  Single-crystal diamond plates with surfaces oriented in a (111) crystal plane
are required for high-performance solid-state device platforms ranging from
power electronics to quantum information processing architectures. However,
producing plates with this orientation has proven challenging. In this paper,
we demonstrate a method for reliably and precisely fabricating (111)-faced
plates from commercially available, chemical-vapor-deposition-grown, type-IIa
single-crystal diamond substrates with (100) faces. Our method uses a
nanosecond-pulsed visible laser to nucleate and propagate a mechanical cleave
in a chosen (111) crystal plane, resulting in faces as large as 3.0
mm$\times$0.3 mm with atomically flat surfaces, negligible miscut angles, and
near zero kerf loss. We discuss the underlying physical mechanisms of the
process along with potential improvements that will enable the production of
millimeter-scale (111)-faced single-crystal diamond plates for a variety of
emerging devices and applications.
