  Single self-assembled InAs/GaAs quantum dots are a promising solid-state
quantum technology, with which vacuum Rabi splitting, single-photon-level
nonlinearities, and bright, pure, and indistinguishable single-photon
generation having been demonstrated. For such achievements, nanofabrication is
used to create structures in which the quantum dot preferentially interacts
with strongly-confined optical modes. An open question is the extent to which
such nanofabrication may also have an adverse influence, through the creation
of traps and surface states that could induce blinking, spectral diffusion, and
dephasing. Here, we use photoluminescence imaging to locate the positions of
single InAs/GaAs quantum dots with respect to alignment marks with < 5 nm
uncertainty, allowing us to measure their behavior before and after
fabrication. We track the quantum dot emission linewidth and photon statistics
as a function of distance from an etched surface, and find that the linewidth
is significantly broadened (up to several GHz) for etched surfaces within a
couple hundred nanometers of the quantum dot. However, we do not observe
appreciable reduction of the quantum dot radiative efficiency due to blinking.
We also show that atomic layer deposition can stabilize spectral diffusion of
the quantum dot emission, and partially recover its linewidth.
