Three-dimensional lithographic patterns can be obtained using a new two component UV sensitive polymer system. The light-sensitive material consists of a chlorine containing conventional polymer, i.e., poly(chloroacrylonitrile) as a typical acceptor, and a heterocyclic or aromatic monomer as the donor, here pyrrole. This two component precomposite can be irradiated by either an excimer laser or the radiation of a high pressure mercury lamp. The resulting image, essentially a black and white pattern, can be developed in wet or dry (ion etching, ablation) modes giving resist patterns with a resolution in the micrometer range.
Reinhard R. Baumann,
"Charge transfer approach to negative resists", Proc. SPIE 1672, Advances in Resist Technology and Processing IX, (1 June 1992); doi: 10.1117/12.59771; https://doi.org/10.1117/12.59771