Reversal nanoimprinting

In practice, there are three variants of the method, depending on the geometry of the mold and pattern size, the thickness of the polymer film, polymer properties, and on the process conditions (temperature, pressure). If the depth of the recessed features is large compared to the thickness of the spin-coated film, the latter carmot planarize the relief features, leaving a large undulation on the coated polymer surface [9]. On the other hand, when the polymer thickness is comparable to the height of mold features, the polymer forms a planarized layer over the whole mold. 

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Fig. 10 (A) Schematic of reverse nanoimprint, and (B) SEM of reverse imprinted PMMA gratings with 350 nm line width/spacing. (View this art in color at www.dekker.com.)...

In reversal nanoimprinting (RNi) a polymer film is spin coated onto a mold, forming a replica of the mold patterns. This film is then transferred to a desired substrate by imprinting at a temperature close to the glass transition temperature (Tg) of the polymer (Figure 5.2a) [8, 9]. 

Zhao, W Low, H.Y., and Suresh, P.S. (2006) Cross-linked and chemically functionalized polymer supports by reactive reversal nanoimprint lithography. Langmuir, 22, 5520-5524. 

Wan J, Deng SR, Yang R, Shn Z, Ln BR, Xie SQ, Chen Y, Huq E, Liu R, Qu XP (2009) Silicon nanowire sensor for gas detection fabricated by nanoimprint on SU8/SiOj/PMMA trilayer. Microelectron Eng 86 1238-1242 Wang XU, Chen X, Xie Z-X, Wang X-R (2008) Reversible optical sensor strip for oxygen. Angew Chem Int Ed 47 7450-7453... 

Kubenz, M., Reuther, F., Gruetzner, G., and Torres, C.M.S. (2007) Reverse-contact UV nanoimprint lithography for multilayered structure fabrication. 

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