2 - Technologies

LIGA (Lithographie, Galvanoformung, Abformung in German) is a technique for fabricating three-dimensional micromechanical structures with high aspect ratios having heights of several hundred micrometers. The process combines X-ray lithography with thick resist layers and electroplated metal layers to form three-dimensional structures. It also can be combined with sacrificial layers, in which case it is called Sacrifical LIGA (SLIGA). Processing starts with the deposition and patterning of the sacrificial layer. The next step involves application of a thick photoresist (PMMA, poly-methyl-methacrylate) layer. After the application of PMMA it is exposed to X-ray photons, and will developed. This step is followed by electroplating of a core material and the removal of PMMA and the plating base. The final step in SLIGA is etching of the sacrificial layer.