Abstract
100 keV electron beams can damage and even cut holes in specimens. It is of great concern for analytical electron microscopy because the damage may result in a change in chemical composition of the irradiated area. During irradiation, low-Z elements tend to be removed faster than the high-Z ones thus leaving a “heavier” substrate. Sometimes, beam damage can not be “seen” via contrast change either in BF (bright field) or ADF (annular dark field). However, it can be observed in the Si first plasmon energy selected image reported in this paper. This image also provides evidence that the oxygen diffuses from the undamaged area to the damaged area.The experiment was carried out in a VG HB501A STEM which is equipped with EELS and a windowless X-ray detector. A sample with a 5200 Å-thick SiO2 film grown on a Si substrate was used in this study. It is found from X-ray analysis that there are only Si, O and a very small amount of S.
Publisher
Cambridge University Press (CUP)
Reference4 articles.
1. 4. This work is supported by SRC under Grant No. 94-SC-069 The UHV STEM was acquired through the NSF (DMR-8314255) and is operated by the Cornell Materials Science Center. The sample is provided by Liz Carr. The useful discussion with David Muller is acknowledged.
2. Electron Beam Induced Nanometre Hole Formation and Surface Modification in Al, Si And MgO
3. Radiation damage processes affecting electron beam lithography of inorganic materials
4. Progress in self-developing metal fluoride resists