A semiconductor structure includes heterojunction bipolar transistors arranged in parallel and disposed on a substrate. The semiconductor structure also includes a landing structure disposed at the edge of the HBTs on the substrate. The semiconductor structure also includes wiring disposed on the HBTs and connected to the landing structure. The semiconductor structure also includes an insulating layer disposed on the landing structure and having a via. The semiconductor structure also includes a bump disposed on the top surface of the insulating layer and connected to the wiring through the via. The sidewall of the landing structure has a recess in a top view.

An under bump metallurgy (UBM) and redistribution layer (RDL) routing structure includes an RDL formed over a die. The RDL comprises a first conductive portion and a second conductive portion. The first conductive portion and the second conductive portion are at a same level in the RDL. The first conductive portion of the RDL is separated from the second conductive portion of the RDL by insulating material of the RDL. A UBM layer is formed over the RDL. The UBM layer includes a conductive UBM trace and a conductive UBM pad. The UBM trace electrically couples the first conductive portion of the RDL to the second conductive portion of the RDL. The UBM pad is electrically coupled to the second conductive portion of the RDL. A conductive connector is formed over and electrically coupled to the UBM pad.