Xe+-irradiation effects on multilayer thin-film optical surfaces in EUV lithography
✍ Scribed by J.P. Allain; A. Hassanein; M.M.C. Allain; B.J. Heuser; M. Nieto; C. Chrobak; D. Rokusek; B. Rice
- Publisher
- Elsevier Science
- Year
- 2006
- Tongue
- English
- Weight
- 121 KB
- Volume
- 242
- Category
- Article
- ISSN
- 0168-583X
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✦ Synopsis
In extreme ultraviolet lithography (EUVL) environments, transient plasma dynamics dictate conditions for particle/surface interactions. A critical challenge facing EUVL development is optical component lifetime in both gas-discharge-produced plasmas (DPP) and laser-produced plasma (LPP) devices. Optical components are exposed to impinging fast ions and neutrals, impurities (H, C, O, N) and debris, leading to component degradation and consequently limiting 13.5-nm light reflection intensity. This paper studies Xe + irradiation-induced mechanisms that affect the performance of EUVL multilayer collector mirror surfaces. Irradiation conditions include: incident particle energies of 1 keV and 5 keV, Xe + fluences ranging from about 3 • 10 14 -5 • 10 16 Xe + /cm 2 and surface temperatures of 273 K and 473 K. Measurements include in situ quartz crystal microbalance for sputtering rate measurements, ion scattering spectroscopy, X-ray reflectivity and atomic force microscopy. Three distinct erosion regimes for bombardment of MLM with Xe + are: a low Xe + fluence regime below $5 • 10 14 Xe + /cm 2 , a moderate regime at fluences between 5 • 10 14 and 5 • 10 16 Xe + /cm 2 and a high fluence regime >10 17 Xe + /cm 2 .