Spatial and spectral characterization of a laser produced plasma source for extreme ultraviolet metrology
2004 (English)In: Review of Scientific Instruments, ISSN 0034-6748, E-ISSN 1089-7623, Vol. 75, no 11, 4981-4988 p.Article in journal (Refereed) Published
We present a laser produced plasma (LPP) source optimized for metrology and the results of its radiometric characterization. The presented (LPP) source can be used for reflectometry and spectroscopy in the soft x-ray range. For these applications, stable operation with high spectral photon yields high reliability in continuous operation and, to reach high spectral resolution, a small source size and high source point stability is necessary. For the characterization of the source, special instruments have been designed and calibrated using the soft x-ray radiometry beamline of the Physikalisch-Technische-Bundesanstalt at BESSY. These instruments are an imaging spectrometer, a double multilayer tool for in-band power measurements, a transmission slit grating spectrograph, and a pinhole camera. From the measurements a source size of 30 mumx55 mum (2sigma, horizontal by vertical) and a stability of better than 5 mum horizontally and 9 mum vertically were obtained. The source provides a flat continuous emission in the extreme ultraviolet (EUV) range around 13.4 nm and a spectral photon flux of up to 1*10(14)/(s sr 0.1 nm) at a pump laser pulse energy of 650 mJ. The shot-to-shot stability of the source is about 5% (1sigma) for laser pulse energies above 200 mJ. It is shown that an Au-LPP source provides spectrally reproducible emission with sufficient power at low debris conditions for the operation of a laboratory based EUV reflectometer and for spectroscopy.
Place, publisher, year, edition, pages
2004. Vol. 75, no 11, 4981-4988 p.
x-ray-absorption, laboratory euv reflectometer, high average power, lithography applications, excimer-laser, light-source, spectroscopy, emission, clusters, debris
IdentifiersURN: urn:nbn:se:kth:diva-23868DOI: 10.1063/1.1807567ISI: 000224962900092OAI: oai:DiVA.org:kth-23868DiVA: diva2:342567
QC 201005252010-08-102010-08-10Bibliographically approved