Slurry Development For Cu/Ultra Low kappa CMP

摘要

Conventional CMP for Cu/Ultra-low kappa (k<2.4) integration faces significant technical challenges [1-2].The majority of ULK materials are made porous to reduce the dielectric constnat,while trading off on the mechanical strength [3-6].With diminished hardness,elasticity and adhesion,the CMP process has to be "kinder and gentler":lower down force,lower relative velocity,softer pad,and slurry,with lower abraasive content [1,7].In a word,the mechanical portion of the planarization process would be greatly reduced.To maintain the same performance,one has to rely on the chemical reactions to make Cu/ULK CMP a viable process.