Figure 1.

Schematic representation of the process. (a) SEM cross-sectional tilted view of a macroporous layer grown on a Ti/Au prepatterned substrate (WP1 geometry) (b) and (c). The etching current was set at the constant value of 91 mA/cm² for 25 min. A fresh HF/DMF mixture was used as electrolyte. The metal layers were released after few minutes of etching.