Demonstration of fast wide angle scatterometry for CD metrology using laboratory DPP-XUV source - (PPT)

摘要

Non-destructive, high precision, high throughput characterization methods of critical dimensions and pattern cross sections are critical to the maturation of sub-30 nm technologies. New demands are arising with sub 20 nm half pitch structured wafers and with reflective EUV masks. Having the drawback of existing and candidate approaches in mind, we suggest that the availability of EUV and XUV technology may provide a path to overcome most of the issues. In a first proof of concept experiment, we realized CD measurements on 50 nm half pith structures on < 0.1 mm~2 footprint with a laboratory discharge source with 5 seconds exposure time With DPP source flexibility, wavelengths can be matched to best process sensitivity and efficiency; e.g. to inband EUV at 13.5 nm for actinic CD measurements on EUV masks. Tool development roadmap and ultimate limits are discussed.