Figure 2
From: Top-down GaN nanowire transistors with nearly zero gate hysteresis for parallel vertical electronics

Bird-view SEM images of vertically aligned n-p-n GaN nanowire (NW) arrays after ICP-DRIE and wet chemical etching with NW numbers of (a) 1, (b) 9, and (c) 100. Varied wire diameters (D) of (d) (221 ± 9) nm, (e) (443 ± 7) nm, and (f) (647 ± 8) nm were obtained originating from different pattern sizes of the used Cr etching mask.