Fabrication of micro-structured tunnels in PMMA using P-beam writing

Deep buried layered microstructures have many potential applications as sensors, micro-electro-mechanical systems (MEMS), and optical devices, but it has always been challenging to obtain a minimum number of process steps to produce these structures. A single step ion irradiation process has been used to fabricate buried tunnels with 3 MeV P-beam writing by utilizing enhanced end-of-range damage in thick polymethylmethacrylate (PMMA). Creation of the buried tunnels in PMMA with a single energy irradiation step was found to be strongly dependent on the ion fluence and chemical developing process. The fabrication of a modular large scale complex pattern involving tunneled microstructures is presented as an example of this novel technique.