A spin-on doping technique was applied for Er incorporation into porous SiC. A distinct Er PL peak close to 1.53 mum appeared after the formation of an Er containing spin-on diffusion source followed by a drive-in thermal annealing step at 1100(0)C. The large internal surface area of the pore channel is beneficial for Er in-diffusion and the formation of optically-active IR complexes. Subsequent treatment of the spin-on doped porous SiC samples in an HF solution resulted in the disappearance of the Er-related PL lines. The drive-in annealing step was then repeated which resulted in the reappearance of the Er PL, indicating that a significant amount of Er-related complexes that are not soluble in HF were present in the Er doped porous SiC. Additional diffusion of Er and the simultaneous formation of oxygen containing luminescent complexes are believed to occur during the second thermal drive-in.