Figure 4From: Silicon-based photonic crystals fabricated using proton beam writing combined with electrochemical etching methodSchematic of fabrication of freestanding silicon wires. (a) Proton beam-writing process and resultant defect distribution in cross-section view. (b) Selective formation of porous silicon in subsequent electrochemical etching. (c) Removal of porous silicon in KOH solution. (d) SEM image of freestanding silicon wires with three different spacings.Back to article page