Wavefront measurement for EUV lithography system through Hartmann sensor

Accurate wavefront aberration measurement are essential for next-generation Extreme Ultraviolet (EUV) Lithography. During the past years several accurate interferometric techniques have been developed, but these techniques have limitation. In this work we discuss a different technique based on the Hartmann Wavefront Sensor that requires no interferometry. We present a mathematical model of this system and describe our experimental setup which demonstrates the feasibility and advantages in terms of dynamic range and accuracy compared to interferometric techniquesImaging Science and TechnologyApplied Science