OPTIMIZATION OF ELECTROTHERMAL VAPORIZATION, INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY CONDITIONS FOR THE DETERMINATION OF IRON, COPPER,NICKEL AND ZINC IN SEMICONDUCTOR GRADE ACIDS

An electrothermal vaporization (ETV) unit, for introducing samples wit h high acid concentration and low volume, into inductively coupled pla sma (ICP) has been described. Some features of ETV-ICP-MS for single-e lement determination have been investigated. A number of studies have been carried out to investigate the optimum operating conditions such as vaporization temperature, vaporization interval and carrier gas flo w rate. The study highlights the determination of Fe, Ni, Cu and Zn. F or all elements except Zn, a vaporization temperature > 2700 degrees C was selected. In accordance with the vaporization nature, elements we re placed in two groups for multi-element determinations. The first gr oup consisted of Fe, Cu and Ni and the second group of Zn. On the basi s of the determinations, we derived the detection limits of these elem ents in 6 inch wafer for our future studies. The results obtained are compared with those of other existing methods.