Oxygen and nitrogen doped diamond-like carbon thin films: A comparative study

Abstract

DLC films were deposited on Si substrates using direct ion beam deposition method, followed by investigating the influence of O2 and N2 doping on their electrical and structural properties. The films were doped with oxygen and nitrogen under flow rates of 5 and 40 sccm (standard cubic centimeters per minute). The structure of the films was studied by Raman spectroscopy. Result showed that by increasing oxygen incorporation, sp2 content decreases, sp3 content increases, and the C-C bonding loses its order. As the size of the sp2-rich cluster increased with N2 content, the disorder in the DLC samples decreased, leading to a decrease in the FWHM of the G peak. The water contact angle measurement showed that an increase in oxygen flow ratio results in a decrease in contact angle from 82.9° ± 2.1° to 50° ± 3°. With increasing nitrogen flow rate from 5 to 40, the contact angle of DLC thin films increased from 78° to 110°.

Keywords

• si substrates
• direct ion beam
• dlc films
• raman spectroscopy
• water contact angle