title: Fabrication of sub-5 nm nanochannels in insulating substrates using focused ion beam milling.
abstract: The use of focused ion beam (FIB) milling to fabricate nanochannels with critical dimensions extending below 5 nm is described. FIB milled lines have narrowing widths as they are milled deeper into a substrate. This focusing characteristic is coupled with a two-layered architecture consisting of a relatively thick (>100 nm) metal film deposited onto a substrate. A channel is milled through the metal layer until it penetrates a prescribed depth into the substrate material. The metal is then removed, leaving a nanochannel with smooth surfaces and lateral dimensions as small as sub-5 nm. These open nanochannels can be sealed with a cover plate and the resulting devices are well-suited for single-molecule DNA transport studies. This methodology is used with quartz, single-crystal silicon, and polydimethylsiloxane substrates to demonstrate its general utility.
authors.affiliation: Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA.
authors.forename: Laurent D
authors.initials: LD
authors.lastname: Menard
authors.forename: J Michael
authors.initials: JM
authors.lastname: Ramsey
mesh_terms: D003460:Crystallization / Q000379:methods*; D004553:Electric Conductivity; D020450:Heavy Ions; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008670:Metals / Q000737:chemistry* / Q000528:radiation effects*; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000528:radiation effects / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D008670:Metals