• Korean Journal of Materials Research
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• v.7 no.6
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• pp.505-509
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• 1997

FRAM(Ferroelectric Random Access memory)에의 응용을 위해 rf magnetron sputtering법을 이용하여 SrB $i_{2}$T $a_{2}$ $O_{9}$(SBT)박막을 증착하였다. 사용된 기판은 Pt/Ti/Si $o_{2}$Si이었으며 50$0^{\circ}C$에서 증착한 후 80$0^{\circ}C$의 산소 분위기 하에서 1시간 동안 열처리하였다. 증착시 증착 압력을 변화시켜 가면서 이에 따른 특성의 변화를 고찰하였다. 박막내의 Bi와 Sr의 부족을 보상하기 위해 20mole%의 Bi $O_{2}$와 30mole%의 SrC $O_{3}$를 과잉으로 넣어 타겟을 제조후 사용하였고 박막들의 두께는 300nm의 두께를 가지며 증착압력에 따라 다른 미세 구조르 보였다. 10mtorr에서 증착한 박막의 조성은 S $r_{0.6}$B $i_{3.8}$Ta/ sub 2.0/ $O_{9.0}$이었다. 이 SBT 박막의 잔류 분극(2 $P_{r}$)과 보전계(2 $E_{c}$)값은 각각 인가 전압 5V에서 18.5 $\mu%C/$\textrm{cm}^2$과 150kV/cm이었고, signal/noise비는 3V에서 4.6을 나타내었다. 5V의 bipolar pulse하에서 $10^{10}$cycle까지 피로 현상이 나타나지 않았으며, 누설 전류 밀도는 133kV/cm에서 약 1x$10^{-7A}$$\textrm{cm}^2$의 값을 보였다.을 보였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.88-92
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• 2003

In this paper, the characteristics of the ZnO films deposited on AI bottom electrode and the temperature effects on the ZnO film growth are presented along with the fabrication and their evaluation of the film bulk acoustic wave resonator (FBAR) devices. All the films used in this work were deposited using a radio-frequency (RF) magnetron sputtering technique. Growth characteristics of the ZnO films are shown to have a strong dependence on the deposition temperatures ranged from room temperature to 35$0^{\circ}C$ regardless of the RF power applied for sputtering the ZnO target. In addition, according to the growth characteristics of the distinguishably different micro-crystal structures and the degree of the c-axis preferred orientation, the deposition temperatures can be divided into 3 temperature regions and 2 critical temperatures in-between. Overall, the ZnO films deposited at/below 20$0^{\circ}C$ are seen to have columnar grains with a highly preferred c-axis orientation where the full width at half maximum (FWHM) of X-ray diffraction rocking curve is 14$^{\circ}$. Based on the experimental findings, several FBAR devices were fabricated and measured. As a result, the FBAR devices show return loss of ~19.5dB at resonant frequency of ~2.05GHz.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.382-382
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• 2012

CIGS thin films have received great attention as a promising material for solar cells due to their high absorption coefficient, appropriate bandgap, long-term stability, and low cost production. CIGS thin films are deposited by various methods such as co-evaporation, sputtering, spray pyrolysis and electro-deposition. The deposition technique is one of the most important processes in preparing CIGS thin film solar cells. Among these methods, co-evaporation is one of the best technique for obtaining high quality and stoichiometric CIGS films. However, co-evaporation method is known to be unsuitable for commercialization. The sputtering is known to be very effective and feasible process for mass production. In this study, CIGS thin films have prepared by rf magnetron sputtering using a $Cu(In_{1-x}Ga_x)Se_2$ single quaternary target without post deposition selenization. This process has been examined by the effects of deposition parameters on the structural and compositional properties of the films. In addition, we will explore the influences of substrate temperature and additional annealing treatment after deposition on the characteristics of CIGS thin films. The thickness of CIGS films will be measured by Tencor-P1 profiler. The crystalline properties and surface morphology of the films will be analyzed using X-ray diffraction and scanning electron microscopy, respectively. The optical properties of the films will be determined by UV-Visible spectroscopy. Electrical properties of the films will be measured using van der Pauw geometry and Hall effect measurement at room temperature using indium ohmic contacts.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.11
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• pp.2385-2390
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• 2009

N-doped ZnO thin films with c-axis preferred orientation were prepared on p-Si(100) wafers, using an RF magnetron sputter deposition. For ZnO deposition, $N_2O$ gas was employed as a dopant source and various deposition conditions such as $N_2O$ gas fraction and RF power were applied. The depth pofiles of the nitrogen [N] atoms incorporated into the ZnO thin films were investigated by Auger Electron Spectroscopy(AES) and the nano-scale structural characteristics of the N-doped ZnO thin films were also investigated by a scanning electron microscope (SEM) technique.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.5
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• pp.361-366
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• 1999

The life of AC PDP depends largely on the sputtering-resistant property of the protecting layer such as MgO thin-film. However, it is very difficult to measure the sputtering-resistant property in the stable driving conditions of AC PDP. In this paper we have suggested a high speed measurement technique of the sputtering-resistant property of MgO thin-film by applying the MgO thin-film as the target of RF magnetron sputtering system. We have also applied this method to the e-beam MgO and sputter-MgO and e-beam MgO superior to sputter-MgO 3 times over. Also, the relation of Xe gas partial pressure(X) and sputtered thickness(Y) was Y=3.4X+13.5.

• Transactions on Electrical and Electronic Materials
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• v.1 no.2
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• pp.28-31
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• 2000

BaTiO$_3$cerameic thin films doped with Mn were manufactured by rf/dc magnetron sputter technique. We have investigated crystal structure, surface morphology and PRCR(positive-temperature coefficient of resistance) characteristics of the specimen depending on second heat-treatment temperature. Second heat treatment of the specimen were performed in the temperature range of 400 to 1350$\^{C}$ X-ray diffraction patterns of BaTiO$_3$ thin films show that the specimen heat treated below 600$\^{C}$ is an amorphous phase and the one heat treated above 1100$\^{C}$ forms a poly-crystallization . In this specimen heat-treated at 1300$\^{C}$, a lattice constant ratio(c/a) was 1.188. Scanning electron microscope(SEM) image of BaTiO$_3$ thin films of the specimen heat treated in between 900 and 1100$\^{C}$ shows a grain growth. At 1100$\^{C}$, the specimen stops grain-growing and becomes a poly-crystallization . A resistivity-temperature characteristics of the specimen depends on the doping concentrations of Mn. A resistivity ratio between the value at room temperature and the one above Curie temperature was 10$^4$ for pure BaTiO$_3$ thin films and 10$\^$5/ fo BaTiO$_3$ : additive 0.127mol% MnO

• Journal of the Korean institute of surface engineering
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• v.29 no.5
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• pp.563-569
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• 1996

Degradation of $Zn_3N_2$ films is studied by using several analytical techniques. Polycrystalline $Zn_3N_2$ films prepared by reactie rf magnetron sputtering are kept in the air. Electrical and optical properties are measured by using van der Pauw technique and double-beam spectrometry. Structure and chemical bonding states are studied by X-ray diffraction(XRD), Fourier transfer infrared ray spectroscopy(FT-IR) and X-ray photoelectron specroscopy (XPS). Significant differences are observed in optical properties between the degraded film and the ZnO film. XRD analysis reveals that the degraded film contains very small ZnO grains because very weak and broad ZnO peaks are observed. XPS and FT-IR measurements reveal the formation of $Zn(OH)_2$ in the degraded film. The existence of N-H bonds in degraded films is exhibited from the N 1s spectra. $Zn_3N_2$ change into the mixture of ZnO, $Zn(OH)_2$ and an ammonium salt.

• Journal of the Korean Ceramic Society
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• v.35 no.7
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• pp.733-739
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• 1998

C-axis oriented zinc oxide thin films were deposited on Cornign 1737 glass substrate by an rf magnetron sputtering technique. The effects of deposition parameters and post heat-treatment on the crystallinity and electical properties of ZnO films were investigaed. As-deposited ZnO films showed the strong c-axis growth and excellent crystallinity under the deposition conditions as follows: substrate temperature 350$^{\circ}C$ ; growth and excellent crystallinity under the deposition conditions as follows ; substrate temperature 350$^{\circ}C$ rf power 75W ; gas pressure 6m Torr; percentage of oxygen 50% The higher heat-treating temperatue was the stronger c-axis growth and the better crystallinity of the deposited ZnO films were. The resistivity of ZnO films was significantly affected by deposition parameters and post heat-treatment. With increasing increased. After post heat-treating at 400$^{\circ}C$ in air the resistivity of ZnO films increased but post heat-treat-ing temperature 500$^{\circ}C$ rather diminished the film resistivity.

• Journal of Sensor Science and Technology
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• v.4 no.2
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• pp.51-57
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• 1995

Indium Tin Oxide (ITO) thin films have been fabricated by the rf magnetron sputtering technique with a target of a mixture $In_{2}O_{3}$ (90mol%) and $SnO_{2}$ (10mol%). We prepared ITO thin films with substrate temperature 100, 200, 300, 400, $500^{\circ}C$ and post-annealing temperature 300, 400, $500^{\circ}C$. And we analyzed X -ray diffraction patterns, electrical properties, transmission spectra and SEM photographs. As a result, the crystallinity, electrical conductivity and transmittance of ITO thin films were improved with increasing substrate temperature. But, as increasing post-annealing temperature in air, conductivity of the film was decreased. When the ITO thin film was fabricated with substrate temperature of $500^{\circ}C$ and thickness of $3000{\AA}$, its resistivity and transmittance were about $2{\times}10^{-4}{\Omega}cm$ and 85% or more, respectively.

• Bulletin of the Korean Chemical Society
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• v.30 no.11
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• pp.2729-2734
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• 2009

We report here the surface behavior of zirconium oxide deposited on Si(100) substrate depending on the different substrate temperatures. The zirconium oxide thin films were successfully deposited on the Si(100) surfaces applying radio-frequency (RF) magnetron sputtering process. The obtained zirconium oxide films were characterized by X-ray photoelectron spectroscopy (XPS) for study about the chemical environment of the elements, X-ray diffraction (XRD) for check the crystallinity of the films, spectroscopic ellipsometry (SE) technique for measuring the thickness of the films, and the morphology of the films were investigated by atomic force microscope (AFM). We found that the oxidation states of zirconium were changed from zirconium suboxides ($ZrO_{x,y}$, x,y < 2) (x; higher and y; lower oxidation state of zirconium) to zirconia ($ZrO_2$), and the surface was smoothed as the substrate temperature increased.