CNT EUV pellicle: balancing options (Conference Presentation)

As EUV lithography wafer volumes increase, throughput and yield require more focus. Yield can be enhanced by introducing a pellicle to hold particles out of the focal plane and minimize their impact to imaging. Using a pellicle also minimizes the extra wafer inspections required to ensure that printable mask defects do not increase over time. However, if the associated transmission loss is high, the yield advantage is offset by reduced throughput. The CNT-based pellicle offers the advantage of very high EUV transmission. CNT pellicles have also demonstrated lifetime at 300W EUV scanner power. The challenge is balancing the CNT membrane design in three areas: physical presence/the ability to stop particles, EUV transmission/imaging impact, and lifetime in the scanner/thermal tolerance. Each of these areas will be described along with simulated and experimental data illustrating the value of a CNT-based EUV pellicle solution for the future.