As EUV approaches high volume manufacturing, reticle defectivity becomes an even more relevant topic for further investigation. Current baseline strategy for EUV defectivity management is to design, build and maintain a clean system without pellicle. In order to secure reticle front side particle adders to an acceptable level for high volume manufacturing, EUV pellicle is being actively investigated. Last year ASML reported on our initial EUV pellicle feasibility. In this paper, we will update on our progress since then. We will also provide an update to pellicle requirements published last year. Further, we present experimental results showing the viability and challenges of potential EUV pellicle materials, including, material properties, imaging capability, scalability and manufacturability.

In this work a two-dimensional, axisymmetric plasma sheath model is presented that is used to predict ion trajectory deviations in the plasma-wafer interface for a given set of physical etch conditions and chamber geometries. The model successfully predicts the plasma sheath deformation and the associated ion tilt in the vicinity of the wafer edge due to electrical discontinuities. We couple the predictive power of the plasma sheath model with a feature-scale kinetic Monte Carlo etch model to determine the asymmetries in post-etched structures and hence on-product overlay. The feature-scale model serves as a tool to translate the ion tilt within plasma sheath to the sidewall angle asymmetries in the etched trenches and the resulting overlay errors in two adjacent layers of a semiconductor device that could ultimately affect the device yield.