Effects of ALE Capabilities and DC Pulsing in Microwave ECR Plasma on Etching Processes for Cutting-Edge Logic LSI

This paper discusses the application of a microwave ECR plasma etching system, which has diverse pulsing functions and ALE (Atomic Layer Etching) capabilities for logic LSI. In fin and WFM/HK etching, verticality and planarity were achieved by applying ALE capabilities pulsing at low gas pressure. In WFM patterning, WFM erosion at the fin top was minimized while eliminating nm-level space residues. We successfully improved this trade-off by employing a novel technology called DC pulsing, which mitigates the charge-up effect.