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Today the molecular fluorine (F2) laser emitting at a wavelength of 157 nm represents the strongest commercially available coherent light source in the vacuum-ultraviolet spectral range. Lambda Physik produces a broad variety of F2-Lasers which cover a wide range of output power (from less than 1 W to more than 20 W), repetition rate (from less than 100 Hz to more than 4 kHz) and single pulse energy (from less than 1 mJ to more than 30 mJ). The parameters of each of these kinds of F2-lasers are designed and suitable for specific fields of application. In the paper we will review the main parameters of these different types of F2-lasers, compare their special features and discuss the principle applications they are used for. The low energy, medium repetition rate is basically used for metrology and calibration tasks, the high energy or high repetition rate and high power F2-laser systems are mainly used for material investigations and in a growing extent for 157 nm-micromachining. Lithography tools use the high repetition rate, high power single-line F2-laser systems. All of these scientific or industrial applications take advantage of the unique properties of the 157 nm radiation, i.e. the ultra-short wavelength of emission and the very high photon energy of nearly 8 eV. Thus, very precise and fine microstructuring in the micrometer range is possible and the 157 nm optical lithography is on target for critical dimensions of integrated circuits below 70 nm. The short pulse duration and high photon energy also enables efficient and exactly located icroscopic ablation of most critical materials without thermal impact on the surrounding area. In the last part of the paper some recent results on F2-laser development and an outlook on future products will be given.
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