Rectangular-shaped oxygen O2+ ion beam thinning for scanning transmission electron microscope (STEM) sample preparation was investigated using a projection ion beam optical system equipped with a duoplasmatron gas ion source. The ion current can be increased by increasing the area of the rectangular-shaped oxygen ion beam and thereby overcome the low brightness of the ion source. Rectangular-shaped O2+ ion beams with different amounts of projection beam edge blur were formed in the X and Y directions by using a limiting mask between the ion source and projection mask. Gallium-contamination-free STEM sample preparation (rough, medium, and fine milling) was demonstrated using a projection ion beam optical system and three types of rectangular-shaped oxygen ion beams.

中文翻译：

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使用投影离子束光学系统通过矩形氧离子束减薄制备 Ga 无污染扫描透射电子显微镜样品

使用配备双等离子体气体离子源的投影离子束光学系统研究了用于扫描透射电子显微镜 (STEM) 样品制备的矩形氧 O2+ 离子束细化。增加矩形氧离子束的面积可以增加离子电流，从而克服离子源亮度低的问题。通过在离子源和投影掩膜之间使用限制掩膜，在 X 和 Y 方向上形成具有不同投影束边缘模糊量的矩形 O2+ 离子束。使用投影离子束光学系统和三种类型的矩形氧离子束演示了无镓污染的 STEM 样品制备（粗磨、中磨和精磨）。