Leveling of Superfilled Damascene Cu Film Using Two-Step Electrodeposition

Abstract

To enhance the compatibility of electrodeposition with the chemical mechanical polishing process, we attempted to prevent step formation on active areas. In the absence of benzotriazole BTA , the step heights increased with the decrease in the pattern width and the increase in the pattern density due to the locally condensed accelerator. However, the addition of BTA significantly suppressed the deposition kinetic through the deactivation of the accelerator. The two-step electrodeposition with modulated accelerator and BTA concentrations was found to be effective in the retardation of bump formation and the prevention of bumps from growing without an impact on the superfilling.