Effect of the Additives on Copper Deposition Process

The behaviors of the additives Cl~-, glue and thiourea in the copper deposition process were studied by the linear sweep voltammetry and the cyclic voltammetry method and XRD and SEM. The(results) indicate that when Cl~-, glue and thiourea alone exists in the eletrolyte, the depolarization action ofCl~- make peak current density of copper deposition reaction increase. The polarization action of glue and thiourea make peak current density of copper deposition reaction decrease and make peak potential shift to more negative direction. When Cl~-, glue and thiourea coexist in the electrolyte, they have stronger(action) of polarization, and could decrease limiting current density and peak current density of copper deposition reaction. The test results of XRD and SEM indicate that over thiourea could change predominant crystal orientation of copper deposition and enlarge crystal granularity.