  Artificial lattices constructed from individual dopant atoms within a
semiconductor crystal hold promise to provide novel materials with tailored
electronic, magnetic, and optical properties. These custom engineered lattices
are anticipated to enable new, fundamental discoveries in condensed matter
physics and lead to the creation of new semiconductor technologies including
analog quantum simulators and universal solid-state quantum computers. In this
work, we report precise and repeatable, substitutional incorporation of single
arsenic atoms into a silicon lattice. We employ a combination of scanning
tunnelling microscopy hydrogen resist lithography and a detailed statistical
exploration of the chemistry of arsine on the hydrogen terminated silicon (001)
surface, to show that single arsenic dopants can be deterministically placed
within four silicon lattice sites and incorporated with 97$\pm$2% yield. These
findings bring us closer to the ultimate frontier in semiconductor technology:
the deterministic assembly of atomically precise dopant and qubit arrays at
arbitrarily large scales.
