SEM micrographs of sample 1 after RIE in two different gas mixtures. Micrographs 1 of (a) and (b) are cross-sectional images, while images 2 and 3 of (a) and (b) are plane view images. Etching was performed in SF6/O2 (images 1 to 3 of (a)) and in SF6/CHF3 (images 1 to 3 of (b)). The etching duration was 40 s in images 1 and 2, and 60 s in images 3. In the cross-sectional images, the PAA mask is present; in the plane view images, it is removed, revealing the nanopatterned Si surface.
Gianneta et al. Nanoscale Research Letters 2013 8:71 doi:10.1186/1556-276X-8-71