A nanopatterning scheme is presented by which the structure height can becontrolled in the tens of nanometers range and the lateral resolution is afactor at least three times better than the point spread function of thewriting beam. The method relies on the initiation of the polymerizationmediated by a very inefficient energy transfer from a fluorescent dye moleculeafter single photon absorption. The mechanism has the following distinctivesteps: the dye adsorbs on the substrate surface with a higher concentrationthan in the bulk, upon illumination it triggers the polymerization, thenisolated islands develop and merge into a uniform structure (percolation),which subsequently grows until the illumination is interrupted. Thispercolation mechanism has a threshold that introduces the needed nonlinearityfor the fabrication of structures beyond the diffraction limit.
展开▼
