Optimization of x-ray sources for proximity lithography produced by a high average power Nd:glass laser. Revision 1

摘要

We measured the conversion efficiency of laser pulse energy into keV x-rays from a variety of solid planar targets and a Xe gas puff target irradiated using a high average power Nd:glass slab laser capable of delivering 13 ns FWHM pulses at up to 20 J at 1.053 (mu)m and 12 J at 0.53 (mu)m. Targets where chosen to optimize emission in the l0--15 (angstrom) wavelength band, including L-shell emission from materials with atomic numbers in the range Z=24-30 and M-shell emission from Xe (Z=54). With 1.053 (mu)m a maximum conversion of 11% into 2(pi) sr was measured from solid Xe targets. At 0.527 (mu)m efficiencies of 12--18%/(2(pi)sr) were measured for all of the solid targets in the same wavelength band. The x-ray conversion efficiency from the Xe gas puff target was considerably lower, at about 3%/(2(pi)sr) when irradiated with 1.053 (mu)m.