Pinch plasmas as intense EUV sources for laboratory applications

Compact pinch plasma devices are intense sources of pulsed EUV radiation with output energies of several joules per pulse in single lines. Their spectrum peaks in a wavelength range where conventional x-ray tubes provide poor intensity. With correct optimization, both continuous radiation or line radiation with lambda/Delta lambda > 1000 can be produced for broadband and narrowband applications, respectively. Because of their low cost and their compact size, pinch plasmas seem well suited to supplement research activities based on synchrotron radiation. In this paper, pinch plasma sources developed for x-ray lithography and x-ray microscopy are described. Their emission characteristics are optimized with regard to specific requirements given by the particular application and are compared to laser produced plasmas. The lithography source is compatible with the electron storage ring printing process with respect to its spectrum and enables full-depth exposures in 1-mu m-thick 60 mJ cm(-2) sensitivity resist at resolution below 0.2 mu m within 10 minutes. The source for microscopy applications enables flash imaging of biological specimens with suboptical resolution (0.1-0.2 mu m) at nanosecond exposure times. In addition, the averaged plasma parameters meet the requirements for an EUV laser medium. The nitrogen 2-3 transition is especially promising for achieving amplified spontaneous emission of hydrogen-like or helium-like ions excited by three-body or charge exchange recombination.