title: Self-aligned formation of sub 1 nm gaps utilizing electromigration during metal deposition.
abstract: We developed a procedure for the fabrication of sub 1 nm gap Au electrodes via electromigration. Self-aligned nanogap formation was achieved by applying a bias voltage, which causes electromigration during metal evaporation. We also demonstrated the application of this method for the formation of nanogaps as small as 1 nm in width, and we found that the gap size can be controlled by changing the magnitude of the applied voltage. On the basis of the electric conductance and surface-enhanced Raman scattering (SERS) measurements, the fabricated gap size was estimated to be nearly equal to the molecular length of 1,4-benzenedithiol (BDT). Compared with existing electromigration methods, the new method provides two advantages: the process currents are clearly suppressed and parallel or large area production is possible. This simple method for the fabrication of a sub 1 nm gap electrode is useful for single-molecule-sized electronics and opens the door to future research on integrated sub 1 nm sized nanogap devices.
authors.affiliation: Nanosystem Research Institute, National Institute of Advanced Industrial Science and Technology (AIST) , Namiki 1-2-1, Tsukuba, Ibaraki 305-8564, Japan.
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Naitoh
authors.forename: Tatsuhiko
authors.initials: T
authors.lastname: Ohata
authors.forename: Ryuji
authors.initials: R
authors.lastname: Matsushita
authors.forename: Eri
authors.initials: E
authors.lastname: Okawa
authors.forename: Masayo
authors.initials: M
authors.lastname: Horikawa
authors.forename: Makiko
authors.initials: M
authors.lastname: Oyama
authors.forename: Masakazu
authors.initials: M
authors.lastname: Mukaida
authors.forename: Dong F
authors.initials: DF
authors.lastname: Wang
authors.forename: Manabu
authors.initials: M
authors.lastname: Kiguchi
authors.forename: Kazuhito
authors.initials: K
authors.lastname: Tsukagoshi
authors.forename: Takao
authors.initials: T
authors.lastname: Ishida