Figure 4.

Evolution of the porous SiC morphology for a constant applied current density of 25.5 mA/cm². The observed sample (SEM) was etched from the Si face, and the total layer thickness is about 20 μm. The increase of the porosity and the pore density with the depth is clearly visible. Moreover, (a) near the surface, the pores are triangular; (b) at a 10-μm depth, they are chevron-shaped; and (c) they look like dendrites at 20 μm.