Patent ID: 8278765
Filing Date: 2012-10-02
Classification: H01L

Abstract:
1. A test key for checking an interconnect structure, comprising: a substrate; a contiguous metal line disposed on the substrate; and a plurality of conductive plugs disposed on the contiguous metal line in order to place the contiguous metal line between the conductive plugs and the substrate, wherein one end of each conductive plug physically contacts with the contiguous metal line, the other ends of the conductive plugs located on two ends of the contiguous metal line are electrically connected to a test apparatus, and the other end of at least one of the other conductive plugs which are not located on the two ends of the contiguous metal line is not connected to any conductor; a top portion of each conductive plug is wider than the other portions of the conductive plug; and a lower surface of the top portion of the conductive plug has a shape caused by selective isotropic etching to the second dielectric layer.