Source characterization for x-ray proximity lithography

Calibrated x-ray spectra from laser-produced plasmas of materials with atomic numbers varying between 12 (Mg) and 83 (Bi) were recorded to optimize the conversion efficiency for proximity lithography in a 0.5-nm band centered at 1 nm. The highest efficiency (~0.8%) was found for L-shell emitters such as Cu ando M-shell emitters such as Ba. First-order debris measurements were carried out by measurement of the layer thickness deposited on witness plates 2 cm away from the target. Layers of 30-nm thickness were deposited in a single laser shot with Au and W targets.