Fabrication of high-density Si and SixGe1−x nanowire arrays based on the single step plasma etching process

Dense arrays of silicon and silicon germanium nanowires are fabricated using a top-down approach, which exploits the excellent patterning capabilities of inductively coupled plasmas. Using standard deep UV lithography on a previously deposited silicon oxide hard mask, silicon nanowires with straight and smooth sidewalls and a high aspect ratio greater than 60:1 can be obtained with SF6/O-2/HBr/SiF4 plasma chemistries. The best results are obtained using Cl-2/N-2 high-density plasmas to pattern Si0.5Ge0.5 nanowires with an aspect ratio of 10:1. (C) 2013 American Vacuum Society.