Cyclic discrete etching of Silicon oxide in deposition-sputtering cycles: towards to ALE

Basic properties of cyclic discrete etching process for Silicon dioxide were studied in conventional plasma etching tool. Process under consideration is based on consequent deposition of fluorocarbon polymer film from plasma of C4F8, and following activation of etching reaction between surface Silicon and Fluorine contained in the film by ion flux from plasma. Deposition rate of polymer film and its etching rate were measured by means of spectral ellipsometry at different wafer temperatures. Atomic layer etching process was demonstrated with usage of Oxygen and Argon plasma. Saturation of per cycle etching rate was achieved with respect to duration of deposition step.