LAUSR

Abstract Nanopatterning electrically insulating oxide lines on organic electronic surfaces can play a role in fabricating future nanoscale devices. Here we write oxide features on rubrene single crystal surfaces by performing local anodic oxidation using the tip of an atomic force microscope. Oxide feature height increases with voltage bias and decreases with tip writing speed, and gaps as small as 22 nm at the surface between two parallel oxide lines were realised. Conductance tomography is employed in a unique way to determine the depths of oxide features, by exposing subsurface layers of the patterned material without using chemical etching while simultaneously mapping material conductance. The oxide line depth exceeds its height, with the depth-to-height ratio frequently being more than 1.6. A critical electric field of ∼3 × 106 V/cm is identified, below which the oxide growth ceases, resulting in a maximum oxide vertical extent of about ∼60 nm at a voltage bias of ∼20 V.