Surface Roughness of Reactive Ion Etched 4H‐SiC in SF 6 / O 2 and CHF 3 / H 2 / O 2 Plasmas

4H‐SiC epitaxy and polished bulk surfaces were examined with atomic force microscopy and scanning electron microscopy before and after reactive ion etching of the surface with fluorinated plasmas. The etching processes were and based recipes with fairly high dc bias (420 and 367 V, respectively). Both etch recipes have negligible impact on polished bulk surface roughness, but both recipes did reduce the epitaxial surface roughness from ∼0.892 to ∼0.45 nm root‐mean‐square roughness.