Plane view SEM images of the Si surface of sample 1. The images show the nanopatterned Si surface of sample 1 after etching through the PAA mask using SF6/CHF3 gas mixture for 20 s (a), 40 s (b), and 60s (c). The alumina film was removed before observation.
Gianneta et al. Nanoscale Research Letters 2013 8:71 doi:10.1186/1556-276X-8-71