A Novel Bottom up Fill Mechanism for the Metallization of Advanced Node Copper Interconnects

A new alkaline copper plating bath enabling a unique and innovative bottom up effect for advanced damascene and dual damascene interconnect metallization is described. The formation of an ultra-stable polynuclear copper(I) complex during the early stage of the deposition process inhibits copper reduction, leading to a very strong suppressing effect. Bottom up growth is then achieved by means of selective breakdown of the suppressing layer from the bottom to the top of the features without any accelerator additive.