X-ray production (approximately)130 (Angstrom) from laser-produced plasmas for projection x-ray lithography applications

摘要

X-ray production in the region around 130 (Angstrom) from laser-produced plasmas have been investigated as a source for projection x-ray lithography. The dependence of x-ray conversion efficiency on target material, intensity, and pulse length has been studied using a 0.53 (mu)m laser with a maximum of 0.3 J. Conversion efficiency of 1% into a 3 (Angstrom) bandwidth has been demonstrated for Sn targets at intensities around 10(sup 11) W /cm(sup 2) using a 7.5 ns pulse. Intensity scaling suggests that laser spot size and two-dimensional expansion are important for optimizing x-ray production at these low irradiation intensities.