  The engineering of defects in diamond, particularly nitrogen-vacancy (NV)
centers, is important for many applications in quantum science. A materials
science approach based on chemical vapor deposition (CVD) growth of diamond and
in-situ nitrogen doping is a promising path toward tuning and optimizing the
desired properties of the embedded defects. Herein, with the coherence of the
embedded defects in mind, we explore the effects of substrate miscut on the
diamond growth rate, nitrogen density, and hillock defect density, and we
report an optimal angle range between 0.66{\deg} < {\theta} < 1.16{\deg} for
the purposes of engineering coherent ensembles of NV centers in diamond. We
provide a model that quantitatively describes hillock nucleation in the
step-flow regime of CVD growth, shedding insight on the physics of hillock
formation. We also report significantly enhanced incorporation of nitrogen at
hillock defects, opening the possibility for templating
hillock-defect-localized NV center ensembles for quantum applications.
