| 摘要 |
The present invention provides a method for forming a void-free copper damascene structure comprising a substrate having a conductive structure, a first dielectric layer on the substrate, a diffusion barrier layer on the first dielectric layer, and a second dielectric layer on the barrier layer. The method comprises forming via and trench openings developing a photoresist through a first and second hard mask. The first hard mask is laterally etched such that it is eroded to a greater extent from the trench opening with respect to the underlying second dielectric layer. Remaining gap fill layer is removed and the diffusion barrier layer within the via opening is etched to expose the conductive structure. The via and trench openings are plated with a barrier metal and a copper seed layer to obtain copper features that fill the openings and form a void-free copper damascene structure.
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