Solid solubility of nitrogen in amorphous carbon films deposited in electron cyclotron resonance plasma

Electron cyclotron resonance plasma is used in the formation of nitrogen-containing carbon films with a CH4 + N-2 gas mixture. To accelerate cations from the plasma room, rf-induced negative de bias voltage is applied to the Si substrate. An increase in negative bias is effective for implantation of nitrogen, however, the nitrogen fraction saturates at [N]/([N] + [C]) = 0.09 at 300 V. The results of X-ray photoelectron spectroscopy suggests that the films have the C-N-C bond or nitrogen terminates the carbon dangling bond. In addition, ion acceleration causes a G-band and a D-band to appeal on IR spectrum, which would normally appear on the Raman spectrum obtained from typical diamond-like cal bon films. Furthermore, the hardness and maximum Young's modulus of nitrogen-containing carbon films are comparable to those of most diamond-like carbon films.