A technique for transferring metal nano patterns from a plastic replica mold by using a metal oxide release layer

Techniques for nano-scale metal patterning on plastic substrates are strongly desired for fabricating various novel devices such as printed electronics (PE), as well as plasmon photonics and optical devices. There are great hopes that PE devices on plastic substrates could replace conventional integrated circuits on silicon, because plastic substrates offer good transparency, flexibility, lightness and low cost. In order to simultaneously achieve high-resolution and high-throughput metal patterning on a plastic substrate, nano transfer printing (nTP) is a promising technique. However, conventional nTP processes require a poly(dimethylsiloxane) (PDMS) stamp. PDMS is a high-viscosity material before curing and thermosetting elastomer, so it is difficult to obtain PDMS stamps quickly by using injection molding or roll-to-roll nanoimprinting. To resolve these issues, we have developed a three-dimensional metal-pattern nanoimprinting technique that uses a metal oxide release layer. In this study, we examined a technique for transferring a metal onto poly(ethylene terephthalate) (PET) substrate using a cycloolefin polymer (COP) replica mold with a metal oxide release layer. We showed that the metal oxide release layer allows the nTP process to be implemented with a COP replica mold.

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► We examined nano transfer printing without poly(dimethylsiloxane) stamp.
► Cycloolefin polymer (COP) was used as a plastic replica mold.
► It was difficult to transfer a silver layer with directly use of the COP mold.
► We coated the COP mold with a chromium oxide release layer.
► The metal oxide release layer allows the nTP process with a plastic replica mold.