With　the　technology　node　of　integrated　circuit　continuous　scaling　below　7　nm,　Co　has　emerged　as　a　promising　alternative　to　Cu　for　local　interconnects.　The　primary　challenges　lie　in　improving　the　material　removal　rate　(MRR)　of　Ti　in　weakly　alkaline　slurry　during　the　chemical　mechanical　polishing　(CMP)　process,　with　Ti　serving　as　the　barrier　layer　for　local　Co　interconnects.　In　the　study,　potassium　citrate　(PC)　has　been　proved　an　effective　complexing　agent　for　both　Co　and　Ti　polishing.　Ultimately,　a　novel　slurry　formula　using　PC　as　complexing　agent　has　been　developed,　which　can　meet　the　Co　buff　CMP　requirements.　The　MRR　of　Ti　is　37.35　nm/min,　the　MRR　of　Co　is　18.05　nm/min　and　the　removal　selectivity　ratio　of　Co　to　Ti　is　1:2.　The　surface　roughness　Ra　of　Ti　after　polishing　is　0.14　nm.　The　complexing　mechanism　of　PC　has　been　explored　through　X-ray　photoelectron　spectroscopy,　inductively　coupled　plasma　mass　spectrometry,　density　functional　theory　calculations　and　molecular　dynamics　simulations.　Citrate　ions　in　PC　can　chemically　complex　with　TiO2　to　form　soluble　complexes　and　then　accelerates　the　chemical　dissolution　of　Ti.　K+　ions　in　PC　can　decrease　the　electrostatic　repulsion　between　TiO2　and　SiO2,　thereby　enhancing　the　efficiency　of　mechanical　abrasion.　Thus,　PC　can　effectively　enhance　the　removal　of　Ti　by　synergistically　promoting　both　the　chemical　dissolution　and　mechanical　abrasion.　These　findings　provide　both　theoretical　insights　and　practical　guidance　for　the　CMP　process　development　of　local　Co　interconnects　in　advanced　integrated　circuits.　©　2025　Elsevier　B.V.