Evaluation of lab-scale EUV microscopy using a table-top laser source

Abstract

High brightness Extreme Ultraviolet (EUV) sources for laboratory operation are needed in nano-fabrication and actinic (“at-wavelength”) inspection of the masks for high volume manufacturing in next generation lithography. Laser-plasma EUV sources have the required compactness and power scalability to achieve the demanding requirements. However, the incoherent emission lacks the brightness for single-shot high contrast imaging. On the other hand, fully coherent sources are considered to be unsuitable for full-field sample illumination and prone to speckles. We evaluate the capabilities of a lab-scale amplified-spontaneous-emission (ASE) EUV laser source to combine brightness and high quality imaging with full-field imaging, along with rapid acquisition and compactness.