Etching, lithography, hole formation, surface restructuring and external machining can all be performed on a nanometre scale using an intense electron beam. Results are presented for a range of different materials which demonstrate the variety of mechanisms by which electron beam nano-etching can occur. For example, in crystalline 13-alumina hole formation occurs by surface indentations growing inwards to join up and form a nanometre diameter hole. In amorphous alumina, on the other hand, hole formation is from the inside-out: oxygen gas bubbles form under the electron beam, coalesce, and burst to leave a well defined nanometre diameter hole. In MgO and Si, holes develop from the electron exit surface: whereas in Al voids form along the irradiated volume, leading eventually to the development of a hole at the electron entrance surface. The potential of electron beam nano-etching to lithography and information storage is demonstrated by showing that the entire contents of the Encyclopaedia Britannica can be written on a pinhead.
Humphreys, C. J.; Bullough, T. J.; Devenish, R. W.; Maher, D. M.; and Turner, P. S.
"Electron Beam Nano-Etching in Oxides, Fluorides, Metals and Semiconductors,"
Scanning Microscopy: Vol. 1990
, Article 13.
Available at: https://digitalcommons.usu.edu/microscopy/vol1990/iss4/13