We present the formation of structures created by barium atoms using a lithographic technique. The interaction of barium atoms with the resist, followed by an etching process, creates well defined structures with features below 100 nm. The interaction of the ground state of Ba atoms with the molecules forming the self-assembled monolayer (SAM) is compared with the metastable Ba atoms-SAM interaction. The results show that metastable atoms require a lower Ba dose per SAM molecule to damage the resist, therefore increasing the efficiency of the process. (c) 2005 Elsevier B.V. All rights reserved.