Journal of the Korean Vacuum Society (한국진공학회지)

The Korean Vacuum Society (한국진공학회)
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Numerical Investigation of Ion and Radical Density Dependence on Electron Density and Temperature in Etching Gas Discharges

식각공정용 가스방전에서 이온 및 활성종 밀도의 전자밀도 및 온도 의존성에 대한 수치해석적 분석

  • An, Choong-Gi (School of Electrical Engineering, Chungbuk National University) ;
  • Park, Min-Hae (School of Electrical Engineering, Chungbuk National University) ;
  • Son, Hyung-Min (School of Electrical Engineering, Chungbuk National University) ;
  • Shin, Woo-Hyung (School of Electrical Engineering, Chungbuk National University) ;
  • Kwon, Deuk-Chul (Convergence Plasma Research Center, National Fusion Research Institute) ;
  • You, Shin-Jae (Center for Vacuum Technology, Korea Research Institute for Standard and Science) ;
  • Kim, Jung-Hyung (Center for Vacuum Technology, Korea Research Institute for Standard and Science) ;
  • Yoon, Nam-Sik (School of Electrical Engineering, Chungbuk National University)
  • Received : 2011.07.25
  • Accepted : 2011.11.01
  • Published : 2011.11.30
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Abstract

Dependence of radical and ion density on electron density and temperature is numerically investigated for $Cl_2$/Ar, $CF_4$, $CF_4/O_2$, $CF_4/H_2$, $C_2F_6$, $C_4F_8$ and $SF_6$ discharges which are widely used for etching process. We derived a governing equation set for radical and ion densities as functions of the electron density and temperature, which are easier to measure relatively, from continuity equations by assuming steady state condition. Used rate coefficients of reactions in numerical calculations are directly produced from collisional cross sections or collected from various papers. If the rate coefficients have different values for a same reaction, calculation results were compared with experimental results. Then, we selected rate coefficients which show better agreement with the experimental results.

식각공정에 주로 사용되는 $Cl_2$/Ar, $CF_4$, $CF_4/O_2$, $CF_4/H_2$, $C_2F_6$, $C_4F_8$, 그리고 $SF_6$ 가스 방전에서 이온, 중성종 및 활성종 밀도의 전자밀도와 온도에 대한 의존성을 수치해석적으로 분석하였다. 이온, 중성종 및 활성종 밀도에 대한 공간평균 유체방정식을 정상상태로 가정하여 상대적으로 측정이 용이한 전자밀도와 온도에 대한 식으로 표현하였고, 이 식을 수치해석적인 방법으로 풀었다. 계산에 사용된 반응계수들은 여러 문헌에서 수집되거나 산란단면적으로부터 계산되었고, 같은 반응에 대해 다른 값을 보일 경우, 계산 결과를 실험 결과와 비교하여 높은 일치도를 보이는 값이 선택되었다.

Keywords

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