“…The SiNWs are then defined from the wafer by a typical etching step [ 44 , 45 ] using the pre-defined mask. For example, millimeter SiNWs can be readily fabricated on SOI wafers using an etched mask patterned from the engineered nano-cavity/undercut structures ( Figure 4 ) [ 44 , 46 , 47 ] or by transforming the vertical thickness of the masking materials into the lateral width of the nanowire patterns [ 41 , 48 , 49 , 50 , 51 ]. Applying this concept, well-ordered SiNWs can be patterned with any desired configurations ranging from sub-10 nm in width [ 46 ], millimeters or more in length [ 45 ] and with high density [ 44 ].…”