Actinometric study on SiO2etching by a dual-frequency magnetic triode reactor

Abstract
The aim of this study is to characterize the SiO2 etching process developed in a magnetic triode experimental system fed by C2F6. The effect of some experimental parameter variation, namely of pressure, C2F6 flow, magnetic field intensity, upper electrode power (40 MHz), lower electrode power (13.56 MHz) on the SiO2 etch rate has been studied and related to the absolute value of the self-induced voltage of the lower substrate electrode. The gas phase has been investigated by means of actinometric optical emission spectroscopy. Good correlation has been found between the gas density trends of CF2 radicals and F atoms and the behaviour of etch rate, showing a significant dependence of the SiO2 etching rate on both ion energy and F:CF2 density ratio.