A method of making a semiconductor device can include providing a plurality of semiconductor die, wherein each semiconductor die comprises an active surface and a backside opposite the active surface. The method can include forming a build-up interconnect structure that extends over the active surface of each of the plurality of semiconductor die within the wafer, and forming a unique identifying mark for each of the plurality of semiconductor die as part of a layer within the build-up interconnect structure while simultaneously forming the layer of the build-up interconnect structure. The layer of the build-up interconnect structure can comprise both the unique identifying marks for each of the plurality of semiconductor die and functionality for the semiconductor device. Each unique identifying mark can convey a unique identity of its respective semiconductor die. The method can further include singulating the plurality of semiconductor die into a plurality of semiconductor devices.