Electron-beam induced nanomasking for metal electrodeposition on semiconductor surfaces

The present work investigates the masking effect of carbon contamination pa tterns deposited by the electron-beam (E-beam) of a scanning electron micro scope (SEM) for metal electrodeposition reactions. Carbon contamination lin es were written at different electron doses on n-type Si(100) surfaces. Sub sequently Au was electrochemically deposited from a 1 M KCN + 0.01M KAu(CN) (2) solution on the E-beam treated surface sites. The carbon masks as well as the Au deposits were characterized by SEM, atomic force microscopy, and scanning Auger electron spectroscopy. We demonstrate that carbon deposits i n the order of 1 nm thickness can be sufficient to achieve a negative resis t effect, i.e., can block the electrodeposition of Au completely selectivel y. The lateral resolution of the process is in the sub-100 nm range. The nu cleation and growth of Au deposits and their morphology as well as the sele ctivity and resolution of the process depend on several factors such as the electron dose during masking, and the applied potential and polarization t ime during Au deposition. The process opens new perspectives for selective electrodeposition, i.e., for high definition patterning of surfaces with a wide range of materials. (C) 2001 The Electrochemical Society.