Automatic measurement of electron beam size by beam metrology technique using 20nm test pattern

A robust operator independent measurement of electron beam sizes in two coordinates is demonstrated by using beam metrology (BEAMETR) technique. This method involves software associated with a specially designed pattern sample. The fabrication of this sample was done using 100keV electron beam lithography and lift-off of metal. A proximity correction was applied to improve pattern quality. The minimum feature size of the fabricated BEAMETR patterns was 20nm; this allowed for the measuring of beam size down to 2nm. Beam size and shape measurements were done using three scanning electron microscopes; their operating conditions (voltage, aperture, and astigmatism) were varied. Repeatability and test pattern dependence were also studied, which demonstrated a good consistency of the results.