Maskless micromachining with high-energy focused ion beams

Abstract

High Energy Focused Ion Beam (HEFIB) direct writing is proving to be an attractive and powerful maskless lithography technique for production of high aspect ratio 3-D microstructures in polymer resists and semiconductors. HEFIB with Proton beam (P-beam writing) offers several unique advantages for microfabrication applications: (a) the focused beam is scanned directly across the sample (no mask), (b) the range of the beam in the sample is well defined with minimal lateral straggling than any other techniques, (c) use of different energies allows different exposure depths, (d) complex shapes are possible and (e) patterns can be made within short exposure time. These characteristics allow P-beam writing to be applied in several areas of microfabrication including (a) rapid (and cheaper) prototyping of 3-D microstructures, (b) custom built structures for basic research, (c) mask production and (d) stamp and mold manufacturing. Recently we have implemented high energy P-beam direct writing with a nuclear microprobe at the Louisiana Accelerator Center (LAC). We are presenting some of the modular structures illustrating the capabilities of this maskless micromachining technique and possible application into Micro-Electro-Mechanical Systems (MEMS) devices.