Method for processing an electroplated copper film in copper interconnect process

摘要

A method for processing an electroplated copper film in copper interconnect process is disclosed by the present invention. Firstly, in the copper back-end-of-line interconnect process, the first annealing process for the electroplated copper film is performed at or below 180° C.; then, after the copper back-end-of-line interconnect process, another annealing process with higher temperature (equal or above 240° C.) to the electroplated copper film is performed to make the copper recrystallize, so as to decrease the resistivity of the electroplated copper film and form an interface state having lower resistivity at the interface of the vias bottom, which decrease the contact resistance between the vias and the underlying copper interconnects and further reduce the RC time delay in the vias. The present invention can be applied in the Cu/Low-k back-end-of-line interconnect process and compatible with the standard Cu/Low-k back-end-of-line process integration.