Proton microbeam micromachining

Micromachining scheme

Nuclear microprobe is optimal tool for direct write process into photosensitive polymers. The process results in the production of threedimensional microstructures with submicron precision. High energy beam from ion accelerator is focused by strong magnetic lens to the cross dimension of order of 500 nm at the surface of the object, consisted of uniform layer of radiation photoresist material. By means of deflecting coils, beam is scanned over the requested pattern. Exposed (positive type photoresists) or unexposed pattern (negative type photoresist) is removed by chemical etching. The characteristic depth of writing in the photoresist is in the range between 10 and 200 micrometers, which is comparable to the LIGA technique available at the X-ray sinchrotron light sources. The characteristic depth of writing could be adjusted by varying the energy of ions. The main advantage if the ion microbeam micromachining is maskless pattern writing, which enables extremely fast designing of mechanical microstructures with high aspect ratio. Comparable techniques require the construction of the pattern mask, ussualy by the electron-beam writing process , which is time-demanding and expensive. Ion microbeam micromachining applies highly focused ion microbeam to directly write the digitized pattern into photoresist material. Due to the direct-writing process, the development of three-dimensional structures is enabled by wafer tilting.

Results: December 2003
Photoresist: SU-8, thickness 50 micrometer
Digital (B&W bitmap) plans and SEM images of the produced nanostructures

Contact person:

Dr. Primož Pelicon

Last updated: 01/22/2014