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 approx.30 nm.