Chemical Mechanical Polishing and Planarization of Mn-Based Barrier/Ru Liner Films in Cu Interconnects for Advanced Metallization Nodes

K. V. Sagi, L. G. Teugels, M. H. van der Veen, Herbert Struyf, S. V. Babu
2017 ECS Journal of Solid State Science and Technology  
Mn-based (referred to simply as Mn in the following) barrier/Ru liner stack has been proposed to replace TaN/Ta barrier-liner in Cu interconnects for 7 nm and 5 nm technology nodes. During chemical mechanical planarization (CMP) of the associated Cu/Ru/Mn/SiCOH pattern structures, the usual galvanic corrosion and removal rate selectivity issues need to be resolved. In this study, we investigated the polishing and electrochemical behavior of Cu, Mn, Ru and SiCOH films on the relevant substrates
more » ... elevant substrates in the alkaline region using silica dispersions containing potassium permanganate (KMnO 4 ), guanidine carbonate (GC) and benzotriazole (BTA) and identified compositions that address these challenges. An XPS study of the as-deposited and annealed Mn films confirmed the formation of amorphous manganese silicate (MnSi x O y ), a self-forming dielectric layer, at the Mn/SiCOH interface. A crosssectional TEM analysis of the polished Cu/Ru/Mn/SiCOH patterned wafers (32 nm half pitch Cu lines) with our candidate slurry showed excellent post-polish performance with no corrosion and no post-CMP loss of either Cu or the Mn barrier/Ru liner film. ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 207.241.231.83 Downloaded on 2018-07-19 to IP ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 207.241.231.83 Downloaded on 2018-07-19 to IP P264 ECS Journal of Solid State Science and Technology, 6 (5) P259-P264 (2017) specimen preparation. We also extend our thanks to Marc De Raedt for performing the XRF measurements. ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 207.241.231.83 Downloaded on 2018-07-19 to IP
doi:10.1149/2.0161705jss fatcat:l44hqxc22jgw7awv35deyvhpca