Abstract
N2 gas flow medium-vacuum arc plasma with titanium cathode is applied to the PVD process producing TiN films.
In this paper, plasma parameters of such arc are measured for the pressure range from 10-3 to 10-1 Torr using the optical emission spectroscopy and the probe technique. The experimental results show that the arc plasma contains Ti and N2 as neutral particles, and Ti+, Ti++ and N2+ as ions. The spectral intensities of Ti+ and N2 have maximum values at pressures of 2×10-2 and 8×10-3 Torr, respectively. As the pressure increases from 10-3 to 10-1 Torr, the electron energy decreases from 1.3 to 0.2eV and the electron density increases from 1.5×1010 to 1.5×1011cm-3.
As a result of analyzing the above characteristics using the corona model, it becomes evident that the pressure at which the number densities of Ti+ ion and N2 molecule are maximum oincides with that at which TiN films are produced in the prevailing arc PVD apparatus.
