The Research Of Micro/Nano Transfer Patterning Based On Poly (Urethane Acrylate) PUA

As one of unconventional micro/nanopatterning techniques, the micro/nano transfer patterning can fabricate micro/nano devices, like solar cell electrode, power generation diode, photovoltaic conversion unit more and more widely, very effectively. In this paper, the poly(urethane acrylate) (PUA) was used in micro/nano transfer experiments, fabrication of metal nanopattern by transfer print using bi-layer PUA/PMMA and the mechanism of PUA micro/nano transfer was anaylzed, which could help the research and application of micro/nano transfer very much.The method involves an inked technique based on the poly(dimethylsiloxane)(PDMS) mould to fabricate a nanopatterned PUA the top-layer poly(andmethyl methacrylate)(PMMA) as the underlayer. The minimal residues are left on the PMMA because PDMS absorbs the organic molecules of PUA after the transferred step. The undercut prolife could be created by an reactive ion etching (RIE) process, a metal film was deposited onto the structure followed by a lift-off process to remove the resist mask. Due to the difference of adhesion work, periodic structures could be patterned in a large area without any adhesion agent during transferring process. The PUA shows high etch resistance to O2 plasma and PMMA serves as an underlying resin to create an undercut profile which is essential for the lift-off process. The etch rates of the PMMA film and PUA by O2 plasma were examined as a function of bias voltage under various oxygen conditions during the etching process. To reveal the mechanism of etch resistance, the chemical composition of PUA was analyzed before and after the O2 plasma etching process by using X-ray photoelectron spectroscopy. We have fabricated the metal nanopattern by this method, then obtaining the micro/nano dots arrays using metal-assisted chemical wet etching.Fabricating the micro/nano mold using inked transfer by PUA. The inked transfer has three critical factors:the result of ink material filling into silicon mold, the adhesion energy between materials and mold, and the dynamics in the process of uncovering the flexible formwork. We have analyzed these factors to explain why the experiment cannot achieve the intended purpose. PUA can fill into the groove using the finite element analysis. The reason the radio of the adhesion between mold and PUA and the adhesion between PUA and substrate is less than critical value C that is related to size of mold by building a physical model causes the failure of transfer. By matlab. We draw the curve about critical C and adhesion between the materials, and have proposed the improvement measure.