Microstructure fabrication with a CO₂ laser system: characterization and fabrication of cavities produced by raster scanning of the laser beam

In this paper we describe the use of a CO₂ laser for production of cavities and microstructures in poly(methyl methacrylate) (PMMA) by moving the laser beam over the PMMA surface in a raster pattern. The topography of the cavities thus produced is studied using stylus and optical profilometry and scanning electron microscopy (SEM). The microstructures display artifacts from the laser ablation process and we describe how the laser ablation parameters can be optimized in order to minimize these artifacts. Using this technique it is possible to generate structures with a depth from 50 µm and a minimum width of approximately 200 µm up to depth and widths of several mm, governed by the beam size and the laser settings.