Parameter analysis and electrochemical properties of 4,6-Dimethyl-2-mercaptopyrimidine for mitigating Cu prominence in through silicon vias filling

Through silicon via (TSV) is the core technology that implements three-dimensional (3D) integrated packaging in integrated circuits. Electrodeposition defects affect the reliability of TSVs. In particular, the surface Cu protrusions can lead to structural deformations, which significantly affect the reliability of TSVs. In this study, 4,6-Dimethyl-2-mercaptopyrimidine (DMP) is studied as a leveller additive for TSV electroplating, along with the effect of the deposition parameters on the TSV filling process and surface morphology. To evaluate the filling performance of DMP, linear sweep voltammetry (LSV) is performed to investigate how the additives affect the filling mechanism. Finally, the conditions of this levelling agent in TSV plating are predicted based on LSV curves and validated using plating experiments.