Capillary force lithography

Fig. 2 SEM image of a patterned silicon substrate. Lines of poly(ferrocenylmethylphen)4-silane) were introduced by capillary force lithography, foUowed by CF4/O2 reactive ion etching (10 min). The polymer mask was subsequently removed using nitric acid...

The principles of capillary force lithography [72,73] and a representative pattern of poly(ferrocenylmethylphenylsilane) (PFMPS) stripes on Si obtained by this technique, are shown in Fig. 8. A PDMS mold was placed in contact with a thin PFMPS film (thickness 27 nm) and, subsequently, the temperature was raised above the Tg (74 °C) of the polymer. The polymer, initially confined in a thin film, is squeezed out from areas of contact between stamp and substrate. It diffuses into the grooves where structures are formed along the vertical walls of the stamp due to capillary rise. Polymer structmes, which are approximately 110 nm high and 500 nm wide, were fabricated. Section analysis of the AFM height images revealed a meniscus of the capillary rise (note the different scales for the vertical and horizontal directions). The structmes were developed by CF4/O2-RIE. After resist removal, a patterned substrate as shown earUer in Fig. 2 was obtained. 

Fig. 8 Capillary force lithography of a thin PFMPS film with a 2 x 3 ixm PDMS stamp. Schematic diagram (left) and AFM height image with section analysis. The height of the resulting features is 110 nm and the initial thin film thickness was 27 nm. Reprinted with permission from [5]. Copyright 2003, American Chemical Society...

There are also a number of other molding techniques to pattern polymers on substrates. One technique is capillary force lithography (CFL), which is a technique in which a patterned PDMS mold is placed on a layer of polymer that is either noncross-linked or heated above its melting point. In CFL, surface tension directs the movement of the polymer melt into the void spaces of the PDMS mold. This process can be merged with different types of polymers to enable cell and protein deposition on substrates. 

Jeong HE, Kwak MK, Park Cl, Suh KY (2009) Wettability of nanoengineered dual-roughness surfaces fabricated by UV-assisted capillary force lithography. J Colloid Interface Sd 339 202... 

FIGURE 9.12 (a) SEM image of patterned poly(3-hexylthiophene) by capillary force lithography, (b) SEM image... 

Liu, Y, Klep, V, Luzinov, I. 2006. To Patterned Binary Polymer Brushes via Capillary Force Lithography and Surface-Initiated Polymerization. 

FIGURE 16.2 (a) The scheme for patterning of cellular cocultures by using capillary force lithography and... 

Jeong, H.E., Kvrak, M.K., Park, C.I., Suh, K.Y., 2009. Wettability of nanoengineered dualroughness surfaces fabricated by uv-assisted capillary force lithography. J. Colloid Interface ScL 339. 

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