Steele A V, Schwarzkopf A, McClelland J J, Knuffman B
zeroKNanotech, Gaithersburg, MD 20879, United States of America.
Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899, United States of America.
Nano Futures. 2017 Jun;1(1):015005. doi: 10.1088/2399-1984/aa6a48. Epub 2017 May 2.
We present measurements of focal spot size and brightness in a focused ion beam system utilizing a laser-cooled atomic beam source of Cs ions. Spot sizes as small as (2.1 ± 0.2) nm (one standard deviation) and reduced brightness values as high as (2.4 ± 0.1) × 10 A m Sr eV are observed with a 10 keV beam. This measured brightness is over 24 times higher than the highest brightness observed in a Ga liquid metal ion source. The behavior of brightness as a function of beam current and the dependence of effective source temperature on ionization energy are examined. The performance is seen to be consistent with earlier predictions. Demonstration of this source with very high brightness, producing a heavy ionic species such as Cs, promises to allow significant improvements in resolution and throughput for such applications as next-generation circuit edit and nanoscale secondary ion mass spectrometry.
我们展示了在使用激光冷却的铯离子原子束源的聚焦离子束系统中对焦斑尺寸和亮度的测量结果。对于10 keV的束流，观察到的光斑尺寸小至(2.1±0.2)nm（一个标准偏差），亮度降低值高达(2.4±0.1)×10 A m Sr eV。该测量亮度比在镓液态金属离子源中观察到的最高亮度高出24倍以上。研究了亮度随束流的变化行为以及有效源温度对电离能的依赖性。观察到该性能与早期预测一致。这种具有非常高亮度、产生诸如铯等重离子物种的源的展示，有望在下一代电路编辑和纳米级二次离子质谱等应用的分辨率和通量方面实现显著提升。
