Scanning probe anodization: Patterning of hydrogen-terminated silicon surfaces for the nanofabrication of gold structures by electroless plating

Abstract

We have developed a nanofabrication method that uses patterned anodic silicon oxide as a template for pattern transfer to a gold (Au) nanostructure. The oxide patterns were prepared on a hydrogen-terminated silicon (Si–H) surface by scanning probe anodization, that is, electrochemical nanolithography based on scanning probe microscopy. These anodic oxide patterns were transferred to Au patterns through area-selective electroless plating, in which Au deposition proceeds selectively on the unanodized Si–H area while the anodic oxide surface remains free of deposits. Due to low Au nucleation density on the Si–H surfaces, Au lines formed by the electroless plating were discontinuous when their linewidth narrowed to less than 50 nm. The nucleation density was increased by a chemical etching of the Si–H surface prior to plating. We have successfully fabricated a continuous Au line as narrow as ∼30 nm.