Understanding molecular weight effects in polymer photoresists and how variations in molecular weight can affect dissolution rates

Extreme ultraviolet (EUV) lithography, utilizing a 13.5nm wavelength, has significantly advanced the semiconductor industry. Key to this progress are developments in chemically amplified photoresists (CAR), though challenges like stochastic effects in photoresists complicate achieving required resolution and line edge roughness. To address these issues, the study explores polymethyl methacrylate (PMMA) as a model system, focusing on the impact of polymer molecular weight on roughness and defectivity. The paper investigates how variations in molecular weight influence the dissolution rate of PMMA in a developer, using commercial PMMA samples mixed with varying molecular weights to assess their dissolution behavior under EUV exposure.