電感偶合式氬氣及四氟甲烷電漿反應器之二維模型研究與電漿診斷

2-D Modeling and Plasma Diagnostics of Inductive-Coupled Ar and CF4 Plasma Reactor

許聖鑫(Shang-Sin Hsu)

指導教授 ： 魏大欽

中原大學/工學院/化學工程研究所/碩士(2004年)

https://doi.org/10.6840/cycu200400556

摘要

本研究針對Ar與CF4建立電感偶合式高密度電漿反應器之二維模型，利用計算流體力學軟體計算求解，探討操作參數(電漿功率、操作壓力)對電子密度及電子溫度之影響。再進一步探討反應器中電子、離子及自由基在不同參數下之徑向濃度變化，且更改反應器之設計(如線圈與介電層設計、腔體大小)，探討其對電漿均勻度之影響。此外，藉由CF4零維電漿模型之敏感性分析，明瞭CF4電漿之主要反應機構，亦利用靜電式探針量測電子密度及電子溫度，將量測值與模型計算值比較，討論模型間之差異及準確性。
在Ar電漿方面：功率增加，電子密度增高，但均勻度下降；壓力增加時，對於電子密度及均勻度皆有提升。反應器設計影響上，發現將線圈與介電層傾斜，可增加電漿密度及其均勻度；提升腔體高度將會有較高電漿密度及較佳電漿均勻度，而腔體半徑放大，需同時增加電漿功率及增加線圈圈數，以提升電漿密度及電漿均勻度。
在CF4電漿方面：低壓與低功率時有較佳之電漿均勻度，但電子密度皆較低。功率上升，自由基與正離子濃度增加，而負離子濃度減少；壓力上升，自由基與負離子濃度增加，而正離子濃度減少。反應物種中以自由基濃度最高，且基材上方徑向濃度變化最為均勻，而帶電粒子均勻度受電子分佈影響則較明顯。

關鍵字

電漿、電漿模擬、氬氣、四氟甲烷、反應器設計

並列摘要

In this study, a two-dimensional planar inductively coupled plasma reactor model was established to calculate the variations of the electron, ion, and radical concentration of Ar and CF4 plasma at the substrate surface as a function of the rf power, pressure, coil design and chamber geometry. Langmuir probe was used to measure the radial profiles of electron density and temperature and the data were compared with model results.
In the Ar model, as power increases, the electron density increases but the radial uniformity decreases; while pressure increases, electron density and its radial uniformity increase. The sloping of coil and the dielectric layer is useful in improving the plasma uniformity but the electron density is decreased. The plasma density and uniformity increase as a result of the increase of chamber height. In order to provide high plasma density and uniformity, as increasing the chamber radius, the rf power and the number of coil turns must be increased at the same time.
In the CF4 model, the uniformity increases but the electron density decreases at low power and low pressure. The densities of radical and positive ion increase with the power, but the negative ion density decrease with power. With the increasing pressure, the densities of radical and negative ion increase, but positive ion decreases. About radial concentration profile, the positive ion is more uniform than other species.

並列關鍵字

model ； reactor design ； argon ； carbon tetrafluoride ； plasma

參考文獻

楊智超 〝高密度氯氣電漿應用於氮化鎵材料蝕刻製程之模型研究〞, 私立中原大學碩士論文(2002).

Abdollahi-Alibeik S., J. P. McVittie, and K. C. Sarawat, J. Vac. Sci. Technol. A 17, 2485 (1999).

Abraham-Shauner B., and C. D. Wang, J. Electrochem. Soc. 143, 672 (1996).

Abraham-Shauner B., IEEE Trans. Plasma Sci. 25, 433 (1997).

Abraham-Shauner B., J. Vac. Sci. Technol. B 17, 158 (1999).