GAZO film decreased to a minimum value of $7.47{\times}10^{-4}{\Omega}cm$ at below $300^{\circ}C$. Furthermore, when 0.05% $H_2$ gas was introduced, resistivity of GAZO film decreased to $6.69{\times}10^{-4}{\Omega}cm$. All the films had a preferred orientation along the (002) direction, indicating that the deposited films have hexagonal wurtzite structure formed by the textured growth along the c-axis. The average transmittance of the films was more than 85% in the visible light range.

• Journal of the Semiconductor & Display Technology
• /
• v.9 no.4
• /
• pp.77-81
• /
• 2010

The AZO thin films were deposited on the corning 1737 glass plate by the RF magnetron sputtering and effects of working pressure and oxygen contents on the electrical properties were investigated. XRD spectra showed a preferred orientation along the c-axis and a minimum FWHM for the 70mTorr. From the surface analysis (AFM), the number of crystal grain of AZO thin film increased as working pressure increased. The film deposited with 70mTorr of working pressure showed n-type semiconductor characteristic having suitable resistivity $-1.59{\times}10^{-2}{\Omega}cm$, carrier concentration $-10.1{\times}10^{19}cm^{-3}$, and mobility $-4.35cm^2V^{-1}s^{-1}$ while other films by 7 mTorr, 20 mTorr of working pressure closed to metallic films. The films including the oxygen represent stoichiometric composition similar to the oxide. The transmittance of the film was over 85% in the visible light range regardless of the changes in working pressure and oxygen contents.

• Journal of the Korean Ceramic Society
• /
• v.28 no.8
• /
• pp.585-592
• /
• 1991

ZnO films were deposited onto Corning glass 7059 substrate in the temperature range from $200^{\circ}C$ to $450^{\circ}C$ by chemical vapor deposition technique using the hydrolysis of Diet ylzinc (DEZ). As the deposition temperature increased from $200^{\circ}C$ to $350^{\circ}C$, the deposition rate increased with the apparent activation energy of ∼23kJ/mole. Further increase of the deposition temperature above $400^{\circ}C$, however, resulted in a reduction of the rate. It was found that ZnO film grew with a strong C-axis preferred orientation at the temperature of $400^{\circ}C$. As the deposition temperature increased, the film resistivity decreased down to ∼0.2 $\Omega$cm at $450^{\circ}C$. The electrical resistivity was governed more likely by electron concentration rather than by electron mobility. Average optical transmission of the films in the optical wavelength range of 400 nm to 900 nm was over 90% and the optical energy band gap of 3.28∼3.32 eV was obtained from the direct transition.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.11a
• /
• pp.463-466
• /
• 2001

In recent year, Ferroelectric BLT($Bi_{4-x}$La$_{x}$Ti$_3$O$_{12}$) is a promising candidate materials. This study was Practiced to make good conditions of BLT targets. In this study, calcination and sintering temperature were kept at 75$0^{\circ}C$, 110$0^{\circ}C$ for 2 hour respectively. the density obtained 7.612, 7.98, 7.877 g/㎤ as La$_2$O$_3$ contents were 0.0mol%, 0.25mo1%, 0.5mol%. Especially, the lanthanum content of 0.5 mol% measured C-axis (117) preferred orientation more than the others targets in the XRD. In $\varepsilon$$_{r}$-f relationship using by HP 4194 A impedance analyzer, the 0.5 mol% observed above 200 relative dielectric constant. but the dissipation factor was higher than others targets at 100Hz~13MHz range. SEM photograph with the content of La$_2$O$_3$ was observed like rod and plate types.types.s.