The ever-decreasing pattern size of structures in integrated circuits requires lithography processes using light of ever-shorter wavelengths. Currently, laser light with wavelengths of 248 nm and 193 nm is used for the illumination in production lines of semiconductor factories. However, since several years many research groups are already dealing with the next generation lithography, the extreme ultraviolet lithography (EUVL) that will use light with a wavelength of 13.5 nm.
The availability of sources and optics for the EUV range opens up new perspectives for numerous applications beyond the lithography. The inherent potential of light with such short wavelengths to obtain resolutions in the nanometer range can also be used e. g. for microscopy or spectroscopy. Within the Fraunhofer association, several institutes have joint together to develop demonstrators for EUV microscopy, where these new EUV components were applied.
One of the key elements of an EUV microscope are the optics. A group of IWS Dresden, Fraunhofer Institute for Material and Beam Technology, has developed collection optics and multilayer mirrors for Schwarzschild objectives, that meet the stringent requirements for high-reflection and precision. Using these optics, a resolution of the EUV microscope far below 1 micron can be obtained. Presently, the resolution is only limited by the pixel size of the CCD detector. Particularly important is the fact, that because of the high power of the source and the high-reflection of the optics even one pulse of light is sufficient to take a picture of the sample under investigation.
Your contact for further information:
Fraunhofer Institute for Material and Beam Technology IWS Dresden
(Fraunhofer-Institut für Werkstoff- und Strahltechnik IWS Dresden)
01277 Dresden, Winterbergstr. 28
Dr. Stefan Braun
Phone: (0351) 25 83 432
Fax: (0351) 25 83 300