A compact microwave plasma has been employed as an ion source for focused ion beam applications, that can provide non-toxic ions and facilitate rapid processing of materials without introducing any metallic contamination. A variety of microstructures with high aspect ratio (line width/depth) (∼100–1000) relevant to the energy and current regimes, are created on copper thin films using 26 keV Ne, Ar and Kr ion beams. A mathematical formulation is developed to calculate the impact of the ion beams, which act as energetic projectiles falling onto the target sample, by defining a new parameter called ‘current normalized force’ which is the total momentum transferred per unit time, normalized with the beam current. Capillary guiding of the plasma ion beams has demonstrated beam self-focusing which can be employed to further reduce the beam source size (plasma electrode aperture) for demagnification. Particle-in-cell (PIC) simulations are performed to interpret the experimental results of self-focusing. Hysteresis in beam current with extraction voltage (ion energy) is observed and the hysteresis area is used to calculate the dissipated charge from the beam during capillary transmission. The effect of plasma and beam parameters on focal dimensions has been investigated, and a unique feature of enhanced nonlinear demagnification is observed when the aperture size of the plasma electrode is reduced to below the Debye length. Submicron focusing of plasma ion beams is observed by minimizing the space charge effects and reducing the plasma electrode aperture (source size).

紧凑的微波等离子体已被用作聚焦离子束应用的离子源，它可以提供无毒离子并促进材料的快速处理，而不会引入任何金属污染。使用 26 keV Ne、Ar 和 Kr 离子束在铜薄膜上创建与能量和电流状态相关的具有高纵横比（线宽/深度）（~100-1000）的各种微结构。通过定义一个称为“当前归一化力”的新参数，开发了一种数学公式来计算离子束的影响，离子束充当落在目标样品上的高能弹丸当前的。等离子体离子束的毛细管引导已经证明了束自聚焦，可用于进一步减小束源尺寸（等离子体电极孔径）以进行缩小。进行细胞内粒子 (PIC) 模拟以解释自聚焦的实验结果。观察束电流与提取电压（离子能量）的滞后现象，滞后面积用于计算毛细管传输过程中束流的耗散电荷。已经研究了等离子体和光束参数对焦距尺寸的影响，并且当等离子体电极的孔径尺寸减小到德拜长度以下时，观察到增强的非线性缩小的独特特征。