Direct patterning of noble metal nanostructures with a scanning tunneling microscope

We demonstrate in this article the controlled deposition of noble metal dot s and lines using local chemical vapor deposition in the tip-sample Sap of a scanning tunneling microscope. 3 nm diam rhodium dots have been patterned by local decomposition of an inorganic precursor, which was synthesized on purpose. Deposition is obtained on gold surfaces by applying a series of n egative voltage pulses on the sample exceeding a voltage threshold of 1.9 V . The influence of kinetics parameters (pulse voltage duration and number, as well as the effect of gas pressure) are presented. In a second step, the deposition process has been applied on hydrogenated silicon (100) surfaces . These samples were previously hydrogen passivated using two different wet etching operations, leading surface dangling bonds saturated by either mon o- or di-hydride bonds. The difference in the deposition processes observed in both cases is discussed. (C) 2000 American Vacuum Society. [S0734-211X( 00)06903-1].