• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.6
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• pp.445-448
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• 2011

In this study, the etching characteristics of $Al_2O_3$ thin films were investigated using an ICP (inductively coupled plasma) of $BCl_3$/Ar gas mixture. The etch rate of $Al_2O_3$ thin films as well as the $SiO_2/Al_2O_3$ etch selectivity were measured as functions of $BCl_3$/Ar mixing ratio (0~100% Ar) at a constant gas pressure (10 mTorr), total gas flow rate (40 sccm), input power (800 W) and bias power (100 W). The behavior of the $Al_2O_3$ etch rate was shown to be quite typical for ion-assisted etch processes with a dominant chemical etch pathway. To analyze the etching mechanism using DLP (double langmuir probe), OES (optical emission spectroscopy) and surface analysis using XPS (x-ray photoelectron spectroscopy) were carried out.

• Journal of the Korean Vacuum Society
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• v.15 no.1
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• pp.89-96
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• 2006

Recent ULSI and multilevel structure trends in microelectronic devices minimize the line width down to less than $0.25{\mu}m$, which results in high current densities in thin film interconnections. Under high current densities, an EM(electromigration) induced failure becomes one of the critical problems in a microelectronic device. This study is to improve thin film interconnection materials by investigating the EM characteristics in Ag, Cu, Au, and Al thin films, etc. EM resistance characteristics of Ag, Cu, Au, and Al thin films with high electrical conductivities were investigated by measuring the activation energies from the TTF (Time-to-Failure) analysis. Optical microscope and XPS (X-ray photoelectron spectroscopy) analysis were used for the failure analysis in thin films. Cu thin films showed relatively high activation energy for the electromigration. Thus Cu thin films may be potentially good candidate for the next choice of advanced thin film interconnection materials where high current density and good EM resitance are required. Passivated Al thin films showed the increased MTF(Mean-time-to-Failure) values, that is, the increased EM resistance characteristics due to the dielectric passivation effects at the interface between the dielectric overlayer and the thin film interconnection materials.

• Journal of the Korean Vacuum Society
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• v.19 no.3
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• pp.206-210
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• 2010

Al-doped ZnO thin films were deposited with various Ar flow rate by RF magnetron sputtering, and theire properties were studied. A high-quality thin film was obtained by controlling the Ar flow rate, and the influence of the Ar flow rate on the Al-doped ZnO thin film was confirmed. In all Al-doped ZnO thin films, light transmittance had above 80%. Through Hall measurement and X-ray photoelectron spectrometer, the sample of 60 sccm, which had the lowest resistivity, showed the lower Al concentration. This result was attributed to oxygen vacancy rather than Al concentration.

• Journal of the Korean Vacuum Society
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• v.9 no.4
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• pp.411-418
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• 2000

$Al_2O_3$ thin films of 300 nm thickness were deposited at room temperature using DC reactive sputtering with variation of the $O_2$ content in the sputtering gas from 30% to 70%. Regardless of the $O_2$ content in the sputtering gas, the sputtered $Al_2O_3$ films were amorphous and exhibited the refractive index of 1.58. When the $O_2$ content in the sputtering gas was higher than 50%, the $Al_2O_3$ films exhibited excellent transmittance of about 98% at 550 nm wavelength. However, the transmittance decreased to about 94% for the $Al_2O_3$ films deposited with the sputtering gas of the 30% and 40% $O_2$contents. The optimum dielectric properties (dielectric constant of 10.9 and loss tangent of 0.01) was obtained for the $Al_2O_3$ film deposited with the sputtering gas of the 50% $O_2$ content. When the $O_2$ content in the sputtering gas was within 40% to 60%, the $Al_2O_3$ films exhibited no shift of flatband voltage $V_{FB}$ in C-V curves and exhibited leakage current density lower than $10^{-5}\textrm{A/cm}^2$ at 150 kV/cm.

• Journal of information and communication convergence engineering
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• v.5 no.3
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• pp.219-222
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• 2007

Highly conductive and transparent aluminum doped ZnO thin films (AZO) films have been prepared by r.f. magnetron sputtering processes on poly carbonate (PC) and onto glass as reference. In addition, the electrical, optical properties of the films prepared at various sputtering powers were investigated. The XRD measurements revealed that all of the obtained films were polycrystalline with the hexagonal structure and had a preferred orientation with the c-axis perpendicular to the substrate. The ZnO:Al films were increasingly dark gray colored as the sputter power increased, resulting in the loss of transmittance. High quality films with the resistivity as low as $9.7{\times}10^{-4}\;{\Omega}-cm$ and transmittance over 90% have been obtained by suitably controlling the r.f. power.

• Journal of the Korean Ceramic Society
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• v.41 no.6
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• pp.476-480
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• 2004

AZO (Al-doped ZnO) thin films were deposited on glass by pulsed magnetron sputtering method, and their structural, electrical and optical properties were investigated. XRD patterns showed that a highly c-axis preferred AZO film was grown in perpendicular to the substrate when pulse frequency of 30 ㎑ was applied to the target. Microstructure of thin films showed that the fibrous grain of tight dome shape was grown. The deposition rate decreased linearly with increase of pulse frequency, and the lowest resistivity was 8.67${\times}$10$\^$-4/ $\Omega$-cm for the film prepared at pulse frequency of 30 ㎑. The optical transmittance spectra of the films showed a very high transmittance of 85∼90%, within visible wavelength region and exhibited the absorption edge of about 350 nm. The characteristics of the low electrical resistivity and high optical transmittance of AXO films suggested a possibility for the application to transparent conducting oxides.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.14 no.6
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• pp.277-280
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• 2004

p-ZnO films have been grown on (0001) sapphire substrates by RF-DC magnetron co-sputtering. The p-ZnO single crystalline thin films of the thickness about 120 nm were grown successfully. The dopant (Aluminum) was sputtered simultaneously from Al metal target by DC sputtering during rf-magnetron sputtering of ZnO at the substrate temperatures of $400^{\circ}C$ and $600^{\circ}C$ respectively. The crystallinity and optical properties of as-grown P-ZnO films have been characterized.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.10
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• pp.1782-1785
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• 2007

In this paper, the effect of substrate temperature on structural, electrical and optical properties of aluminium-doped zinc oxide (AZO) films were investigated. AZO thin films were prepared on glass substrate by pulsed DC magnetron sputtering technique. The properties of AZO were measured by using XRD, AFM, UV spectrophotometer, and hall effect measurement system. The resistivity of AZO films was improved under the condition of high substrate temperature. The resistivity decreased from $9.95{\times}10^{-2}\;{\Omega}-cm\;to\;1.1{\times}10^{-3}\;{\Omega}-cm$ as a result of high substrate temperature and the average transmittances in visible range were above 80%.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.725-728
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• 2001

We have fabricated thin films using the DC/RF magnetron sputtering of 74wt%Ni-l8wt%Cr-4wt%Al-4wt%Cu alloy target and studied the effect of the process parameters on the electrical properties for low TCR(Temperature Coefficient of Resistance) films. In sputtering process, pressure, power and substrate temperature, are varied as controllable parameter. The films are annealed to 400$^{\circ}C$ in air and nitrogen atmosphere. The sheet resistance, TCR of the films increases with increasing annealing temperature. It abruptly increased as annealing temperature increased over 300$^{\circ}C$ in air atmosphere. From XRD, it is found that these results are due to the existence of NiO on film surface formed by annealing. As a results of them, TCR can be controlled by variation of sputter process parameter and annealing of thin film.

• Journal of the Optical Society of Korea
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• v.16 no.1
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• pp.76-79
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• 2012

$Tb_3Al_5O_{12}:Ce$ (TAG:Ce) thin films were successfully deposited by a pulsed laser ablation method on a quartz substrate, and low-temperature post-annealing effects on luminescent properties were investigated in detail. TAG:Ce thin films were analyzed by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and photoluminescence spectroscopy. The as-deposited films were amorphous, and post-annealing above $700^{\circ}C$ was required for crystallization. The post-annealed TAG:Ce thin films showed strong and broad emission bands around 542 nm and excitations at 451 nm, which all corresponded to transitions between the 4f ground level to the $5d^1$ excited levels of Ce ion.