Analysis of plasma-induced modification of ULK and eULK Materials: Dual damascene processing challenges for 45nm (κ ≤ 2.4) and beyond BEOL technologies

Abstract

Plasma induced modification of porous SiCOH (OSG) ultra low-κ (ULK) and extreme ultra low-κ (eULK) dielectric materials during "resist" removal is investigated. Angular resolved X-ray photoelectron spectroscopy (ARXPS) was applied to specially-designed 200mm test structures exposed to a variety of plasma ash processing conditions. Characterization of the plasma for each of these applied ash conditions was achieved via optical emission spectroscopy/actinometry and modeling. This data was used in conjunction with ARXPS analytical data to propose mechanisms for film modification as a function of critical plasma parameters such as reactive species densities and ion scattering. These trends/mechanisms were electrically tested on 200 and 300mm patterned wafers. These and other results are presented and discussed. © 2006 IEEE.