Methods and semiconductor structures are provided. A semiconductor structure according to the present disclosure includes a plurality of transistors, an interconnect structure electrically coupled to the plurality of transistors, a metal feature disposed over the interconnect structure and electrically isolated from the plurality of transistors, an insulation layer disposed over the metal feature, and a first redistribution feature and a second redistribution feature disposed over the insulation layer. A space between the first redistribution feature and the second redistribution feature is disposed directly over at least a portion of the metal feature.