Mask stretching for next generation lithography masks

摘要

Next generation lithography tools, such as X-ray, ion, or electronnbeam lithography equipment set different standards for mask fabrication.nA thin film membrane is now the carrier of the pattern to be copied on ansubstrate. Systematic aberrations are inevitable due to heat distortionnduring exposure and other influences. The possibility of integrating annactive correction system in the mask is investigated and the mechanicsnfor the elastic in-plane stretching of the mask are developed. Equationsnthat relate actuator displacements to the displacement of a finitennumber of measurement points (or precision points) are derived fornin-plane actuation of the mask membrane. A large-scale experimentalnmodel as well as a finite-element model was used to demonstrate thenvalidity of this method