Reduction of punch-thru defects in damascene processing

摘要

A semiconductor device is fabricated while mitigating conductive void formation in metallization layers. A substrate is provided. A first dielectric layer is formed over the substrate. A conductive trench is formed within the first dielectric layer. An etch stop layer is formed over the first dielectric layer. A second dielectric layer is formed over/on the etch stop layer. A resist mask is formed over the device and via openings are etched in the second dielectric layer. The resist mask is removed by an ash process. A clean process is performed that mitigates/reduces surface charge on exposed portions of the etch stop layer. Additional surface charge reduction techniques are employed. The via openings are filled with a conductive material and a planarization process is performed to remove excess fill material.