Figure 4.

Comparison of SEM micrographs of macropores formed in HF solutions with and without Et2O. Cross-sectional views of porous layers anodized in a 10–20 Ωcm prepatterned p-type silicon at 14 mAcm−2 for 1 h in (a) HF:H2O:EtOH with a composition of 5:6:29 and (b) HF:H2O:EtOH:Et2O with a composition of 5:6:15:14 in volume.

Urata et al. Nanoscale Research Letters 2012 7:329   doi:10.1186/1556-276X-7-329
Download authors' original image