Method of removing a via fence

摘要

A method of fabricating a dual damascene structure includes etching a via through a first dielectric layer above a substrate, a barrier layer on the first dielectric layer, and a second dielectric layer on the barrier layer. The via is at least partially filled with a photoresist plug. The plug is etched back. A trench is etched through the second dielectric layer. The trench is aligned with the via. The substrate having the first and second dielectric layers thereon is wet with an acid for a sufficient length of time to remove a via fence formed in the trench. The via and the trench are filled with metal.