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In the past 10 years improvements in micro-lithography have generated increasing demands on the performance of optical components in lithography machines and inspection devices as well. At this time typically used illumination sources are 248nm and 193nm lasers (KrF and ArF excimer lasers). Systems with 157nm (F2) excimer lasers are in a launching phase. Inspection with 266nm solid state laser (4th harmonic of Nd: YAG) or 193nm excimer laser is getting increasing interest too. First approaches to DUV or VUV coatings were focussed on realising useful windows, output couplers and folding or end mirrors with acceptable high transmission or reflection, respectively. In addition the laser induced damage threshold (LIDT) of the coated elements should be as high as possible when tested in so called 1-on-1 or 1-on-N tests (1 or N high-power laser pulses focussed on one point of an elements surface). After fulfilling these fundamental requirements the elements must meet additional specifications defined also for user-optimised component applications. In detail there are typical demands related to long-term and climatic stability, component lifetime during application, shift behaviour of the optical function, hardness of coating surfaces and resistance against chemical solvents together with a possibility of careful cleaning contaminated surfaces. Also mechanical film stress got more and more interest as a reason for deformation of ultra-precise finished optical surfaces and related wavefront distortions. Furthermore, the optical functions of UV components have become more complicated. Now the DUV and VUV filters, polarisers or attenuators show similar or more sophisticated optical performances compared to those components used for applications in the visible range. In this paper there will be presented some examples for improvements of component properties
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