Deposition of Diamond-Like Carbon Films by High-Intensity PulsedIon Beam Ablation at Various Substrate Temperatures

Diamond-like carbon (DLC) films have been deposited onto Si substrates at substrate temperatures from 25°C to 400°C 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 sp³ carbon in the films is about 40% when the substrate temperature is below 300°C. With the increase of substrate temperature from 25°C to 400°C, the concentration of sp³ carbon decreases from 43% to 8%. In other words, sp³ carbon is graphitized into sp² carbon when the substrate temperature is above 300°C. The results of x-ray diffraction and atomic force microscopy show that, with the increase of the substrate temperature, the surface roughness and the friction coefficient increase, and the microhardness and the residual stress of the films decrease.