Wafer-Scale Pattern Transfer of Metal Nanostructures on Polydimethylsiloxane (PDMS) Substrates via Holographic Nanopatterns

Abstract

In this paper, we report on a cost-effective and simple, nondestructive pattern transfer method that allows the fabrication of metallic nanostructures on a polydimethylsiloxane (PDMS) substrate on a wafer scale. The key idea is to use holographic nanopatterns of a photoresist (PR) layer as template structures, where a metal film is directly deposited in order to replicate the nanopatterns of the PR template layer. Then, the PDMS elastomer is molded onto the metal film and the metal/PDMS composite layer is directly peeled off from the PR surface. Many metallic materials including Ti, Al, and Ag were successfully nanopatterned on PDMS substrates by the pattern transfer process with no use of any adhesion promoter layer or coating. In case of Au that has poor adhesion to PDMS material, a salinization of the metal surface with 3-(aminopropyl)-triethoxysilane (APTES) monolayer promoted the adhesion and led to successful pattern transfer. A series of adhesion tests confirmed the good adhesion of the transferred metal films onto the molded PDMS substrates, including scotch-tape and wet immersion tests. The inexpensive and robust pattern transfer approach of metallic nanostructures onto transparent and flexible PDMS substrates will open the new door for many scientific and engineering applications such as micro-/nanofluidics, optofluidics, nanophotonics, and nanoelectronics.

Stencil Lithography for Scalable Micro- and Nanomanufacturing

“…It is possible to pattern metal micro- and nanostructures onto flexible substrates by using other techniques such as pattern transfer [ 42 , 43 , 44 ]; however, the surface properties have to be characterized. An adhesion layer and heat are normally applied between metal patterns and the target substrate to improve transfer [ 45 ].…”

A silver self‐assembled monolayer‐decorated polydimethylsiloxane flexible substrate for in situ SERS detection of low‐abundance molecules

“…An equal amount of DCM was then mixed with silver sol . It was critical to add a very small amount of tetrabutylammonium nitrate (50 μL of 1 mM TBA + per milliliter of silver sol) as inducer . The centrifuge tube was violently shaken for 1 min and allowed to stand for 30 s (Figure S1).…”

“…[40] It was critical to add a very small amount of tetrabutylammonium nitrate (50 μL of 1 mM TBA + per milliliter of silver sol) as inducer. [41,42] The centrifuge tube was violently shaken for 1 min and allowed to stand for 30 s ( Figure S1). Finally, the silver monolayer was obtained at the liquid-liquid interface of the water and DCM.…”

Fabrication of hierarchical nanostructures using free-standing trilayer membrane

“…[35][36][37] The interference lithography systems and processes used in this study were especially developed for the large-area (i.e., full wafer-scale) nanopatterning, as reported earlier. 12,[38][39][40][41][42][43] In this work, the nanopore patterns of two different periods (500 and 900 nm) were prepared by using a He-Cd laser of a wavelength of 325 nm (IK3501R-G, Kimmon Koha Co., Ltd.). After the exposure, the samples were postexposure baked on a hotplate at 100 C for 1 min.…”