Reliable integration of robust porous ultra low-k (ULK) for the advanced BEOL interconnect

Abstract

In order to address the increasing RC and reliability challenges at the advanced technology nodes, a new robust ULK was developed that incorporates the bridging carbon atoms (Si-[CH2]x-Si) in p-SiOCH matrix. Its elastic modulus and plasma damage resistance were improved more than 40% at the same dielectric constant than the commercially available ULK. These improvements are attributed to 80% higher atoms that exist in both Si-[CH2]x-Si and Si-CH3 structures with its pore size 23% smaller. Furthermore, its superb properties resulted in 3~4% capacitance reduction, and improvement of TDDB and EM TTF (time to failure) by 2 order and 2~3 times, respectively, on an advanced BEOL vehicle.