LIF MEASUREMENTS OF METALLIC SPUTTERING DURING THE DEPOSITION OF A-C-H AND A-C B-H FILMS/

Laser induced fluorescence (LIF) has been used for the first time to m easure the density of Cr atoms sputtered by C-containing molecular ion s during the plasma assisted deposition of a-C:H and a-C/B:H films on a stainless steel chamber. The density of sputtered Cr atoms was found to decrease as the a-C:H film grows and after a critical time, t(c), the sputtering of Cr reached a steady value corresponding to a reducti on factor of more than 10. A fluence of 2 X 10(16) cm(-2) was estimate d at t(c) and related with the complete formation of a carbide on the substrate by means of XPS analysis. A high contribution of C containin g molecular ions to the initial film growth has been inferred from the sputtering yield at the beginning of the deposition. Sputtering of Cr was observed only during the initial stage of the deposition of a-C/B :H films from admixtures of H-2/TMB in a glow discharge. Finally, LIF measurement of Cr atoms sputtered in an Ar glow discharge was used to evaluate the removal efficiency of the deposited films.