Fabrication of 3D Micro‑Optical Interferometric structures using grayscale Lithography

Our work focuses on developing DMD-maskless grayscale lithography and silicon ICP-etching processes to create 3D micro optical structures with precisely controlled nanometric height variations in the framework of the SCARBOn project. These processes are used to fabricate staircase interferometric plates for compact SWIR spectrometers dedicated to atmospheric measurements. We investigate how optical effects inside photoresists—such as standing waves—impact surface quality, pattern transfer, and profile accuracy during fabrication. Our work combines design, process optimization, and metrology to ensure reliable and reproducible Fabry–Perot cavities for the NanoCarb hyperspectral spectro-imagers aimed at greenhouse gas monitoring.