An electric field is applied below a resist to reduce proximity effects associated
with electron beam scattering, thereby improving the resolution of features or
lines written into the resist. Although the electrons in the electron beam can
be very energetic (e.g., 10 keV), it is shown that even a small electric
field can reduce the number of electrons that re-enter the resist material after
being scattered in the substrate, and thus reduce the energy deposited in the resist
from these electrons. One advantage of this technique is that high potentials and
high fields are not required. Accordingly, the methods described can be applied
to existing tooling with little modification to the electron beam system.