Amano J, Seidman D N
Department of Materials Science and Engineering and the Materials Science Center, Bard Hall, Cornell University, Ithaca, New York 14853, USA.
Rev Sci Instrum. 1979 Sep;50(9):1125-9. doi: 10.1063/1.1135998.
An ultrahigh-vacuum (UHV) differentially pumped low-energy (50-3000 eV) ion beam system for the in situ irradiation of specimens in a UHV atom-probe field-ion microscope (FIM) was designed and constructed. The ion beam system consisted of a Finkelstein-type ion source, an Einzel lens, and a magnetic mass analyzer. The ion source was connected to the analyzer chamber by small apertures which resulted in differential pumping between the ion source and the analyzer chamber; during a typical in situ irradiation of a specimen in the atom-probe FIM the total pressure was maintained at approximately 10(-7) Torr. In the case of helium ion irradiation the optimum ion-current density was approximately 0.5 microA cm(-2) for 300-eV He+ ions at the atom-probe FIM specimen. After the completion of a helium ion irradiation the pumpdown time from 5 x 10(-7) to approximately 3 x 10(-10) Torr in the atom-probe FIM chamber was 0.5 h.
设计并构建了一种超高真空（UHV）差分抽气低能（50 - 3000 eV）离子束系统，用于在超高真空原子探针场离子显微镜（FIM）中对样品进行原位辐照。该离子束系统由一个芬克尔斯坦型离子源、一个单透镜和一个磁质量分析器组成。离子源通过小孔与分析室相连，这导致了离子源和分析室之间的差分抽气；在原子探针FIM中对样品进行典型的原位辐照期间，总压力保持在约10^(-7) 托。在氦离子辐照的情况下，对于原子探针FIM样品上300 eV的He+离子，最佳离子电流密度约为0.5 μA cm^(-2)。氦离子辐照完成后，原子探针FIM腔从5×10^(-7) 托抽至约3×10^(-10) 托的抽气时间为0.5小时。
