Nano-Scratch Response of Diamond-Like Carbon Film Deposited by Pulsed Direct Current Magnetron Sputtering

Diamond-like carbon (DLC) films are known for thermal, chemical and mechanical properties. Hydrogen free and hydrogenated DLC films are deposited using pulsed direct current magnetron sputtering. The influence of sputtering conditions on the nano-scratch properties of these films is investigated. Raman spectra reveals that structural disorder in the a-C:H matrix decreases with increase in acetylene flow. Increased acetylene flow reduces frictions, residual stress and retains hardness. The friction responses of the deposited defects free ultra-smooth films are influenced by pull off forces at low load and by formation of carbonaceous layer at high load.