碰撞对非对称射频鞘层特性的影响

Collisional effects on characteristics of asymmetric radio-frequency sheaths

对于大多数活性射频等离子体刻蚀工艺 ,由于放电室中两个电极的面积不等 ,使得两个电极附近的等离子体鞘层是非对称性的 .考虑离子与中性粒子的碰撞效应 ,建立了一种描述这种非对称射频鞘层动力学特性的自洽动力学模型 .数值结果显示碰撞效应对极板上的瞬时电压降、瞬时电子鞘层厚度。

For most reactive radio frequency plasma etching processing, the plasma sheaths near two electrodes are asymmetric due to the powered electrode area being smaller than the grounded electrode area. Taking collisional effects of ions with neutrals in the sheaths into account, a self consistent dynamic model is proposed here to describe the characteristics of radio frequency sheaths. Numerical results show the collisional effects on some physical quantities, such as instantaneous voltages on the electrodes, instantaneous thicknesses of the electron sheathes, spatial distributions of the ion density and the electric field in the sheaths, and instantaneous voltage difference between two electrodes.