Real- and Quasi-Atomic Layer Etching for Ultra-High Resolution Patterning

Abstract: An attempt was made at developing atomic layer etching from a cyclic etching process in an ICP-RIE tool. During the process OES was used for contamination monitoring and estimation of the relative amount of Cl2 left in the chamber during the etch step of cyclic etching processes. The process parameters were then optimized resulting in a quasi-ALE process suitable for pattern transfer as shown by the patterned samples used in the process. Due to the precise control of the etch rate and the smooth etched surface, the optimized process could be applicable for ultra-high resolution patterning.