Optimization of technological parameters in plasma chemical etching of quartz single crystals

Abstract

Main technological parameters of the process of local plasmochemical etching of single-crystal quartz were optimized. The etching was performed in a gas mixture of CF₄ and H₂ under radio frequency (RF, 13.56 MHz) discharge excitation. The scientific experiment design by the Taguchi matrix method was used to examine the effect of chamber pressure, RF generator power, negative bias applied to the substrate holder, and hydrogen flow rate on the rate of the etching process. The experimental results made it possible to evaluate for the first time the influence exerted by the technological parameters on the etching rate. It was shown that the influence exerted by the technological parameters in the conditions under study decreases in the following order: pressure in the reaction chamber, bias potential, RF power, hydrogen flow rate.