• 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 Institute of Electronics Engineers of Korea SD
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• v.41 no.1
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• pp.9-14
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• 2004

In this paper, temperature dependence of effective ionization coefficient in Si is formulated as a single polynomial function of temperature, which allows analytical expressions for breakdown voltage of Si $p^+n$ junction as a function of temperature. The analytical breakdown voltages agree well with the simulation as well as the experimental ones reported within $3\%$ in error for the doping concentrations in the range of $10^{14}cm^{-3}{\~} 10^{17}cm^{-3}$ at 100K, 300K and 500K.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.1
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• pp.44-47
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• 2009

This paper describes the information for quantitative simulation of weakly ionized plasma. We must grasp the meaning of the plasma state condition to utilize engineering application and to understand materials of plasma state. $SF_6$ gas is widely used in industrial of insulation field. In this paper, $N_2$ is mixed to improve pure $SF_6$ gas characteristics. Electron transport coefficients in $SF_6-N_2$ mixture gases are simulated in range of E/N values from 70 to 400 [Td] at 300K and 1 Torr by using Boltzmann equation method. The results of this method. which are ionization coefficient, attachment coefficient, effective ionization coefficient, and critical E/N, can be important data to present characteristic of gas for 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 $SF_6-N_2$ mixture gases.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.4
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• pp.375-380
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• 2005

CF₄ molecular gas is used in most of semiconductor manufacture processing and SF/sub 6/ molecular gas is widely used in industrial of insulation field. but both of gases have defect in global warming. C₃F/sub 8/ gas has large attachment cross-section more than these gases, moreover GWP, life-time and price of C₃F/sub 8/ gas is lower than them, therefor it is important to calculate transport coefficients of C₃F/sub 8/ gas 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 imformation of the insulation strength and efficiency of etching process. In this paper, we calculated the electron drift velocity (W) in pure C₃F/sub 8/ molecular gas over the range of E/N=0.1∼250 Td at the temperature was 300 K and gas pressure was 1 Torr by the Boltzmann equation method. The results of this paper 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.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.9
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• pp.1-9
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• 2004

Analytical expressions for breakdown voltages of abrupt pn junction in GaP, GaAs and InP of III-V binary semiconductors was induced. Getting analytical breakdown voltage, effective ionization coefficients were extracted using ionization coefficient parameters for each materials. The result of analytical breakdown voltages followed by ionization integral agrees well with numerical and experimental results within 10% in error.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.4
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• pp.226-231
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• 1999

Temperature dependence of effective ionization coefficients in GaAs is formulated as a single polynomial function of temperature, which allows analytical expressions for breakdown voltage of GaAs $p^+n$ junctions as a function of temperature. At 300 K, extracted effective ionization coefficient of GaAs $p^+n$ junction especially agrees well with the published result of <111> oriented GaAs. The analytic results agree with the simulation as well as the experimental ones reported within 10% in error for the doping concentrations in the range of $10_{14}cm_{-3}~10_{17}cm_{-3}$ at 100 K, 300 K and 500 K.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.1
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• pp.12-17
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• 2002

In this paper, an effective ionization coefficient for 4H-SiC is extracted in the form of c .E$^{m}$ from ionization coefficients of electron and hole. Analytical expressions for critical electric field and breakdown voltage of 4H-SiC p$^{+}$n junction are derived by employing the effective ionization coefficient. The analytic results agree well with the experimental ones reported within 10% in error for the doping concentration in the range of 10$^{15}$ cm$^{-3}$ ~10$^{18}$ cm$^{-3}$ . .

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.2
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• pp.78-81
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• 2000

The closed-form analytic solutions for the breakdown voltage of 6H-SiC RTD(silicon carbide reachthrough diode) having metal$-n^--n^+$ Schottky structure or $p^+-n^--n^+$, are successfully derived by solving impact ionization integral using an effective ionization coefficient. For the lightly doped n- epitaxial layer, the breakdown voltage of SiC RTD are nearly constant with the increased doping concentration while the breakdown voltages decrease for the heavily doped epitaxial layer.

• 전자공학회논문지 IE
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• v.44 no.1
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• pp.10-14
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• 2007

Analytical expression for breakdown voltages of InP diodes is induced by employing the effective ionization coefficient extracted from ionization coefficients for electron and hole in InP. The analytical results for breakdown voltage are compared with numerical and experimental results for the doping concentration, $N_D=6\times10^{14}cm^{-3}\sim3\times10^{17}cm^{-3}$. The analytical results show good agreement with the numerical data. Good fits with the experimental results are found for the breakdown voltages within 10% in error at each doping concentration.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.60 no.1
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• pp.27-31
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• 2011

In this paper, the electron transport characteristics in $CF_4$ has been analysed over the E/N range 1~300[Td] by a two-term approximation Boltzmann equation method and by a Monte Carlo simulation. The motion has been calculated to give swarm parameters for the electron drift velocity, longitudinal diffusion coefficient, the ratio of the diffusion coefficient to the mobility, electron ionization and attachment coefficients, effective ionization coefficient, mean energy, collision frequency and the electron energy distribution function. The electron energy distribution function has been analysed in $CF_4$ at E/N=5, 10, 100, 200 and 300[Td] for a case of the equilibrium region in the mean electron energy and respective set of electron collision cross sections. The results of Boltzmann equation and Monte Carlo simulation have been compared with experimental data by Y. Nakamura and M. Hayashi. The swarm parameter from the swarm study are expected to serve as a critical test of current theories of low energy electron scattering by atoms and molecules, in particular, as well as crucial information for quantitative simulations of weakly ionized plasmas.