Titanium density analysed by optical absorption and emission spectroscopy in a dc magnetron discharge

This paper presents an optical diagnostic examination of dc planar magnetron discharge used for titanium deposition at 30 mTorr in argon bulk gas. The results were obtained by optical absorption (OAS) and emission (OES) spectroscopy for two distances from the target without substrate. The absolute density of titanium in the ground and metastable states at 4 cm from the target ranged, respectively, between 8 × 10 10 cm −3 and 10 12 cm −3 and between 6 × 10 10 cm −3 and 3 × 10 11 cm −3 , in the range 0.2–1.0 A. OES results were used to prepare an assumed interpretation in terms of differences in loss mechanisms, mainly by either diffusion towards the walls for all particles at 8 cm from the target or collision losses for non-radiative species at 4 cm from the target, except for the titanium ground state. This was confirmed by our results of the argon metastable density measurement at 4 cm which was constant at around 7 × 10 10 cm −3 with discharge current.