title: Wetting transition for carbon nanotube arrays under metal contacts.
abstract: Structural arrays with nanoscale spacing arise in many device concepts. Carbon nanotube transistors are an extreme example, where a practical technology will require arrays of parallel nanotubes with spacing of order 10 nm or less. We show that with decreasing pitch there is a first-order transition, from a robust structure in which the metal wets the substrate between tubes, to a poorly wetting structure in which the metal rides atop the nanotube array without touching the substrate. The latter is analogous to the superhydrophobic "lotus leaf effect." There is a sharp minimum in the delamination energy of metal contacts at the transition pitch. We discuss implications for contact resistance and possible mitigation strategies.
authors.affiliation: IBM T.J. Watson Research Center, Yorktown Heights, New York 10598, USA.
authors.forename: V
authors.initials: V
authors.lastname: Perebeinos
authors.affiliation: IBM T.J. Watson Research Center, Yorktown Heights, New York 10598, USA.
authors.forename: J
authors.initials: J
authors.lastname: Tersoff