Optical emission diagnostic of a pulsed arc discharge

A spectroscopic analysis of plasma properties produced in a new type of pulsed-vacuum arc system, is presented herein. The system is used to produce TiN coatings and the process is carried out by using a vacuum chamber filled with nitrogen. Inside the chamber there are two opposite electrodes (the anode being the sample and the cathode acting as the target). A bank of capacitors is charged up to 300 V. Thereafter, it is discharged between the electrodes by means of a RLC circuit producing the plasma. Some species (Ti, Ti I, N, N I, N-2, N-2 I, and TiN) have been identified in the plasma. Electron and excitation temperatures were calculated by means of titanium atomic lines assuming local thermodynamic equilibrium (LTE), but supposing that T-exc is different to T-e, using the Boltzmann plot and line-continuum ratio, obtaining approximate values of 1 eV. Electron density in the order of 10(13) cm(-3) was calculated using stark broadening of atomic nitrogen lines at 414.6 and 492.8 nm. Moreover, the plasma behavior as a function of the pressure was studied in this article. (C) 2004 American Vacuum Society.