Surface morphology, cohesive and adhesive properties of amorphous hydrogenated carbon nanocomposite films

摘要

In this work, amorphous hydrogenated carbon (a-C:H), SiO_x containing a-C:H (a-C:H/SiO_x) and nitrogen-doped a-C:H/SiO_x(a-C:H:N/SiO_x) thin films were deposited on chromium thin film coated glass using a closed drift ion beam source. Acetylene gas, hexamethyldisiloxane and hydrogen or 20% nitrogen/hydrogen mixture were used as precursors. Resulting hydrogenated carbon thin film surface morphology as well as their cohesive and adhesive properties were studied using progressive loading scratch tests followed by optical microscopy analysis. Surface analysis was also performed using atomic force microscopy via topography, surface morphology parameter, height distribution histogram and bearing ratio curve based hybrid parameter measurements. The a-C:H/SiO_x and a-C:H:N/SiO_x thin films showed better mechanical strength as compared to the conventional a-C:H films. X-ray photoelec-tron spectroscopy was used to determine the chemical composition of these films. It showed increased amounts of silicon and absence of terminal oxygenated carbon bonds in a-C:H:N/SiO_x thin film which was attributed to its improved mechanical properties.