Plasma treatment and repair processes for reducing sidewall damage in low-k dielectrics

Abstract

A method of forming an interconnect structure for an integrated circuit, including the steps of providing a substrate and forming a dielectric stack on the substrate including an etch-stop layer, a low-k dielectric layer, and a hardmask layer. The method further includes the steps of patterning a photoresist masking layer on the dielectric stack to define a plurality of feature defining regions and plasma processing the substrate in a plasma-based reactor, The processing step includes etching a plurality of features into the hardmask layer and at least a portion of the low-k dielectric layer and performing a plasma treatment process in situ in the plasma-based reactor, where the plasma treatment process includes flowing at least one hydrocarbon into the reactor and generating a plasma, where a mass flow rate of the hydrocarbon is at least 0.1 sccm. The method also includes forming a metal conductor in the plurality of features.