Hans-Stephan Albrecht

Sub-0.25-pm 50-W amplified excimer laser system for 193-nm lithography

We report performance parameters of a robust, 50 W, high repetition rate amplified ArF excimer laser system with FWHM bandwidth of less than 0.25 pm, 95% energy content bandwidth of less than 0.55 pm, and ultra-low ASE level. Proprietary design solutions enable stable operation with a substantial reliability margin at this high power level. We report on characterization of all the key parameters of importance for the next generation microlithography tools, such as spectrum and dose control stability, in various operating modes.

High pulse energy excimer lasers for nanotechnology

Stable, high energy excimer lasers provide pulsed output energies ranging from 50 mJ up to 1000 mJ in the ultraviolet region with photon energies as high as 5 eV (248 nm), 6.3 eV (193 nm) or 7.9 eV (157 nm). Shortest ablation wavelengths strongly couple with every material, deliver highest lateral and depth resolution and significantly reduce the size of particulates in the plasma. Most important for thin film reproducibility, next to shortest possible ablation wavelength, is a stable behavior of consecutive laser pulses as well as the homogeneity of the on-sample laser fluence. These requirements constitute the superiority of excimer lasers as pulsed UV laser sources when it comes to precision and reproducibility in surface treatment and micromachining. Spectral properties, temporal pulse and laser beam parameters of state of the art excimer lasers will be compared with frequency converted high pulse energy laser sources with regard to the requirements of applications in nanotechnology.Stable, high energy excimer lasers provide pulsed output energies ranging from 50 mJ up to 1000 mJ in the ultraviolet region with photon energies as high as 5 eV (248 nm), 6.3 eV (193 nm) or 7.9 eV (157 nm). Shortest ablation wavelengths strongly couple with every material, deliver highest lateral and depth resolution and significantly reduce the size of particulates in the plasma. Most important for thin film reproducibility, next to shortest possible ablation wavelength, is a stable behavior of consecutive laser pulses as well as the homogeneity of the on-sample laser fluence. These requirements constitute the superiority of excimer lasers as pulsed UV laser sources when it comes to precision and reproducibility in surface treatment and micromachining. Spectral properties, temporal pulse and laser beam parameters of state of the art excimer lasers will be compared with frequency converted high pulse energy laser sources with regard to the requirements of applications in nanotechnology.