Effects of nitrogen addition on hydrogen plasma etching of diamond

We evaluate the H₂ + N₂ plasma etching of (100) and (111) oriented diamonds. The crystallographic anisotropy of H 2 + N 2 etching is comparable to pure H 2 plasma etching, with etching rates of μm/h and with typical root-mean-square roughness after etching of Rq ≤ 1 nm. The etching rate increases with increasing N₂/H₂ ratio. Optical emission spectroscopy (OES) data indicate that N and NH radicals are reacting with surface carbon atoms on diamond. A desorption of CN-molecules takes place. These findings indicate that nitrogen is part of the etching process using MPCVD technique. This etching technology is expected to advance device fabrication and deepen the understanding of growth mechanisms of nitrogen-doped diamond, including the fabrication and optimization of diamond based power electronics and NV center quantum applications. • H₂ + N₂ plasma etches diamond (100), (111). • The etching rate increases with the N₂/H₂ ratio. • N/NH react with diamond surface carbon, desorbing as CN-containing species. • Maintains planarity (Rq ≤ 1 nm) with etch rate of μm/h.