Helium ion microscopy and energy selective scanning electron microscopy _ two advanced microscopy techniques with complementary applications

Electron Microscopy and Analysis Group Conference 2013

Rodenburg, C.^1 ; Jepson, M.A.E.^2 ; Boden, Stuart A.^3 ; Bagnall, Darren M.^3

Department of Engineering Materials, University of Sheffield, Mappin Street, SI 3JD Sheffield, United Kingdom^1

Department of Materials, Loughborough University, LEI 1 3TU Loughborough, United Kingdom^2

Electronics and Computer Science, University of Southampton, Highfield, SO17 1BJ Southampton, United Kingdom^3

关键词: Contamination layers;    Helium ion microscopes;    Helium ion microscopies;    Information depth;    Microscopy technique;    Secondary electron emission spectra;    Secondary electrons;    The scanning electron microscopes (SEM);   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/522/1/012049/pdf
DOI  :  10.1088/1742-6596/522/1/012049

来源: IOP

【 摘 要 】

Both scanning electron microscopes (SEM) and helium ion microscopes (HeIM) are based on the same principle of a charged particle beam scanning across the surface and generating secondary electrons (SEs) to form images. However, there is a pronounced difference in the energy spectra of the emitted secondary electrons emitted as result of electron or helium ion impact. We have previously presented evidence that this also translates to differences in the information depth through the analysis of dopant contrast in doped silicon structures in both SEM and HeIM. Here, it is now shown how secondary electron emission spectra (SES) and their relation to depth of origin of SE can be experimentally exploited through the use of energy filtering (EF) in low voltage SEM (LV-SEM) to access bulk information from surfaces covered by damage or contamination layers. From the current understanding of the SES in HeIM it is not expected that EF will be as effective in HeIM but an alternative that can be used for some materials to access bulk information is presented.