Achievement of Bottom-Up Electroless Nickel Filling on the SiO2 Surface with Pd-Activated SAM

Abstract

To fill electroless nickel to submicrometer trenches on the SiO2 surface, a Pd-activated self assembled monolayer (SAM) of amino-propyltrimethoxy silane was formed on the surface of SiO2 substrate. The bottom-up electroless nickels filling was first achieved by electroless plating bath with an addition of polyacrylic acid, and the trenches with the widths ranging from 80 to 280 nm were filled completely by electroless nickel. The effects of polyacrylic acid on the polarization behaviors of nickel reduction and sodium hypophosphite oxidation were investigated by the linear sweep voltammetry method and mixed potential theory.