Thermally Stable Organic–Inorganic Hybrid Photoresists for Fabrication of Photonic Band Gap Structures with Direct Laser Writing

A recently developed methylsilsesquioxane-based photoresist is combined with direct laser writing to define 3D microstructures (see image). Because the resulting structures exhibit thermal stability above 500 °C without cracking or significant distortions, they should allow photonic crystals and other microstructures to be obtained from a large variety of materials. This is demonstrated by infiltrating a “woodpile” photonic crystal with silicon using chemical vapor deposition.