Plasma induced dielectric modification: Etching challenges for 65nm and beyond technology nodes

Abstract

This paper discusses the issue of plasma-induced dielectric modification as it applies to ultra-low-κ SiCOH-based materials during the removal of photoresist or other organic films. These dielectrics have been proposed for the sub-90nm technology nodes, to enable higher speed integrated circuits (ICs) for CMOS applications. For these materials, this issue of ILD modification becomes even more critical than their dense predecessors currently in production for 90nm technology. As such, more intense efforts are directed toward finding potential plasma ash solutions or alternative integration approaches that respectively address or circumvent this issue. The former approach inevitably demands increased understanding of the mechanism(s) via which these plasma chemistries modify ULK ILD films. To these ends, we have employed several analytical and electrical techniques on both 200 and 300mm wafers to attempt to characterize the effect of various plasma chemistries on and propose probable mechanism(s) of ULK ILD film modification.