Nanoparticle-based lift-off technique for ultra-thin nanoporous film preparation

Ultra-thin membrane with nanoscale through hole has great potential in biomedical applications, where precise controllability of porosity, pore size and film thickness is urgently required. The present work proposed a cost-effective way to prepare the ultra-thin nanoporous film with a promising controllability. Monodispersed nanoparticle, rather than photoresist, is used as the sacrificial material for this new lift-off process. By releasing the particles, holes can be achieved with predetermined characters. A 110 nm-thick nanoporous aluminum film with well-controlled pore’s diameter was successfully fabricated to validate the technique. The technique has wider process window and better applicability than other nanofabrication methods. Supported by the National Natural Science Foundation of China (Grant Nos. 60606014 and 90607004)