A major issue in low voltage lithography is surface charging, which
results in beam deflection presented as uneven exposure between
adjacent structures. In this study, charge-induced pattern distortions
in low-voltage energy beam lithography (LVEBL) were investigated using
a silicide direct-write electron beam lithography process. Two
methodologies have been proposed to avert charging effects in LVEBL,
namely, pattern randomizing and lithography using the crossover
voltage. Experimental results demonstrated that these methods are
effective in significantly reducing the problems associated with
charging. They indicate that charging on a sample is a function of time
interval and proximity between line structures. In addition, the
optimum time and distance between exposures for no charge-induced
pattern distortion were determined. By using the crossover voltage of
the material for lithography, charging effect can be significantly
minimized.