  Diamond has recently attracted considerable attention as a promising platform
for quantum technologies, photonics and high resolution sensing applications.
Here we demonstrate a chemical approach that enables the fabrication of
functional diamond structures using gas-mediated electron induced etching. The
method achieves chemical etching at room temperature through the dissociation
of surface-adsorbed H2O molecules by electron irradiation in a water vapor
environment. High throughput, parallel processing is possible by electron flood
exposure and the use of an etch mask, while single step, mask-free three
dimensional fabrication and iterative editing are achieved using a variable
pressure scanning electron microscope. The electron induced chemical etching
paves the way to a transformative technology for nanofabrication of diamond and
other wide band-gap semiconductors.
