Medusa 84 SiH -- A novel high Selectivity Electron Beam Resist for Diamond Quantum Technologies

We investigate the novel electron beam resist Medusa 84 SiH by Allresist GmbH (Germany) for nanostructuring of single crystal diamond and its effects on the spin properties of nitrogen vacancy (NV) centers in nanopillars as prototypes for photonic structures. We find contrast curves comparable to those of resists previously used for this task (Hydrogensilsequioxane FOx). We present a minimum selectivity for diamond etching of 6$\pm$1. Using an adhesion-promoting silicon interlayer enables fabrication yields of up to 98%. We measure $T_2$ times of up to $\sim$25 $\mu$s before and after processing, demonstrating that the manufactured structures are usable for diamond-based quantum sensing.