Organic conductors as electron beam resist materials

Conducting organic π-donor halide complexes such as tetrathiafulvalene bromide were discovered to act as electron beam resists, which display a unique combination of useful properties. Exposure of sublimed films to an electron beam generates the neutral π donor and the halogen which is subsequently lost from the film. Depending on exposure conditions, either negative (solvent developed) or positive (in-situ developed) resist images with a resolution of the order of 0.5 μ can be generated. The strongly absorbing (UV,vis.) and highly conducting (∼10/Ω cm) films were found to become transmitting and insulating upon electron beam irradiation.