Carbon films from polyacrylonitrile

Polyacrylonitrile (PAN) films have been fabricated by both spin and solvent casting techniques, and pyrolyzed to produce carbon films in the thickness range of 200–50000 Å. These films have higher electrical conductivities than carbon films produced from most other precursors at similar temperatures. The chemical structure of the films at different stages of processing was investigated by UV, IR, Raman, and XPS spectroscopies. An extra degree of control over the final electrical conductivity was obtained by varying the PAN content of copolymer precursors. Oxidation rates and an activation energy were determined. Finally, processing techniques are described which allow both dry and wet film transfer and lithographic patterning.