Diamond-like carbon films synthesized by cathodic arc evaporation

Abstract

Abstract Diamond-like carbon (DLC) films can be prepared by various techniques. Among these processes, the cathodic arc evaporation of a pure carbon source has the advantage that variables such as evaporation rate, substrate temperature and substrate bias voltage can be independently managed. Furthermore, it allows us to synthesize hydrogenated or hydrogen-free carbon films. Because of its negative temperature coefficient of electrical resistivity, carbon is a diffucult material to evaporate and the plasma stream generated from arc spots contains a large quantity of macroparticles. The present study of DLC films synthesized by arc evaporation introduces the solution employed to produce a pure carbon plasma stream for the formation of hard carbon films. The enhanced arc process based on a modified rectilinear plasma optic system is described and the influence of the process and deposition conditions in steering the arc spot motion and refining the plasma stream of macroparticles for carrying out high rate carbon film deposition are studied. The carbon films' features as analyzed by Raman spectroscopy, Fourier transform IR spectroscopy and scanning electron microscopy show that the films are dense non-hydrogenated DLC films under certain process conditions. These DLC films exhibit promising mechanical results such as a good hardness and an excellent adhesion level on high speed steel substrates.