  The Nitrogen Vacancy color center (NV-) in diamond is of great interest for
novel photonic applications. Diamond nano-photonic structures are often
implemented using Focused-Ion-Beam (FIB) processing, leaving a damaged surface
which has a detrimental effect on the color center luminescence. The FIB
processing effect on single crystal diamond surfaces and their photonic
properties is studied by Time of Flight Secondary Ion Mass Spectrometry
(TOF-SIMS) and photoluminescence (PL). Exposing the processed surface to
hydrogen plasma, followed by chemical etching, drastically decreases implanted
Ga concentration, resulting in a recovery of the NV- photo-emission and in a
significant increase of the NV-/NV0 ratio.
