Electrical to EUV conversion efficiency is a key parameter for systems scaled to EUV emission in the 100W regime. Improvement in efficiency of conversion from laser radiation at the EUV source, reduces the required laser power and as such can lend itself to reduced heat load and debris emission. Also, improvement in the electrical to laser conversion efficiency results in a direct reduction in cost of ownership. Laser solutions optimised for efficient conversion to high M<SUP>2</SUP> CW laser radiation are not optimised in design for efficient short-pulsed operation; the mode of operation required for EUV generation. Aspects of both EUV source and laser design are discussed, with a view to optimising conversion efficiency for scalable EUV solutions.
A high resolution fast readout camera system has been developed around a specialized full frame 512 * 512 pixel format CCD sensor in conjunction with EEV Ltd. An equivalent readout rate of 600 frames per second with a spatial resolution of 24 line pairs per mm at the Nyquist limit is achieved. A binning capability increases the readout rate by up to a factor of four. The system dynamic range is in excess of 1000:1. System features include image analysis for computer with dedicated software, non volatile memory, high resolution and real time displays, instantly reset able, single shot image capture capability and remote head operation.