微波等离子体电子回旋共振放电粒子模拟分析

电子回旋共振放电产生的等离子体在微电子工业中材料加工、空间电推进方面有着广泛的应用。为了研究微波等离子体电子回旋共振的放电特性,使电子回旋共振放电产生的等离子体密度和能量转换效率更高,建立了微波等离子体电子回旋共振放电的1D3V模型,描述了带电粒子在外加静磁场、微波场共同作用下的微观运动。结果表明:微波频率为2.45 GHz时,随着静磁场磁感应强度的增加,平均电子能量先持续增大达到峰值,随后又不断地减小,且在0.087 5 T时电子加速效果最明显,结果符合电子的回旋频率公式,验证了该模型的正确性;共振区域内,发现在0.087 5 T磁感应强度下,微波频率为2.45 GHz下拟合的电子速度分布才与微波电场分布趋势相似,说明微波电场推动了电子运动。这为进一步研究微波等离子体放电的粒子模拟-蒙特卡罗碰撞模拟奠定了基础,也为进一步研究微波等离子体源中粒子产生效率及微波等离子体源的物理性质提供了重要参考。

Particle-in-cell simulation of microwave plasma electron cyclotron resonance discharge

Plasma produced by electron cyclotron resonance discharge is widely used in material processing and space electric propulsion in microelectronics industry. In order to study the discharge characteristics of electron cyclotron resonance (ECR) in microwave plasma, and make the plasma produced by ECR discharge have higher density and higher energy conversion efficiency, a 1D3V model of ECR discharge in microwave plasma was established, and the microscopic movement of charged particles under the combined action of external static magnetic field and microwave field was described. The results show that when the microwave frequency is 2.45 GHz, with the increase of the magnetic induction intensity of static magnetic field, the average electron energy increases continuously and reaches the peak value, and then decreases continuously, and the acceleration effect of electrons is most obvious at 0.0875 T, which accords with the cyclotron frequency formula of electrons and verifies the correctness of the model. In the resonance region, it is found that under the magnetic induction intensity of 0.0875 T and the microwave frequency of 2.45 GHz, the fitted electron velocity distribution is similar to the microwave electric field distribution trend, which indicates that the microwave electric field promotes the electron motion. This lays a foundation for further research on particle simulation-Monte Carlo collision simulation of microwave plasma discharge, and also provides an important reference for further research on particle generation efficiency and physical properties of microwave plasma source.