Excimer laser micromachining has emerged as an important manufacturing process for microsized mechanical and optical components. Using the projection mask technique this work presents and evaluates two new mask types capable of fabricating a variety of microstructures. The first new mask type is a combination of contour and gray scale mask made of chromium on quartz leading to an improved surface quality of the scanned polymer surface. The second new mask type is entirely made of quartz and makes use of tailored diffractive gratings which deflect parts of the originally illuminating laser beam beyond the solid angle of the used imaging system. This new type of gray scale mask has been applied in static laser ablation of polycarbonate fabricating 49 separate depth levels.
"Fabrication of MEMS structures by laser machining", Proc. SPIE 4236, Smart Electronics and MEMS II, (16 March 2001); doi: 10.1117/12.418759; https://doi.org/10.1117/12.418759