SURFACE-ROUGHNESS OF REACTIVE ION ETCHED 4H-SIC IN SF6 O-2 AND CHF3/H-2/O-2 PLASMAS/

4H-SiC epitaxy and polished bulk surfaces were examined with atomic fo rce microscopy and scanning electron microscopy before and after react ive ion etching of the surface with fluorinated plasmas. The etching p rocesses were SF6/O-2 and CHF3/H-2/O-2 based recipes with fairly high de bias (420 and 367 V, respectively). Both etch recipes have negligib le impact on polished bulk surface roughness, but both recipes did red uce the epitaxial surface roughness from similar to 0.892 to similar t o 0.45 nm root-mean-square roughness.