Nitrogen doped tetrahedral amorphous carbon (ta-C:N) thin films have been interesting for electrochemical analysis since it was reported recently that ta-C:N films could be a novel electrode material for sensing trace heavy metals such as lead,copper and mercury at about μM levels.However,there is still a need to systematically investigate the effect of N doping on the corrosion performance of the films because the corrosion resistance can strongly affect the electrochemical performance of the films,such as repeatability,sensitivity,long-term stability,durability,etc.In this study,the ta-C:N thin films were prepared on highly conductive n-Si (100) substrates using filtered cathodic vacuum arc deposition by varying nitrogen flow rates.The elemental composition,bonding structure and surface morphology of the ta-C:N films were investigated using X-ray photoelectron spectroscopy (XPS),Raman spectroscopy and atomic force microscopy (AFM).The corrosion behavior of the ta-C:N films was diagnosed in Hanks balanced salt solution by using electrochemical impedance spectroscopy (EIS) in terms of nitrogen concentration in the films.