Multiple centimetre-long fluidic-channels with smooth and vertical sidewall fabricated by novel NIL mould and thermal bonding

Abstract

In this paper, we demonstrate a new method for fabrication centimetre-long, dense and vertical sidewalls silicon-on-insulator (SOI) mould using holographic method combine with crystallographic anisotropic etching. Holographic method can make narrow dense and multiple continuous lines in large area while crystallographic anisotropic etching could eliminate line-edge-roughness (LER) in sidewalls and make the sidewalls nearly atomic-scale smoothness. Therefore, the line width of the SOI mould will in a high uniformity and the sidewalls will be smooth and vertical over centimetre lengths. Compare to common NIL mould, the smooth and vertical sidewall of SOI mould provided an easier demoulding process after NIL. Multiple centimetre-long fluidic-channels with smooth and vertical sidewall fabricated by faithfully imprint of SU-8 and an optimised sealing process using free-standing SU-8 bonding film.