ABSTRACTWe present here a reactive ion etching recipe to fabricate germanium nanowires.
We used a combination of Cl2, N2 and O2 and
studied the influence of both the gas pressure and the O2 mass flow
on the morphology of the nanowires. 5 µm long nanowires with an aspect
ratio of 20 are demonstrated with smooth surfaces and a tapering below 20
nm/µm. We also show that both gold and aluminum can be used as hard
mask; the latter achieving a selectivity with germanium above 100.
