Silicon doped diamond-like carbon (Si-DLC) thin films with Si contents in the 0-15 at.% range were deposited on silicon substrates using a reactive-sputtering method. The thermal stability of the films was investigated by 1 h open-air tube furnace heat treatment from 200 οC to 700 οC at intervals of 100 οC. The thickness changes and structural modification of the annealed films as a function of annealing temperature were closely studied. Raman spectroscopy and cross-sectional FESEM images were used to determine the structure and thickness changes of the annealed pure DLC and Si-DLC films, respectively. It was found that, as the Si content was increased, the graphitization (sp3-to-sp2 transition) temperature increased and the thickness loss decreased, which reflected the good thermal stability of the Si-DLC films. The tribological behaviors of the films, as evaluated using a ball-on-disk tribometer, reflected the property of low friction.

Keywords: Si-DLC, thin films, reactive sputtering, thermal stability, microstructure.