Hydrogen-free fluorinated DLC films with high hardness prepared by using T-shape filtered arc deposition system

Abstract

Fluorinated diamond-like carbon (F-DLC) films have good surface properties. DLC films with high mechanical hardness are prepared using filtered arc deposition, which is a physical vapor deposition method. In this work, the fabrication of F-DLC films using filtered cathodic arc deposition while introducing a fluorocarbon gas was carried out, and the characteristics of the F-DLC films were investigated. The F-DLC films were deposited on Si and WC substrates using the T-shape filtered arc deposition (T-FAD) system while introducing fluorocarbon gases. The fluorocarbon gases used for this purpose were C3F8, C6F14, or C7F14. The F-DLC characteristics such as surface appearance, film structure, film density, nanoindentation hardness, substrate adhesion, and water contact angle were investigated. The characteristics of the fabricated DLC films were as follows: the fluorine content ranged from 0 to 22 at.%, film density ranged from 2.1 to 3.1 g/cm3, nanoindentation hardness ranged from 10 to 48 GPa, elastic modulus ranged from 140 to 360 GPa, and water contact angle ranged from 66 to 95°. In addition, the F-DLC films showed good adhesion strength on WC substrates. F-DLC films with high mechanical hardness and water repellency were obtained using T-FAD.