PECVD of biocompatible coatings on 316L stainless steel

This study details the variation of the SiOxCyHz film properties deposited on 316L stainless steel in a 13.56 MHz RF Plasma Enhanced Chemical Vapor Deposition (PECVD) reactor. The films were characterized for their hardness, hydrocarbon content and wettability. The film properties are found to be dependent on the oxygen/HMDSO flow ratio and RF power. The hardness increases with increased O2/HMDSO flow and with RF power. Films deposited on a powered electrode show a linear dependency of hardness with RF power. The hardness correlates with the hydrocarbon and silica content of the films as measured by FTIR spectroscopy. The water contact angle was found to decrease with an increase in O2/HMDSO ratio and RF power. The high hydrophilicity observed immediately after deposition for high O2/HMDSO ratio was temporary and the contact angle increased with time and saturated. Preliminary biocompatibility studies were carried out using Rat Aortic Smooth Muscle (RASM) cells. The results of cell proliferation, viability and toxicity are presented.