Effects of organic compounds rich in phosphate functional groups as multifunctional inhibitors on copper film chemical-mechanical polishing properties: Combined experiment and theoretical calculation

For copper (Cu) interconnection chemical mechanical polishing (CMP) process, the Cu film slurry follows the principles of high efficiency, environmentally friendly and low cost. In this study, hydroxyethylene diphosphonic acid (HEDP), amino-trimethylene phosphonic acid (ATMP) and ethylenediamine etramethylenephosphonic acid (EDTMP) were used as green inhibitors to study the effects of organic compounds rich in two, three and four phosphate functional groups on the corrosion inhibition properties of Cu films. The results indicated that the Cu film material removal rate (MRR) of HEDP reaches 5879 A/min and the surface roughness (Sq) is 0.85 nm, superior to the other two inhibitors. Through mechanical action analysis, electrochemical experiment, UV-Visible, X-ray photoelectron spectroscopy (XPS) test analysis and theoretical calculation, it was observed that three inhibitors could not only form stable complexes with Cu, which have the effect of corrosion inhibition, but also play a lubricating role of surfactant, and simplify the composition of slurry, and the inhibition efficiency order of them is HEDP > ATMP > EDTMP.