Thin films of polyaniline have been spin cast from solutions of formic
acid in concentrations of up to 3 wt.% which give thicknesses between
80 and 250 nm. These films have been patterned using positive photore
sist and etched in an oxygen plasma. Silicon wafers with 200 nm of dry
thermal oxide and 100 nm of sputtered silicon nitride were used as su
bstrates. Platinum leads in a four-probe configuration were built on t
op of the insulators and the polyaniline was spun on top of these. Dif
ferent adhesion promoters were examined for electrical interference. T
he spin-cast films are sufficiently electroactive to allow for the gro
wth of polyaniline on top of them by electrochemical means.