• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.10 no.12
• /
• pp.2251-2257
• /
• 2006

We fabricated ZnO thin film successfully by using RF magnetron sputtering and investigated its potential for being utilized as the key material of piezoelectric device with the characterization of ZnO thin film such as such as crystallinity, surface morphology, c-axis orientation, film density. In thin study, $Ar/O_2$ gas ratio is fixed 70/30, RF power 125W, working pressure 8mTorr, distance between substrate and target 70mm, but the substrate temperature is varied from room temperature to $400^{\circ}C$. The relative intensity ($I_{(002)}/I_{(100)}$) or (002) peak in ZnO thin film deposited at $300^{\circ}$ was exhibited as 94%, then its FWHM was $0.571^{\circ}C$. Also, from the surface morphology evaluated by SEM and AFM, the film deposited at $300^{\circ}C$ showed uniform particle shape and excellent surface roughness of 4.08 m. The tendency of ZnO thin film density was exhibited to be denser with increasing substrate temperature but slightly decreased at near $400^{\circ}C$.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2011.10a
• /
• pp.21.1-21.1
• /
• 2011

Vertically aligned single-crystal ZnO nanowires have been successfully grown on c-plane sapphire substrate using chemical vapor deposition (CVD) without catalyst. According to growth temperatures, it was changed ZnO growth characteristic. We investigated the effect of substrate temperatures on the growth ZnO films or nanowires on c-plane (0001) sapphire substrates. The ZnO films were acquired at $500^{\circ}C$, whereas the ZnO nanowires were obtained at $600^{\circ}C$, $700^{\circ}C$, and $800^{\circ}C$. The growth behavior diameter and growth rate of ZnO were changed due to different temperature. As a result of analyzing in-plane residual stress by X-ray diffraction, the optimized condition of ZnO nanowires were at $600^{\circ}C$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.07b
• /
• pp.880-883
• /
• 2003

ZnO thin films for Film Bulk Acoustic Resonator(FBAR) were prepared by FTS (Facing Target Sputtering) system. The FTS methode enable to generate high density plasma, and it has a high deposition rate at 1mTorr pressure. Therefore, the ZnO thin films were deposited on $AZO/SiO_2/Si$ substrates with oxygen gas flow rate, and the other sputtering conditions were fixed such as a sputtering current of 0.8A, a substrate temperature at room temperature. AZO bottom electrode were deposited on $SiO_2/Si$ substrate and by Zn:Al(Al:2wt%) metal target. ZnO thin film thickness and the c-axis preferred orientation of ZnO thin film were evaluated by ${\alpha}-step$ and XRD.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.23 no.1
• /
• pp.78-84
• /
• 2009

In this paper, ZnO:Al thin film was deposited on polyethylene terephthalate(PET) substrate by capacitively coupled r. f. magnetron sputtering method from a ZnO target mixed with 2wt[%] Al2O3 to investigate the possible application of ZnO:Al film as a transparent conducting electrode for film typed DSCs. The effect of substrate bias on the electrical properties and film structure were studied. The results showed that a positive bias applied to the substrate during sputtering contributed to an improvement of electrical properties of the film by attracting electrons in the plasma to bombard the growing films. These bombardments provided additional energy to the growing ZnO:Al film on the substrate, resulting in significant variations in film structure and electrical properties. Electrical resistivity of the film decreases significantly as the positive bias increases up to +30[V] However, as the positive bias increases over +30[V], the resistivity decreases. The transmittance varies little as the substrate bias is increased from 0 to +60[V], and as r. f. powers increases from 160[W] to 240[W]. The film with electrical resistivity as low as $1.8{\times}10^{-3}[{\Omega}-cm]$ and optical transmittance of about 87.8[%] were obtained for 1,012[nm] thick film deposited with a substrate bias of +30[V].

• Korean Journal of Materials Research
• /
• v.4 no.1
• /
• pp.90-96
• /
• 1994

ZnO thin films were deposited using Diethylzinc and $N_{2}O$ gas by plasma enhanced CVD (PECVD) at low substrate temperatures below $300^{\circ}C$. The effect of deposition parameters on the growth rate and the structural properties was determined at various deposition conditions. Crystallized ZnO thin films were successfully deposited even at $150^{\circ}C$ of substrate temperature. Above $200^{\circ}C$ c-axis oriented ZnO thin films, of which a standard deviation of X-ray rocking curve was less than $6^{\circ}$. were deposited on glass substrates. The variation of deposition rate showed different trends depending on substrate temperature and rf-input power. According to the deposition rate behavior as a function of substrate temperature, the transition points were observed resulting from crystallization of ZnO thin films. The activation energies for the deposition of ZnO thin films were 3.1KJ/mol and 1.9KJ/mol for the rf powers of 200W and 250W, respectively.

• KIEE International Transactions on Electrophysics and Applications
• /
• v.3C no.6
• /
• pp.241-245
• /
• 2003

ZnO thin films on (l00) p-type Si and sapphire substrates have been deposited by a pulsed laser deposition technique using an Nd:YAG laser with a wavelength of 266 nm. The influence of the deposition parameters such as oxygen pressure, substrate temperature and laser energy density on the properties of the grown films was studied. The experiments were performed for substrate temperatures in the range of 200∼50$0^{\circ}C$ and oxygen pressure in the range of 100∼700 sccm. All of the films grown in this experiment show strong c-axis orientation with (002) textured ZnO peak. With increasing substrate temperature, the FWHM (full width at half maximum) and surface roughness were decreased. In the case of using sapphire substrate, the intensity of PL spectra increased with increasing ambient oxygen flow rate. We investigated the structural and morphological properties of ZnO thin films using X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.07a
• /
• pp.151-152
• /
• 2005

ZnO films were deposited on MgO substrates (ZnO/MgO) by ultrasonic spray pyrolysis. Substrate temperature varied from $250^{\circ}C$ to $350^{\circ}C$. The crystallographic properties and surface morphologies of the ZnO/MgO films were studied by X ray diffraction and scanning electron microscopy. The properties of photoluminescence (PL) for the films were investigated by dependence of PL spectra on the substrate temperature and the annealing temperature. The ZnO/MgO films prepared at $350^{\circ}C$ showed the strongest UV emission peak at 18 K and 300 K among the films in this study.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.17 no.7
• /
• pp.738-746
• /
• 2004

Recently zinc oxide(ZnO) has emerged as one of the most promising transparent conducting films with a strong demand of low cost and high performance optoelectronic devices, ZnO film has many advantages such as high chemical and mechanical stabilities, and abundance in nature. In this paper, in order to obtain the excellent transparent conducting film with low resistivity and high optical transmittance for Plasma Display Pannel(PDP), aluminium doped zinc oxide films were deposited on Corning glass substrate by dc magnetron sputtering method. The effects of the discharge power and doping amounts of $Al_2$$O_3$ on the electrical and optical properties were investigated experimentally. Particularly in order to lower the electrical resistivity, positive and negative bias voltages were applied on the substrate, and the effect of bias voltage on the electrical properties of ZnO:Al thin film were also studied and discussed. Films with lowest resistivity of $4.3 \times 10 ^{-4} \Omega-cm$ and good transmittance of 91.46 % have been achieved for the films deposited at 1 mtorr, $400^{\circ}C$, 40 W, Al content of 2 wt% with a substrate bias of +30 V for about 800 nm in film thickness.

• Korean Journal of Crystallography
• /
• v.7 no.2
• /
• pp.175-182
• /
• 1996

ZnO thin films were deposited on Corning 7059 glass substrates to study fundamental properties of films. According to the experimental results, (002) preferred ZnO thin films were grown by purging Ar/O2 mixed gas, but not without oxygen gas. The structure and the orientation of ZnO thin films were much affected by the substrate temperature and rf power. High quality ZnO films were obtained by increasing their values. Optimum deposition parameters were : 300W rf power, 300℃ substrate temperature, Ar/O2=70/30. To characterize SAW propagation properties, IDT was fabricated by etching Al films deposited on diamond/Si wafer with RIE. Measured λ(wavelength) was 24μm and experimental results were well matched with simulation. Center frequency was 250MHz, and the calculated phase velocity of ZnO/ diamond structure was about 6000m/s.

• Journal of Sensor Science and Technology
• /
• v.14 no.5
• /
• pp.362-367
• /
• 2005

ZnO films were deposited on MgO substrates (ZnO/MgO) by ultrasonic spray pyrolysis. Substrate temperature varied from $250^{\circ}C$ to $350^{\circ}C$. The crystallographic properties and surface morphologies of the ZnO/MgO films were studied by X-ray diffraction and scanning electron microscopy. The properties of photoluminescence (PL) for the films were investigated by dependence of PL spectra on the substrate temperature and the annealing temperature. The ZnO/MgO films prepared at $350^{\circ}C$ showed the strongest Ultraviolet light emission peak at 18 K and 300 K among the films in this study. The annealing process increases the visible light emission, which is due to the increased oxygen vacancies.