Effect of Temperature and Ion Bombardment on DLC Relief Generation and Modification

DLC were deposited by arc-pulse sputtering of graphite. Raman spectroscopy was used for determination of sp3/sp2 ratio. DLC deposition temperature was varied by change of pulse frequency. After deposition DLC were etched by argon or oxygen ions (E = 3 keV). Study of DLC surface relief were carried out by means of atomic-force and laser microscopes. It is shown that DLC surface has domain-like structure with ranges of peaks along boundaries. Separate protrusions are observed on DLC surface. Their height is comparable to coating thickness. Generation of DLC relief strongly depends on intensity of diffusion process taking place on the growing film surface. Increase of deposition temperature leads to growth of rough relief (agglomerations of protrusions). DLC relief modification by ion bombardment depends on chemical type of ions. There are peculiarities of DLC relief modification by reactive oxygen and inert argon. The peculiarities are related with changing of different components of DLC relief by oxygen and argon. Argon bombardment lowers the height of peaks and partially removes them from DLC surface without noticeable change of protrusions and areas of inside domains. Oxygen etching (physical and chemical) smoothes areas of inside domains, decreases height of protrusions and makes the hollows near peaks deeper.