Preparation Of Diamond-like Carbon Films By High Power Impulse Magnetron Sputtering

Diamond-like carbon films are amorphous carbon films containing sp3 bonds and sp2 bonds, showing excellent properties on mechanics, optics, electrics, and so on. High power impulse magnetron sputtering (HiPIMS) technique has advantage on higher ionization ratio, lower and focused ion energy, denser and uniform film structure. Therefore, DLC films were prepared by DC magnetron sputtering and HiPIMS technique. By adopting different sputtering parameters, such as sputtering pressure, sputtering bias voltage and sputtering temperature, DLC films’ microstructure and physical properties were researched. Element N’s doping was also researched. The results are as follows:1. DC magnetron sputtering is a steady technique for preparing large area, uniform DLC films. The surface topography is dominated by sputtering pressure and sputtering bias voltage. Surface roughness reduces with sputtering pressure’s decreasing and sputtering bias voltage’s increasing. Sp3 fraction is influenced by sputtering pressure. DLC films prepared at 0.4Pa show lager sp3 fraction than samples prepared at 1Pa. Samples prepared by DC magnetron sputtering show general nano-hardness lower than 10GPa.2. During DLC’s deposition, HiPIMS technique has a voltage range and pressure range for stable discharge. With sputtering pressure’s decreasing and sputtering bias voltage’s increasing, size of surface particles and the ratio of ID/IG decreases, while sp3 fraction increases. Nano-hardness of DLC films is inversely proportional to ID/IG-Sample prepared at 1Pa with bias voltage 100V show highest nano-hardness of 18.4GPa. Compared to DC magnetron sputtering technique, samples prepared by HiPIMS show generally higher nano-hardness.3. Nitrogen doped DLC films(DLC:N) were prepared in mixed sputtering atmosphere filled with N2 and Ar using HiPIMS technique. With N2 flow ratio’s increasing, surface roughness increases, and sp3 fration decreases, while nano-hardness decreases from 16.7GPa to 11.1GPa. With 50V bias voltage’s applying, DLC:N film becomes denser, and its nano-hardness increases from 13.7GPa to 16.0GPa. Sp3 fraction of DLC:N film prepared at 300℃ decreases,but is nano-hardness increases from 16.7GPa to 18.8GPa.