KLA Corporation
Methods And Systems For Compact, Small Spot Size Soft X-Ray Scatterometry

Abstract:

Methods and systems for performing measurements of semiconductor structures based on high-brightness, Soft X-Ray (SXR) illumination over a small illumination spot size with a small physical footprint are presented herein. In one aspect, the focusing optics of an SXR based metrology system project an image of the illumination source onto a specimen under measurement with a demagnification of at least 1.25. In a further aspect, an illumination beam path from the x-ray illumination source to the specimen under measurement is less than 2 meters. In another aspect, SXR based measurements are performed with x-ray radiation in the soft x-ray region (i.e., 80-3000 eV). In some embodiments, SXR based measurements are performed at grazing angles of incidence in a range from near zero degrees to 90 degrees. In some embodiments, the illumination optics project an image of an illumination source onto a specimen under measurement with a demagnification of 50, or less.