title: Template-stripped, ultraflat gold surfaces with coplanar, embedded titanium micropatterns.
abstract: Ultraflat gold surfaces with coplanar, embedded titanium micropatterns, exhibiting extremely low roughness over the entire surface, have been obtained by a modified template-stripping procedure. Titanium is deposited onto photolithographically predefined regions of a silicon template. Following photoresist lift-off, the entire surface is backfilled with gold, template stripping is conducted, and an ultraflat micropatterned surface is revealed. Atomic force microscopy confirms a roughness of <0.5 nm RMS on both Ti and Au regions, with a topographically indistinguishable gold-titanium interface. Detailed surface-chemical maps of the patterned surfaces have been obtained by means of imaging X-ray photoelectron spectroscopy (i-XPS) as well as time-of-flight secondary-ion mass spectrometry (ToF-SIMS). They confirm the presence of well-separated Ti and Au regions, with a chemical contrast that is sharp (as determined by ToF-SIMS) and complete (as determined by i-XPS) across the Ti-Au interface. Thus, a surface has been fabricated that is physically homogeneous down to the nanoscale incorporating chemically distinct micropatterns consisting of two different metals, with totally contrasting surface chemistries.
authors.affiliation: Laboratory for Surface Science and Technology, Department of Materials, ETH Zurich, Wolfgang-Pauli-Strasse 10, CH-8093 Zurich, Switzerland.
authors.forename: Nagaiyanallur V
authors.initials: NV
authors.lastname: Venkataraman
authors.forename: Jia
authors.initials: J
authors.lastname: Pei
authors.forename: Clément V M
authors.initials: CV
authors.lastname: Cremmel
authors.forename: Antonella
authors.initials: A
authors.lastname: Rossi
authors.forename: Nicholas D
authors.initials: ND
authors.lastname: Spencer
mesh_terms: D006046:Gold / Q000737:chemistry*; D010316:Particle Size; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D006046:Gold; D014025:Titanium