EUV resist screening update: progress towards high-NA lithography

The improvement of EUV photoresists is a key enabler for the deployment of High-NA EUV lithography and future technology nodes. Research in this field is supported by a joint research program between PSI and ASML. This program is dedicated to supporting the EUVL community with the development of materials by carrying out resist screening experiments with the EUV interference lithography tool at PSI, with an emphasis on resolution improvement towards reaching High-NA EUV scanner specifications. The tool enables high-resolution patterning without limitations in terms of chemical outgassing or contamination and is, therefore, an effective method for the testing of novel EUV photoresists. In this work, we consider the progress monitored in the second half of 2021. We describe the exposure tool as well as the updates made to the resist characterization metrology implemented at PSI. Resist performances are quantified with regards to resolution, linewidth roughness, and sensitivity. We show an overview of the current development status through a comparative study of different resist platforms. Recent results show chemically amplified resists (CAR) and non-CAR printing 12 nm and 11 nm lines/spaces features, respectively. Limitations of each platform are displayed and general progress and perspectives are discussed to lead the way to higher resolution results.