Method of forming a dual damascene structure including smoothing the top part of a via

摘要

A dual damascene manufacturing process, which is applicable on a dual damascene structure, is described. The etching stop layer at a bottom of the trench line is removed followed by a thermal treatment to smooth out the surface at the bottom of the trench line and in the via to form a larger and smoother opening at the top part of the via. The via and the trench line are then filled with a barrier layer and a metal layer.