Deep proton writing of high aspect ratio SU-8 micro-pillars on glass

Deep proton writing (DPW) is a fabrication technology developed for the rapid prototyping of polymer micro-structures. We use SU-8, a negative resist, spincoated in a layer up to 720 mu m-thick in a single step on borosilicate glass, for irradiation with a collimated 12 MeV energy proton beam. Micro-pillars with a slightly conical profile are irradiated in the SU-8 layer. We determine the optimal proton fluence to be 1.02 x 10(4) mu m(-2), with which we are able to repeatably achieve micro-pillars with a top-diameter of 138 +/- 1 mu m and a bottom-diameter of 151 +/- 3 mu m. The smallest fabricated pillars have a top-diameter of 57 +/- 5 mu m. We achieved a root-mean-square sidewall surface roughness between 19 nm and 35 nm for the fabricated micro-pillars, measured over an area of 5 x 63.7 mu m. We briefly discuss initial testing of two potential applications of the fabricated micro-pillars. Using similar to 100 mu m-diameter pillars as waveguides for gigascale integration optical interconnect applications, has shown a 4.7 dB improvement in optical multimode fiber-to-fiber coupling as compared to the case where an air-gap is present between the fibers at the telecom wavelength of 1550 nm. The 140 pm-diameter pillars were used for mold fabrication with silicone casting. The resulting mold can be used for hydrogel casting, to obtain hydrogel replicas mimicking human tissue for in vitro bio-chemical applications. (C) 2016 Elsevier B.V. All rights reserved.

Jaar van publicatie:2016

Trefwoorden:FABRICATION, LITHOGRAPHY, COMPONENTS, INTERCONNECTIONS, MICROSTRUCTURES, PHOTORESIST, CELL

CSS-citation score:1

Auteurs:International

Toegankelijkheid:Closed