Shape deviations of DLW microstructures in dependency of fabrication parameters

Abstract

Deep understanding of the effects associated with fabrication parameters and their influence on the resulting structures shape is essential for the further development of direct laser writing (DLW). In particular, it is critical for development of reference materials, where structure parameters are precisely fabricated and should be reproduced with use of DLW technology. In this study we investigated the effect of various fabrication and preparation parameters on the structural precision of interest for reference materials. A well-studied photo-curable system, SZ2080 negative photo-resist with 1 wt.% Michler’s ketone (Bis) photo-initiator, was investigated in this work. The correlation between applied laser power, laser velocity, fabrication direction on the deviations in the structure shape were observed by means of white light interferometry microscopy. Moreover, influence of slicing and hatching distances as well as prebake time were studied as function of sample shape. Deviations in the structure form between the theoretically expected and the one detected after DLW fabrication were observed in the range up to 15%. The observed shape discrepancies show the essential importance of fine-tuning the fabrication parameter for reference structure production.

First of its kind: a test artifact for direct laser writing

“…Bauer et al [28] investigated the relationship between laser velocity, laser power and hatch/slice distance and found a mechanical enhancing effect at higher overlaps. On the other hand, an increase in size was also observed for SZ080, which also depended on the manufacturing direction [29].…”

“…This changes the overlap between the voxels and therefore the mechanical properties also change. For SZ2080, it has also been shown [29] that the time between each manufactured line or cut distorts the shape of a structure.…”

First of its Kind: A Test Artifact for Direct Laser Writing

“…Bauer et al [25] investigated the relationship between laser velocity, laser power and hatch/slice distance and found a mechanical enhancing effect at higher overlaps. On the other hand, an increase in size was also observed for SZ080, which also depended on the manufacturing direction [26].…”

“…This changes the overlap between the voxels and therefore the mechanical properties also change. For SZ2080, it has also been shown [26] that the time between each manufactured line or cut distorts the shape of a structure.…”