Influence of thermal heating on diamond-like carbon film properties prepared by filtered cathodic arc

• Tetrahedral-amorphous diamond-like carbon (ta-DLC) by filtered cathodic arc
• ta-DLC used in magnetic recording head as head overcoat
• ta-DLC thickness range of less than 2 nm
• ta-DLC property dependence on heating
• Temperature effect range of up to 300 °C

Tetrahedral amorphous diamond-like carbon (ta-DLC) films were deposited on magnetic recording heads using the filtered cathodic arc method. The deposited film thickness was on the order of several nanometers. The DLC films were then annealed to 100 °C–300 °C for 30 and 60 min, and the structure of the ta-DLC films was investigated using Raman spectroscopy, where the gross changes were observed in the Raman D and G peaks. Detailed interpretation concluded that there was sp2 clustering as a function of temperature, and there was no sp3-to-sp2 conversion after heating up to 300 °C. Furthermore, X-ray photoelectron spectroscopy suggested that oxidation of both the ta-DLC film and the adhesion layer occurs at 300 °C. Additionally, more film wear was observed with heating as measured by a nanoindenter.