Fig. 1: Scheme of the multistep miniaturization approach using prestressed polymer films.

a, b Fabrication of polymer working stamp. c Hot embossing the prestressed film. d Constrained shrinking. e Cast PDMS mold. f Soft imprint polymer pattern on Si substrate. g RIE Si substrate. h Clean patterned Si substrate which is used as a master for the next miniaturization step. SEM images of the results of a complete miniaturization cycle for i Si master, j imprint on prestressed film, k shrunk pattern, l new Si master