Deposition of diamond-like carbon films by high-intensity pulsed ion beam ablation at various substrate temperatures

Diamond-like carbon (DLC) Elms have been deposited on to Si substrates at substrate temperatures from 25degreesC to 400degreesC by a high-intensity pulsed-ion-beam (HIPIB) ablation deposition technique. The formation of DLC is confirmed by Raman spectroscopy. According to an x-ray photoelectron spectroscopy analysis, the concentration of sp(3) carbon in the Elms is about 40% when the substrate temperature is below 300degreesC. With increasing substrate temperature from 25degreesC to 400degreesC, the concentration of sp(3) carbon decreases from 43% to 8%. In other words, sp(3) carbon is graphitized into sp(2) carbon when the substrate temperature is above 300degreesC. The results of x-ray diffraction and atomic force microscopy show that, with increasing the substrate temperature, the surface roughness and the friction coefficient increase, and the microhardness and the residual stress of the films decrease.