Characterisation and microcorrosion of DLC ultrathin films with acetylene and ethylene source gases by PECVD

Abstract

Diamond like carbon (DLC) films were deposited by plasma enhanced chemical vapour deposition, whose purpose is in the application of the films to further improve read/write durability of next generation recording discs. The effects of acetylene (C₂H₂) and ethylene (C₂H₄) source gases and deposition parameters on roughness, structure, hardness, resistivity, silicone contamination, glide performance and microcorrosion measurement on the cobalt concentration of DLC films are studied utilising the following equipment: AFM, Raman, nanoindenter, resistivity gauge meter, phase metrics, time of flight SIMS and inductively coupled plasma mass spectroscopy. Results show that the Raman I_d/I_g ratio, G and D peak wavenumber, hardness, glide noise and avalanche, silicone contamination and cobalt concentration of the C₂H₄ source gas films are significantly lower than those of C₂H₂ gas. Diamond like carbon films prepared at the higher gas flow exhibit a lower I_d/I_g and cobalt concentration. Films deposited with a higher voltage bias and heater power will induce a higher I_d/I_g and cobalt concentration.