This paper aims to give a short overview on some relevant processing issues existing in SiC and GaN power devices technology. The main focus is put on the importance of the channel mobility in transistors, which is one of the keys to reduce R ON and power dissipation. Specifically, in the case of the 4H-SiC planar MOSFETs the most common solutions and recent trends to improve the channel mobility are presented. In the case of GaN, the viable routes to achieve normally-off HEMTs operation are briefly introduced, giving emphasis to the case of the recessed hybrid MISHEMT.