Micro- and nano-patterns fabricated by embossed microscale stamp with trenched edges

A submicron width of Au line patterns was fabricated from a polydimethylsiloxane (PDMS) line stamp of micron width by utilizing capillary-force and edge-transfer lithography (ETL). A template composed of Al(OH)(3) was fabricated by capillary-force lithography (CFL) carried out by KOH ink-loaded microscale PDMS stamping on an Au nanomembrane (30 nm)-deposited Al thin layer (50 nm) on a glass substrate. Because the Au nanomembrane works as an OH- ion channel, protruding Al(OH)(3) micro-structures are obtained by a pH-dependent molding process reacting underneath the Al thin layer. The protruding Al(OH)(3) template has sharp edges at the molding area resulting from the capillary force working on the walls of the molding PDMS stamp and aqueous Al(OH)(3) solution during the molding process. For example, the highest and widest ring edges of the protruding Al(OH)(3) fabricated by a dot PDSM stamp (phi: 4.5 mu m, gap: 3 mm) are obtained through a molding time of 20 min with 1 M KOH ink. The protruding Al(OH)(3) micro-structures were used as templates to fabricate dot and line PDMS stamps. The replicated PDMS stamps have deep trenches around the contact area of the stamps; thus, the replicated PDMS stamp has an advantage of holding ink solution in the recessed space. Through (ETL) with a replicated line PDMS stamp, which has deep trenches around the line shape contact area, an Au line-pattern array of 700 nm in width was fabricated by 16-mercaptohexadecanoic acid (MHA) patterning on Au/Ti (30 nm/5 nm)-deposited silicon substrate and sequential Au etching for 20 min. In this study, we successfully demonstrated that an advantageous PDMS stamp for (ETL) is obtained by a solid Al(OH)(3) template fabricated by Au nanomembrane-based CFL.