We present nanometer-scale date storage on 3-phenyl-1-ureidonitrile thin film using scanning
tunneling microscopy ~STM!. This monomer film can become polymerized when a voltage pulse is
applied between the STM tip and the substrate. The affected region changes from being electrically
resistant to electrically conductive along the direction of the polymeric molecular chain. The
recorded mark of the data occurs in the region, and is 0.8 nm. We have obtained recorded marks
arranged regularly as 638 arrays. A possible chemical mechanism of this data storage would be the
phase transition from the monomer state to the polymeric state. The small marks are very stable.
© 2000 American Vacuum Society. @S0734-211X~00!04103-2#