C-90% SiC coatings are fabricated on the stainless steel which is used as waste containers of tritium to pre-vent the diffusion of hydrogen and its radioisotopes. The bonding strength between the coating and substrate is the key issue todecide the life of the coating. In this work, C-90% SiC coatings were fabricated using middle frequency magnetron sputteringand ion-beam mixing to enhance the adhension strength. SIMS and SEM morphology analyses were used to characterize thebonding structure. The results show that Cu pre-deposition can enhance the adhesion of coatings to substrate due to the elementintermixing effect of the substrate and coating.