Reduction in hole periodicity. SEM images of (a) surface of porous alumina mask and (b) Ag nanodot arrays with 60-nm periodicity formed on Si substrate. (c) Cross-sectional SEM image of Si hole arrays fabricated by metal-assisted chemical etching in 5 mol dm-3 HF - 1 mol dm-3 H2O2 solution for 1 min.
Asoh et al. Nanoscale Research Letters 2013 8:410 doi:10.1186/1556-276X-8-410