• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.628-631
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• 2004

A tetrafluoromethane$(CF_4)$ is most useful gas in plasma dry etching, because it has a electron attachment cross-section. therefor it is important to calculate transport coefficients like electron drift velocity, ionization coefficient, attachment coefficient, effective ionization coefficient. and critical E/N. The aim of this study is to get these transport coefficients for information of the insulation strength and efficiency of etching process. Electron transport coefficients in $CF_4+Ar$ gas mixture are simulated in range of E/N values from 1 to 250 [Td] at 300[K} and 1 [Torr] by using Boltzmann equation method. The results of this method can be important data to present characteristic of gas for plasma etching and insulation, specially critical E/N is a data to evaluate insulation strength of a gas. and is presented in this paper for various mixture ratios of $CF_4+Ar$ gas mixture.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.8
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• pp.634-639
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• 2001

We investigated the etching characteristics of chromium films by using Cl$_2$/O$_2$ gas mixtures with electron cyclotron resonance plasma. In order to examine the chemical etch characteristics of Cr films by using Cl$_2$/O$_2$ gas plasma, we obtained the etch rate with various gas mixing ratios. By X-ray photoelectron spectroscopy, the surface reaction on the chromium films during the etch was examined. From narrow scan analyses of Cr, Cl, and O, it was confirmed that a chromium oxychlorie (CrCl$_{x}$O$_{y}$) layer was formed on the surface by the etch using Cl$_2$/O$_2$ gas mixtures. We observed a new characteristic emission line during the etch of chromium films using Cl$_2$/O$_2$ gas mixtures by an optical emission spectroscopy. It was found that the peak intensity of this emission line had a tendency compatible with the etch rate. The origin of this emission line was discussed in detail. At the same time, the etched profile was also examined by scanning electron microscope.e.e.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.5
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• pp.405-410
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• 2006

We fabricated gas sensors using carbon nanotubes (CNTs) as electron emitters for the purpose of detecting inert gases. By using the silicon-glass anodic bonding and glass patterning technologies with the typical Si process, we improved the compactness of the sensors and the reliability in process. The proposed sensor, based on, an electrical discharge theory known as Paschen's law in principle, works by figuring the variation of the discharge current depending on gas concentration. In the experiment, the initial breakdown characteristics were measured for air and Ar as a function of gas pressure. As the result, even though it should be realized that there are many other factors which have an effect on the breakdown of a gap, the sensors led to similar result as predicted by Paschen's law, and they showed a possibility as gas sensors which enable to detect the gas density ranged to the vacuum pressure from 1 to $10^{-3}$ Torr.

• Applied Microscopy
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• v.45 no.4
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• pp.195-198
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• 2015

Gas-assisted etching (GAE) with focused ion beam (FIB) was applied to prepare plan-view specimens of Cu thin-layer on a silicon substrate for transmission electron microscopy (TEM). GAE using $XeF_2$ gas selectively etched the silicon substrate without volume loss of the Cu thin-layer. The plan-view specimen of the Cu thin film prepared by FIB milling with GAE was observed by scanning electron microscopy and $C_S$-corrected high-resolution TEM to estimate the size and microstructure of the TEM specimen. The GAE with FIB technique overcame various artifacts of conventional FIB milling technique such as bending, shrinking and non-uniform thickness of the TEM specimens. The Cu thin film was uniform in thickness and relatively larger in size despite of the thickness of <200 nm.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.1102-1105
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• 2003

Energy distribution function for electrons in $SF_6$-Ar mixtures gas used by MCS-BEq algorithm has been analysed over the E/N range $30{\sim}300[Td]$ by a two term Boltzmann equation and by a Monte Carlo Simulation using a set of electron cross sections determined by other authors, experimentally the electron swarm parameters for 0.2(%) and 0.5(%) $SF_6$-Ar mixtures were measured by time-of-flight(TOF) method, The results show that the deduced electron drift velocities, Electrons Drift Velocities for a rang of E/N values. As a consequence, it was known that the spatial growth rates and the dielectric behaviors in $SF_6$-Ar mixtures are strongly dependent on the addition rate of $SF_6$ gas but the transport coefficients of electrons are insensitive to the addition rate of $SF_6$ gas. The results obtained from Boltzmann equation method and Monte Carlo simulation have been compared with present and previously obtained data and respective set of electron collision cross sections of the molecules.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.12a
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• pp.91-95
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• 2006

In whole world consciousness of environment maintenance have increased very quickly for the end of the 20th century. To use and disuse toxic substances have been controled at the field of industry. Also the field of lighting source belong to environmental control. And in the future the control will be strong. In radiational mechanism of fluorescence lamp mercury is the worst environmental problem. In radiational mechanism of fluorescence lamp mercury is the worst environmental problem root. In the mercury free lighting source system the Xe gas lamp is one type. And the Ne:Xe mixing gas lamp improvements firing voltage of Xe gas lamp. Purpose and subject of this study are understand, efficiency, ideal of Ne:Xe plasma which mercury free lamp. Before ICP was designed, basic parameters of plasma, which are electron temperature and electron density, were measured and calculated by langmuir probe data. Property of electron temperature and electron density were confirmed by changing ratio of Ne:Xe.

• Electrical & Electronic Materials
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• v.8 no.6
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• pp.685-692
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• 1995

The electron transport coefficients in argon gas is studied over the range of E/N values from 85 to 566 Td by the Monte Carlo method considering the latest cross section data. The result of the Monte Carlo method analysis shows that the value of the electron transport coefficients such as the electron drift velocity, the ratio of the longitudinal and transverse diffusion coefficients to the mobility. It is also found that the electron transport coefficients calculated by the two-term approximation analysis agree well with those by Monte Carlo calculation. The electron energy distributions function were analysed in argon at E/N=283, and 566 Td for a case of the equilibrium region in the mean electron energy. A momentum transfer cross section for the argon atom which was consistent with both of the present electron transport coefficients was derived over the range of mean electron energy from 10.3 to 14.5 eV, also suggested as a set of electron cross section for argon atom. The validity of the results obtained has been confirmed by a Monte Carlo simulation method.

• Proceedings of the KIEE Conference
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• 1990.07a
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• pp.459-461
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• 1990

Me performed an experiment about preionization electron number density of charge transfer type KrF excimer laser. At the total pressure of 1.8 and 2.2 atm with helium (He) buffer gas, the experimental range of the electron number density is 8-9 ${\times}$ 10 cm The distance between electrode and preionization pin is 15 mJ at charging voltage of 27kV,gas pressure of 2.2 atm,gas mixture of F /Kr/He = 0.3/396.7(%).

• Journal of the Korean Society for Heat Treatment
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• v.24 no.2
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• pp.87-91
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• 2011

Single layer Sn doped $In_2O_3$ (ITO) films and ITO 50 nm / Au 10 nm / ITO 40 nm (IAI) multilayer films were prepared with electron beam assisted magnetron sputtering on glass substrates. The effects of the Au interlayer, post-deposition atmosphere annealing and intense electron irradiation on the methanol gas sensitivity were investigated at room temperature. As deposited ITO films did not show any diffraction peaks in the XRD pattern, while the IAI films showed the diffraction peak for $In_2O_3$ (400). In this study, the gas sensitivity of ITO and IAI films increased proportionally with the methanol vapor concentration and an intense electron beam irradiated IAI film shows the higher sensitivity than the others film. From the XRD pattern, it is supposed that increased crystallization promotes the gas sensitivity. This approach is promising in gaining improvement in the performance of IAI gas sensors used for the detection of methanol vapor at room temperature.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.7
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• pp.1211-1217
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• 2016

Discharge characteristics of inductively coupled plasma were investigated by using electrostatic probe and fluid simulation. The Inductively Coupled Plasma source driven by 13.56 Mhz was prepared. The signal attenuation ratios of the electrostatic probe at first and second harmonic frequency was tuned in 13.56Mhz and 27.12Mhz respectively. Electron temperature, electron density, plasma potential, electron energy distribution function and electron energy probability function were investigated by using the electrostatic probe. Experiment results were compared with the fluid simulation results. Ar plasma fluid simulations including Navier-Stokes equations were calculated under the same experiment conditions, and the dependencies of plasma parameters on process parameters were well agreed with simulation results. Because of the reason that the more collision happens in high pressure condition, plasma potential and electron temperature got lower as the pressure was higher and the input power was higher, but Electron density was higher under the same condition. Due to the same reason, the electron energy distribution was widening as the pressure was lower. And the electron density was higher, as close to the gas inlet place. It was found that gas flow field significantly affect to spatial distribution of electron density and temperature.