摘要 |
A semiconductor structure includes a substrate, a conductive feature over the substrate, a conductive plug structure contacting a portion of an upper surface of the conductive feature, a first etch stop layer over another portion of the upper surface of the conductive feature, and a second etch stop layer over the first etch stop layer. The first etch stop layer is a doped etch stop layer. The first etch stop layer is to function as an etch stop layer during a predetermined etching process for etching the second etch stop layer. |