Electroplating copper in sub-100 nm gaps by additives with low consumption and diffusion ability

Abstract

This work presents a novel leveler with low consumption and low diffusion that achieved defect-free filling in vias as small as 0.1 μm and generated as-deposited films with low resistivities. Experimental results indicate that the additive, 2-aminobenzothiazole (2-ABT), with benzyl and amino (–NH2) functional groups, is a desirable leveler. It produced a highly selective concentration gradient between the opening and the bottom of the feature. This novel leveler, with weaker adsorption, also reduced the consumption during copper electroplating, and eventually deposited a film with a high conductivity.