Seminars Archive
Full-field microscopy with extreme ultraviolet laser illumination
NSF Engineering Research Center for Extreme Ultraviolet Science and technology; and Electrical and Computer Engineering Department, Colorado State University, USA
Abstract
The development of soft x-ray (SXR)/extreme ultraviolet (EUV) lasers at wavelengths in the 50 nm to 10 nm range at Colorado State University has opened many opportunities for the development of novel table-top metrology tools.
In this talk I will described the imaging efforts carried out at Colorado State University, with emphasis in the development of a compact full-field microscope for the characterization of extreme ultraviolet lithography (EUVL) masks. The masks’ resonant-reflective multilayer coatings and wavelength-specific response call for at-wavelength inspection. This microscope combines the output of a 13.2 nm wavelength table-top Ni-like Cd laser with state-for-art Fresnel zone plates to acquire high quality images with exposure times of less than 90 seconds, capturing broad area images of periodic objects with a spatial resolution of 55 nm using the same numerical aperture and illumination angle of a 4× EUV stepper. These results open the path for the realization of convenient stand-alone metrology systems for on-site evaluation of EUVL masks.
