Argon Implantation in Tetrahedral Amorphous Carbon Deposited by Filtered Cathodic Vacuum Arc

The implantation of argon in tetrahedral amorphous carbon (ta-C), deposited by the filtered cathodic vacuum arc technique and concurrently bombarded with argon ions (Ar+), is investigated in this study. The ta-C films were prepared with a 5-ms DC-pulsed arc, a current of 190 A, and a frequency of 3 Hz, and they were deposited on a ground substrate holder. The argon atoms were implanted into the film by simultaneously bombarding the films with a beam of Ar+ in the 0-180 eV energy range. The concentration of argon, determined by Rutherford backscattering spectroscopy, was investigated as a function of the Ar+ energy. Raman scattering spectroscopy was used to investigate the structure of the films. The stress of the films depends on the Ar+ energy and reduces significantly as a function of the annealing temperature. A study of argon effusion, ranging from room temperature up to 1000 °C, shows that the argon atoms evolve from the films at different temperatures depending on the Ar+ energy. Scanning electron microscopy revealed the formation of bubbles after argon effusion. It was observed that the structural transformations that promote the relaxation of the carbon matrix and the argon effusion are different from each other.