Compact SR beamline for fabrication of high aspect ratio MEMS microparts

Taking advantage of the small synchrotron radiation (SR) equipment 'AURORA' at Ritsumeikan University, we developed a compact beamline, which has a distance of about 3 meters between the SR source and exposure stages, to carry out deep X-ray lithography for fabrication of high aspect ratio MEMS microparts. Since the beamline is compact, a relatively high photon density can be achieved with the very small SR equipment so 1000 μm-high microstructures with an aspect ratio of 10 in an area of 1.5 mm × 30 mm of the PMMA resist could be produced with 160 minutes exposure. 200 μm-high microstructures with as aspect ratio of 10 were fabricated in a PMMA resist sheet and then used as a template for nickel electroforming, in order to further fabricate the high aspect ratio MEMS microparts in other materials. A large-area (4-inch) exposure can also be carried out by scanning X-Y stages controlled by a personal computer.