Top and profile images of dry etched-holes. SEM images of holes after dry etching with resist remaining on the surface. Regularly shaped circular holes are observed in the top view (a) while the profile in (b) shows the vertical sidewalls. The resist is affected near the holes and pushed back. Therefore, the holes increase with etching time in lateral dimension.
Mayer et al. Nanoscale Research Letters 2013 8:504 doi:10.1186/1556-276X-8-504