Diffusion in Porous SiC

Slight decrease in the doping concentrations for both impurities at the surface of the porous layer apparently is associated with the out-diffusion process, which was also observed during diffusion of the same impurities into nonporous SiC substrates [7]. 

Such uniform dopant distribution in the porous layer was observed in all SiC samples in which the thicknesses of porous layers varied from 2 to 10 pm in our experiments on diffusion. This can be explained by the fact that diffusion of dopant atoms in a porous layer occurs not only via diffusion through the SiC walls of porous layer but also through gas-phase transport within pore openings and surface diffusion. 

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