ECR-MPCVD fabricated nitrogen doped DLC films for potential biomedical application

Abstract

In this work, nitrogen doped diamond like carbon (DLC) films were fabricated on silicon wafers by varying CH4–N2 flow rates in an ECR-MPCVD system. The morphology, roughness and physicochemical nature of as-deposited films were characterized using SEM, AFM and XPS. With the increase of CH4 flow rate from 5 to 20 sccm, the coverage and surface roughness of DLC film have improved, while sp2/sp3 ratio decreases. Subsequently, the in vitro osteogenesis of N doped DLC films with 20 sccm CH4 was evaluated in terms of their apatite forming ability by soaking the samples in simulated body fluid (SBF) at 37 °C. The results show a very fast formation of crystalline apatite coatings on DLC films in 28 days, compared to reported more than 12 weeks. Moreover, the water contact angle (70°), the hemolysis rate (3.63%), the relative growth rate of HEK293T cell (101.2 ∼ 127.96%) and the cytotoxicity level (0) prove its promising potential for biomedical application.