Development and structuring of combined positive-negative/negative-positive resists using laser ablation as positive dry etching technique

Novel photopolymers, based on cinnamylidenemalonyl groups, were designed fo r excimer laser ablation lithography. These polymers are highly sensitive t o laser ablation at a specific irradiation wavelength, i.e., 308 nm, but ca n also be applied as classical, negative photoresist. The crosslinking of t he polymer is accomplished by irradiation at >395 nm. The sensitivity of th e photopolymers to laser ablation before and after crosslinking is nearly e qual, The combination of these two processes, i.e., laser ablation and phot ocrosslinking, can be applied for the fabrication of arrays of microstructu res. The laser ablation step is used to fabricate microstructures, while th e classical wet processing is used for large area structuring. Combined pro cesses of crosslinking-wet development and laser microstructuring, but also vice versa were carried out. The microstructures had the same high resolut ion, independent of the processing order.