Fig. 5: Reactive ion beam etching (RIBAE).

a Graphical depiction of RIBAE. b RIBAE fabrication steps (i) Top-down etching of a diamond sample mounted perpendicular to the ion beam path on a rotating sample stage. (ii) Sample is tilted to obtain an acute angle between the sample and ion beam, uniformly etching underneath the etch mask. (iii) Mask removal yields undercut nanostructures from a bulk substrate.