Chemical Origins of Environmental Modifications to MOR Lithographic Chemistry

Researchers at imec presented a study at SPIE Advanced Lithography + Patterning 2025 focusing on the chemical mechanisms behind environmental modifications in metal oxide resists (MORs) used in extreme ultraviolet (EUV) lithography. The study highlights the impact of gases like O₂, CO₂, and H₂O on post-exposure delay (PED) and bake (PEB) processes, which can lead to critical dimension (CD) drift. Through the use of the BEFORCE platform, which integrates EUV exposure, FTIR spectroscopy, and controlled environments, researchers were able to study the effects of different atmospheres on MORs. Findings suggest that O₂ plays a significant role in ligand cleavage and sensitivity enhancement in MORs, potentially reducing EUV doses without sacrificing resolution. This research provides valuable insights for optimizing MOR processes in semiconductor manufacturing.