REACTIVE-FLOW SIMULATION ON THE GROWTH OF CVD DIAMOND

Abstract

열-필라멘트 화학증착법(HFCVD)에 의해 생성된 다이아몬든의 성장에 관하여 2차원 반응유동 전산모사를 수행하였다. 모델식은 질량, 운동량, 에너지 및 각 화학종들의 보존식을 적절한 경계조건으로 결합하였다. 이 결합된 편미분방정식들을 수치적으로 풀어서 반응기내의 가스속도, 온도 및 가스상의 농도분포를 결정하였다. 이 모델로부터 HFCVD계에서 다이아몬드 성장의 전구체로 알려진 CH₃의 생산량에 미치는 CH₄-원료가스- 의 농도와 필라멘트온도의 영향을 조사하였다. 그 결과 예측된 화학종들의 농도는 이전의 실험으로 직접 측정된 값들과 잘 일치하였고 또한 CH₃의 농도는 CH₄의 농도와 필라멘트의 온도에 비례하여 증가한다는 것을 알았다. 이것은 다이아몬드의 성장속도 역시 메탄의 농도와 필라멘트의 온도에 비례하여 증가한다는 것을 의미한다.

Two-dimensional reactive-flow simulations on the growth of diamond in a hot-filament chemical vapor deposition (HFCVD) system were carried out. The model combines equations of the conservation of mass, momentum, energy and chemical species with appropriate boundary conditions. The coupled partial different5ial equations were solved numerically to determine the gas velocity, temperature and gas-phase composition profiles in a reactor. The model was then used to investigate the effects of CH₄-source gas- concentration and the filament temperature on the production of CH₃that is known as the diamond precursor in HFCVD system. From the result, the predicted chemical species concentration are well agreed with previously measured experimental values and the concentration of CH₃is shown to increase with increasing CH₄concentration and the filament temperature. This means that the growth rate of diamond increases also at highter CH₄comcentration and he filament temperaue.

Two-dimensional reactive-flow simulations on the growth of diamond in a hot-filament chemical vapor deposition (HFCVD) system were carried out. The model combines equations of the conservation of mass, momentum, energy and chemical species with appropriate boundary conditions. The coupled partial different5ial equations were solved numerically to determine the gas velocity, temperature and gas-phase composition profiles in a reactor. The model was then used to investigate the effects of CH₄-source gas- concentration and the filament temperature on the production of CH₃that is known as the diamond precursor in HFCVD system. From the result, the predicted chemical species concentration are well agreed with previously measured experimental values and the concentration of CH₃is shown to increase with increasing CH₄concentration and the filament temperature. This means that the growth rate of diamond increases also at highter CH₄comcentration and he filament temperaue.