title: Reduced plasma-induced damage to near-surface nitrogen-vacancy centers in diamond.
abstract: Understanding plasma etch damage on near-surface nitrogen vacancy (NV) centers in diamond is essential for preserving NV emission in photonic structures and magnetometry systems. We have developed a methodology to compare the optical properties of ensemble NV centers initially 70 nm from the surface brought closer to the surface through etching with O2 plasmas in three different reactors. We employ a conventional reactive ion etcher, a barrel etcher, and a downstream etcher. We find that, irrespective of the etcher used, NV luminescence dims steadily as NVs are brought closer to the surface due to optical and surface effects. When NVs are less than 40 nm from the surface, differences in damage from the three different plasma processes affect the NV emission intensity in different ways. Diamond that is etched using the conventional etching method shows a greatly reduced NV luminescence, whereas NVs 15 nm from the surface still survive when the diamond is etched in the downstream reactor. As a result, downstream etching provides a possible alternative method for low damage etching of diamond for preservation of near surface NV properties.
authors.affiliation: †School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States.
authors.forename: Shanying
authors.initials: S
authors.lastname: Cui
authors.affiliation: †School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States.
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Greenspon
authors.affiliation: ‡Department of Physics, University of California, Santa Barbara, California 93106, United States.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Ohno
authors.affiliation: ‡Department of Physics, University of California, Santa Barbara, California 93106, United States.
authors.forename: Bryan A
authors.initials: BA
authors.lastname: Myers
authors.affiliation: ‡Department of Physics, University of California, Santa Barbara, California 93106, United States.
authors.forename: Ania C Bleszynski
authors.initials: AC
authors.lastname: Jayich
authors.affiliation: §Institute for Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States.
authors.forename: David D
authors.initials: DD
authors.lastname: Awschalom
authors.affiliation: †School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States.
authors.forename: Evelyn L
authors.initials: EL
authors.lastname: Hu
keywords: etching; nitrogen vacancy; optics; plasma damage