PRELIMINARY-STUDY OF THE ROLE OF DISCHARGE CONDITIONS ON THE IN-DEPTHANALYSIS OF CONDUCTING THIN-FILMS BY RADIOFREQUENCY GLOW-DISCHARGE OPTICAL-EMISSION SPECTROMETRY

A radiofrequency glow discharge (rf GD) device was evaluated for the i n-depth profile analysis of thin conducting films by optical emission spectrometry. Samples consisted of steel with Al-Zn coatings of approx imately 20 mu m thickness, The role of the discharge conditions, inclu ding rf generator power, pressure in the discharge chamber and the lim iting orifice (anode) diameter on the temporal evolution of the intens ity of Zn I 334.5 nm emission and on the shape and depth of the crater s produced were investigated, These studies provide information about the variations in the in-depth resolution and sputtering rates when th e discharge conditions are varied, Results show the critical role of t he internal diameter of the anode upon the crater shape and the penetr ation depth as well as a strong dependence of the etching rate with rf power and gas pressure of the discharge, The shapes of craters obtain ed after different sputtering times (from 3 to 60 min) were also measu red, with a linear relationship between penetration depth and the sput tering time verified.