Anuja De Silva
Technical Director at Lam Research
Patterning Solutions for Accelerated Scaling: Enabling High NA EUV Lithography
With each technology generation, device dimensions continue to shrink, driven by ongoing advances in lithography. Extreme ultraviolet (EUV) lithography at a 13.4 nm wavelength is now in high‑volume manufacturing, while high‑numerical‑aperture (high‑NA) EUV is under active development. The introduction of high‑NA EUV with the TWINSCAN EXE:5000 enables feature scaling below 28 nm pitch using a single EUV exposure, placing new demands on photoresist materials and patterning processes. Realizing the full benefits of high‑NA EUV requires innovations that extend beyond conventional solution‑processed EUV resists.
All‑dry EUV resist technologies provide differentiated process knobs that enable enhanced performance relative to traditional resist systems. Lam’s Aether® dry resist technology has been adopted in high‑volume manufacturing, overcoming long‑standing trade‑offs among resolution, sensitivity, line‑edge roughness and defectivity while delivering full productivity entitlement for 0.33 NA EUV lithography. In this work, we demonstrate continued progress in dry resist development to address the specific challenges of high‑NA EUV. In particular, expanding depth of focus (DoF) while maintaining high pattern fidelity at low dose is critical at 0.55 NA. We present 3D engineered dry resist films that enable through‑thickness composition tuning and profile modulation, providing scalable benefits as pattern pitch continues to shrink. Validation of 3D engineered resist concept through high NA patterning at pitch 20nm and below will be demonstrated.
About Anuja De Silva
Anuja De Silva is a technical director within dry resist group at Lam Research. Her expertise is in development of new materials and processes for advanced patterning. She is a co-author of ~50 publications and ~75 patents. She is a senior member of SPIE and a member of the IRDS patterning roadmap committee. She is a keen advocate of technical leadership among women in Semiconductor research and a mentor within SPIE’s Women in Optics and Semi org. Previous to joining Lam, Anuja was part of the advanced patterning group at IBM research. She obtained her PhD in Chemistry from Cornell University and BA in Chemistry from Mount Holyoke College.





