Influence of Thickness on Bond-Structures and Properties of Tetrahedral Amorphous Carbon Film

Tetrahedral amorphous carbon(ta-C) film,an advance electronics device material,was synthesized on the substrate of p-typed Si(110) substrate by double bending magnetic filtration cathode arc deposition.The influence of the film thickness(or deposition-time at 1.6 nm/min) on the C-bond structure and residual stress was investigated with Raman spectroscopy,scanning electron microscopy ellipsometer and spectrophotometer.The results show that the film thickness had a major impact.For instance,as the film thickness increased,many changes occurred,i) the sp³C ratio decreased,because an increasing number of sp³-bond turned into sp²-bond,however,in a thicker ta-C coatings sp³C-ratio was fairly high;ii) the down-shift of G-peak slightly increased;and iii) the dispersion and residual stress of the ta-C films decreased,indicating a decreasing topological disorder;and the film thickness little affected the surface roughness,uniformity and compactness.