  Shallow neutral donors (D$^{0}$) in ZnO have emerged as a promising candidate
for solid-state spin qubits. Here, we report on the formation of D$^{0}$ in ZnO
via implantation of In and subsequent annealing. The implanted In donors
exhibit optical and spin properties on par with $\textit{in situ}$ doped
donors. The inhomogeneous linewidth of the donor-bound exciton transition is
less than 10 GHz, comparable to the optical linewidth of $\textit{in situ}$ In.
Longitudinal spin relaxation times ($T_1$) exceed reported values for
$\textit{in situ}$ Ga donors, indicating that residual In implantation damage
does not degrade $T_1$. Two laser Raman spectroscopy on the donor spin reveals
the hyperfine interaction of the donor electron with the spin-9/2 In nuclei.
This work is an important step toward the deterministic formation of In donor
qubits in ZnO with optical access to a long-lived nuclear spin memory.
