Nanopatterning of Si(111) surfaces by atomic force microscope scratching of an organic monolayer

In this work, we demonstrate selective electroless deposition of Cu into nanoscratches produced on n-type Si(111) surfaces covered with an organic monolayer. The organic layer (undecylenic acid) was covalently attached to a hydrogen-terminated Si surface. The nanosize scratches were produced with an atomic force microscope (AFM) in contact mode using a diamond-coated tip. Copper was deposited in the scratched regions with an electroless (immersion plating) approach using a 0.05 M CuSO4 + 1% HF electrolyte. The results show clearly that the organic layer can be used as a mask for the deposition of Cu. Optimization of the electrochemical parameters, leads to a very high selectivity and uniform and well-defined nanostructures. This process represents a novel approach for a direct patterning of Si surfaces using an immersion plating reaction. (C) 2003 Elsevier Science B.V. All rights reserved.