Characterization of plasma polymerized organosilicon thin films deposited on 316L stainless steel

This study focused on the characterization of the organosilicon films deposited on 316L stainless steel (316L SS) substrate using a plasma polymerization process with hexamethyldisiloxane (HMDSO) precursor and different N2 gas flow rates. The organosilicon film had a C-rich composition as deposited using only HMDSO precursor. The nitrogen content of thin film consecutively increased with increasing N2 flow rate up to 15 sccm. The film deposition rate increased with increasing N2 flow rate. All films exhibited the smooth and pinhole free surfaces. Good adhesion property was obtained for each film after scratch test. Better biocompatibility and cell adhesion was observed for the nitrogen free organosilicon film as compared with that of the untreated 316L SS. Further enhancement of biocompatibility was found for those films with N2 addition. The best biocompatibility, highest transmittance, less hydrophobic surface, and excellent wear resistance were noted for the film grown under 5 sccm N2 flow rate. Such film performance makes it become a promising candidate as the surface coating layer on 316L SS for biomedical application.