射频感性耦合Ar/O₂等离子放电特性模拟研究

Study on Discharge Characteristics of Radio-Frequency Inductively Coupled Ar/O₂ Plasma

摘要: 感性耦合等离子体(Inductively Coupled Plasma, ICP)处理是半导体及相关领域的重要支撑技术，本研究针对实际工艺中常用的感性耦合Ar/O₂放电建立二维流体模型，研究不同气压(10~50 mTorr)和线圈功率(300~1200 W)下的放电特性。结果表明，随着气压的升高，各活性粒子的密度峰值从腔室中心逐渐向线圈方向移动，其中电子与O原子密度都显著提升，但$O_2^{+}$ 密度先上升后下降。线圈功率增大推动电子密度与角向电场协同增长，导致Ar⁺、$O_2^{+}$ 密度持续上升，而亚稳态$O_2^{\text{a}}$ 密度峰值呈现先不变后缓慢变化的趋势，并且其密度峰值从腔室中心向腔室边缘移动。本研究揭示了气压与功率对等离子体粒子密度及空间分布的调控机制，为工业大面积ICP应用的参数优化提供了理论依据。

Abstract: Inductively Coupled Plasma (ICP) processing is a key enabling technology in the semiconductor industry and related fields. In this study, a two-dimensional fluid model is developed for Ar/O₂ ICP discharges under typical industrial process conditions to investigate the discharge characteristics at varying gas pressures (10–50 mTorr) and coil powers (300~1200 W). The results show that as the gas pressure increases, the peak densities of all active species gradually shift from the chamber center toward the coil region. Specifically, the densities of electrons and oxygen atoms increase significantly, whereas the $O_2^{+}$ density first rises and then declines. Increasing the coil power promotes the synergistic growth of electron density and azimuthal electric field, leading to a continuous increase in the densities of Ar⁺ and $O_2^{+}$ . In contrast, the peak density of metastable $O_2^{\text{a}}$ remains nearly unchanged at lower powers and then varies slowly at higher powers, while its peak position shifts from the chamber center toward the chamber edge. This study elucidates the regulatory mechanisms of gas pressure and coil power on the densities and spatial distributions of plasma species, providing a theoretical foundation for parameter optimization in large-area industrial ICP applications.