Synthesis of nitrogen incorporated carbon films by plasma immersion ion implantation and deposition

Nitrogen incorporated carbon films were synthesized using plasma immersion ion implantation and deposition at room temperature. Nitrogen partial pressure was varied from 1.0×10−3 to 1.0×10−2 Pa. Thickness of films was about 200 nm. Fourier transmission infrared spectrum, Raman spectrum and X-ray photoelectron spectrum were employed to analyze the bonding states and chemical composition of the films. With increasing N2 flow, the core level of C1s spectra shifted to high energy. In the Raman spectra, G-bands are broader and shifted toward a lower frequency from 1572 to 1557 cm−1. A four-probe tester and an ultraviolet spectrophotometer were employed to measure the resistance and the optical band gap of the films. The results show that the films are of semiconducting nature and the resistivity decreases with the increase of N2 flow. Nano-indentation results show that the nano-hardness increases with increasing N content, and the value of recovery R reveals that coatings undergo not only plastic deformation but also elastic deformation during indentation testing.