• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2018.06a
• /
• pp.57-57
• /
• 2018

Zinc-oxide (ZnO), II-VI semiconductor with a wide and direct band gap (Eg: 3.2~3.4 eV), is one of the most potential candidates to substitute for ITO due to its excellent chemical, thermal stability, specific electrical and optoelectronic property. However, the electrical resistivity of un-doped ZnO is not low enough for the practical applications. Therefore, a number of doped ZnO films have been extensively studied for improving the electrical conductivities. In this study, Ti-doped ZnO films were successfully prepared by atomic layer deposition (ALD) techniques. ALD technique was adopted to careful control of Ti doping concentration in ZnO films and to show its feasible application for 3D nanostructured TCO layers. Here, the structural, optical and electrical properties of the Ti-doped ZnO depending on the Ti doping concentration were systematically presented. Also, we presented 3D nanostructured Ti-doped ZnO layer by combining ALD and nanotemplate processes.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2009.10a
• /
• pp.428-430
• /
• 2009

C-axis-oriented ZnO thin films were successfully deposited on p-Si (100) in an RF magnetron sputtering system. Deposition conditions such as deposition power, working pressure, and oxygen gas ratio were varied. Crystalline structures of the deposited ZnO films were investigated by a scanning electron microscope (SEM) technique. Results show that the deposition parameters can have a strong impact on the preferred orientations and grain sizes of the deposited ZnO films.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2000.11a
• /
• pp.324-327
• /
• 2000

ZnO(Zinc Oxide) thin films were deposited on glass substrate by Facing Targets Sputtering. Facing Targets Sputtering system can deposit thin films in plasma-free situation and change the sputtering conditions in wide range. The characteristics of ZnO thin films deposited at variation of sputtering conditions films thickness, power and substrate temperature were evaluated by XRD(x-ray diffractometer), ${\alpha}$-step (Tencor). The excellently c-axis oriented ZnO thin films were obtained at sputter pressure ImTorr, power 150W, substrate temperature 200$^{\circ}C$. In these conditions, the rocking curve of ZnO thin films deposited on glass was 3.3$^{\circ}$.

• Journal of the Korean Ceramic Society
• /
• v.35 no.1
• /
• pp.17-22
• /
• 1998

B-doped ZnO thin films on glass substrates were prepared by sputtering the ceramic targets which had been prepared by sintering disks consisting of ZnO and various amounts of B2O3 While pure ZnO films show-ed a c-axis oriented growth the B-doping retarded the prefered orientation and grain growth of the film. Electron concentrations for undoped and B-doped ZnO films were on the order of 7.8${\times}$1018 cm-3 and 5${\times}${{{{ {10 }^{20 } }} c{{{{ {m }^{-3 } }} respectively. The electron mobility however decreased with the B-doping concentration. Optical meas-urements on the films showed that the average transmittance in the visible range was higher than 85% The measurements also indicated a blueshift of the absorption edge with doping.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.25 no.12
• /
• pp.1219-1227
• /
• 2014

For development of the surface acoustic wave bandpass filter(SAW-BPF), we fabricated the high quality ZnO thin films through the step-by-step(double) deposition using two different deposition methods which are pulsed laser deposition(PLD) and RF sputtering techniques. The second growth of ZnO thin films was completed by RF sputtering method on the first ZnO thin films pre-deposited by PLD method. The characteristics of ZnO thin films were analyzed by XRD, SEM and AFM systems. The FWHM of ${\omega}$-scan analysis and the minimum RMS value of surface roughness of step-by-step grown ZnO thin films were $0.79^{\circ}$ and 1.108 nm respectively. As a result, the crystallinity and the preferred orientation of the grown ZnO thin films were kept good quality and the surface roughnesses of those were improved by post-annealing process as comparison with ZnO thin film fabricated by the conventional PLD technique only. Using these proposed ZnO thin films, we demonstrated the RF device such as SAW-BPF, built by the proposed ZnO thin films, shows that it has the bandwidth of 2.98 MHz and the insertion loss of 36.5 dB at the center frequency of 260.8 MHz, respectively.

• Korean Journal of Materials Research
• /
• v.16 no.7
• /
• pp.445-448
• /
• 2006

Highly c-axis oriented ZnO thin films were grown on Si(100)substrates with Zn buffer layers. Effects of the Zn buffer layer thickness on the structural and optical qualities of ZnO thin films were investigated using X-ray diffraction (XRD), photoluminescence (PL) and Atomic force microscopy (AFM) analysis techniques. It was confirmed that the quality of a ZnO thin film deposited by rf magnetron sputtering was substantially improved by using a Zn buffer layer. The highest ZnO film quality was obtained with a Zn buffer layer 110 nm thick. The surface roughness of the ZnO thin film increases as the Zn buffer layer thickness increases.

• Journal of the Korean institute of surface engineering
• /
• v.39 no.6
• /
• pp.250-254
• /
• 2006

Effect of hydrogen partial pressure ratio on the structural and electrical properties of highly c-axis oriented ZnO films deposited by oxygen ion-assisted pulsed filtered vacuum arc at a room temperature was investigated. The hydrogen partial pressure ratio were $1.4%\sim9.8%$ at 40% oxygen pressure ratio. The conductivity of ZnO:H films was increased from 1.4% up to 4.2% due to relatively high carrier mobility caused by improvement of crystallinity While the conductivity of ZnO:H films were decreased over than 4.2% and (0002) orientation was also deteriorated. The lowest resistivity of ZnO:H films was $2.5{\times}10^{-3}\;{\Omega}{\cdot}cm$ at 4.2% of hydrogen pressure ratio. Transmittance of ZnO:H films in visible range was 85% which is lower than that of undoped ZnO films because of declined preferred orientation.

• KIEE International Transactions on Electrophysics and Applications
• /
• v.5C no.3
• /
• pp.97-101
• /
• 2005

ZnO thin films were grown at different plume-substrate (P-S) angles of 90$^{\circ}$ (on-axis PLD), 45$^{\circ}$ and 0$^{\circ}$ (off-axis PLD) using pulsed laser deposition. The x-ray diffraction pattern exhibiting a dominant (002) and a minor (101) peak of ZnO indicates all films were strongly c-axis oriented. By observing of (002) peak, the FWHMs of ZnO (002) peaks decreased and c-axis lattice constant approached the value of bulk ZnO as P-S angle decreased. Whereas the carrier concentration of ZnO thin film deposited at P-S angle of 90$^{\circ}$ was ~ 10$^{19}$ /cm$^{3}$, the Hall measurement of ZnO thin films deposited at P-S angles of 0$^{\circ}$ and 45$^{\circ}$ was impossible due to the decrease of the carrier concentration by the improvement of stoichiometry and crystalline quality. By decreasing P-S angle, the grain size of the films and the UV intensity investigated by photoluminescence (PL) increased and UV peak position showed red shift. The improvement of properties in ZnO thin films deposited by off-axis technique was due to the decrease of repulsive force between a substrate and the particle in plume and the relaxation of supersaturation.

• Transactions on Electrical and Electronic Materials
• /
• v.14 no.4
• /
• pp.208-210
• /
• 2013

ZnO films were deposited on glass substrates by radio frequency (RF) magnetron sputtering and exposed to intense electron beam irradiation to investigate the effects of electron irradiation on the properties of the films. Although all of the films had ZnO (002) textured structure regardless of electron irradiation, the grain sizes of the films decreased with electron irradiation. Surface roughness also depended on electron irradiation. The surface roughness varied between 2.3 and 1.6 nm, depending on the irradiation energy. Based on photoluminescence (PL) characterization, the most intense UV emission was observed from ZnO films irradiated at 900 eV. Since the intensity of UV emission is dependent upon the stoichiometric of ZnO films, we conclude that 900 eV was the optimum electron irradiation energy to achieve the best stoichiometric of ZnO films in this study.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1994.11a
• /
• pp.129-133
• /
• 1994

$ZnO_{x}$ films were deposited by conventional thermal evaporation method. Zinc acetate was used as precursor. XRD and SEM results shows films as mixed stats of ZnO and zinc acetate. And EDX measurements reseal composition of films as $ZnO_{x}$.