Capillary force lithography with impermeable molds

Abstract

Capillary force lithography (CFL) with impermeable mold is presented. For the CFL to be operative over large area, either the mold or the substrate has to be flexible. With a silicon wafer mold and a flexible substrate, a repeated line and space pattern with a spacing of 30 nm is shown to be well patterned. With a flexible mold and a hard substrate, a similar pattern with a spacing of 60 nm is demonstrated by CFL. The flexibility is needed for the intimate contact that is required between the mold and the substrate for the capillarity to take hold over large area. The forte of CFL with impermeable mold lies in the fact that the driving force for the patterning, which is capillary force, increases with decreasing pattern size.