In an electron beam (EB) lithography system, beam positional vibration
is one of the most influential factors of positioning accuracy degrad
ation. We propose a new correction method for improving this accuracy
and investigate its effectiveness by applying it to a nanometer EB sys
tem. In our method, first, the correction signal is detecting the beam
positional vibration as the variation of tile backscattered or the tr
ansmitted electron signal and then extracting one period of this signa
l. Then, the correction signal is added to that of the beam deflection
control. The effectiveness of this correction is evaluated by measuri
ng beam positional vibration and stitching accuracy of the delineated
pattern between subfields with size of 8 mu m x 8 mu m. As a result, b
oth an amplitude of the beam vibration of less than 10 nm and a stitch
ing accuracy of less than 8 nm (3 sigma) are achieved, which confirms
that the beam vibration has been actively corrected, and the positioni
ng accuracy has been improved. The above results indicate that this co
rrection method is very valuable for the EB lithography system.