7874
Langmuir 2007, 23, 7874-7879
Directed Electroless Growth of Metal Nanostructures on Patterned Self-Assembled Monolayers Jayne C. Garno,† Christopher D. Zangmeister, and James D. Batteas*,‡ Chemical Sciences and Technology Laboratory, National Institute of Standards and Technology, 100 Bureau DriVe, Gaithersburg, Maryland 20899 ReceiVed January 3, 2007. In Final Form: February 22, 2007 The directed placement of Cu nanostructures on surfaces has been studied using a combination of scanning probe lithography and electroless metal deposition onto nanopatterned SAMs of 16-mercaptohexadecanoic acid (16-MHA) on Au. In situ studies using nanoscale molecular gradients reveal how controlling the areal density of the 16-MHA molecules dictates the nucleation and growth of the metal nanostructures. The influence of controlling pattern line spacing and tip path on pattern feature fidelity is also discussed.
Introduction Metallic nanostructures exhibit unique optical properties due to the collective excitations of electrons that result when they are irradiated. These coupled excitations, known as plasmons, have been used to enhance the optical performance of several important devices with diverse applications, including nanoantennas,1,2 plasmonic waveguides,3,4 and solid-state light sources, such as quantum dots5 and quantum well structures.6 This enhancement occurs by coupling of the plasmon resonance of the metallic nanostructure to the electronic states of the device of interest. The wedding of electronics research to optics research has led to the development of the area known as plasmonics.3,7 A significant challenge in the area of plasmonics is the ability to fabricate and precisely position metallic features with nanoscale dimensions (