Surface nanostructuring of poly- and monocrystalline copper substrates by laser embossing

M. Ehrhardt, P. Lorenz, F. Frost, K. Zimmer
IOM Leipzig, DE

Keywords: laser embossing, excimer laser, copper

Summary:

The importance of nanostructured surfaces is rapid grown in the recent decades due to the large range of application of these functionalized surfaces in the fields of, e.g., optics, biomedicine, and micromechanics. Laser microembossing is a manufacturing technology which combines laser processing with nanoimprint techniques. Laser embossing bases on the non-thermal deformation of a work piece onto a structured mould. In the present study an improved experimental set up is shown which enables the replication of nanostructures from a master mould into a thick work piece without fundamental limitations of the workpiece thickness and the size of the processed area. Within the experiments a KrF excimer laser was used for embossing a nickel shim of different 3D topographies into monocrystalline and polycrystalline copper surfaces. The surface topography and morphology of the replicated 3D structures, which have lateral sizes below ~ 500 nm were investigated by atomic force microscopy and scanning electron microscopy, are shown and discussed in relation to the processing parameters. To investigate how the crystal structure of the copper is affected by the formed nanostructure transmission electron microscopy investigations of the embossed structures were performed.