The availability of reliable excimer lasers and the unique light-materials interactions at far UV wavelengths (308, 248, and 193 nm) have brought about demanding requirements for an optical beam delivery system for micromachining. An optical system is described which uses a split-lens Kohler illuminator in conjunction with a reflecting Schwarzchild objective to deliver a uniform (± 5%) beam with a fluence up to 12 J/cm2 into a target area of up to 200 x 200 μm. Design and construction of the illuminator is described, as well as examples of results demonstrating beam uniformity, fluence, and resolution.
K . J. Harte,
B. P. Piwczyk,
"Excimer Laser Light Delivery System For Micromachining", Proc. SPIE 0998, Excimer Beam Applications, (16 December 1988); doi: 10.1117/12.960202; https://doi.org/10.1117/12.960202