• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.1 s.92
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• pp.40-48
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• 2005

In this paper, we explore the inductively coupled concept and propose a class of electrically small planar antennas. The antennas are optimized using NEC in conjunction with a Pareto GA. These antennas show good efficiency and bandwidth performance without any additional matching network. Several optimized designs are fabricated and measured. We explain the operating principle of these antennas using a simple lumped element circuit model. The proposed antennas are translated as printed lines on Duroid for RFID tag antennas.

• KIEE International Transactions on Electrophysics and Applications
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• v.2C no.5
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• pp.246-252
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• 2002

Two-dimensional steady state simulations of planar type radio frequency inductively coupled plasma (RFICP) have been performed. The characteristics of RFICP were investigated in terms of power transfer efficiency, equivalent circuit analysis, spatial distribution of plasma density and electron temperature. Plasma density and electron temperature were determined from the equations of ambipolar diffusion and energy conservation. Joule heating, ionization, excitation and elastic collision loss were included as the source terms of the electron energy equation. The electromagnetic field was calculated from the vector potential formulation of ampere's law. The peak electron temperature decreases from about 4eV to 2eV as pressure increases from 5 mTorr to 100 mTorr. The peak density increases with increasing pressure. Electron temperatures at the center of the chamber are almost independent of input power and electron densities linearly increase with power level. The results agree well with theoretical analysis and experimental results. A single turn, edge feeding antenna configuration shows better density uniformity than a four-turn antenna system at relatively low pressure conditions. The thickness of the dielectric window should be minimized to reduce power loss. The equivalent resistance of the system increases with both power and pressure, which reflects the improvement of power transfer efficiency.

• Transactions on Electrical and Electronic Materials
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• v.11 no.5
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• pp.202-205
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• 2010

In this study, the etch properties of $Al_2O_3$ thin films deposited by atomic layer deposition were investigated as a function of the $O_2$ content in $BCl_3$/Ar inductively coupled plasma. The experiments were performed by comparing the etch rates and selectivity of $Al_2O_3$ over the hard mask materials as functions of the input plasma parameters, such as the gas mixing ratio, DC-bias voltage, ratio-frequency (RF) power and process pressure. The highest obtained etch rate was 477 nm/min at an RF power of 700 W, $O_2$ to $BCl_3$/Ar gas ratio of 15%, DC-bias voltage of -100 V and process pressure of 15 mTorr. The deposition occurred on the surfaces when the amount of $O_2$ added to the $BCl_3$/Ar gas was too high at a low DC-bias voltage or high process pressure. X-ray photoelectron spectroscopy was used to investigate the chemical reactions on the etched surface.

• Transactions on Electrical and Electronic Materials
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• v.9 no.1
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• pp.1-5
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• 2008

ZnS is an attractive material for future optical and electrical devices since it has a direct and wide band gap to provide blue emission at room temperature. In this study, inductively coupled $BCl_3/Ar$ plasma was used to etch ZnS:Mn thin films. The maximum etch rate of 164.2 nm/min for ZnS:Mn was obtained at a $BCl_3(20)/Ar(80)$ gas mixing ratio, an rf power of 700 W, a dc bias voltage of -200V, a total gas flow of 20 sccm, and a chamber pressure of 1Pa. The etch behaviors of ZnS:Mn thin films under various plasma parameters showed that the ZnS:Mn were effectively removed by the chemically assisted physical etching mechanism. The surface reaction of the ZnS:Mn thin films was investigated by X-ray photoelectron spectroscopy. The XPS analysis revealed that Mn had detected on the surface ZnS:Mn etched in $BCl_3/Ar$ plasma.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.5
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• pp.560-566
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• 2004

In this paper, the electrical and emission properties of electrodeless fluorescent lamp were discussed using the inductively coupled plasma (ICP) with the variation of argon gas pressure and RF power. The RF output was applied to the antenna in the range of 5∼50 W at 13.56 MHz. The internal plasma voltage of the chamber and the probe current were measured while varying the supply voltage to the Langmuir probe in the range of －100V∼＋100V. When the pressure of argon gas was increased, electric current was decreased. There was a significant electric current increase from 10 to 30 W. Also, when the RF power was increased, electron density was increased. Also, the emission spectrum, Ar- I lins, luminance were investigated. At this time, the input parameter for ICP RF plasma, Ar gas pressure and RF power were applied in the range of 10∼60 mTorr, 10∼300 W, respectively. This implies that this method can be used to find an optimal RF power for efficient light illumination in an electrodeless fluorescent lamp.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.65-66
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• 2005

Etching characteristics of $Ge_2Sb_2Te_5$ (GST) films were investigated using $Cl_2$/Ar inductively coupled plasma.We examined the etching characteristics such as etching rate and selectivity over oxide films of GST films using inductively coupled plasma (ICP) with various etching parameters such as $Cl_2$/Ar gas mixing ratios, ICP source power, pressure, and bias power. The maximum etch rate of GST film was $2,815{\AA}$/min and the selectivity higher than 12:1 over the oxide films was also obtained at the $Cl_2$ flow rates of 40 sccm.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.400-403
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• 2003

Etching characteristics of (Pb,Sr)$TiO_3$(PST) thin films were investigated using inductively coupled chlorine based plasma system as functions of gas mixing ratio, RF power and DC bias voltage. It was found that increasing of Ar content in gas mixture lead to sufficient increasing of etch rate and selectivity of PST to Pt. The maximum etch rate of PST film is $562\;{\AA}$/min and the selectivity of PST film to Pt is 0.8 at $Cl_2/(Cl_2+Ar)$ of 20 %. It was proposed that sputter etching is dominant etching mechanism while the contribution of chemical reaction is relatively low due to low volatility of etching products.

• Journal of the Korean institute of surface engineering
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• v.41 no.4
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• pp.134-141
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• 2008

We have developed a numerical model for a remote ICP(inductively coupled plasma) system in 2D and 3D with gas distribution configurations and confirmed it by plasma diagnostics. The ICP source has a Cu tube antenna wound along a quartz tube driven by a variable frequency rf power source($1.9{\sim}3.2$ MHz) for fast tuning without resort to motor driven variable capacitors. We investigated what conditions should be met to make the plasma remotely localized within the quartz tube region without charged particles' diffusing down to a substrate which is 300 mm below the source, using the numerical model. OES(optical emission spectroscopy), Langmuir probe measurements, and thermocouple measurement were used to verify it. To maintain ion current density at the substrate less than 0.1 $mA/cm^2$, two requirements were found to be necessary; higher gas pressure than 100 mTorr and smaller rf power than 1 kW for Ar.

• Journal of Korean Society for Atmospheric Environment
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• v.8 no.3
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• pp.155-161
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• 1992

A simple, fast yet sensitive method is described for the determination of fifty elements in coal by inductively coupled plasma mass spectrometry. The method involves complete dissolution of coal with mixed acid $(HNO_3, HF, HClO_4)$ in hish pressure Teflon bomb and subsequent inductively coupled plasma mass spectrometric(ICP-MS) measurement. The accuracy of the method, being evaluated by the analysis of NIST SRMs (1632a, 1632b) is better than 20% RSD for most elements. The limits of detection defined by two times $\sigma$ (standard deviation of operational blank) are in order of sub-ppm to ppm, which are low enough to quantitate most elements. However, the determiantions for few elements such as V, As, Se are severely interfered by molecular ions such that their accurate determiantions are not possible. Analytical results for twentyon coals from eight countries including six ones world major coal producing, Korea, Japan, China, I.C.S., U.S.A., Canada, Australia, and South Africa are presented. While the results for major elements agree well with the existing ones, those for a few trace elements disagree considerably. The existing values are considerably higher. It is not possible to judge which are more accurate. However, the exisisting values are more likely to be errorous inasmuch as they are obtained without using high purity reagents and clean laboratory techniques.

• Transactions on Electrical and Electronic Materials
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• v.8 no.6
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• pp.229-233
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• 2007

In this study, we carried out an investigation of the etching characteristics(etch rate, selectivity) of $HfO_2$ thin films in the $CH_4/Ar$ inductively coupled plasma. It was found that variations of input power and negative dc-bias voltage are investigated by the monotonic changes of the $HfO_2$ etch rate as it generally expected from the corresponding variations of plasma parameters. At the same time, a change in either gas pressure or in gas mixing ratio result in non-monotonic etch rate that reaches a maximum at 2 Pa and for $CH_4(20%)/Ar(80%)$ gas mixture, respectively. The X-ray photoelectron spectroscopy analysis showed an efficient destruction of the oxide bonds by the ion bombardment as well as showed an accumulation of low volatile reaction products on the etched surface. Based on these data, the ion-assisted chemical reaction was proposed as the main etch mechanism for the $CH_4-containing$ plasmas.