Magnetometers employing nitrogen-vacancy (NV) centers in diamond promise to be extremely sensitive, high- resolution sensors.  To maximize the performance of such magnetometers, depth control of the NV centers within the diamond sample is crucial; near-surface NV centers with long coherence times are favorable. To achieve this, we employ a nitrogen δ-doping technique during plasma-enhanced chemical vapor deposition of diamond to introduce thin layers of nitrogen at precise depths within the sample. The subsequent conversion of doped nitrogen to NV centers is an important parameter to optimize because a high density of unconverted nitrogen spins reduces the NV’s coherence. To better understand the nitrogen to NV conversion and its depth dependence, we grow a four layer δ- doped sample with nitrogen-rich layers at 5 nm, 20 nm, 50 nm, and 100 nm depths. We attempt to maximize the nitrogen to NV conversion in the shallow (5 nm) layer by tuning the parameters of electron irradiation, which introduces vacancies in the diamond. We tune the electron energy, current, and dose using both a Van de Graff electron source and a transmission electron microscope. Generating high conversion ratios with minimal damage for NVs at shallow depths could enable magnetic resonance imaging of single nuclear spins with nanoscale resolution.