FIB micro/nano fabrication of silicon master for biomedical applications

We exploit the fabrication capabilities of the Ultra High Resolution Field Emission Scanning Electron Microscopy (UHR-FE-SEM) and Focused Ion Beam (FIB), model CrossBeam® 1540XB by Zeiss, equipped with EDX, GIS, and STEM modules, in order to mill a silicon master for a first step of a wider project of designing, developing, and producing of biomedical lab on chips. In some case the maskless FIB machining is followed by a soft lithography process (polymeric replica moulding or air moulding) for the aim of reaching an high throughput production and consequently to lower the cost of the device. In details we are able to fabricate: nano molecular sieves to sort and manipulate biomolecules, nanochannels and nanopores devices for detection of single molecules, smooth micropipettes for a planar patch clamp, and nano holes for high accuracy gas flow controllers. Here we show the silicon master prototypes, included milling parameters. The presentation also points out the artefacts due to FIB sputtering, with a tentative to explore the strategies to reduce them, or, alternatively, to take them into account for the best choose of fabrication parameters.