EXCIMER-LASER MACHINING FOR THE FABRICATION OF ANALOGOUS MICROSTRUCTURES

Excimer laser ablation is normally used for micromachining of binary s tructures, for instance holes or cuts. We investigated new machining t echniques for the fabrication of three-dimensional (3D) structures wit h analogous topology by excimer laser ablation: (i) line scan with a c ontour mask which correlates with the desired topology and (ii) gray s cale mask projection. The structuring methods make use of the dependen ce of the machined depth (i) on the locally applied pulse quantity or (ii) on the energy density. The details of the methods, the process pa rameters and the resultant structure properties are discussed. Example s for the structuring of cylindrical and spherical microlenses and mic roarrays with dimensions in the micron range are given.