Experimentally observed density profile of CO₂ laser-produced Sn plasma was compared with that predicted by one dimensional hydrodynamic radiation numerical code. Experimental data showed a much smaller corona and a much shorter shift distance of the critical density from the initial target surface as compared with those predicted by an isothermal model and the numerical simulation. The possible reason may come from thin localized laser deposition region, less energy transport into the corona and into the dense region beyond the critical density. This research suggests that more efforts to understand the fundamental dominating the interaction of CO₂ laser with high Z plasma are necessary to form a more solid foundation for the application of numerical method to the development of the EUVL source.

Date Published: 20 March 2010
PDF: 8 pages
Proc. SPIE 7636, Extreme Ultraviolet (EUV) Lithography, 76360D (20 March 2010); doi: 10.1117/12.848407

Published in SPIE Proceedings Vol. 7636:
Extreme Ultraviolet (EUV) Lithography
Bruno M. La Fontaine, Editor(s)